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Электронный компонент: PT4665C

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For technical support and further information, visit http://power.ti.com
PT4660 Series
Description
The PT4660 ExcaliburTM Series
is a 30-A rated, dual-output isolated
DC/DC converter that combines
state-of-the-art power conversion
technology with unparalleled flex-
ibility. These modules operate from
a standard telecom (48 V) central
office (CO) supply to produce two
independantly regulated outputs.
The PT4660 series is characterized
with high efficiencies and ultra-fast
transient response, and incorporates
many features to facilitate system
integration. These include a flexible
"On/Off" enable control, output
current limit, over-temperature
30-A Dual Output Isolated
DC/DC Converter
Features
Dual 15-A Outputs
(Independantly Regulated)
Power-up/Down Sequencing
Input Voltage Range:
36 V to 75 V
1500 VDC Isolation
Temp Range: 40 to 100 C
High Efficiency: 88 %
Fixed Frequency Operation
Over-Current Protection
(Both Outputs)
Ordering Information
Pt. No.
Vo
1
/Vo
2
PT4661
o
= 5.0/3.3 Volts
PT4662
o
= 3.3/2.5 Volts
PT4663
o
= 3.3/1.8 Volts
PT4665
o
= 3.3/1.5 Volts
PT4666
o
= 2.5/1.8 Volts
PT4667
o
= 5.0/1.8 Volts
PT4668
o
= 3.3/1.2 Volts
Typical Application
PT4660
+Vin
EN 1*
EN 2
Vin
Vo
1
adj
Vo
2
adj
Vo
1
Vo
2
C O M
912
2124
1419
L
O
A
D
L
O
A
D
V o
1
V o
2
V
1
Adjust
V
2
Adjust
+ V
IN
V
IN
20
13
1
4
3
2
C O M
* Inverted logic
Dual Logic On/Off Control
Over-Temperature Shutdown
Over-Voltage Protection
(Coordinated Shutdown)
Under-Voltage Lockout
Input Differential EMI Filter
IPC Lead Free 2
Safety Approvals:
UL1950
CSA 22.2 950
protection, and an input under-voltage
lockout (UVLO). In addition, both
output voltages are designed to meet
the power-up/power-down sequenc-
ing requirements of popular DSPs.
The PT4660 series is housed in
space-saving solderable copper case.
The package does not require a
heatsink and is available in both
vertical and horizontal configura-
tions, including surface mount. The
`N' configuration occupies less than 2
in of PCB area.
PT Series Suffix
(PT1234
x
)
Case/Pin
Order
Package
Configuration
Suffix
Code
Vertical
N
(EKD)
Horizontal
A
(EKA)
SMD
C
(EKC)
(Reference the applicable package code draw-
ing for the dimensions and PC board layout)
SLTS140C MAY 2001 REVISED OCTOBER 2003
For technical support and further information, visit http://power.ti.com
PT4660 Series
30-A Dual Output Isolated
DC/DC Converter
Pin Descriptions
+Vin:
The positive input supply for the module with respect
to V
in
. When powering the module from a 48 V telecom
central office supply, this input is connected to the primary
system ground.
Vin:
The negative input supply for the module, and the
0 VDC reference for the EN 1, EN 2, TEMP, and AUX
signals. When the module is powered from a +48-V supply,
this input is connected to the 48-V Return.
EN 1:
This an open-collector (open-drain) negative logic
input that enables the module output. This pin is TTL
compatible and referenced to -V
in
. A logic `0' at this pin
enables the module's outputs, and a logic `1' or high
impedance disables the module's outputs. If not used,
the pin must be connected to V
in
.
EN 2:
An open-collector (open-drain) positive logic input
that enables the module output. This pin is TTL compat-
ible and referenced to V
in
. A logic `1' or high impedance
enables the module's outputs. If not used, the pin should
be left open circuit.
AUX:
Produces a regulated output voltage of 11.6 V 5 %,
which is referenced to V
in
. The current drawn from the
pin must be limited to 10mA. The voltage may be used
to indicate the output status of the module to a primary
referenced circuit, or power a low-current amplifer.
TEMP:
This is the output voltage produced by the module's
internal temperature sensor. The voltage at this pin is
referenced to V
in
and rises approximately 10 mV/C
from an intital value of 0.1 VDC at 40 C.
V
temp
=0.5 + 0.01T
sense
The signal is available whenever the module is supplied
with a valid input voltage, and is independant of the enable
logic status. (
Note:
A load impedance of less than 1 M
will
adversly affect the module's over-temperature shutdown threshold.
Use a high-impedance input when monitoring this signal.)
Vo
1
:
The higher regulated output voltage, which is refer-
enced to the COM node.
Vo
2
:
The lower regulated output voltage, which is refer-
enced to the COM node.
COM:
The secondary return reference for the module's two
regulated output voltages. It is dc isolated from the input
supply pins.
Vo
1
Adjust:
Using a single resistor, this pin allows Vo
1
to
be adjusted higher or lower than the preset value. If not
used, this pin should be left open circuit.
Vo
2
Adjust:
Using a single resistor, this pin allows Vo
2
to
be adjusted higher or lower than the preset value. If not
used, this pin should be left open circuit.
