IR1168STRPBF - INFINEON TECHNOLOGIES AG

September 26, 2011

IR1168S

DUAL SMART RECTIFIER DRIVER IC

Features

• Secondary-side high speed controller for

synchronous rectification in resonant half bridge

topologies

• 200V proprietary IC technology

• Max 500KHz switching frequency

• Anti-bounce logic and UVLO protection

• 4A peak turn off drive current

• Micropower start-up & ultra low quiescent current

• 10.7V gate drive clamp

• 70ns turn-off propagation delay

• Wide Vcc operating range

• Direct sensing for both Synchronous Rectifiers

• Minimal component count

• Simple design

• Lead-free

Typical Applications

• LCD & PDP TV, Telecom SMPS, AC-DC adapters

Product Summary

Topology LLC Half-bridge

VD 200V

V

OUT

10.7V Clamped

I

o+

& I

o-

(typical) +1A & -4A

Turn on Propagation Delay 60ns (typical)

Turn off Propagation Delay 70ns (typical)

Package Options

8-Lead SOIC

Typical Connection Diagram

LOAD

SR1

SR2

Cdc

1 2

Lr

C1

C2

Rtn

Vin

VD2 5

VS2 6

VS1

3VCC

2

VD1

4

GND 7

GATE2 8

GATE1

1

IR1168

Cout

Rg2

Rg1

M1

M2

Datasheet No

–

PD97382

IR1168

IR1168S

2

Table of Contents Page

Description 3

Qualification Information 4

Absolute Maximum Ratings 5

Electrical Characteristics 6

Functional Block Diagram 8

Input/Output Pin Equivalent Circuit Diagram 9

Lead Definitions 10

Lead Assignments 10

Application Information and Additional Details 12

Package Details 16

Tape and Reel Details 17

Part Marking Information 18

Ordering Information 19

IR1168S

3

Description

IR1168 is dual smart secondary-side rectifier driver IC designed to drive two N-Channel power MOSFETs used as

synchronous rectifiers in resonant converter applications. The IC can control one or more paralleled N MOSFETs

to emulate the behavior of Schottky diode rectifiers. The drain to source for each rectifier MOSFET voltage is

sensed differentially to determine the level of the current and the power switch is turned ON and OFF in close

proximity of the zero current transition. Ruggedness and noise immunity are accomplished using an advanced

blanking scheme and double-pulse suppression that allows reliable operation in fixed and variable frequency

applications.

IR1168S

4

Qualification Information

†

Qualification Level

Industrial

††

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 SOIC8N MSL2

†††

260°C

(per IPC/JEDEC J-STD-020)

ESD Machine Model Class B

(per JEDEC standard JESD22-A115)

Human Body Model Class 2

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

IC Latch-Up Test Class I, Level A

(per JESD78)

RoHS Compliant Yes

†

Qualification standards can be found at International Rectifier’s web site http://www.irf.com/

†† Higher qualification ratings may be available should the user have such requirements. Please contact

your International Rectifier sales representative for further information.

†††

Higher MSL ratings may be available for the specific package types listed here. Please contact your

International Rectifier sales representative for further information.

IR1168S

5

Absolute Maximum Ratings

Absolute maximum ratings indicate sustained limits beyond which damage to the device may occur. All voltage

parameters are absolute voltages referenced to COM, all currents are defined positive into any lead. The thermal

resistance and power dissipation ratings are measured under board mounted and still air conditions.

Parameters Symbol

Min. Max. Units Remarks

Supply Voltage V

CC

-0.3 20 V

Cont. Drain Sense Voltage V

D

-3 200 V

Pulse Drain Sense Voltage V

D

-5 200 V

Source Sense Voltage V

S

-3 20 V

Gate Voltage V

GA

TE

-0.3 20 V V

CC

=20V, Gate off

Operating Junction Temperature T

J

-40 150 °C

Storage Temperature T

S

-55 150 °C

Thermal Resistance R

θ

JA

128 °C/W SOIC-8

Package Power Dissipation P

D

970 mW SOIC-8, T

AMB

=25°C

Switching Frequency fsw 500 kHz

IR1168S

6

Electrical Characteristics

The electrical characteristics involve the spread of values guaranteed within the specified supply voltage and

junction temperature range TJ 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

= 15 V is assumed for test condition.

