Microsoft Word - IR1153S_TR_PBF FINAL DS 2-21-11.doc

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

www.irf.com 

© 2011 International Rectifier 

 

 

Feb 21, 2011 

IR1153S

FIXED 22.2kHz FREQUENCY, µPFC  ONE CYCLE

 

CONTROL 

IC WITH BROWN-OUT PROTECTION

 

Features

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Description

                                                                                                   

Package 

 

 
   

 

 

  

  

  

  

 

  

 

  

  

  

  

  

  

  

  

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

  

  

 
 
 

IR1153 Application Diagram                                                                                 

 

  

  

  

  

  

  

  

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

 

 

 

 

 

 

  

  

  

  

  

  

  

  

  

 

• PFC IC with IR proprietary “One Cycle Control” 
• Continuous conduction mode boost type PFC 
• Fixed 22.2kHz switching frequency 
• Average current mode control 
• Input line sensed brownout protection  
• Output overvoltage protection  
• Open loop protection 

• Cycle by cycle peak current limit 
• VCC under voltage lockout 
• Programmable soft start 
• Micropower startup  
• User initiated micropower “Sleep Mode” 
• 750mA peak gate drive 
• Latch immunity and ESD protection 

The  μPFC IR1153 power factor correction IC, based on IR proprietary 
"One Cycle Control" (OCC) technique, provides for high PF, low THD 
and excellent DC Bus regulation while enabling drastic reduction in 
component count, PCB area and design time as compared to traditional 
solutions. The IC is designed to operate in continuous conduction mode 
Boost PFC converters with average current mode control at a fixed 
22.2kHz switching frequency.   The IR1153 features include input-line 
sensed brown-out protection, dedicated pin for over voltage protection, 
cycle by cycle peak current limit, open loop protection, VCC UVLO, soft-
start and micropower startup current of less than 75µA. In addition, for 
standby power requirements, the IC can be driven into a micropower 
sleep mode by pulling the OVP/EN pin low where the current 
consumption is less than 75uA. IR1153 is available in SO-8 package. 

COM

1

BOP

4

VFB

6

VCC

7

GATE

8

ISNS

3

COMP

2

OVP/EN

5

ACIN1

ACIN2

IR1144

VOUT

RTN

VCC

  

  

-

+

IR1153

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

2

 

© 2011 International Rectifier 

 

Qualification Information 
 

Industrial 

Qualification Level 

Comments: This family of ICs has passed JEDEC’s Industrial qualification.  
IR’s Consumer qualification level is granted by extension of the higher 
Industrial level. 

Moisture Sensitivity Level 

MSL2 260°C 

(per IPC/JEDEC J-STD-020) 

Machine Model 

Class A 

(per JEDEC standard JESD22-A115) 

ESD 

Human Body Model 

Class 1A  

(per EIA/JEDEC standard EIA/JESD22-A114) 

IC Latch-Up Test 

Class I, Level A 

(per JESD78) 

RoHS Compliant 

Yes 

 
 

Absolute Maximum Ratings

 

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the 
device. These are stress ratings only and functional operation of the device at these conditions is not implied. 
All voltages are absolute voltages referenced to COM. Thermal resistance and power dissipation are 
measured under board mounted and still air conditions. 
 

Parameters Symbol

Min. 

Max. 

Units  Remarks 

V

CC

 Voltage 

V

CC

 

-0.3 

20 

Not internally clamped 

ISNS voltage 

V

ISNS

 -10  0.3  V  

 

ISNS Current 

I

ISNS

 

 -2 

mA 

  

  

  

V

FB

 voltage 

V

FB

 

-0.3 

6.5 

  

  

  

V

OVP

 voltage 

V

OVP

 -0.3  6.5  V  

 

 

V

BOP

 voltage 

V

BOP

 -0.3  9 

V  

 

COMP voltage 

V

COMP

 -0.3  6.5 

V  

 

Gate Voltage 

V

GATE

 

-0.3 

18 

  

  

  

Junction Temperature Operating 
Range T

J

 -40 150 °C 

 

 

Storage Temperature 

T

S

 -55 150 °C 

 

 

Thermal Resistance 

R

θJA

   128 

°C/W 

SOIC-8 

Package Power Dissipation 

P

D

  976 

mW 

T

AMB

=25°C SOIC-8 

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

3

 

© 2011 International Rectifier 

 

 

Electrical Characteristics 

 

 

 

 

 

 

 

The electrical characteristics involve the spread of values guaranteed within the specified supply voltage and  
 junction temperature range T

J

 from – 25° C to 125°C. Typical values represent the median values, which are 

related to 25°C. If not otherwise stated, a supply voltage of V

CC

 =15V is assumed for test condition. 