On/Off Logic
Pin 3
Pin 4
Output Status
1
Off
0
1
On
0
Off
Pin-Out Information
Pin
Function
1
+Vin
2
-Vin
3
EN 1
4
EN 2
5
TEMP
6
AUX
7
Do Not Connect
8
Do Not Connect
9
+Vo
1
Pin
Function
10
+Vo
1
11
+Vo
1
12
+Vo
1
13
Vo
1
Adjust
14
COM
15
COM
16
COM
17
COM
18
COM
Notes:
Logic 1 =Open collector
Logic 0 = Vin (pin 2) potential
For positive Enable function, connect pin 3
to pin 2 and use pin 4.
For negative Enable function, leave pin 4
open and use pin 3.
Note: Shaded functions indicate signals that are
referenced to the input (-Vin) potential.
Pin
Function
19
COM
20
Vo
2
Adjust
21
+Vo
2
22
+Vo
2
23
+Vo
2
24
+Vo
2
25
Do Not Connect
26
Do Not Connect
SLTS140C MAY 2001 REVISED OCTOBER 2003
For technical support and further information, visit http://power.ti.com
PT4660 Series
30-A Dual Output Isolated
DC/DC Converter
SLTS140C MAY 2001 REVISED OCTOBER 2003
Specifications
(Unless otherwise stated, T
a
=25 C, V
in
=48 V, & Io
1
=Io
2
=10 A)
PT4660 SERIES
Characteristics
Symbols
Conditions
Min
Typ
Max
Units
Output Current
Io
1
, Io
2
Vo
1
Vo
1
3.3 V
0
--
15
A
Vo
1
=
5.0 V
0
--
10
Vo
2
All voltages
0
--
15
A
Io
1
+Io
2
Total (both outputs)
Vo
1
3.3 V
0
--
30
A
Vo
1
=
5.0 V
0
--
25
Input Voltage Range
V
in
36
48
75
V
Set Point Voltage Tolerance
V
o
tol
--
1
2
%V
o
Temperature Variation
Reg
temp
40 to +100 C Case, Io
1
=Io
2
=0 A
--
0.5
--
%V
o
Line Regulation
Reg
line
Over V
in
range with Io
1
=Io
2
=5 A
--
5
10
mV
Load Regulation
Reg
load
1 A
Io
1
Io
1
max, Io
2
=1 A
Vo
1
--
2
10
mV
1 A
Io
2
Io
1
max, Io
1
=1 A
Vo
2
--
2
10
Cross Regulation
Reg
cross
1 A
Io
2
Io
1
max, Io
1
=1 A
Vo
1
--
2
10
mV
1 A
Io
1
Io
1
max, Io
2
=1 A
Vo
2
--
2
5
Total Output Variation
V
o
tol
Includes set-point, line load,
Vo
1
--
2
3
%V
o
40 C to +100 C case
Vo
2
--
2
3
Efficiency
PT4661
--
88
--
PT4662
--
87
--
PT4663
--
86
--
PT4665
--
86
--
%
PT4666
--
85
--
PT4667
--
88
--
PT4668
--
86
--
V
o
Ripple (pk-pk)
V
r
Io
1
=Io
2
=5 A, 20 MHz bandwidth
V
o
=5 V
--
--
75
mV
pp
V
o
<5 V
--
--
50
Transient Response
t
tr
1 A/s load step from 50 % to 100 % I
o
max
--
25
100
Sec
(either output)
--
6.0
--
%V
o
Current Limit
I
LIM
Each output with other unloaded
15.5
18
--
A
Output Rise Time
t
on
At turn-on to within 90 % of V
o
--
5
10
mSec
Output Over-Voltage Protection
OVP
Either output; shutdown and latch off
--
125
(1)
--
%V
o
Output Voltage Adjustment
V
o
adj
Vo
1
, Vo
2
--
10
--
%V
o
Switching Frequency
f
s
270
--
330
kHz
Under-Voltage-Lockout
UVLO
Rising
--
34
36
V
Falling
30
32
--
Internal Input Capacitance
C
in
--
2
--
F
Enable Control Inputs
Referenced to V
in
Input High Voltage
V
IH
3.5
--
--
V
Input Low Voltage
V
IL
0
--
0.8
(2)
Input Low Current
I
IL
--
0.5
--
mA
Standby Current
I
in
standby
Pins 2, 3, & 4 connected
--
3
5
mA
External Output Capacitance
C
out
Per each output
0
--
5,000
F
Primary/Secondary Isolation
V
iso
1500
--
--
V
C
iso
--
1500
--
pF
R
iso
10
--
--
M
Temperature Sense
V
temp
Output voltage at temperatures:-
40 C
--
0.1
(3)
--
V
100 C
--
1.5
(3)
--
Operating Temperature Range
T
a
Over V
in
range
40
--
85
(4)
C
Over-Temperature ProtectionOTP
Case temperature (auto restart)
100
--
--
C
Solder Reflow Temperature
T
reflow
Surface temperature of module pins or case
--
--
215
(5)
C
Storage Temperature
T
s
--
40
--
125
C
Mechanical Shock
--
Per Mil-STD-883D, Method 2002.3
--
500
--
G's
Mechanical Vibration
--
Per Mil-STD-883D, Method 2007.2, Suffix N
--
10
(6)
--
G's
202,000 Hz
Suffixes A, C
--
20
(6)
--
Weight
--
--
--
90
--
grams
Flammability
--
Materials meet UL 94V-0
Notes: (1) This is a fixed parameter. Adjusting Vo
1
or Vo
2
higher will increase the module's sensitivity to over-voltage detection. For more information, see the
application note on output voltage adjustment.