Supply Section

Parameters Symbol

Min. Typ. Max. Units Remarks

Supply Voltage Operating

Range V

CC

8.6 18 V GBD

V

CC

Turn On Threshold V

CC ON

7.5 8.1 8.5 V

V

CC

Turn Off Threshold V

CC UVLO

7 7.6 8 V (Under Voltage Lock Out)

V

CC

Turn On/Off Hysteresis V

CC HYST

0.5 V

Operating Current I

CC

14 18 mA C

LOAD

=1nF, f

SW

= 400kHz

48 60 mA C

LOAD

=4.7nF, f

SW

= 400kHz

Quiescent Current I

QCC

2.6 3.8 mA

Start-up Current I

CC START

140 µA V

CC

=V

CC

ON

- 0.1V

Comparator Section

Parameters Symbol

Min. Typ. Max. Units Remarks

Turn-off Threshold V

TH1

-12 -6 0 mV

Turn-on Threshold V

TH2

-220 -140 -80 mV

Hysteresis V

HYST

141 mV

Input Bias Current I

IBIAS1

1 10 µA V

D

= -50mV

Input Bias Current I

IBIAS2

10 50 µA V

D

= 200V

Comparator Input Offset V

OFFSET

2 mV GBD

One-Shot Section

Parameters Symbol

Min. Typ. Max. Units Remarks

Blanking pulse duration t

BLANK

9 17 25 µs

Reset Threshold V

TH3

2.5 V V

CC

=10V – GBD

5.4 V V

CC

=20V – GBD

Hysteresis V

HYST3

40 mV V

CC

=10V - GBD

Minimum On Time Section

Parameters Symbol

Min. Typ. Max. Units Remarks

Minimum on time T

ONmin

500 750 1000 ns

IR1168S

7

Electrical Characteristics

The electrical characteristics involve the spread of values guaranteed within the specified supply voltage and

junction temperature range TJ 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

= 15 V is assumed for test condition.

Gate Driver Section

Parameters Symbol

Min. Typ. Max. Units Remarks

Gate Low Voltage V

GLO

0.3 0.5 V I

GATE

= 200mA

Gate High Voltage V

GTH

8.5 10.7 13.5 V V

CC

=12V-18V (internally clamped)

Rise Time t

r1

10 ns C

LOAD

= 1nF

t

r2

80 ns C

LOAD

= 4.7nF

Fall Time t

f1

5 ns C

LOAD

= 1nF

t

f2

25 ns C

LOAD

= 4.7nF

Turn on Propagation Delay t

Don

60 120 ns V

DS

to V

GATE

-100mV overdrive

Turn off Propagation Delay t

Doff

70 120 ns V

DS

to V

GATE

-100mV overdrive

Pull up Resistance r

up

5 Ω I

GATE

= 15mA - GBD

Pull down Resistance r

down

1.2 Ω I

GATE

= -200mA

Output Peak Current (source)

I

O source

1 A C

LOAD

= 1nF - GBD

Output Peak Current (sink) I

O sink

4 A C

LOAD

= 1nF - GBD

IR1168S

8

Functional Block Diagram

IR1168S

9

I/O Pin Equivalent Circuit Diagram

IR1168S

10

Lead Definitions

PIN# Symbol Description

1 GATE1 Gate Drive Output 1

2 VCC Supply Voltage

3 VS1 Sync FET 1 Source Voltage Sense

4 VD1 Sync FET 1 Drain Voltage Sense

5 VD2 Sync FET 2 Drain Voltage Sense

6 VS2 Sync FET 2 Source Voltage Sense

7 GND Analog and Power Ground

8 GATE2 Gate Drive Output 2

Lead Assignments

4

3

2

1

5

6

7

8

VD2VD1

GND

GATE2

VCC

VS1 VS2

GATE1

IR1168S

11

Detailed Pin Description

VCC: Power Supply

This is the supply voltage pin of the IC and it is monitored by the under voltage lockout circuit. It is possible to turn

off the IC by pulling this pin below the minimum turn off threshold voltage, without damage to the IC.

