IR11662SPBF - International Rectifier

March 23, 2010

IR11662S

ADVANCED SMART RECTIFIER TM CONTROL IC

Features

• Secondary side high speed SR controller

• DCM, CrCM flyback and 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

• 50ns turn-off propagation delay

• Vcc range from 11.3V to 20V

• Direct sensing of MOSFET drain voltage

• Enable function synchronized with MOSFET VDS

transition

• Cycle by Cycle MOT Check Circuit prevents multiple

false trigger GATE pulses

• Lead-free

• Compatible with 0.3W Standby, Energy Star, CECP,

etc.

Typical Applications

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

ATX SMPS, Server SMPS

Product Summary

Topology Flyback,

Resonant Half-bridge

VD 200V

VOUT 10.7V Clamped

Io+ & I o- (typical) +1A & -4A

Turn on Propagation

Delay 60ns (typical)

Turn off Propagation

Delay 50ns (typical)

Package Options

8-Lead SOIC

Typical Connection Diagram

RMOT

Cdc

VD 5

VS 6

MOT

OVT

GND 7

VGATE 8

VCC

IR11671

XF M

LOAD

Rdc

Vin

Rtn

*Please note that this datasheet contains advance information that could change before the product is

released to production.

IR11662S

Datasheet No - PD97468

IR11662S

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 22

Tape and Reel Details 23

Part Marking Information 24

Ordering Information 25

IR11662S

Description

IR11662 is a smart secondary-side driver IC designed to drive N-Channel power MOSFETs used as

synchronous rectifiers in isolated Flyback and resonant half-bridge converters. The IC can control one or

more paralleled N-MOSFETs to emulate the behavior of Schottky diode rectifiers. The drain to source voltage

is sensed differentially to determine the polarity of the current and turn the power switch on and off in

proximity of the zero current transition. The cycle-by-cycle MOT protection circuit can automatically detect no

load condition and turn off gate driver output to avoid negative current flowing through the MOSFETs.

Ruggedness and noise immunity are accomplished using an advanced blanking scheme and double-pulse

suppression which allow reliable operation in all operating modes.

IR11662S

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 B

(per JEDEC standard JESD22-A115)

ESD

Human Body Model Class 1C (1500V)

(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.

IR11662S

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 VCC -0.3 20 V

Enable Voltage VEN -0.3 20 V

Cont. Drain Sense Voltage VD -1 200 V

Pulse Drain Sense Voltage VD -5 200 V

Source Sense Voltage VS -3 20 V

Gate Voltage VGATE -0.3 20 V VCC=20V, Gate off

Operating Junction Temperature TJ -40 150 °C

Storage Temperature TS -55 150 °C

Thermal Resistance RJA 128 °C/W SOIC-8

Package Power Dissipation PD 970 mW SOIC-8, TAMB=25°C

Switching Frequency fsw 500 kHz

Recommended Operating Conditions

For proper operation the device should be used within the recommended conditions.

Symbol Definition Min. Max. Units

VCC Supply voltage 11.4 18

VD Drain Sense Voltage -3 † 200 V

TJ Junction Temperature -25 125 °C

Fsw Switching Frequency --- 500 kHz

† VD -3V negative spike width ≤100ns

Recommended Component Values

Symbol Component Min. Max. Units

RMOT MOT pin resistor value 5 75 kΩ

IR11662S

Electrical Characteristics

VCC=15V and TA = 25°C unless otherwise specified. The output voltage and current (VO and IO) parameters

are referenced to GND (pin7).