(2) The EN
1
and EN
2
control inputs (pins 3 & 4) have internal pull-ups and may be controlled with an open-collector (or open-drain) transistor. Both
inputs are diode protected and can be connected to +V
in
. The maximum open-circuit voltage is 5.4 V.
(3) Voltage output at "TEMP" pin is defined by the equation:- V
TEMP
= 0.5 + 0.01T, where T is in C. See pin descriptions for more information.
(4) See SOA curves or consult the factory for the appropriate derating.
(5) During solder reflow of SMD package version do not elevate the module case, pins, or internal component temperatures above a peak of 215 C. For
further guidance refer to the application note, "Reflow Soldering Requirements for Plug-in Power Surface Mount Products," (SLTA051).
(6) The case pins on the through-holed package types (suffixes N & A) must be soldered. For more information see the applicable package outline drawing.
For technical support and further information, visit http://power.ti.com
Note A:
All Characteristic data in the above graphs has been developed from actual products tested at 25C. This data is considered typical data for the converter.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer's maximum rated operating temperatures.
PT4661--48 V
30-A Dual Output Isolated
DC/DC Converter
Typical Characteristics
PT4661 (V
1
/V
2
=5.0V/3.3V); V
in
=48V
(See Notes A & B)
Efficiency vs I
1
out; I
2
out @1A, 3A, and 6A
Power Dissipation vs (Io
1
+ Io
2
)
Cross Regulation: V
1
out vs I
2
out @I
1
out =1A
Cross Regulation: V
2
out vs I
1
out @I
2
out =1A
Efficiency vs I
1
out; I
2
out @9A, 12A, and 15A
Safe Operating Area: (Io
1
+ Io
2
)
50
60
70
80
90
100
0
2
4
6
8
10
I
1
out (A)
Efficiency - %
6
3
1
I
2
out
50
60
70
80
90
100
0
2
4
6
8
10
I
1
out (A)
Efficiency - %
9
12
15
I
2
out
4.95
4.975
5
5.025
5.05
0
3
6
9
12
15
I
2
out (A)
V
1
out (V)
3.28
3.29
3.3
3.31
3.32
0
2
4
6
8
10
I
1
out (A)
V
2
out (V)
0
4
8
12
16
20
0
5
10
15
20
25
Io
1
+ Io
2
(A)
Pd - Watts
20
30
40
50
60
70
80
90
0
5
10
15
20
25
Io
1
+ Io
2
(A)
Ambient Temperature (C
)
300LFM
200LFM
100LFM
Nat Conv
Airflow
SLTS140C MAY 2001 REVISED OCTOBER 2003
For technical support and further information, visit http://power.ti.com
PT4662--48 V
30-A Dual Output Isolated
DC/DC Converter
Note A:
All Characteristic data in the above graphs has been developed from actual products tested at 25 C. This data is considered typical data for the converter.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer's maximum rated operating temperatures.
PT4662 (V
1
/V
2
=3.3 V/2.5 V); V
in
=48 V
(See Notes A & B)
Efficiency vs I
1
out; I
2
out @1 A, 3 A, and 6 A
Power Dissipation vs (Io
1
+ Io
2
)
Cross Regulation: V
1
out vs I
2
out @I
1
out =1 A
Cross Regulation: V
2
out vs I
1
out @I
2
out =1 A
2.470
2.485
2.500
2.515
2.530
0
3
6
9
12
15
I
1
out (A)
V
2
out (V)
3.24
3.27
3.30
3.33
3.36
0
3
6
9
12
15
I
2
out (A)
V
1
out (V)
Efficiency vs I
1
out; I
2
out @9 A, 12 A, and 15 A
Safe Operating Area: (Io
1
+ Io
2
)
Typical Characteristics
20
30
40
50
60
70
80
90
0
5
10
15
20
25
30
Io
1
+ Io
2
(A)
Ambient Temperature (

C)
300LFM
200LFM
100LFM
Nat conv
Airflow
70
75
80
85
90
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
6
3
1
I
2
out
70
75
80
85
90
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
9
12
15
I
2
out
0
4
8
12
16
20
0
6
12
18
24
30
Io
1 +
Io
2
(A)
Pd - Watts
SLTS140C MAY 2001 REVISED OCTOBER 2003
For technical support and further information, visit http://power.ti.com
Note A:
All Characteristic data in the above graphs has been developed from actual products tested at 25 C. This data is considered typical data for the converter.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer's maximum rated operating temperatures.