To prevent noise problems, a bypass ceramic capacitor connected to Vcc and COM should be placed as close as

possible to the IR1168. This pin is not internally clamped.

GND: Ground

This is ground potential pin of the integrated control circuit. The internal devices and gate driver are referenced to

this point.

VD1 and VD2: Drain Voltage Sense

These are the two high-voltage pins used to sense the drain voltage of the two SR power MOSFETs. Routing

between the drain of the MOSFET and the IC pin must be particularly optimized.

VS1 and VS2: Source Voltage Sense

These are the two differential sense pins for the two source pins of the two SR power MOSFETs. This pin must

not be connected directly to the GND pin (pin 7) but must be used to create a kelvin contact as close as possible

to the power MOSFET source pin.

GATE1 and GATE2: Gate Drive Outputs

These are the two gate drive outputs of the IC. The gate voltage is internally clamped and has a +1A/-4A peak

drive capability. Although this pin can be directly connected to the synchronous rectifier (SR) MOSFET gate, the

use of gate resistor is recommended (specifically when putting multiple MOSFETs in parallel). Care must be taken

in order to keep the gate loop as short and as small as possible in order to achieve optimal switching performance.

IR1168S

12

Application Information and Additional Details

State Diagram

POWER ON

Gate Inactive

UVLO MODE

VCC < VCCon

Gate Inactive

ICC = ICC START

NORMAL

Gate Active

Gate PW ≥MOT

VCC > VCCon VCC < VCCuvlo

UVLO Mode:

The IC is in the UVLO mode when the VCC pin voltage is below VCCUVLO.

The UVLO mode is accessible from

any other state of operation. In the UVLO state, most of the internal circuitry is unbiased and the IC draws a

quiescent current of ICCSTART.

The IC remains in the UVLO condition until the voltage on the VCC pin exceeds the VCC turn on threshold

voltage, VCC ON.

Normal Mode:

The IC enters in normal operating mode once the UVLO voltage has been exceeded. At this point the gate

drivers

are operating and the IC will draw a maximum of ICC from the supply voltage source.

IR1168S

13

General Description

The IR1168 Dual Smart Rectifier controller IC is the industry first dedicated high-voltage controller IC for

synchronous rectification in resonant converter applications. The IC can emulate the operation of the two

secondary rectifier diodes by correctly driving the synchronous rectifier (SR) MOSFETs in the two secondary legs.

The core of this device are two high-voltage, high speed comparators which sense the drain to source voltage of

the MOSFETs differentially. The device current is sensed using the R

DSON

as a shunt resistance and the GATE pin

of the MOSFET is driven accordingly. Dedicated internal logic then manages to turn the power device on and off in

close proximity of the zero current transition.

IR1168 further simplifies synchronous rectifier control by offering the following power management features:

-Wide VCC operating range allows the IC to be directly powered from the converter output

-Shoot through protection logic that prevents both the GATE outputs from the IC to be high at the same time

-Device turn ON and OFF in close proximity of the zero current transition with low turn-on and turn-off propagation

delays; eliminates reactive power flow between the output capacitors and power transformer

-Internally clamped gate driver outputs that significantly reduce gate losses.

The SmartRectifier™ control technique is based on sensing the voltage across the MOSFET and comparing it with

two negative thresholds to determine the turn on and off transitions for the device. The rectifier current is sensed

by the input comparators using the power MOSFET R

DSON

as a shunt resistance and its GATE is driven depending

on the level of the sensed voltage vs. the 3 thresholds shown below.