Supply Section

Parameters Symbol Min. Typ. Max. Units Remarks

Supply Voltage Operating

Range VCC 11.4 18 V GBD

VCC Turn On Threshold VCC ON 9.8 10.55 11.3 V

VCC Turn Off Threshold

(Under Voltage Lock Out) VCC UVLO 8.4 9 9.7 V

VCC Turn On/Off Hysteresis VCC HYST 1.55 V

8.5 10 mA CLOAD = 1nF, fSW = 400kHz

Operating Current ICC 50 65 mA CLOAD = 10nF, fSW = 400kHz

Quiescent Current IQCC 1.8 2.2 mA

Start-up Current ICC START 100 200 µA VCC=VCC ON - 0.1V

Sleep Current I SLEEP 150 200 µA VEN=0V, VCC =15V

Enable Voltage High VENHI 2.15 2.70 3.2 V

Enable Voltage Low VENLO 1.2 1.6 2.0 V

Enable Pull-up Resistance REN 1.5 M

GBD

Comparator Section

Parameters Symbol Min. Typ. Max. Units Remarks

-7 -3.5 0 OVT = 0V, VS=0V

-15 -10.5 -7 OVT floating, VS=0V

Turn-off Threshold VTH1

-23 -19 -15

OVT = VCC, VS=0V

Turn-on Threshold VTH2 -150 -50 mV

Hysteresis VHYST 55 mV

Input Bias Current IIBIAS1 1 7.5 µA VD = -50mV

Input Bias Current IIBIAS2 30 100 µA VD = 200V

Comparator Input Offset VOFFSET 2 mV GBD

Input CM Voltage Range VCM -0.15 2 V

One-Shot Section

Parameters Symbol Min. Typ. Max. Units Remarks

Blanking pulse duration tBLANK 8 15 24 µs

2.5 V VCC=10V – GBD

Reset Threshold VTH3 5.4 V VCC=20V – GBD

Hysteresis VHYST3 40 mV VCC=10V – GBD

Minimum On Time Section

Parameters Symbol Min. Typ. Max. Units Remarks

180 240 300 ns RMOT =5kVCC=12V

Minimum on time TOnmin 2.25 3 3.75 µs RMOT =75kVCC=12V

IR11662S

Electrical Characteristics

VCC=15V and TA = 25°C unless otherwise specified. The output voltage and current (VO and IO) parameters

are referenced to GND (pin7).

Gate Driver Section

Parameters Symbol Min. Typ. Max. Units Remarks

Gate Low Voltage VGLO 0.3 0.5 V IGATE = 200mA

Gate High Voltage VGTH 9.0 10.7 12.5 V VCC=12V-18V (internally clamped)

Rise Time tr1 21 ns CLOAD = 1nF, VCC=12V

tr2 181 ns CLOAD = 10nF, VCC=12V

Fall Time tf1 10 ns CLOAD = 1nF, VCC=12V

tf2 44 ns CLOAD = 10nF, VCC=12V

Turn on Propagation Delay tDon 60 95 ns VDS to VGATE -100mV overdrive

Turn off Propagation Delay tDoff 50 75 ns VDS to VGATE -100mV overdrive

Pull up Resistance rup 5  IGATE = 1A – GBD

Pull down Resistance rdown 1.2  IGATE = -200mA

Output Peak Current(source) IO source 1 A CLOAD = 10nF – GBD

Output Peak Current (sink) IO sink 4 A CLOAD = 10nF – GBD

IR11662S

Functional Block Diagram

UVLO

REGULATOR

VCC

VTH1

GND

VGATE

VTH3

VTH1

VTH2 VTH3

Vgate

VDS

MOT

OVT

VCC

Min OFF Time

RESET

Min ON Time

RESET

DRIVER

VCC

Cycle by Cycle

MOT Check

Circuit

IR11662S

I/O Pin Equivalent Circuit Diagram

GND

ESD

Diode

200V

Diode

RESD

IR11662S

Lead Definitions

PIN# Symbol Description

1 VCC Supply Voltage

2 OVT Offset Voltage Trimming

3 MOT Minimum On Time

4 EN Enable

5 VD FET Drain Sensing

6 VS FET Source Sensing

7 GND Ground

8 VGATE Gate Drive Output

Lead Assignments

GND

VGATE

VCC

MOT

OVT

IR11662S

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 IR11662. This pin is internally clamped.

OVT: Offset Voltage Trimming

The OVT pin will program the amount of input offset voltage for the turn-off threshold VTH1.

