For technical support and further information, visit http://power.ti.com
Standard Application
Features
36 V to 75 V Input Voltage Range
Programmable Output Voltage
Range: 6.5 V to 17.5 V
-40 to +85C Operating Temp
1500 VDC Isolation
89% Efficiency
On/Off Inhibit
Differential Remote Sense
17 A Output with PT4497
SLTS121C SEPTEMBER 2000 REVISED OCTOBER 2004
Description
The PT4486 ExcaliburTM DC/DC
converter module combines state-of-the-
art power conversion technology with
un-paralleled flexibility. Incorporating
high efficiency and ultra-fast transient
response, these modules provide up to
8.5 A of output current over the program-
mable voltage range of 6.5 V to 17.5 V.
The modules include a number of
inbuilt features to facilitate system
integration. These include a foldback
output current limit, over-temperature
protection, and an inhibit on/off control.
A differential remote sense is also provided
to compensate for voltage drop between
the converter and load.
For additional output current, one
PT4486 may be operated with up to two
PT4497 compatible booster modules.
Each PT4497 adds an additional 8.5A of
output current capability.
Over-Current Protection
Over-Temperature Protection
Over-Voltage Protection
Space-Saving Package
Solderable Copper Case
Safety Approvals:
UL 60950
CSA 22.2 950
VDE EN60950
L
O
A
D
PT4486
+V
sns
+V
out
-V
out
-V
sns
7
8-13
14-19
20
25
22
24
23
VID0 - VID4
+V
in
V
in
1
2
3
Inhibit
C
1
+
PROGRAMMING PINS
+V
OUT
+V
IN
V
IN
V
OUT
C
o
+
21
C
2
C
o
= Optional 33-F electrolytic capacitor
C
1
= Optional 33-F, 100-V electrolytic capacitor
C
2
= Optional 1-F, 100-V ceramic capacitor
Programming pins, VID0VID4, are shown
configured for Vo =12 V
For normal operation, pin 3 (Inhibit) must be
connected to Vin.
Ordering Information
PT4486
= 6.5 to 17.5 Volts
PT4497
= 8.5-A Booster
PT Series Suffix
(PT1234
x
)
Case/Pin
Order
Package
Configuration
Suffix
Code *
Vertical
N
(EKD)
Horizontal
A
(EKA)
SMD
C
(EKC)
* Previously known as package styles 1200,
1210, and 1215.
(Reference the applicable package code draw-
ing for the dimensions and PC board layout)
Pin-Out Information
Pin
Function
1
+V
in
2
V
in
3
Inhibit
4
V
r
5
V
a
6
Do not connect
7
(+)Remote Sense
8
+V
out
9
+V
out
10 +V
out
11 +V
out
12 +V
out
13 +V
out
Pin
Function
14
V
out
15
V
out
16
V
out
17
V
out
18
V
out
19
V
out
20
()Remote Sense
21
VID0
22
VID1
23
VID2
24
VID3
25
VID4
26
DRV
PT4486--48V
100-W 8.5-A Programmable
Isolated DC/DC Converter
Pins 4, 5, & 26 are used for booster applications. For
stand-alone operation, leave open circuit.
Shaded functions indicate those pins that are
referenced to primary-side potential.
For technical support and further information, visit http://power.ti.com
PT4480 Series Comparison
Output Voltage
Configuration for
Functionality
Program Range
Current Sharing
PT4481
Regulator
1.3 V 3.5 V
N+1 with other PT4481s
PT4482
Regulator
1.3 V 3.5 V
With PT4499 boosters
PT4499
PT4482 Booster
N/A
Used only with PT4482
PT4483
Regulator
4.6 V5.7 V
N+1 with other PT4483s
PT4484
Regulator
4.6 V5.7 V
With PT4498 boosters
PT4498
PT4484 Booster
N/A
Used only with PT4484
PT4485
Regulator
6.5 V 17.5 V
N+1 with other PT4485s
PT4486
Regulator
6.5 V17.5 V
With PT4497 boosters
PT4497
PT4486 Booster
N/A
Used only with PT4486
PT4486--48V
100-W 8.5-A Programmable
Isolated DC/DC Converter
Programming Information
VID4=1
VID4=0
VID3 VID2 VID1 VID0
Vout
Vout
1
1
1
1
10.0 V
6.50 V
1
1
1
0
10.5 V
6.75 V
1
1
0
1
11.0 V
7.00 V
1
1
0
0
11.5 V
7.25 V
1
0
1
1
12.0 V
7.50 V
1
0
1
0
12.5 V
7.75 V
1
0
0
1
13.0 V
8.00 V
1
0
0
0
13.5 V
8.25 V
0
1
1
1
14.0 V
8.50 V
0
1
1
0
14.5 V
8.75 V
0
1
0
1
15.0 V
9.00 V
0
1
0
0
15.5 V
9.25 V
0
0
1
1
16.0 V
9.50 V
0
0
1
0
16.5 V
9.75 V
0
0
0
1
17.0 V
10.00 V
0
0
0
0
17.5 V
10.25 V
Logic 0 = Connect to ()Remote Sense, pin 20
Logic 1 = Open circuit (no pull-up resistors)
VID3 & VID4 must not be changed while the unit is operating.