V

Gate

V

TH1

V

TH2

V

TH3

V

DS

Figure 1: Input comparator thresholds

Turn-on phase

When the conduction phase of the SR FET is initiated, current will start flowing through its body diode, generating

a negative V

DS

voltage across it. The body diode has generally a much higher voltage drop than the one caused by

the MOSFET on resistance and therefore will trigger the turn-on threshold V

TH2

.

When V

TH2

is triggered, IR1168 will drive the gate of MOSFET on which will in turn cause the conduction voltage

VDS to drop down to I

D

*R

DSON

. This drop is usually accompanied by some amount of ringing, that could trigger the

input comparator to turn off; hence, a fixed Minimum On Time (MOT) blanking period is used that will maintain the

power MOSFET on for a minimum amount of time.

The fixed MOT limits the minimum conduction time of the secondary rectifiers and hence, the maximum switching

frequency of the converter.

Turn-off phase

Once the SR MOSFET has been turned on, it will remain on until the rectified current will decay to the level where

V

DS

will cross the turn-off threshold V

TH1

.

IR1168S

14

Since the device currents are sinusoidal here, the device VDS will cross the V

TH1

threshold with a relatively low

dV/dt. Once the threshold is crossed, the current will start flowing again through the body diode, causing the VDS

voltage to jump negative. Depending on the amount of residual current, VDS may once again trigger the turn-on

threshold; hence, VTH2 is blanked for a time duration t

BLANK

after VTH1 is triggered. When the device VDS

crosses the positive reset threshold VTH3, t

BLANK

is terminated and the IC is ready for next conduction cycle as

shown below.

Gate Drive

VDS

Blanking

time

T1 T2

VTH1

VTH2

VTH3

MOT tBLANK

IDS

Figure 2: Secondary currents and voltages

IR1168S

15

t

VCC

VCC ON

UVLO

VCC UVLO

NORMALUVLO

Figure 3: Vcc UVLO

10%

90%

t

rise

V

TH2

t

fall

V

TH1

t

Doff

t

Don

50%

V

DS

V

Gate

Figure 4: Timing waveform

IR1168S

16

0.01

0.1

1

10

6 V 8 V 10 V 12 V 14 V 16 V 18 V

I

SUPPLY

(mA)

Supply voltage

Figure 5: Supply Current vs. Supply Voltage

7.0 V

7.5 V

8.0 V

8.5 V

9.0 V

-50 °C 0 °C 50 °C 100 °C 150 °C

VCC UVLO Thresholds

Temperature

VCC ON

VCC UVLO

Figure 6: Undervoltage Lockout vs. Temperature

2.35

2.40

2.45

2.50

2.55

2.60

2.65

2.70

-50 °C 0 °C 50 °C 100 °C 150 °C

ICC Supply Current (mA)

Temperature

I

QCC

Figure 7: Icc Quiescent Currrent vs. Temperature

14.1

14.2

14.3

14.4

14.5

14.6

14.7

14.8

14.9

-50 °C 0 °C 50 °C 100 °C 150 °C

I

CC

Supply Current (mA)

Temperature

Icc @400KHz, C

LOAD

=1nF

Figure 8: Icc Supply Currrent @1nF Load vs.

Temperature

IR1168S

17

-5.2

-5.0

-4.8

-4.6

-4.4

-4.2

-4.0

-3.8

-50 °C 0 °C 50 °C 100 °C 150 °C

V

TH1

Threshold (mV)

Temperature

Ch2

Ch1

Figure 9: V

TH1

vs. Temperature

-131.0

-130.0

-129.0

-128.0

-127.0

-126.0

-125.0

-124.0

-50 °C 0 °C 50 °C 100 °C 150 °C

V

TH2

Thresholds (mV)

Temperature

Ch2

Ch1

Figure 10: V

TH2

vs. Temperature

-126.0

-125.0

-124.0

-123.0

-122.0

-121.0

-120.0

-119.0

-50 °C 0 °C 50 °C 100 °C 150 °C

Comparator Hysteresis V

HYST

(mV)

Temperature

Ch2

Ch1

Figure 11: Comparator Hysteresis vs.