 

 
Supply Section 

 

 

 

 

 

 

 

 

Parameters Symbol 

Min. 

Typ. 

Max. 

Units 

Remarks 

Supply Voltage Operating 
Range 

V

CC

  14 

17 

  

  

  

V

CC

 Turn On Threshold 

V

CC ON

 12.2 13.1  14  V   

 

V

CC

 Turn Off Threshold 

(Under Voltage Lock Out) 

V

CC UVLO

 9.4  10.1 10.8  V 

  

V

CC

 Turn On/Off Hysteresis  V

CC HYST

 2.4  3  3.6  V   

 

  

  

mA 

C

LOAD

 =1nF 

  

  

  

mA 

C

LOAD

 =4.7nF 

  

Operating Current  

I

CC

 

  

3.5 

mA 

OVP Mode, Inactive gate  

Start-up Current 

I

CC START

  

  26  75 µA 

V

CC

=V

CC

 

ON  

- 0.2V 

Sleep current 

I

SLEEP

  26 

75 

µA 

Pin 

OVP/EN=V

SLEEP

-0.2V 

Sleep Mode Threshold 

V

SLEEP

 

0.5 

  

0.8 

Bias on OVP/EN pin 

 
Oscillator Section 

 

 

 

 

 

 

 

 

Parameters Symbol 

Min. 

Typ. 

Max. 

Units 

Remarks 

20.2 22.2 24.2 

T

AMB

=25

°C 

Fixed Oscillator Frequency 

f

SW

 

18.3   25 kHz 

 -25

°C < T

AMB

 < 125

°C 

Maximum Duty Cycle 

D

MAX

 

93  

 99 % 

V

COMP

=5V 

Minimum Duty Cycle 

D

MIN

 

  

  

Pulse Skipping 

 
Protection Section 

 

 

 

 

 

 

 

 

Parameters Symbol 

Min. 

Typ. 

Max. 

Units

Remarks 

Open Loop Protection 
(OLP)Threshold 

V

OLP

 17 19 21 

V

REF

 

Bias on VFB pin 

 

Output Overvoltage 
Protection (OVP) 
Threshold 

V

OVP

 104 106 108 

V

REF

 

Bias on OVP/EN pin 

Output Overvoltage 
Protection Reset Threshold 

V

OVP(RST)

 101  103  105 

V

REF

 

Bias on OVP/EN pin 

OVP Input Bias Current 

I

OVP(Bias)

     -0.2 µA 

 

Brown-out Protection 
(BOP) Threshold 

V

BOP

 

0.66 

0.76 

0.86 

Bias on BOP pin 

Brown-out Protection 
Enable Threshold 

V

BOP(EN)

 

1.46 

1.56 

1.66 

Bias on BOP pin 

BOP Input Bias Current 

I

BOP(Bias)

     -0.2 µA 

 

Peak Current Limit 
Protection ISNS Voltage 
Threshold (IPK LIMIT) 

V

ISNS(PK)

  -0.58  -0.51  -0.44 

Bias on ISNS pin 

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

4

 

© 2011 International Rectifier 

 

 

Internal Voltage Reference Section 

 

 

 

 

 

 

Parameters Symbol 

Min. 

Typ. 

Max. 

Units 

Remarks 

Reference Voltage 

V

REF

 4.9 5  5.1  V 

Regulation Voltage on VFB pin, 
T

AMB

=25°C 

Line Regulation 

R

REG

 

  

10 

20 

mV 

14V < V

CC

 < 17V 

Temp Stability 

T

STAB

 

  

0.4 

  

 -25°C < T

AMB

 < 125°C, Note 1 

Total Variation 

ΔV

TOT

 

4.83

  

5.12 

Line & Temperature 

 
Voltage Error Amplifier Section 

 

 

 

 

 

 

 

Parameters Symbol 

Min. 

Typ. 

Max. 