The pin can be optionally tied to ground, to VCC or left floating, to select 3 ranges of input offset trimming.

This programming feature allows for accommodating different RDson MOSFETs.

MOT: Minimum On Time

The MOT programming pin controls the amount of minimum on time. Once VTH2 is crossed for the first time,

the gate signal will become active and turn on the power FET. Spurious ringings and oscillations can trigger

the input comparator off. The MOT blanks the input comparator keeping the FET on for a minimum time.

The MOT is programmed between 200ns and 3us (typ.) by using a resistor referenced to COM.

EN: Enable

This pin is used to activate the IC “sleep” mode by pulling the voltage level below 1.6V (typ). In sleep mode

the IC will consume a minimum amount of current. All switching functions will be disabled and the gate will be

inactive.

VD: Drain Voltage Sense

VD is the voltage sense pin for the power MOSFET Drain. This is a high voltage pin and particular care must

be taken in properly routing the connection to the power MOSFET drain.

Additional filtering and or current limiting on this pin are not recommended as it would limit switching

performance of the IC.

VS: Source Voltage Sense

VS is the differential sense pin for the power MOSFET Source. This pin must not be connected directly to the

power ground pin (7) but must be used to create a Kelvin contact as close as possible to the power MOSFET

source pin.

GND: Ground

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

referenced to this point.

VGATE: Gate Drive Output

This is the gate drive output of the IC. Drive voltage is internally limited and provides 1A peak source and 4A

peak sink capability. Although this pin can be directly connected to the power MOSFET gate, the use of

minimal gate resistor is recommended, especially when putting multiple FETs 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.

IR11662S

Application Information and Additional Details

State Diagram

UVLO/Sleep Mode

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

voltage, VCC ON. During the time the IC remains in the UVLO state, the gate drive circuit is inactive and the IC

draws a quiescent current of ICC START. The UVLO mode is accessible from any other state of operation

whenever the IC supply voltage condition of VCC < VCC UVLO occurs.

The sleep mode is initiated by pulling the EN pin below 1.6V (typ). In this mode the IC is essentially shut

down and draws a very low quiescent supply current.

Normal Mode and Synchronized Enable Function

The IC enters in normal operating mode once the UVLO voltage has been exceeded and the EN voltage is

above VENHI threshold. When the IC enters the Normal Mode from the UVLO Mode, the GATE output is

disabled (stays low) until VDS exceeds VTH3 to activate the gate. This ensures that the GATE output is not

enabled in the middle of a switching cycle. This logic prevents any reverse currents across the device due to

the minimum on time function in the IC. The gate will continuously drive the SR MOSFET after this one-time

activation. The Cycle by Cycle MOT protection circuit is enabled in Normal Mode.

MOT Protection Mode

If the secondary current conduction time is shorter than the MOT (Minimum On Time) setting, the next drive

output is disabled. This function can avoid reverse current that occurs when the system works at very low

duty-cycles or at very light/no load conditions and reduce system standby power consumption by disabling

GATE outputs. The Cycle by Cycle MOT Check circuit is always activated under Normal Mode and MOT

Protection Mode, so that the IC can automatically resume normal operation once the load increases to a level

and the secondary current conduction time is longer than MOT.

IR11662S

General Description

The IR11662 Smart Rectifier IC can emulate the operation of diode rectifier by properly driving a

Synchronous Rectifier (SR) MOSFET. The direction of the rectified current is sensed by the input comparator

using the power MOSFET RDson as a shunt resistance and the GATE pin of the MOSFET is driven

accordingly.

Internal blanking logic is used to prevent spurious transitions and guarantee operation in continuous (CCM),

discontinuous (DCM) and critical (CrCM) conduction mode.

IR11662 is suitable for Flyback and Resonant Half-Bridge topologies.

Gate

TH1

TH2

TH3

Figure 1: Input comparator thresholds

Flyback Application

The modes of operation for a Flyback circuit differ mainly for the turn-off phase of the SR switch, while the

turn-on phase of the secondary switch (which corresponds to the turn off of the primary side switch) is

identical.

Turn-on phase

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

generating a negative VDS 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 VTH2.

At that point the IR11662 will drive the gate of MOSFET on which will in turn cause the conduction voltage

VDS to drop down. This drop is usually accompanied by some amount of ringing, that can trigger the input

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

power MOSFET on for a minimum amount of time.

The programmed MOT will limit also the minimum duty cycle of the SR MOSFET and, as a consequence, the

max duty cycle of the primary side switch.

DCM/CrCM 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 VDS will cross the turn-off threshold VTH1. This will happen differently depending on the mode of

operation.

In DCM the current will cross the threshold with a relatively low dI/dt. Once the threshold is crossed, the

current will start flowing again thru the body diode, causing the VDS voltage to jump negative. Depending on

the amount of residual current, VDS may trigger once again the turn on threshold: for this reason VTH2 is

blanked for a certain amount of time (TBLANK) after VTH1 has been triggered.

The blanking time is internally set. As soon as VDS crosses the positive threshold VTH3 also the blanking time

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

IR11662S

PRIM

SEC

PRIM

time

T1 T2 T3

Figure 2: Primary and secondary currents and voltages for DCM mode

PRIM

SEC

PRIM

time

T1 T2

Figure 3: Primary and secondary currents and voltages for CrCM mode

CCM Turn-off phase

In CCM mode the turn off transition is much steeper and dI/dt involved is much higher. The turn on phase is

identical to DCM or CrCM and therefore won’t be repeated here.

During the SR FET conduction phase the current will decay linearly, and so will VDS on the SR FET.

Once the primary switch will start to turn back on, the SR FET current will rapidly decrease crossing VTH1

and turning the gate off. The turn off speed is critical to avoid cross conduction on the primary side and

reduce switching losses.

Also in this case a blanking period will be applied, but given the very fast nature of this transition, it will be

reset as soon as VDS crosses VTH3.

IR11662S

PRIM

SEC

PRIM

time

T1 T2

Figure 4: Primary and secondary currents and voltages for CCM mode

The operation waveforms of IR11662 in a flyback converter under CCM mode and DCM/CrCM were shown

in Figure 5 and Figure 6 respectively.

SEC

time

T1 T2

TH1

TH2

TH3

Blanking

MOT time

Gate Drive

Figure 5: Secondary side CCM operation

IR11662S

Gate Drive

SEC

Blanking

time

T1 T2

TH1

TH2

TH3

10us blankingMOT

Figure 6: Secondary side DCM/CrCM operation

Resonant Half-Bridge Application

The typical application circuit of IR11662 in LLC half-bridge is shown in Figure 7.

Rmot2

CVCC2

Rcc2

Rmot1

CVCC1

Rcc1

VCC

OVT

MOT

GATE 8

GND 7

VS 6

VD 5

IR11662

Cout

LmM2

Vin

Rtn

Rg1

VOUT

VCC

OVT

MOT

GATE 8

GND 7

VS 6

VD 5

IR11662

Rg2

Figure 7: Resonant half-bridge application circuit

In resonant half-bridge converter, the turn-on phase and turn-off phase is similar to Flyback except the

current shape is sinusoid. The typical operation waveform can be found below.

IR11662S

Figure 8: Resonant half-bridge operation waveform

MOT Protection Mode

The MOT protection prevents reverse current in SR MOSFET which could happen at light load if the MOT

time is set very long. The IC disables the gate output in the protection mode and automatically resume to

normal operation as the load increasing to a level where the SR current conduction time is longer than MOT.

This function works in both flyback and resonant half-bridge topologies. Figure 9 is an example in Flyback

converter.

Figure 9: MOT Protection Mode

IR11662S

Synchronized Enable Function

Sync Enable function guarantees the VGATE always starts switching at the beginning of a switching cycle.

This function works in both flyback and resonant half-bridge topologies. Figure 10 is an example in resonant

half-bridge converter.

Figure 10: Synchronized Enable Function (resonant half-bridge)

General Timing Waveform

VCC

VCC ON

UVLO

VCC UVLO

NORMALUVLO

Figure 11: Vcc UVLO

10%

90%

rise

TH2

fall

TH1

Doff

Don

50%

Gate

Figure 12: Timing waveform

IR11662S

0.01

0.1

5 V 10 V 15 V 20 V

SUPPLY

(mA)

Supply voltage

Figure 13: Supply Current vs. Supply Voltage

8 V

9 V

10 V

11 V

-50 °C 0 °C 50 °C 100 °C 150 °C

VCC UVLO Thresholds

Temperature

VCC ON

VCC UVLO

Figure 14: Undervoltage Lockout vs.

Temperature

1.0

1.5

2.0

-50 °C 0 °C 50 °C 100 °C 150 °C

ICC Supply Current (mA)

Temperature

QCC

Figure 15: Icc Quiescent Currrent vs.

Temperature

7.5

8.0

8.5

-50 °C 0 °C 50 °C 100 °C 150 °C

Supply Current (mA)

Te m p e r a t u r e

Icc @400KHz, C

LOAD

=1nF

Figure 16: Icc Supply Currrent @1nF Load vs.

Temperature

IR11662S

-30.0

-25.0

-20.0

-15.0

-10.0

-5.0

0.0

-50 °C 0 °C 50 °C 100 °C 150 °C

TH1

Thr eshold (m V )

Temperature

OVT=GND

OVT=Floating

OVT=VCC

Figure 17: VTH1 vs. Temperature

-150.0

-100.0

-50.0

0.0

-50 °C 0 °C 50 °C 100 °C 150 °C

TH2

Thr esholds (m V )

Temperature

Figure 18: VTH2 vs. Temperature

50.0

75.0

100.0

-50 °C 0 °C 50 °C 100 °C 150 °C

Com parator Hy ster esis V HYST (mV)

Temperature

Figure 19: Comparator Hysteresis vs.

Temperature

-15.0

-12.0

-9.0

-6.0

-50 °C 0 °C 50 °C 100 °C 150 °C

TH1

Threshold (mV)

Temperature

VS=-150mV

VS=0V

VS=+2V

Figure 20: VTH1 vs. Temperature at Common

Mode (OVT=Floating)

IR11662S

-150.0

-100.0

-50.0

-50 °C 0 °C 50 °C 100 °C 150 °C

TH2

Thr eshold (m V )

Temperature

VS=-150mV

VS=0V

VS=+2V

Figure 21: VTH2 vs. Temperature at

Common Mode

0 us

1 us

2 us

3 us

4 us

-50 °C 0 °C 50 °C 100 °C 150 °C

Minimum On Time (us)

Temperature

RMOT=5k

RMOT=75k

Figure 22: MOT vs Temperature

1.0 V

1.5 V

2.0 V

2.5 V

3.0 V

-50 °C 0 °C 50 °C 100 °C 150 °C

Enable Thresholds

Temperature

VEN HI

VEN LO

Figure 23: Enable Threshold vs. Temperature

35 ns

40 ns

45 ns

50 ns

55 ns

60 ns

65 ns

70 ns

75 ns

-50 °C 0 °C 50 °C 100 °C 150 °C

Propagation Delay

Temperature

Turn-on Propagation Delay

Turn-off Propagation Delay

Figure 24: Turn-on and Turn-off Propagation

Delay vs. Temperature

IR11662S

Package Details: SOIC8N

IR11662S

Tape and Reel Details: SOIC8N

OTE : CONTROLLING

DIMENSION IN MM

LOADED TAPE FEED DIRECTION

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

IR11662S

Part Marking Information

IR11662S

Ordering Information

Standard Pack

Base Part Number Package Type Form Quantity

Complete Part Number

Tube/Bulk 95 IR11662SPBF

IR11662S SOIC8N

Tape and Reel 2500 IR11662STRPBF

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