View IR11672AS_4631243.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Datasheet No - PD97469 Nov 2, 2009
IR11672AS
ADVANCED SMART RECTIFIER TM CONTROL IC Features
* * * * * * * * * * * * * * *
Product Summary
Flyback, Resonant Half-bridge 200V 10.7V +2A & -7A 60ns (typical) 50ns (typical)
Secondary side high speed SR controller Topology DCM, CrCM flyback and Resonant half-bridge topologies 200V proprietary IC technology VD Max 500KHz switching frequency VOUT Anti-bounce logic and UVLO protection 7A peak turn off drive current Io+ & I o- (typical) Micropower start-up & ultra low quiescent current Turn on Propagation 10.7V gate drive clamp Delay 50ns turn-off propagation delay Vcc range from 11.3V to 20V Turn off Propagation Direct sensing of MOSFET drain voltage Delay Enable function synchronized with MOSFET VDS transition Cycle by Cycle MOT Check Circuit prevents multiple Package Options 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 8-Lead SOIC
Typical Connection Diagram
Vin
Rs XFM Cs 1 Ci 2 3 RMOT 4
Rdc
U1 VCC OVT MOT EN VGATE GND VS VD 8 7 6 5 Rg IR11671 IR11672AS
Cdc
Co
Rtn
Q1
*Please note that this datasheet contains advance information that could change before the product is released to production.
www.irf.com
(c) 2009 International Rectifier
LOAD
IR11672AS
Table of Contents
Description Qualification Information Absolute Maximum Ratings Electrical Characteristics Functional Block Diagram Input/Output Pin Equivalent Circuit Diagram Lead Definitions Lead Assignments Application Information and Additional Details Package Details Tape and Reel Details Part Marking Information Ordering Information
Page
3 4 5 6 8 9 10 10 12 22 23 24 25
www.irf.com
(c) 2009 International Rectifier
2
IR11672AS
Description
IR11672A 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. Ruggedness and noise immunity are accomplished using an advanced blanking scheme and double-pulse suppression which allow reliable operation in all operating modes.
www.irf.com
(c) 2009 International Rectifier
3
IR11672AS
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. MSL2 260C (per IPC/JEDEC J-STD-020) Class B (per JEDEC standard JESD22-A115) Class 2 (per EIA/JEDEC standard EIA/JESD22-A114) Class I, Level A (per JESD78) Yes
Moisture Sensitivity Level Machine Model ESD Human Body Model IC Latch-Up Test RoHS Compliant
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.
www.irf.com
(c) 2009 International Rectifier
4
IR11672AS
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 Supply Voltage Enable Voltage Cont. Drain Sense Voltage Pulse Drain Sense Voltage Source Sense Voltage Gate Voltage Operating Junction Temperature Storage Temperature Thermal Resistance Package Power Dissipation Switching Frequency Symbol VCC VEN VD VD VS VGATE TJ TS RJA PD fsw Min. -0.3 -0.3 -3 -5 -3 -0.3 -40 -55 Max. 20 20 200 200 20 20 150 150 128 970 500 Units V V V V V V C C C/W mW kHz Remarks
VCC=20V, Gate off
SOIC-8 SOIC-8, TAMB=25C
Recommended Operating Conditions
For proper operation the device should be used within the recommended conditions. Symbol VCC VD TJ Fsw Definition Supply voltage Drain Sense Voltage Junction Temperature Switching Frequency Min. 11.4 -3 -25 --Max. 18 200 125 500 Units V C kHz
Recommended Component Values
Symbol RMOT Component MOT pin resistor value Min. 5 Max. 75 Units k
www.irf.com
(c) 2009 International Rectifier
5
IR11672AS
Electrical Characteristics
VCC=15V and TA = 25C unless otherwise specified. The output voltage and current (VO and IO) parameters are referenced to GND (pin7). Supply Section Parameters Supply Voltage Operating Range VCC Turn On Threshold VCC Turn Off Threshold (Under Voltage Lock Out) VCC Turn On/Off Hysteresis Operating Current Quiescent Current Start-up Current Sleep Current Enable Voltage High Enable Voltage Low Enable Pull-up Resistance Comparator Section Parameters Turn-off Threshold Turn-on Threshold Hysteresis Input Bias Current Input Bias Current Comparator Input Offset Input CM Voltage Range One-Shot Section Parameters Blanking pulse duration Reset Threshold Hysteresis
Symbol VCC VCC ON VCC UVLO VCC HYST ICC IQCC ICC START I SLEEP VENHI VENLO REN
Min. 11.4 9.8 8.4
Typ.