Units 

Remarks 

Transconductance g

m

 35 

49 59 µS 

  

30 

44 

58 T

AMB

=25°C 

Source Current (Normal 
Mode) 

I

OVEA(SRC)

17   80 

µA 

 -25°C < T

AMB

 < 125°C 

-58 -44  -30 

T

AMB

=25°C 

Sink Current (Normal Mode) 

I

OVEA(SNK)

-80   -17 

µA 

 -25°C < T

AMB

 < 125°C 

Soft Start Delay Time 
(calculated) 

t

SS

 

  

35  msec 

R

GAIN

=8k

Ω, C

ZERO

=0.33

μF, 

C

POLE

=2nF 

V

COMP

 Voltage (Fault) 

V

COMP FLT

 

 

1.5 

@100uA steady state 

Effective V

COMP

 voltage 

V

COMP EFF

 

 4.7 

4.9 

5.1  

V  

  

  

  

VFB Input Bias Current 

I

FB(Bias)

 

  

 

-0.2 

µA 

 

Output Low Voltage 

V

OL

 

  

  

0.25 

  

  

  

Output High Voltage 

V

OH

 

5  

 5.45 V 

  

  

  

V

COMP

 Start Voltage 

V

COMP 

START

 

210 325  435  mV 

 

 

 

 

 

 

 

 

 

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

5

 

© 2011 International Rectifier 

 

 

Current Amplifier Section

 

 

 

 

 

 

 

 

Parameters Symbol 

Min. 

Typ. 

Max. 

Units

Remarks 

DC Gain 

g

DC

 

  

5.65 

  

V/V 

  

  

  

Corner Frequency 

f

C

 

  

  

kHz 

Average Current Mode, Note 1 

Input Offset Voltage 

V

IO

 

  

16 

mV 

Note 1 

  

  

ISNS Input Bias Current 

I

ISNS(Bias)

 

-57  

 -13 µA 

 

Blanking Time  

T

BLANK

 

170 320 470  ns  

 

  

  

 
Gate Driver Section 

 

 

 

 

 

 

 

 

Parameters Symbol 

Min. 

Typ. 

Max. 

Units

Remarks 

Gate Low Voltage 

V

GLO

  

   0.8 V 

I

GATE

 = 200mA 

13.1 14.1 15.1 

V

CC

=17V, Internally Clamped 

Gate High Voltage 

V

GTH

 

9.5 

  

  

V

CC

=11.5V 

 

 25  

 ns 

C

LOAD

 = 1nF, VCC=15V  

Rise Time 

t

r

 

 

 60  

 ns 

C

LOAD

 = 4.7nF, VCC=15V  

 

 35  

 ns 

C

LOAD

 = 1nF, VCC=15V 

Fall Time 

t

f

 

 

 65  

 ns 

C

LOAD

 = 4.7nF, VCC=15V 

Output Peak Current 

I

OPK

 

750 

  

  

mA 

C

LOAD

 = 4.7nF, VCC=15V, Note 1 

Gate Voltage at Fault 

V

G fault

 

  

  

0.08 

I

GATE

 = 20mA 

Note 1:

 Guaranteed by design, but not tested in production 

 

 

 

 

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

6

 

© 2011 International Rectifier 

 

Block Diagram 
 

 

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

7

 

© 2011 International Rectifier 

 

 

Lead Assignments & Definitions 
 

IRS1144

IRS1144

IR1144S  

IRS1144

IRS1144

IR1144S  

IR1153 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

8

 

© 2011 International Rectifier 

 

IR1153 General Description 
 
 
 

The  μPFC IR1153 IC is intended for power factor 
correction in continuous conduction mode Boost PFC 
converters operating at fixed switching frequency with 
average current mode control.  The IC operates based 
on IR's proprietary "One Cycle Control" (OCC) PFC 
algorithm based on the concept of resettable 
integrator. 
 
Theory of Operation 
The OCC algorithm based on the resettable integrator 
concept works using two loops - a slow outer voltage 
loop and a fast inner current loop. The outer voltage 
loop monitors the VFB pin and generates an error 
signal which controls the amplitude of the input current 
admitted into the PFC converter. In this way, the outer 
voltage loop maintains output voltage regulation. The 
voltage loop bandwidth is kept low enough to not track 
the 2xf

AC

 ripple in the output voltage and thus 

generates an almost DC error signal under steady 
state conditions.  
 