# This specification covers only the PT4486 regulator and PT4497 current booster.
#
#
Specifications
(Unless otherwise stated, T
a
=25C, V
in
=48 V, V
o
=12 V, C
o
=0 F, and I
o
=I
o
max)
PT4486
Characteristic
Symbol
Conditions
Min
Typ
Max
Units
Output Current
I
o
Over V
in
range
0.1
(1)
--
8.5
(2)
A
Input Voltage Range
V
in
Over I
o
Range
36
48
75
VDC
Set Point Voltage Tolerance
V
o
tol
--
1
1.5
%V
o
Temperature Variation
Reg
temp
40
T
case
+100C, I
o
=0
--
0.5
--
%V
o
Line Regulation
Reg
line
Over V
in
range
--
0.1
1
%V
o
Load Regulation
Reg
load
Over I
o
range
--
0.5
1
%V
o
Total Output Voltage Variation
V
o
tot
Includes set-point, line, load,
--
2
3
%V
o
40
T
case
+100C
Efficiency
I
o
=5 A
89
--
%
V
o
Ripple (pk-pk)
V
r
20 MHz bandwidth
--
120
150
mV
pp
Transient Response
t
tr
0.1 A/s load step, 50% to 75% I
o
max
--
N/A
--
s
V
tr
V
o
over/undershoot
--
1
--
%V
o
1 A/s load step, 50% to 100% I
o
max
--
200
--
s
V
o
over/undershoot
--
5
--
%V
o
Current Limit
I
lim
V
in
=36 V,
V
o
= 1%
--
10
--
A
foldback continuous limit
Current Share Tolerance
I
shr
tol
with PT4497 booster
--
10
--
%
Over-Voltage Protection
OVP
Shutdown and latch off
--
125
--
%V
o
Switching Frequency
s
Over V
in
range
270
300
350
kHz
Under-Voltage Lockout
UVLO
--
34.5
--
V
Inhibit (Pin 3)
Referenced to V
in
(pin 2)
Input High Voltage
V
IH
2.5
--
Open
(3)
V
Input Low Voltage
V
IL
0.5
--
+0.8
Input Low Current
I
IL
--
0.2
--
mA
Standby Input Current
I
in
standby
pins 3 & 2 connected
--
4
10
mA
Internal Input Capacitance
C
in
--
3
--
F
External Output Capacitance
C
out
Between +V
o
and V
o
0
--
10,000
F
Isolation Voltage
Inputoutput/inputcase
1500
--
--
V
Capacitance
Input to output
--
1100
--
pF
Resistance
Input to output
10
--
--
M
Operating Temperature Range
T
c
Case temperature, over V
in
range
-40
--
+100
(4)
C
Over-Temperature Shutdown
OTP
Case temperature, auto reset
--
110
--
C
Storage Temperature
T
s
--
-40
--
+125
C
Reliability
MTBF
Per Bellcore TR-332
1.7
--
--
10
6
Hrs
50% stress, T
a
=40C, ground benign
Mechanical Shock
--
Per Mil-Std-883D, method 2002.3,
--
500
--
G's
1mS, half-sine, mounted to a fixture
Mechanical Vibration
--
Mil-Std-883D, Method 2007.2
Horizontal
--
20
(5)
--
G's
20-2000 Hz, pcb mounted
Weight
--
--
--
90
--
grams
Flammability
--
Materials meet UL 94V-0
Notes:
(1) The converter requires a 100 mA load to ensure proper operation.
(2) The maximum output current is limited to 8.5 A or 100/V
OUT
, whichever is less.
(3) The Inhibit (pin 3) has an internal pull-up, and must be pulled to Vin potential to enable the output. If it is left open circuit the converter output will
be disabled. The open-circuit voltage is limited to 6.5 V. Refer to the application notes for other interface considerations.