PT4663--48 V
30-A Dual Output Isolated
DC/DC Converter
Typical Characteristics
PT4663 (V
1
/V
2
=3.3 V/1.8 V); V
in
=48 V
(See Notes A & B)
Efficiency vs I
1
out; I
2
out @1 A, 3 A, and 6 A
Power Dissipation vs (Io
1
+ Io
2
)
Cross Regulation: V
1
out vs I
2
out @I
1
out =1 A
Cross Regulation: V
2
out vs I
1
out @I
2
out =1 A
Efficiency vs I
1
out; I
2
out @9 A, 12 A, and 15 A
Safe Operating Area: (Io
1
+ Io
2
)
3.24
3.26
3.28
3.3
3.32
3.34
3.36
0
3
6
9
12
15
I
2
out (A)
V
1
out (V)
20
30
40
50
60
70
80
90
0
5
10
15
20
25
30
Io
1
+ Io
2
(A)
Ambient Temperature (

C)
300LFM
200LFM
100LFM
Nat Conv
Airflow
70
75
80
85
90
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
6
3
1
I
2
out
70
75
80
85
90
0
3
6
9
12
15
Iout (A)
Efficiency - %
9
12
15
I
2
out
0
4
8
12
16
20
0
6
12
18
24
30
Io
1
+ Io
2
(A)
Pd - Watts
1.78
1.79
1.8
1.81
1.82
0
3
6
9
12
15
I
1
out (A)
V
2
out (V)
SLTS140C MAY 2001 REVISED OCTOBER 2003
For technical support and further information, visit http://power.ti.com
PT4665--48 V
30-A Dual Output Isolated
DC/DC Converter
Efficiency vs I
1
out; I
2
out @1 A, 3 A, and 6 A
Power Dissipation vs (Io
1
+ Io
2
)
Cross Regulation: V
1
out vs I
2
out @I
1
out =1 A
Cross Regulation: V
2
out vs I
1
out @I
2
out =1 A
Efficiency vs I
1
out; I
2
out @9 A, 12 A, and 15 A
Safe Operating Area: (Io
1
+ Io
2
)
Typical Characteristics
PT4665 (V
1
/V
2
=3.3 V/1.5 V); V
in
=48 V
(See Notes A & B)
Note A:
All Characteristic data in the above graphs has been developed from actual products tested at 25 C. This data is considered typical data for the converter.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer's maximum rated operating temperatures.
3.28
3.29
3.3
3.31
3.32
0
3
6
9
12
15
I
2
out (A)
V
1
out (V)
1.49
1.495
1.5
1.505
1.51
0
3
6
9
12
15
I
1
out (A)
V
2
out (V)
20
30
40
50
60
70
80
90
0
5
10
15
20
25
30
Io
1
+ Io
2
(A)
Ambient Temperature (

C)
300LFM
200LFM
100LFM
Nat Conv
Airflow
50
60
70
80
90
100
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
6
3
1
I
2
out
50
60
70
80
90
100
0
3
6
9
12
15
I
2
out (A)
Efficiency - %
9
12
15
I
2
out
0
4
8
12
16
20
0
6
12
18
24
30
Io
1
+ Io
2
(A)
Pd - Watts
SLTS140C MAY 2001 REVISED OCTOBER 2003
For technical support and further information, visit http://power.ti.com
Note A:
All Characteristic data in the above graphs has been developed from actual products tested at 25 C. This data is considered typical data for the converter.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer's maximum rated operating temperatures.
PT4666 (V
1
/V
2
=2.5 V/1.8 V); V
in
=48 V
(See Notes A & B)
PT4666--48 V
30-A Dual Output Isolated
DC/DC Converter
Typical Characteristics
Efficiency vs I
1
out; I
2
out @1 A, 3 A, and 6 A
Power Dissipation vs I
1
out and I
2
out
Cross Regulation: V
1
out vs I
2
out @I
1
out =1 A
Cross Regulation: V
2
out vs I
1
out @I
2
out =1 A
Efficiency vs I
1
out; I
2
out @9 A, 12 A, and 15 A
Safe Operating Area: (Io
1
+ Io
2
)
2.48
2.49
2.5
2.51
2.52
0
3
6
9
12
15
I
2
out (A)
V
1
out (V)
1.79
1.795
1.8
1.805
1.81
0
3
6
9
12
15
I
1
out (A)
V
2
out (V)
20
30
40
50
60
70
80
90
0
5
10
15
20
25
30
Io
1
+ Io
2
(A)
Ambient Temperature (

C)
300LFM
200LFM
100LFM
Nat Conv
Airflow
50
60
70
80
90
100
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
6
3
1
I
2
out
50
60
70
80
90
100
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
9
12
15
I
2
out
0
2
4
6
8
10
0
3
6
9
12
15
Io
1
+ Io
2
(A)
Pd - Watts
SLTS140C MAY 2001 REVISED OCTOBER 2003
For technical support and further information, visit http://power.ti.com
PT4667--48 V
30-A Dual Output Isolated
DC/DC Converter
Efficiency vs I
1
out; I
2
out @1 A, 3 A, and 6 A
Power Dissipation vs (Io
1
+ Io
2
)
Cross Regulation: V
1
out vs I
2
out @I
1
out =1 A
Cross Regulation: V
2
out vs I
1
out @I
2
out =1 A
Efficiency vs I
1
out; I
2
out @9 A, 12 A, and 15 A
Safe Operating Area: (Io
1
+ Io
2
)
Typical Characteristics
PT4667 (V
1
/V
2
=5 V/1.8 V); V
in
=48 V
(See Notes A & B)
Note A:
All Characteristic data in the above graphs has been developed from actual products tested at 25 C. This data is considered typical data for the converter.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer's maximum rated operating temperatures.