The inner current loop maintains the sinusoidal profile 
of the input current and thus is responsible for power 
factor correction. The information about the sinusoidal 
variation in input voltage is inherently available in the 
input line current (or boost inductor current).  Thus 
there is no need to sense the input voltage to 
generate a current reference. The current loop 
employs the boost inductor current information to 
generate PWM signals with a proportional sinusoidal 
variation. This controls the shape of the input current 
to be proportional to and in phase with the input 
voltage. Average current mode operation is envisaged 
by filtering the switching frequency ripple from the 
current sense signal using an appropriately sized on-
chip RC filter. This filter also contributes to the 
bandwidth of the current control loop. Thus the filter 
bandwidth has to be high enough to track the 120Hz 
rectified, sinusoidal current waveform and also filter 
out the switching frequency ripple in the inductor 
current. In IR1153 this averaging function can 
effectively filter high ripple current ratios (as high as 
40% at maximum input current) to accommodate 
designs with small boost inductances. 
 
The IC determines the boost converter instantaneous 
duty cycle based on the resettable integrator concept. 
The required signals are the voltage feedback loop 
error signal V

m

 (which is the V

COMP

 pin voltage minus a 

DC offset of V

COMP,START

) and the current sense signal 

V

ISNS

. The resettable integrator generates a cycle-by-

cycle, saw-tooth signal called the PWM Ramp which 
has an amplitude V

m

 and period 1/f

SW

 hence a slope of 

V

m*

f

SW

 

The current sense signal is amplified by the current 
amplifier by a factor g

DC

 and fed into the summing 

node where it is subtracted from V

m

 to generate the 

summer voltage (= V

m

–g

DC

*V

ISNS

). The summer 

voltage is compared with the PWM ramp by the 
PWM comparator of the IC to determine the gate 
drive duty cycle. The instantaneous duty is 
mathematically given by: 
D = (V

m

 - g

DC

.V

ISNS

)/V

m

 

Assuming steady state condition where the voltage 
feedback loop is well regulated (V

m

 & V

OUT

 are DC 

signals) & hence instantaneous duty cycle follows 
the boost-converter equation (D = 1 – V

IN

(t)/V

OUT

), 

the control equation can be re-written as: 
V

m

 = g

DC

.V

ISNS

/(V

IN

(t)/V

OUT

Further, recognizing that V

ISNS

 = I

L

(t).R

SNS

 and re-

arranging yields: 
g

DC

.I

L

(t).R

SNS

 = V

m

V

IN

(t)/V

OUT

 

Since V

m

, V

OUT

 & g

DC

 are constant terms:  

I

L

(t) 

α V

IN

(t) 

Thus the inductor current follows the input voltage 
waveform & by definition power factor correction is 
achieved. 
 
Feature set 
Fixed Frequency Operation 
The IC is programmed to operate at a fixed 
frequency of 22.2kHz (Typ). Internalization of the 
oscillator offers excellent noise immunity even in 
the noisy PFC environment while integration of the 
oscillator into the OCC core of the IC eliminates 
need for digital calibration circuits. Both these 
factors render the gate drive jitter free thus 
contributing to elimination of audible noise in PFC 
magnetics. 
 
IC Supply Circuit & Low start-up current 
The IR1153 UVLO circuit maintains the IC in UVLO 
mode during start-up if VCC pin voltage is less than 
the VCC turn-on threshold, V

CC,ON

 and current 

consumption is less than 75uA. Should VCC pin 
voltage should drop below V

CC,UVLO

 during normal 

operation, the IC is pushed back into UVLO mode 
and VCC pin has to exceed V

CC,ON

 again for normal 

operation. There is no internal voltage clamping of 
the VCC pin. 
 
User initiated Micropower Sleep mode 
The IC can be actively pushed into a micropower 
Sleep Mode where current consumption is less 
than 75uA by pulling OVP/EN pin below the Sleep 
threshold, V

SLEEP

 even while VCC is above V

CC,ON

This allows the user to disable PFC during 
application stand-by situations in order to meet 
stand-by regulations. Since V

SLEEP

 is less than 1V, 

even logic level signals can be employed. 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

9

 

© 2011 International Rectifier 

 

IR1153 General Description 

Programmable Soft Start 
The soft start process controls the rate of rise of the 
voltage feedback loop error signal thus providing a 
linear increase of the RMS input current that the 
PFC converter will admit. The soft start time is 
essentially controlled by voltage error amplifier 
compensation components selected and is 
therefore user programmable to some degree 
based on desired voltage feedback loop crossover 
frequency. 
 