Max. 18 11.3 9.7
Units V V V V mA mA mA A A V V M GBD
Remarks
10.55 9 1.55 8.5 50 1.8 100 150 2.70 1.6 1.5
2.15 1.2
10 65 2.2 200 200 3.2 2.0
CLOAD=1nF,fSW=400kHz CLOAD=10nF,fSW=400kHz VCC=VCC ON - 0.1V VEN=0V, VCC =15V
GBD
Symbol VTH1 VTH2 VHYST IIBIAS1 IIBIAS2 VOFFSET VCM
Min. -7 -14 -22 -150
Typ. -3.5 -9.5 -18 55 1 30
Max. 0 -6 -14 -50 7.5 100 2 2
Units mV mV mV A A mV V
Remarks OVT = 0V, VS=0V OVT floating, VS=0V OVT = VCC, VS=0V
VD = -50mV VD = 200V GBD
-0.15
Symbol tBLANK VTH3 VHYST3
Min. 9
Typ. 17 2.5 5.4 40
Max. 25
Units Remarks s V VCC=10V - GBD V VCC=20V - GBD mV VCC=10V - GBD
www.irf.com
(c) 2009 International Rectifier
6
IR11672AS
Electrical Characteristics
VCC=15V and TA = 25C unless otherwise specified. The output voltage and current (VO and IO) parameters are referenced to GND (pin7). Minimum On Time Section Parameters Symbol Minimum on time TONmin
Min. 190 2.48
Typ. 240 3.1
Max. 290 3.72
Units Remarks ns RMOT =5k, VCC=12V s RMOT =75k, VCC=12V
Gate Driver Section Parameters Gate Low Voltage Gate High Voltage Rise Time Fall Time
Symbol VGLO VGTH tr1 tr2 tf1 tf2 tDon tDoff rup rdown
Min.
Typ. 0.3 10.7 18 125 10 30 60 50 4 0.7 2 7
Max. 0.5 12.5
9.0
Turn on Propagation Delay Turn off Propagation Delay Pull up Resistance Pull down Resistance Output Peak Current(source) IO source Output Peak Current (sink) IO sink
95 75
Units Remarks V IGATE = 200mA VCC=12V-18V (internally clamped) V ns CLOAD = 1nF, VCC=12V ns CLOAD = 10nF, VCC=12V ns CLOAD = 1nF, VCC=12V ns CLOAD = 10nF, VCC=12V ns VDS to VGATE -100mV overdrive ns VDS to VGATE -100mV overdrive IGATE = 1A - GBD IGATE = -200mA A CLOAD = 10nF - GBD A CLOAD = 10nF - GBD
www.irf.com
(c) 2009 International Rectifier
7
IR11672AS
Functional Block Diagram
MOT VCC
VCC
EN
UVLO & REGULATOR Cycle by Cycle MOT Check Circuit
VCC
VD Min ON Time VTH1
RESET
VS
DRIVER
VGATE
GND OVT Min OFF Time
Vgate RESET
VTH3
VTH2
VTH1
VTH3
VDS
www.irf.com
(c) 2009 International Rectifier
8
IR11672AS
I/O Pin Equivalent Circuit Diagram
VD ESD Diode RESD
200V Diode
GND
www.irf.com
(c) 2009 International Rectifier
9
IR11672AS
Lead Definitions
PIN# 1 2 3 4 5 6 7 8 Symbol VCC OVT MOT EN VD VS GND VGATE Description Supply Voltage Offset Voltage Trimming Minimum On Time Enable FET Drain Sensing FET Source Sensing Ground Gate Drive Output
Lead Assignments
www.irf.com
(c) 2009 International Rectifier
10
IR11672AS
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 IR11672A. 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. referenced to this point.
The internal devices and gate driver are
VGATE: Gate Drive Output This is the gate drive output of the IC. Drive voltage is internally limited and provides 2A peak source and 7A 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.
www.irf.com
(c) 2009 International Rectifier
11
IR11672AS
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 driver 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.
www.irf.com
(c) 2009 International Rectifier
12
IR11672AS
General Description
The IR11672A 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. IR11672A is suitable for Flyback and Resonant Half-Bridge topologies.
VGate
VDS VTH2 VTH1 VTH3
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 IR11672A 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.
www.irf.com
(c) 2009 International Rectifier
13
IR11672AS
IPRIM
VPRIM
T1 ISEC VSEC
T2
T3
time
time
Figure 2: Primary and secondary currents and voltages for DCM mode
IPRIM
VPRIM
T1 ISEC VSEC
T2
time
time
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.
www.irf.com
(c) 2009 International Rectifier
14
IR11672AS
IPRIM
VPRIM
T1 ISEC VSEC
T2
time
time
Figure 4: Primary and secondary currents and voltages for CCM mode The operation waveforms of IR11672A in a flyback converter under CCM mode and DCM/CrCM were shown in Figure 5 and Figure 6 respectively.