SLTS140C MAY 2001 REVISED OCTOBER 2003
50
60
70
80
90
100
0
2
4
6
8
10
I
1
out (A)
Efficiency - %
6
3
1
I
2
out
50
60
70
80
90
100
0
2
4
6
8
10
I
1
out (A)
Efficiency - %
9
12
15
I
2
out
4.98
4.99
5
5.01
5.02
0
3
6
9
12
15
I
2
out (A)
V
1
out (V)
1.79
1.795
1.8
1.805
1.81
0
2
4
6
8
10
I
1
out (A)
V
2
out (V)
0
4
8
12
16
20
0
5
10
15
20
25
Io
1
+ Io
2
(A)
Pd - Watts
20
30
40
50
60
70
80
90
0
5
10
15
20
25
Io
1
+ Io
2
(A)
Ambient Temperature (

C)
300LFM
200LFM
100LFM
Nat conv
Airflow
For technical support and further information, visit http://power.ti.com
Note A:
All Characteristic data in the above graphs has been developed from actual products tested at 25 C. This data is considered typical data for the converter.
Note B:
SOA curves represent operating conditions at which internal components are at or below manufacturer's maximum rated operating temperatures.
PT4668 (V
1
/V
2
=3.3 V/1.2 V); V
in
=48 V
(See Notes A & B)
PT4668--48 V
30-A Dual Output Isolated
DC/DC Converter
Typical Characteristics
Efficiency vs I
1
out; I
2
out @1 A, 3 A, and 6 A
Power Dissipation vs (Io
1
+ Io
2
)
Cross Regulation: V
1
out vs I
2
out @I
1
out =1 A
Cross Regulation: V
2
out vs I
1
out @I
2
out =1 A
Efficiency vs I
1
out; I
2
out @9 A, 12 A, and 15 A
3.28
3.29
3.3
3.31
3.32
0
3
6
9
12
15
I
2
out (A)
V
1
out (V)
1.19
1.195
1.2
1.205
1.21
0
3
6
9
12
15
I
1
out (A)
V
2
out (V)
20
30
40
50
60
70
80
90
0
5
10
15
20
25
30
Io
1
+ Io
2
(A)
Ambient Temperature (

C)
300LFM
200LFM
100LFM
Nat Conv
Airflow
Safe Operating Area: (Io
1
+ Io
2
)
50
60
70
80
90
100
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
6
3
1
I
2
out
50
60
70
80
90
100
0
3
6
9
12
15
I
1
out (A)
Efficiency - %
9
12
15
I
2
out
0
4
8
12
16
20
0
6
12
18
24
30
Io
1
+ Io
2
(A)
Pd - Watts
SLTS140C MAY 2001 REVISED OCTOBER 2003
Application Notes
For technical support and further information, visit http://power.ti.com
PT4660 & PT4680 Series
Operating Features & System Considerations for the
PT4660 & PT4680 Dual-Output Converters
Over-Current Protection
The dual-outputs of the PT4660 and PT4680 series of
DC/DC converters have independent output voltage
regulation and current limit control. Applying a load
current in excess of the current limit threshold at either
output will cause the respective output voltage to drop.
However, the voltage at Vo
2
is derived from Vo
1
. There-
fore a current limit fault on Vo
1
will also cause Vo
2
to
drop. Conversely, a current limit fault applied to Vo
2
will only cause Vo
2
voltage to drop, and Vo
1
will remain
in regulation.
The current limit is continuous with some current fold-
back. This means that at short circuit, the value of the
output current can be less than the rated output of the
converter. This is to reduce power dissipation when a fault
is present. As with any foldback-limited source, if a con-
stant current load is applied to the converter with a value
greater than the short-circuit current, the output voltage
will not come up. Resistive and non-linear load circuits
are not affected by this characteristic as long as the cur-
rent at startup does not exceed the short-circuit current
of the converter. The majority of low-voltage analog
and digital applications are not affected by this restric-
tion. However, when testing with an electronic load the
constant resistance setting should be used.
Output Over-Voltage Protection
Each output is monitored for over voltage (OV). For fail
safe operation and redundancy, the OV fault detection
circuitry uses a separate reference to the voltage regula-
tion circuits. The OV threshold is fixed, and set nominally
25 % higher than the set-point output voltage. If either
output exceeds the threshold, the converter is shutdown
and must be actively reset. The OV protection circuit
can be reset by momentarily turning the converter off.
This is accomplished by either cycling one of the output
enable control pins (EN1 or EN2), or by removing the
input power to the converter. Note: If Vo
1
or Vo
2
is adjusted
to a higher voltage, the margin between the respective steady-
state output voltage and its OV threshold is reduced. This can
make the module sensitive to OV fault detection, that may
result from random noise and load transients.