Gate Drive Capability 
The gate drive output stage of the IC is a totem 
pole driver with 750mA peak current drive 
capability. The gate drive is internally clamped at 
14.1V (Typ). Gate drive buffer circuits (especially 
cost-effective base-followers) can be easily driven 
with the GATE pin of the IC to suit any system 
power level. 
 
System Protection Features 
IR1153 protection features include Brown-out 
protection (BOP), Open-loop protection (OLP), 
Overvoltage protection (OVP), Cycle-by-cycle peak 
current limit (IPK LIMIT), Soft-current limit and VCC 
under voltage lock-out (UVLO). 
 
- BOP is based on direct input line sensing using a 
resistor divider/RC filter network. If BOP pin falls 
below the Brown-out protection threshold V

BOP

, a 

Brown-out situation is immediately detected the 
following response is executed - the gate drive 
pulse is disabled, VCOMP is actively discharged 
and IC is pushed into Stand-by Mode. The IC re-
enters normal operation only after BOP pin 
exceeds V

BOP(EN)

. During start-up the IC is held in 

Stand-by Mode until this pin exceeds V

BOP(EN)

 
- OLP is activated whenever the VFB pin voltage 
falls below V

OLP

 threshold. Once open loop is 

detected the following response is immediately 
executed - the gate drive is immediately disabled, 
VCOMP is actively discharged and the IC is 
pushed into Stand-by mode. There is no voltage 
hysteresis associated with this feature. During 
start-up the IC is held in Stand-by Mode until VFB 
exceeds V

OLP

 

- The OVP pin is a dedicated pin for overvoltage 
protection that safeguards the system even if 
there is a break in the VFB feedback loop due to 
resistor divider failure etc. An overvoltage fault is 
triggered when OVP pin voltage exceeds the V

OVP

 

threshold of 106%VREF. The response of the IC 
is to immediately terminate the gate drive output 
and hold it in that state. The gate drive is re-
enabled only after OVP pin voltage drops below 
V

OVP(RST)

 threshold of 103% VREF. The exact 

voltage level at which overvoltage protection is 
triggered can be programmed by the user by 
carefully designing the OVP pin resistor divider. It 
is recommended NOT to set the OVP voltage 
trigger limit less than 106% of DC bus voltage, 
since this can endanger the situation where the 
OVP reset limit will be less than the DC bus 
voltage regulation point – in this condition the 
voltage loop can become unstable.  
 
- Soft-current limit is an output voltage fold-back 
type protection feature encountered when the 
PFC converter input current exceeds to a point 
where the V

m

 voltage saturates. As mentioned 

earlier, the amplitude of input current is directly 
proportional to V

m

, the error voltage of the 

feedback loop.  V

m

 is clamped to a certain 

maximum voltage inside the IC (given by 
V

COMP,EFF

 parameter in datasheet). If the input 

current causes the V

m

 voltage to saturate at its 

maximum value, then any further increase in input 
current will cause the duty cycle to droop which 
immediately forces the V

OUT

 voltage of the PFC 

converter to fold-back. Since the highest current 
is at the peak of the AC sinusoid, the droop in 
duty cycle commences at the peak of the AC 
sinusoid when the soft-current limit is 
encountered. In most converters, the design of 
the current sense resistor is performed based on 
soft-current limit (i.e. V

m

 saturation) and at the 

system condition which demands highest input 
current (minimum V

AC

 & maximum P

OUT

). 

 
- Cycle-by-cycle peak current limit protection 
instantaneously turns-off the gate output 
whenever the ISNS pin voltage exceeds V

ISNS(PK)

 

threshold in magnitude. The gate drive is held in 
the low state as long as the overcurrent condition 
persists. The gate drive is re-enabled when the 
magnitude of ISNS pin voltage falls below the 
V

ISNS(PK)

 threshold. This protection feature 

incorporates a leading edge blanking circuit to 
improve noise immunity.