VTH3 ISEC VDS
T1 VTH1
T2 time
VTH2 Gate Drive time Blanking MOT time
Figure 5: Secondary side CCM operation
www.irf.com
(c) 2009 International Rectifier
15
IR11672AS
VTH3 ISEC VDS
T1 VTH1
T2 time
VTH2 Gate Drive time Blanking MOT 10us blanking
Figure 6: Secondary side DCM/CrCM operation
Resonant Half-Bridge Application
The typical application circuit of IR11672A in LLC half-bridge is shown in Figure 7.
M3
Rcc1 CVCC1 Vin 1 2 3 4 Lr T1 Rmot1 8 7 6 5 Rg1
M1
VCC OVT MOT EN
GATE GND VS VD
IR11672A
M2 Cr Rtn
Lm Rcc2 CVCC2 1 2 3 4 Rmot2 8 7 6 5 Rg2 Cout
VOUT
VCC OVT MOT EN
GATE GND VS VD
IR11672A
M4
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.
www.irf.com (c) 2009 International Rectifier
16
IR11672AS
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
www.irf.com
(c) 2009 International Rectifier
17
IR11672AS
Synchronized Enable Function
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
VCC UVLO
t
UVLO NORMAL UVLO
Figure 11: Vcc UVLO
VTH1 VDS VTH2 t Don VGate 90% 50% 10% t rise tfall t Doff
Figure 12: Timing waveform
www.irf.com
(c) 2009 International Rectifier
18
IR11672AS
Figure 13: Supply Current vs. Supply Voltage
Figure 14: Undervoltage Lockout vs. Temperature
Figure 15: Icc Quiescent Currrent vs. Temperature
Figure 16: Icc Supply Currrent @1nF Load vs. Temperature
www.irf.com
(c) 2009 International Rectifier
19
IR11672AS
Figure 17: VTH1 vs. Temperature
Figure 18: VTH2 vs. Temperature
Figure 19: Comparator Hysteresis vs. Temperature
Figure 20: VTH1 vs. Temperature and Common Mode (OVT=Floating)
www.irf.com
(c) 2009 International Rectifier
20
IR11672AS
Figure 21: VTH2 vs. Temperature and Common Mode
Figure 22: MOT vs Temperature
Figure 23: Enable Threshold vs. Temperature
Figure 24: Turn-on and Turn-off Propagation Delay vs. Temperature
www.irf.com
(c) 2009 International Rectifier
21
IR11672AS
Package Details: SOIC8N
www.irf.com
(c) 2009 International Rectifier
22
IR11672AS
Tape and Reel Details: SOIC8N
LOADED TAPE FEED DIRECTION
B
A
H
D F C
NOTE : CONTROLLING DIM ENSION IN M M
E G
CARRIER TAPE DIMENSION FOR Metric Code Min Max A 7.90 8.10 B 3.90 4.10 C 11.70 12.30 D 5.45 5.55 E 6.30 6.50 F 5.10 5.30 G 1.50 n/a H 1.50 1.60
8SOICN Imperial Min Max 0.311 0.318 0.153 0.161 0.46 0.484 0.214 0.218 0.248 0.255 0.200 0.208 0.059 n/a 0.059 0.062
F
D C E B A
G
H
REEL DIMENSIONS FOR 8SOICN Metric Code Min Max A 329.60 330.25 B 20.95 21.45 C 12.80 13.20 D 1.95 2.45 E 98.00 102.00 F n/a 18.40 G 14.50 17.10 H 12.40 14.40
Imperial Min Max 12.976 13.001 0.824 0.844 0.503 0.519 0.767 0.096 3.858 4.015 n/a 0.724 0.570 0.673 0.488 0.566
www.irf.com
(c) 2009 International Rectifier
23
IR11672AS
Part Marking Information
www.irf.com
(c) 2009 International Rectifier
24
IR11672AS
Ordering Information
Standard Pack Base Part Number Package Type Form IR11672AS SOIC8N Tube/Bulk Tape and Reel Quantity 95 2500 IR11672ASPBF IR11672ASTRPBF Complete Part Number
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
www.irf.com
(c) 2009 International Rectifier
25

▲Up To Search▲

Price & Availability of IR11672AS

	To Download IR11672AS Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .