TECHNICAL DATA
External Components Reliable and Flexible SMPS Controller
IL44608N
DESCRIPTION
The IL44608N is a high performance voltage mode controller designed
for offline converters. This high voltage circuit that integrates the startup
current source and the oscillator capacitor, requires few external components
while offering a high flexibility and reliability.
The device also features a very high efficiency standby management
consisting of an effective Pulsed Mode operation. This technique enables the
reduction of the standby power consumption to approximately 1.0 W while
delivering 300 mW in a 150 W SMPS.
Integrated StartUp Current Source
Lossless OffLine StartUp
Direct OffLine Operation
Fast StartUp
General Features
Flexibility
Duty Cycle Control
Under-voltage Lockout with Hysteresis
On Chip Oscillator Switching Frequency 40, 75, or 100 kHz
Secondary Control with Few External Components
Protections
Maximum Duty Cycle Limitation
Cycle by Cycle Current Limitation
Demagnetization (Zero Current Detection) Protection
"Over VCC Protection" Against Open Loop
Programmable Low Inertia Over Voltage Protection against Open Loop
Internal Thermal Protection
SMPS Controller
Pulsed Mode Techniques for a Very High Efficiency Low Power Mode
Lossless Startup
Low dV/dT for Low EMI Radiations
Ordering Information
Device Switching
Frequency
Package
IL44608N40 40
kHz
Plastic
DIP8
IL44608N75 75
kHz
Plastic
DIP8
IL44608N100 100
kHz
Plastic
DIP8
Pin Connection
PACKAGE
PDIP-8
1
IL44608N
PIN FUNCTION DESCRIPTION
Pin Symbol
Function
1 Demag
The Demag pin offers 3 different functions: Zero voltage crossing detection (50 mV), 24 A cur-
rent detection and 120 A current detection. The 24 A level is used to detect the secondary re-
configuration status and the 120 A level to detect an Over Voltage status called Quick OVP.
2 Isense
The Current Sense pin senses the voltage developed on the series resistor inserted in the source of
the power MOSFET. When Isense reaches 1.0 V, the Driver output (pin 5) is disabled. This is
known as the Over Current Protection function. A 200 A current source is flowing out of the pin
3 during the startup phase and during the switching phase in case of the Pulsed Mode of opera-
tion. A resistor can be inserted between the sense resistor and the pin 2, thus a programmable
peak current detection can be performed during the SMPS standby mode.
3
Control
Input
A feedback current from the secondary side of the SMPS via the optocoupler is injected into this
pin. A resistor can be connected between this pin and GND to allow the programming of the
Burst duty cycle during the Standby mode.
4
Ground
This pin is the ground of the primary side of the SMPS.
5
Driver
The current and slew rate capability of this pin are suited to drive Power MOSFETs.
6 V
This pin is the positive supply of the IC. The driver output gets disabled when the voltage be-
comes higher than 15 V and the operating range is between 6.6 V and 13 V. An intermediate
voltage level of 10 V creates a disabling condition called Latched Off phase.
7
This pin is to provide isolation between the V
i
pin 8 and the V
CC
pin 6.
8 V
i
This pin can be directly connected to a 500 V voltage source for startup function of the IC. Dur-
ing the Startup phase a 9.0 mA current source is internally delivered to the V
CC
pin 6 allowing a
rapid charge of the V
CC
capacitor. As soon as the IC startsup, this current source is disabled.
Figure 1. Representative Block Diagram
2
IL44608N
MAXIMUM RATINGS
Rating Symbol
Value
Unit
Total Power Supply Current
I
CC
30 mA
Output Supply Voltage with Respect to Ground
V
CC
16 V
All Inputs except Vi
V
inputs
1.0 to +16
V
Line Voltage Absolute Rating
V
i
500 V
Recommended Line Voltage Operating Condition
V
i
400 V
Power Dissipation and Thermal Characteristics
Maximum Power Dissipation at TA = 85C
Thermal Resistance, JunctiontoAir
P
D
R
QJA
600
100
mV
C/W
Operating Junction Temperature
T
J
150 C
Operating Ambient Temperature
T
A
25 to +85
C
ELECTRICAL CHARACTERISTICS
(V
CC
= 12 V, for typical values T
A
= 25C, for min/max values T
A
= 25C to +85C unless otherwise
noted)
Characteristic Symbol
Min
Typ
Max
Unit
OUTPUT SECTION
Output Resistor
Sink Resistance
Source Resistance
ROL
ROH
5.0
-
8.5
15
15
-
Output Voltage Rise Time (from 3.0 V up to 9.0 V) (Note 1.)
t
r
- 50 - ns
Output Voltage Falling Edge SlewRate (from 9.0 V down to 3.0 V)
(Note 1.)
t
f
- 50 - ns
CONTROL INPUT SECTION
Duty Cycle @ I
pin3
= 2.5 mA
d
2mA
- - 2.0
%
Duty Cycle @ I
pin3
= 1.0 mA
d
1mA
36 - 48 %
Control Input Clamp Voltage (Switching Phase) @ I
pin3
= 1.0 mA
4.75
-
5.25
V
Latched Phase Control Input Voltage (Standby) @ I
pin3
= +500 _A
V
LPstby
3.4 - 4.3 V
Latched Phase Control Input Voltage (Standby) @ I
pin3
= +1.0 mA
V
LPstby
3.4 - 3.7 V
CURRENT SENSE SECTION
Maximum Current Sense Input Threshold
V
CSth
0.95 - 1.05 V
Input Bias Current
I
Bcs
-1.8 - 1.8 A
StandBy Current Sense Input Current
I
CSstby
180 - 220 A
Startup Phase Current Sense Input Current
I
CSstup
180 - 220 A
Propagation Delay (Current Sense Input to Output @ V
TH
T MOS = 3.0 V)
Leading Edge Blanking Duration IL44608N40
T
PLH(In/Out)
T
LEB
-
-
220
480
-
-
ns
ns
Leading Edge Blanking Duration IL44608N75
T
LEB
- 250 - ns
Leading Edge Blanking Duration IL44608N100
T
LEB
- 200 - ns
Leading Edge Blanking + Propagation Delay IL44608N40
T
DLY
500 - 900 ns
Leading Edge Blanking + Propagation Delay IL44608N75
T
DLY
370 - 570 ns
Leading Edge Blanking + Propagation Delay IL44608N100
T
DLY
300 - 500 ns
OSCILLATOR SECTION
Normal Operation Frequency IL44608N40
f
osc
36 - 44
kHz
Normal Operation Frequency IL44608N75
f
osc
68 - 82
kHz
Normal Operation Frequency IL44608N100
f
osc
90 - 110
kHz
Maximum Duty Cycle @ f = f
osc
d
max
78 - 86 %
OVERVOLTAGE SECTION
Quick OVP Input Filtering (R
demag
= 100 k ) T
filt
- 250 - ns
Propagation Delay (I
demag
> I
ovp
to output low)
T
PHL(In/Out)
- 2.0 - s
Quick OVP Current Threshold
I
OVP
105 - 140 A
Protection Threshold Level on V
CC
V
CCOVP
14.8 - 15.8 V
Minimum Gap Between V
CCOVP
and V
stupth
V
CCOVP
V
stup
1.0 - - V
NOTE 1: This parameter is measured using 1.0 nF connected between the output and the ground.
3
IL44608N
ELECTRICAL CHARACTERISTICS
(V
CC
= 12 V, for typical values T
A
= 25C, for min/max values T
A
= 25C to +85C unless otherwise
noted) (Note2 )
Characteristic Symbol
Min
Typ
Max
Unit
DEMAGNETIZATION DETECTION SECTION (Note 3.)
Demag Comparator Threshold (V
pin1
increasing)
V
dmgth
30 - 69
mV
Demag Comparator Hysteresis (Note 4.)