  

 

/var/www/html/datasheet/sites/default/files/pdfhtml_dummy/ir1153-html.html
background image

 

IR1153S

 

 

www.irf.com 

10

 

© 2011 International Rectifier 

 

IR1153 Pin Description 

Pin COM:

 This is ground potential pin of the IC.   

All internal devices are referenced to this point.   
 
Pin COMP:

 External circuitry from this pin to 

ground compensates the system voltage loop and 
programs the soft start time. The COMP pin is 
essentially the output of the voltage error 
amplifier. The voltage loop error signal V

m

 used in 

the control algorithm is derived from V

COMP

 (V

m

 

=V

COMP

–V

COMP,START

). V

COMP

 is actively discharged 

using an internal resistance to below V

COMP,START

 

threshold whenever the IC is pushed into Stand-
by mode (BOP or OLP condition) or UVLO/Sleep 
mode. The gate drive output and logic functions of 
the IC are inactive if VCOMP is less than 
V

COMP,START

. Also during start-up, the VCOMP 

voltage has to be less than V

COMP,START

 in order to 

commence operation (i.e. a pre-bias on VCOMP 
will not allow IC to commence operation). 
 
Pin ISNS:

 ISNS pin is tied to the input of the 

current sense amplifier of the IC.  The voltage at 
this pin, which provides the current sense 
information to the IC, has to be a negative voltage 
wrt the COM pin. Also since the IC is based on 
average current mode, the entire inductor current 
information is necessary. A current sense resistor, 
located below system ground along the return 
path to the bridge rectifier, is the preferred current 
sensing method. ISNS pin is also the inverting 
input to the cycle-by-cycle peak current limit 
comparator. Whenever V

ISNS

 exceeds V

ISNS(PK)

 

threshold in magnitude, the gate drive is 
instantaneously disabled. Any external filtering of 
the ISNS pin must be performed carefully in order 
to ensure that the integrity of the current sense 
signal is maintained for cycle-by-cycle peak 
current limit protection. 
 
Pin BOP (Brown-out Protection): 

This pin is 

used to sense the rectified AC input line voltage 
through a resistor divider/capacitor network which 
is in effect a voltage division and averaging 
network, representing a scaled down signal of the 
average rectified input voltage (average DC 
voltage + 2xf

AC

 ripple). During start-up the BOP 

pin voltage has to exceed V

BOP(EN)

 in order to 

enable the IC to exit Stand-by mode and enter 
normal operation. A Brown-out situation is 
detected whenever the pin voltage falls below 
V

BOP

 and the IC is pushed into Stand-by mode.  

Subsequently the pin has to exceed V

BOP(EN)

 for 

the IC to exit Stand-by and resume normal 
operation. 
 
Pin OVP/EN:

 The OVP/EN pin is connected to the 

non-inverting input of the OVP(OVP) overvoltage 
comparator shown in the block diagram and thus 
is used to detect output overvoltage situations. 
The output voltage information is communicated 
to the OVP pin using a resistive divider. This pin 
also serves the second purpose of an ENABLE 
pin. The OVP/EN pin can be used to activate the 
IC into “micropower sleep” mode by pulling the 
voltage on this pin below the V

SLEEP

 threshold.   

 
Pin VFB: 

The converter output voltage is sensed 

via a resistive divider and fed into this pin. VFB 
pin is the inverting input of the output voltage error 
amplifier. The non-inverting input of this amplifier 
is connected to an internal 5V reference.  The 
impedance of the divider string must be low 
enough that it does not introduce substantial error 
due to the input bias currents of the amplifier, yet 
high enough to minimize power dissipation. 

 

Typical value of external divider total impedance 
will be around 2MΩ. VFB pin is also the inverting 
input to the Open Loop comparator. The IC is held 
in Stand-by Mode whenever VFB pin voltage is 
below V

OLP

 threshold.   

 
Pin VCC:

 This is the supply voltage pin of the IC 

and sense node for the undervoltage lock out 
circuit.  It is possible to turn off the IC by pulling 
this pin below the minimum turn off threshold 
voltage, V

CC(UVLO)

 without damage to the IC.  This 

pin is not internally clamped. 
 
Pin GATE:

 This is the gate drive output of the IC.  

It provides a drive current of ±0.75A peak with 
matched rise and fall times. The gate drive output 
of the IC is clamped at 14.1V(Typ). 

 
 
 
 
 

Maker
Infineon Technologies
Datasheet PDF Download