Over-Temperature Protection
The converter has an internal temperature sensor. At a
case temperature of approximately 115 C the converter
will shut down, and will automatically restart when the
temperature returns to about 100 C. The analog voltage
generated by the sensor is also made available at the
TEMP output (pin 5), and can be monitored by the
host system for diagnostic purposes. Consult the `Pin
Descriptions' section of the data sheet for further infor-
mation on this feature.
Under-Voltage Lock-Out
The Under-Voltage Lock-Out (UVLO) circuit prevents
operation of the converter whenever the input voltage to
the module is insufficient to maintain output regulation.
The UVLO has approximately 2 V of hysterisis. This is
to prevent oscillation with a slowly changing input volt-
age. Below the UVLO threshold the module is off and
the enable control inputs, EN1 and EN2 are inoperative.
Primary-Secondary Isolation
The PT4460 and PT4680 series of DC/DC converters
incorporate electrical isolation between the input termi-
nals (primary) and the output terminals (secondary). All
converters are production tested to a withstand voltage
of 1500 VDC. The isolation complies with UL60950 and
EN60950, and the requirements for operational isolation.
This allows the converter to be configured for either a
positive or negative input voltage source.
The regulation control circuitry for these modules is
located on the secondary (output) side of the isolation
barrier. Control signals are passed between the primary
and secondary sides of the converter via a proprietory
magnetic coupling scheme. This eliminates the use of
opto-couplers. The data sheet `Pin Descriptions' and
`Pin-Out Information' provides guidance as to which
reference (primary or secondary) that must be used for
each of the external control signals.
Fuse Requirements
To comply with safety agency requirements, these con-
verters must be operated with an external input fuse.
A fast-acting 250-V fuse is required. Table 1-1 gives
the recommended current rating for the product series
being used.
Table 1-1; Recommended Fuse Rating
Product
Input
Total
Fuse
Series
Bus
Iout
Rating
PT4660
48 V
30 A
7 A
PT4680
24 V
20 A
10 A
Application Notes
For technical support and further information, visit http://power.ti.com
0
5
10
15
20
25
30
35
t (milliseconds)
Vo
1
(2V/Div)
Vo
2
(2V/Div)
I
IN
(0.5A/Div)
Figure 2-3; Vo
1
, Vo
2
Power-Up Sequence
PT4660 & PT4680 Series
On/Off Output Voltage Sequencing
The output voltages from these dual-output DC/DC
converters are independantly regulated, and are inter-
nally sequenced to meet the power-up requirements of
popular microprocessor and DSP chipsets. Figure 2-3
shows the waveforms from a PT4661 after the converter
is enabled at t=0s. During power-up, the Vo
1
and Vo
2
voltage waveforms typically track within 0.4V prior to
Vo
2
reaching regulation. The waveforms were measured
with a 5-Adc resistive load at each output, and with a
48-VDC input source applied. The converter typically
produces a fully regulated output within 25ms. The
actual turn-on time will vary slightly with input voltage,
but the power-up sequence is independent of the load at
either output.
Using the On/Off Enable Controls on the PT4660
& PT4680 Series of Dual-Output Converters
The PT4660 (48V input) and PT4680 (24V input) se-
ries of dual-output DC/DC converters incorporate
both positive and negative logic output enable controls.
EN1 (pin 3) is the negative enable input, and EN2 (pin 4)
is the positive enable input. Both inputs are TTL logic
compatible, and are electrically referenced to -V
in
(pin 2)
on the primary (input) side of the converter. A pull-up
resistor is not required, but may be added if desired.
Adding a pull-up resistor from either EN1 or EN2, up to
+V
in
, will not damage the converter.
Automatic (UVLO) Power-Up
Connecting EN1 (pin 3) to -V
in
(pin 2) and leaving EN2
(pin 4) open-circuit configures the converter for automatic
power up. (See data sheet "Typical Application"). The
converter control circuitry incorporates an "Under Voltage
Lockout" (UVLO) function, which disables the output
until the minimum specified input voltage is present
(See data sheet Specifications). The UVLO circuitry
ensures a clean transition during power-up and power-
down, allowing the converter to tolerate a slow-rising
input voltage. For most applications EN1 and EN2, can
be configured for automatic power-up.
Positive Output Enable (Negative Inhibit)
To configure the converter for a positive enable function,
connect EN1 (pin 3) to -V
in
(pin 2), and apply the system
On/Off control signal to EN2 (pin 4). In this configura-
tion, a logic `0' (-V
in
potential) applied to pin 4 disables
the converter outputs. An example of this configuration
is detailed in Figure 2-1.
Negative Output Enable (Positive Inhibit)
To configure the converter for a negative enable function,
EN2 (pin 4) is left open circuit, and the system On/Off
control signal is applied to EN1 (pin 3). A logic `0' (-V
in
potential) must then be applied to pin 3 in order to enable
PT4660
EN 1*
EN 2
Vin
V
I N
1 = O u t p u t s O f f
4
3
2
BSS138
P T 4 6 6 0
EN 1*
EN 2
Vin
V
IN
4
3
2
1 = O u t p u t s O n
BSS138
Figure 2-2; Negative Enable Configuration
Figure 2-1; Positive Enable Configuration
During turn-off, both outputs drop rapidly due to the
discharging effect of actively switched rectifiers. The
voltage at Vo
1
remains higher than Vo
2
during this
period. The discharge time is typically 100s, but will
vary with the amount of external load capacitance.
the outputs of the converter. An example of this configu-
ration is detailed in Figure 2-2. Note: The converter will
only produce and output voltage if a valid input voltage is
applied to V
in
.
Application Notes
For technical support and further information, visit http://power.ti.com
Adjusting the Output Voltage of the PT4660
& PT4680 Series of Dual-Output Converters
The dual output voltages from the PT4660 (48-V Bus),
and PT4680 (24-V Bus) series of DC/DC converters can
be independently adjusted by up to 10 %, higher or lower
than the factory trimmed pre-set voltage. The adjustment
method requires the addition of a single external resistor
1
.
Table 3-1 gives the adjustment range of Vo
1
and Vo
2
for
each model in the series as V
a
(min) and V
a
(max).
Vo
1
Adjust Down:
Add a resistor
(R
1
)
, between pin 13
(Vo
1
Adj) and pin 12 (Vo
1
)
2
.
Vo
1
Adjust Up:
To increase the output, add a resistor R
2
between pin 13 (Vo
1
Adj) and pin 14 (COM)
2, 4
.
Vo
2
Adjust Down:
Add a resistor
(R
3
)
between pin 20
(Vo
2
Adj) and pin 21 (Vo
2
)
2
.
Vo
2
Adjust Up:
Add a resistor R
4
between pin 20
(Vo
2
Adj) and pin 19 (COM)
2, 4
.
Refer to Figure 3-1 and Table 3-2 for both the placement and
value of the required resistor.
Notes:
1. Adjust resistors are not required if Vo
1
and Vo
2
are to
remain at their respective nominal set-point voltage.
In this case, Vo
1
Adj (pin 13) and Vo
2
Adj (pin 20) are
left open-circuit
2. Use only a single 1% resistor in either the
(R
1
)
or R
2
location to adjust Vo
1
, and in the
(R
3
)
or R
4
location
to adjust Vo
2
. Place the resistor as close to the converter
as possible.
Figure 3-1; Placement of Output Adjust Resistors
3. Vo
2
must always be at least 0.3 V lower than Vo
1
.
4. The over-voltage protection threshold is fixed, and is set
nominally 25 % above the set-point output voltage.
Adjusting Vo
1
or Vo
2
higher will reduce the voltage
margin between the respective steady-state output
voltage and its over-voltage (OV) protection threshold.
This could make the module sensitive to OV fault
detection, as a result of random noise and load tran-
sients.
Note: An OV fault is a latched condition that shuts down
both outputs of the converter. The fault can only be cleared
by cycling one of the Enable control pins (EN
1
* / EN
2
), or
by momentarily removing the input power to the module.
5. Never connect capacitors to either the Vo
1
Adj or
Vo
2
Adj pins. Any capacitance added to these control
pins will affect the stability of the respective regulated
output.
The adjust up and adjust down resistor values can also be
calculated using the following formulas. Be sure to select
the correct formula parameter from Table 3-1 for the
output and model being adjusted.
(R
1
)
or
(R
3
)
=
R
o
(V
a
V
r
)
R
s
k
(V
o
V
a
)
R
2
or R
4
=
R
o
V
r
R
s
k
V
a
V
o
Where: V
o
= Original output voltage, (Vo
1
or Vo
2
)
V
a
= Adjusted output voltage
V
r
= The reference voltage from Table 3-1
R
o
= The resistance constant in Table 3-1
R
s
= The series resistance from Table 3-1
PT4660 & PT4680 Series
P T 4 6 6 0
+Vin
EN 1*
E N 2
Vin
V o
1
adj
V o
2
adj
V o
1
V o
2
C O M
9 1 2
2 1 2 4
1 4 1 9
L
O
A
D
L
O
A
D
V o
1
V o
2
+ V
IN
V
IN
2 0
1 3
1
4
3
2
C O M
* Inverted logic
R 2
( R 1 )
( R 3 )
R 4
Application Notes
For technical support and further information, visit http://power.ti.com
5.5
5.0 k
5.4
11.2 k
5.3
21.6 k
5.2
42.4 k
5.1
105.0 k
5.0
4.9
(99.8) k
4.8
(37.4) k
4.7
(16.6) k
4.6
(6.2) k
4.5
(0.0)
R
1
=
(Blue)
, R
2
= Black
Table 3-2a; ADJUSTMENT RESISTOR VALUES, Vo
1
24 V Bus Pt.# PT4681/7
PT4682/3/5
PT4686
48 V Bus Pt.# PT4661/7
PT4662/3/5/8
PT4666
Adj. Resistor
(R1)
/R2
(R1)
/R2
(R1)
/R2
V
o
(nom)
5.0 V
3.3 V
2.5 V
V
a
(req'd)
V
a
(req'd)
V
a
(req'd)
Table 3-1; ADJUSTMENT RANGE AND FORMULA PARAMETERS
Vo
1
Bus
Vo
2
Bus
(2)
24 V Bus Pt.#
PT4681/7
PT4682/3/5/8
PT4686
PT4681
PT4682
PT4683/7
PT4686
PT4685
48 V Bus Pt.#
PT4661/7
PT4662/3/5/8
PT4666
PT4661
PT4662
PT4663/7
PT4666
PT4665
PT4668
Adj. Resistor
(R1)
/R2
(R1)
/R2
(R1)
/R2
(R3)
/R4
(R3)
/R4
(R3)
/R4
(R3)
/R4
(R3)
/R4
(R3)
/R4
V
o
(nom)
5.0 V
3.3 V
2.5 V
3.3 V
2.5 V
1.8 V
1.8 V
1.5 V
1.2 V
Va(min)
4.5 V
2.97 V
2.25 V
2.97 V
2.25 V
1.62 V
1.62 V
1.35 V
1.08 V
Va(max)
5.5 V
3.63 V
2.75 V
3.63 V
2.75 V
1.98 V
1.98 V
1.65 V
1.32 V
Vr
2.5 V
1.65 V
1.25
1.65 V
1.25 V