H
dmg
- 30 - mV
Propagation Delay (Input to Output, Low to High)
t
PHL(In/Out)
- 300 - ns
Input Bias Current (V
demag
= 50 mV)
I
demlb
-0.6 - - A
Negative Clamp Level (I
demag
= 1.0 mA)
V
clnegdem
-0.9 - -0.4 V
Positive Clamp Level @ I
demag
= 125 A
V
clpos
demH
2.05 - 2.8 V
Positive Clamp Level @ I
demag
= 25 A
V
clpos
demL
1.4 - 1.9 V
OVERTEMPERATURE SECTION
Trip Level Over Temperature
T
high
- 160 - C
Hysteresis T
hyst
- 30 - C
STANDBY MAXIMUM CURRENT REDUCTION SECTION
Normal Mode Recovery Demag Pin Current
Threshold
IdemNM
20 - 30 A
K FACTORS SECTION FOR PULSED MODE OPERATION
I
CCS
/ I
stup
IL44608N40
10 x K
1
2.4 - 3.8 -
I
CCS
/ I
stup
IL44608N75
10 x K
1
2.8 - 4.2 -
I
CCS
/ I
stup
IL44608N100
10 x K
1
3.1 - 4.5 -
I
CCL
/ I
stup
10
3
x K
2
46 - 63 -
(V
stup
UVLO2) / (V
stup
UVLO1)
10
2
x K
sstup
1.8 - 2.6 -
(UVLO1 UVLO2) / (V
stup
UVLO1)
10
2
x K
sl
90 - 150 -
I
CS
/ V
csth
10
6
x Y
cstby
175 - 225 -
Demag ratio I
ovp
/ I
dem
NM
Dmgr 3.0 - 5.5 -
(V3
1.0 mA
V3
0.5 mA
) / (1.0 mA 0.5 mA)
R3
-
1800
-
V
control
Latchoff
V3
- 4.8 - V
SUPPLY SECTION
Minimum Startup Voltage
V
ilow
- - 50 V
V
CC
Startup Voltage
V
stupth
12.5 - 13.8 V
Output Disabling VCC Voltage After Turn On
V
uvlo1
9.5 - 10.5 V
Hysteresis (V
stupth
V
uvlo1
) H
stupuvlo1
- 3.1 - V
V
CC
Undervoltage Lockout Voltage
V
uvlo2
6.2 - 7.0 V
Hysteresis (V
uvlo1
V
uvlo2
) H
uvlo1uvlo2
- 3.4 - V
Absolute Normal Condition V
CC
Start Current @ (V
i
= 100 V) and
(V
CC
= 9.0 V)
(I
CC
) 7.0 - 12.8
mA
Switching Phase Supply Current (no load) IL44608N40
IL44608N75
IL44608N100
I
CCS
2.0
2.4
2.6
-
-
-
3.6
4.0
4.5
mA
Latched Off Phase Supply Current
I
CClatch
0.3 - 0.68
mA
Hiccup Mode Duty Cycle (no load)
_H
iccup
- 10 - %
NOTE 2 : Adjust V
CC
above the startup threshold before setting to 12 V. Low duty cycle pulse techniques are used during test to maintain junction
temperature as close to ambient as possible.
NOTE 3 : This function can be inhibited by connecting pin 1 to GND.
NOTE 4 : Guaranteed by design (non tested).
4
IL44608N
OPERATING DESCRIPTION
The pin 3 senses the feedback current provided by the
opto coupler. During the switching phase the switch S2 is
closed and the shunt regulator is accessible by the pin 3.
The shunt regulator voltage is typically 5.0 V. The dy-
namic resistance of the shunt regulator represented by the
zener diode is 20 . The gain of the Control input is given
on Figure 11/, which shows the duty cycle as a function of
the current injected into the pin 3.
A 4.0 kHz filter network is inserted between the shunt
regulator and the PWM comparator to cancel the high fre-
quency residual noise.
The switch S3 is closed in Standby mode during the
Latched Off Phase while the switch S2 remains open. (See
section PULSED MODE DUTY CYCLE CONTROL).
The resistor Rdpulsed (Rduty cycle burst) has no effect on
the regulation process. This resistor is used to determine
the burst duty cycle described in the chapter "Pulsed Duty
Cycle Control"
PWM Latch
The IL44608 works in voltage mode. The ontime is
controlled by the PWM comparator that compares the os-
cillator sawtooth with the regulation block output (refer to
the block diagram on page 2).
The PWM latch is initialized by the oscillator and is re-
set by the PWM comparator or by the current sense com-
parator in case of an over current. This configuration en-
sures that only a single pulse appears at the circuit output
during an oscillator cycle.
Current Sense
The inductor current is converted to a positive voltage
by inserting a ground reference sense resistor R
Sense
in se-
ries with the power switch.
The maximum current sense threshold is fixed at 1.0 V.
The peak current is given by the following equation:
)
A
(
R
1
Ipk
)
(
SENSE
max
=
In standby mode, this current can be lowered as due
activation of a 200
A
current source:
(A)
)
(
R
0,2)
)
(k
(R
-
1
Ipk
SENSE
cs
stby
max
=
-
The current sense input consists of a filter (6.0 k , 4.0
pF) and of a leading edge blanking. Thanks to that, this pin
is not sensitive to the power switch turn on noise and
spikes and practically in most applications, no filtering
network is required to sense the current.
Finally, this pin is used:
as a protection against over currents (Isense > I)
as a reduction of the peak current during a Pulsed
Mode switching phase.
The overcurrent propagation delay is reduced by produc-
ing a sharp output turn off (high slew rate). This results in
an abrupt output turn off in the event of an over current
and in the majority of the pulsed mode switching sequence.
5
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