Temperature

730 ns

740 ns

750 ns

760 ns

770 ns

780 ns

790 ns

800 ns

810 ns

-50 °C 0 °C 50 °C 100 °C 150 °C

Minimum On Time

Temperature

MOT_Ch1

MOT_Ch2

Figure 12: MOT vs Temperature

IR1168S

18

35 ns

40 ns

45 ns

50 ns

55 ns

60 ns

65 ns

70 ns

-50 °C 0 °C 50 °C 100 °C 150 °C

Propagation Delay

Temperature

Ch1 Turn-on Propagation Delay

Ch2 Turn-on Propagation Delay

Figure 13: Turn-on Propagation Delay vs.

Temperature

35 ns

40 ns

45 ns

50 ns

55 ns

60 ns

-50 °C 0 °C 50 °C 100 °C 150 °C

Propagation Delay

Temperature

Ch1 Turn-off Propagation Delay

Ch2 Turn-off Propagation Delay

Figure 14: Turn-off Propagation Delay vs.

Temperature

10.0 V

10.5 V

11.0 V

11.5 V

-50 °C 0 °C 50 °C 100 °C 150 °C

Gate Clamping Voltage

Temperature

Ch1 VGH@Vcc=12V

Ch2 VGH@Vcc=12V

Ch1 VGH@Vcc=18V

Ch2 VGH@Vcc=18V

Figure 15: Gate Clamping Voltage vs.

Temperature

5 ns

6 ns

7 ns

8 ns

9 ns

-50 °C 0 °C 50 °C 100 °C 150 °C

Gate Tr and Tf @ 1nF Load

Temperature

Tr_Ch1 Tr_Ch2

Tf_Ch1 Tf_Ch2

Figure 16: Gate Output Tr and Tf time @ 1nF

Load vs. Temperature

IR1168S

19

Package Details: SOIC8N

IR1168S

20

Tape and Reel Details: SOIC8N

E

F

A

C

D

G

A

B

H

NOTE : CONTROLLING

DIMENSION IN MM

LOADED TAPE FEED DIRECTION

A

H

F

E

G

D

B

C

CARRIER TAPE DIMENSION FOR 8SOICN

Code Min Max Min Max

A 7.90 8.10 0.311 0.318

B 3.90 4.10 0.153 0.161

C 11.70 12.30 0.46 0.484

D 5.45 5.55 0.214 0.218

E 6.30 6.50 0.248 0.255

F 5.10 5.30 0.200 0.208

G 1.50 n/a 0.059 n/a

H 1.50 1.60 0.059 0.062

Metric Imperial

REEL DIMENSIONS FOR 8SOICN

Code Min Max Min Max

A 329.60 330.25 12.976 13.001

B 20.95 21.45 0.824 0.844

C 12.80 13.20 0.503 0.519

D 1.95 2.45 0.767 0.096

E 98.00 102.00 3.858 4.015

F n/a 18.40 n/a 0.724

G 14.50 17.10 0.570 0.673

H 12.40 14.40 0.488 0.566

Metric Imperial

IR1168S

21

Part Marking Information

IR1168S

22

Ordering Information

Base Part Number Package Type Standard Pack Complete Part Number

Form Quantity

IR1168 SOIC8N Tube/Bulk 95 IR1168SPBF

Tape and Reel 2500 IR1168STRPBF

The information provided in this document is believed to be accurate and reliable. However, International Rectifier assumes no

responsibility for the consequences of the use of this information. International Rectifier assumes no responsibility for any

infringement of patents or of other rights of third parties which may result from the use of this information. No license is granted by

implication or otherwise under any patent or patent rights of International Rectifier. The specifications mentioned in this document are

subject to change without notice. This document supersedes and replaces all information previously supplied.

For technical support, please contact IR’s Technical Assistance Center

http://www.irf.com/technical-info/

WORLD HEADQUARTERS:

233 Kansas St., El Segundo, California 90245

Tel: (310) 252-7105