0.9 V
0.9 V
0.75 V
0.6V
R
o
(k
)
4.99
4.99
4.99
1.21
1.21
1.21
1.21
1.21
1.21
R
s
(k
)
20.0
20.0
20.0
4.99
4.99
4.99
3.32
4.99
3.32
PT4660 & PT4680 Series
3.6
7.4 k
3.54
14.3 k
3.48
25.7 k
3.42
48.6 k
3.36
117.0 k
3.3
3.24
(112.0 k
)
3.18
(43.6 k
)
3.12
(20.8 k
)
3.06
(9.3 k
)
3.0
(2.5 k
)
1.95
2.3 k
3.9 k
1.9
5.9 k
7.6 k
1.85
16.8 k
18.5 k
1.8
1.75
(15.6) k
(17.3) k
1.7
(4.7) k
(6.4) k
1.65
(1.1) k
(2.7) k
1.1 k
1.6
4.1 k
1.55
13.2 k
1.5
1.45
(12.0) k
1.4
(2.9) k
1.35
(0.0) k
1.3
3.9 k
1.275
6.4 k
1.25
11.2 k
1.225
25.7 k
1.2
1.175
(24.5) k
1.15
(10.0) k
1.125
(5.2) k
1.1
(2.7) k
Table 3-2b; ADJUSTMENT RESISTOR VALUES, Vo
2
24 V Bus Pt.#
PT4681
PT4682
PT4683/6/7
PT4686
PT4685
48 V Bus Pt.#
PT4661
PT4662
PT4663/6/7
PT4666
PT4665
PT4668
Adj. Resistor
(R3)
/R4
(R3)
/R4
(R3)
/R4
(R3)
/R4
(R3)
/R4
(R3)
/R4
V
o
(nom)
3.3 V
2.5 V
1.8 V
1.8 V
1.5 V
1.2 V
V
a
(req'd)
V
a
(req'd)
3.6
1.7 k
3.54
3.3 k
3.48
6.1 k
3.42
11.6 k
3.36
28.3 k
3.3
3.24
(27.1) k
3.18
(10.4) k
3.12
(4.9) k
3.06
(2.1) k
3.0
(0.5) k
2.75
1.1 k
2.7
2.6 k
2.65
5.1 k
2.6
10.1 k
2.55
25.3 k
2.5
2.45
(24.1) k
2.4
(8.9) k
2.35
(3.9) k
2.3
(1.4) k
2.25
(0.0)k
R
3
=
(Blue)
, R
4
= Black
2.75
5.0 k
2.7
11.2 k
2.65
21.6 k
2.6
42.4 k
2.55
105.0 k
2.5
2.45
(99.8 k
)
2.4
(37.4 k
)
2.35
(16.6 k
)
2.3
(6.2 k
)
2.25
(0.0 k
)
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package
Type
Package
Drawing
Pins Package
Qty
Eco Plan
(2)
Lead/Ball Finish
MSL Peak Temp
(3)
PT4661A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4661C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4661N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4662A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4662C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4662N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4663A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4663C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4663N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4665A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4665C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4665N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4666A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4666C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4666N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4667A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4667C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4667N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4668A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4668C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4668N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
PACKAGE OPTION ADDENDUM
www.ti.com
24-Jun-2005
Addendum-Page 1
(2)
Eco
Plan
-
The
planned
eco-friendly
classification:
Pb-Free
(RoHS)
or
Green
(RoHS
&
no
Sb/Br)
-
please
check
http://www.ti.com/productcontent
for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com
24-Jun-2005
Addendum-Page 2
IMPORTANT NOTICE
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amplifier.ti.com
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www.ti.com/audio
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dataconverter.ti.com
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dsp.ti.com
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www.ti.com/broadband
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interface.ti.com
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www.ti.com/digitalcontrol
Logic
logic.ti.com
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www.ti.com/military
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power.ti.com
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www.ti.com/opticalnetwork
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microcontroller.ti.com
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www.ti.com/telephony
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www.ti.com/video
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www.ti.com/wireless
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2005, Texas Instruments Incorporated