(4) See Safe Operating Area curves or contact the factory for the appropriate derating.
(5) The case pins on through-hole pin configuration (suffix A) must be soldered. For more information see the applicable package outline drawing.
SLTS121C SEPTEMBER 2000 REVISED OCTOBER 2004
For technical support and further information, visit http://power.ti.com
Note A:
Characteristic data has been developed from actual products tested at 25C. This data is considered typical data for the Converter.
Note B:
SOA curves represent the conditions at which internal components are at or below the manufacturer's maximum operating temperatures
Efficiency vs Output Current
Power Dissipation vs Output Current
Typical Characteristics
PT4486--48V
100-W 8.5-A Programmable
Isolated DC/DC Converter
Efficiency vs Output Current
Performance Characteristics, V
o
=15 V
(See Note A)
Performance Characteristics, V
o
=12 V
(See Note A)
Safe Operating Area, V
O
=12 V
( See Note B)
Safe Operating Area, V
O
=15 V
( See Note B)
Power Dissipation vs Output Current
20
30
40
50
60
70
80
90
0
1
2
3
4
5
6
7
8
Iout (A)
A
m
b
i
en
t
T
e
mp
er
at
u
r
e (
C
)
Nat conv
100LFM
200LFM
300LFM
400LFM
500LFM
Airflow
20
30
40
50
60
70
80
90
0
1
2
3
4
5
6
Iout (A)
A
m
b
i
en
t
T
e
mp
er
at
u
r
e (
C
)
500LFM
400LFM
300LFM
200LFM
100LFM
Nat conv
Airflow
60
65
70
75
80
85
90
95
0
1
2
3
4
5
6
7
8
Iout (A)
E
f
f
i
ci
en
cy -
%
36 V
48 V
60 V
75 V
V
IN
0
2
4
6
8
10
12
14
16
18
0
1
2
3
4
5
6
7
8
Iout (A)
Pd
- W
a
tts
75 V
60 V
48 V
36 V
V
IN
60
65
70
75
80
85
90
95
0
1
2
3
4
5
6
Iout (A)
Effi
c
i
e
n
c
y
- %
36 V
48 V
60 V
75 V
V
IN
0
2
4
6
8
10
12
14
0
1
2
3
4
5
6
Iout (A)
Pd
- W
a
tts
75 V
60 V
48 V
36 V
V
IN
SLTS121C SEPTEMBER 2000 REVISED OCTOBER 2004
For technical support and further information, visit http://power.ti.com
Application Notes
Increasing the Output Current of the PT4486
with the PT4497 Compatible Current Booster
The PT4497 is a 8.5-A "Current Booster" module
designed specifically for the PT4486 programmable
DC/DC converter. The booster is controlled directly
by the regulator, and effectively adds an additional
output stage that operates in parallel. This allows
the system to run sychronously, providing a low
noise solution. Up to two booster modules can be
connected to a PT4486 converter. Each booster
module increases the available output current by
8.5 A. A combination of one PT4486 converter and
two PT4497 booster modules can supply up to 25.5 A
of output current; enough power to supply a moder-
ately sized rack-mounted system. Figure 1-1 shows
the connection schematic for the regulator and cur-
rent booster combination.
A current booster is not a stand-alone product, and
can only operate with a regulator. It is housed in
the same package as its compatible regulator, and
shares the same mechanical outline. Except for an
increase in output current, the overall performance
of a converter/booster combination is identical to
that of a stand-alone converter.
Figure 1-1; Current Booster Application Schematic
Table 1-1; Booster Pin-Out Information
Pin
Function
Pin Function
Pin Function
1
+V
in
10 +V
out
19 V
out
2
V
in
11 +V
out
20 ()Vsense
3
Do not connect
12 +V
out
21 Do not connect
4
V
r
13 +V
out
22 Do not connect
5
V
a
14 V
out
23 Do not connect
6
Do not connect
15 V
out
24 Do not connect
7
Do not connect
16 V
out
25 Do not connect
8
+V
out
17 V
out
26 DRV
9
+V
out
18 V
out
Notes:
1. Refer to the PT4486 specification table for the
performance of the regulator/booster combination.
2. The pin-out of the current booster modules include a
number pins identified, "Do not connect" (see Table 1-1).
These pins are not connected internally to the module
but must be soldered to a pad to preserve the unit's
mechanical integrity.
3. A minimum of 33 F of output capacitance is required
across the output of each PT4497 booster for proper
operation. A value greater than 33 F will further
reduce transients due to large and/or fast load steps.
4. The converter and all boosters must be located on
the same printed circuit board. A similar footprint
and trace layout for each module will also facilitate
current sharing.
PT4486, PT4497
PT4497
PT4486
1
2
8 - 13
V
IN
-V
OUT
+V
OUT
20
7
REMOTE SENSE (+)
REMOTE SENSE (-)
VID0
VID1
VID2
VID3
PROGRAMMING PINS
Inhibit
3
C
IN
33F
Optional
+
C
IN
33F
Optional
+
LOAD
1
8 - 13
14 - 19
+V
IN
25
VID4
24
23
22
21
14-19
2
4 5 26
20
4 5 26
C
OUT
33F
Optional
+
C
OUT
33F
Required
3
+
Application Notes
For technical support and further information, visit http://power.ti.com
Operating Features of the PT4470 and PT4480
Series of Isolated DC/DC Converters
Under-Voltage Lockout
An Under-Voltage Lock-Out (UVLO) inhibits the
operation of the converter until the input voltage is
above the UVLO threshold (see the applicable data
sheet specification). Below this voltage, the module's
output is held off, irrespective of the state of the Inhibit
control (pin 3). If the Inhibit control is connected to V
in
(pin 2), the module will automatically power up when
the input voltage rises above the UVLO threshold. The
UVLO allows the module to produce a clean transition
during both power-up and power-down, even when the
input voltage is rising or falling slowly. It also reduces
the high start-up current during normal power-up of
the converter, and minimizes the current drain from the
input source during low-input voltage conditions. The
UVLO threshold includes about 2 V of hysteresis. Once
operational, the converter will conform to its operating
specifications when the minimum specified input voltage
is reached.
Over-Current Protection
To protect against load faults, the PT4470/80 series of
DC/DC converters incorporate an output current limit.
Once the load current drawn from the module reaches
the current limit threshold, any attempt by the load to
draw additional current will result in a significant drop
in the module's regulated output voltage. The current
limit circuitry incorporates a limited amount of foldback.
This has the effect of slightly reducing the output current
from the module when supplying an absolute short circuit.
Upon removal of the load fault, the output voltage from
the converter will automatically recover to its programmed
regulation voltage.
Output Over-Voltage Protection
The PT4470/80 series of DC/DC converters incorporate
circuitry that continually senses the output for an over-
voltage (OV) condition. The OV threshold automatically
tracks the VID output voltage program setting to a level
25% higher than that programmed at the control pins,
VID0 through VID4. If the converter output voltage
exceeds the OV threshold, the converter is immediately
shut down and remains in a latched-off state. To resume
normal operation the converter must be actively reset.
This is accomplished by either cycling the status of the
Inhibit control (pin 3) from "On" to "Off" and then back
"On" again, or by momentarily removing the input power
to the converter. For failsafe operation and redundancy,
the OV protection uses circuitry that is independent of
the converter's internal feedback loop.
Over-Temperature Protection
Over-temperature protection is provided by an internal
temperature sensor, which closely monitors the tempera-
ture of the converter's metal case. If the case temperature
exceeds the specified limit (see applicable data sheet),
the converter will shut down. The converter will then
automatically restart when the sensed temperature drops
by about 10C. When operated outside its recommended
thermal derating envelope (see data sheet SOA curves),
the converter will typcially cycle on and off at intervals
from a few seconds to one or two minutes. This is to ensure
that the internal components are not permanently damaged
from excessive thermal stress.
Primary-Secondary Isolation
Electrical isolation is provided between the input terminals
(primary) and the output terminals (secondary). All con-
verters are production tested to a primary-secondary
withstand voltage of 1500VDC. This specification com-
plies with UL60950 and EN60950 and the requirements
for operational isolation. Operational isolation allows
these converters to be configured for either a positive or
negative input voltage source. The data sheet `Pin-Out
Information' uses shading to indicate which pins are
associated with the primary. They include pins 1 through
5, inclusive.
Fuse Recommendations
If desired, an input fuse may be added to protect against
the application of a reverse input voltage.
Thermal Considerations
Airflow may be necessary to ensure that the module can
supply the desired load current in environments with
elevated ambient temperatures. The required airflow
rate may be determined from the Safe Operating Area
(SOA) thermal derating chart (see converter specifica-
tions). The recommended direction for airflow is into
the longest side of the module's metal case. See Figure 1.
Recommended direction for airflow is
into (perpendicular to) the longest side.
Figure 1
PT4470, PT4480 Series
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