D a t a s he et , V 1 . 4 , 2 7 A p ri l 2 00 4 ICE 1QS01 Controller for Quasiresonant Switch Mode Power Supplies Supporting Low Power Standby and Power Factor Correction Pow er Mana geme nt & Sup ply N e v e r s t o p t h i n k i n g . ICE1QS01 Revision History: Current Version: 200404-27 Previous Version: 200311-28 Page13 (in Page 13 (in previous version) current version) Diagram mains undervoltage lockout curent added Page 16-18 (in Page 16-18 (in previous version) current version) Min.- max.- values added, typ. values adapted, according to measuring results. Page 20 (in Page 20 (in previous version) current version) Application circuit changed to new 250 W demo board with PFC current pump. Edition 2004-04-27 Published by Infineon Technologies AG, St.-Martin-Strasse 53, D-81541 München © Infineon Technologies AG 2004. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as warranted characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Infineon Technologies is an approved CECC manufacturer. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office in Germany or our Infineon Technologies Representatives worldwide (see address list). Warnings Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office. Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons ICE1QS01 Controller for Switch Mode Power Supplies Supporting Low Power Standby and Power Factor Correction (PFC) P-DIP-8-4 Features P-DIP-8-4 • • • • • • • • • • • • • • Quasiresonant Operation Primary and Secondary Regulation Primary Current Simulation Standby Input Power < 1 W Low Power Consumption Very Low Start-up Current Soft-Start for noiseless Start-up Standby Burst Mode with and without Control Signal for lowered Output Voltages Digital Frequency Reduction in small Steps at Decreasing Load Over- and Undervoltage Lockout Switch Off at Mains Undervoltage Mains Voltage Dependent Fold Back Point Correction Ringing Suppression Time Controlled from Output Voltage Free usable Fault Comparator P-DSO-8-3 P-DSO-8-3 Functional Description The ICE1QS01 is optimized to control free running flyback converters with and without Power Factor Correction (with PFC Charge Pump). The switching frequency is reduced in small steps with decreasing load towards a minimum of 20 kHz in standby mode. This function is performed by a digital circuit to avoid any jitter also with periodically pulsed loads. To provide extremely low power consumption at light loads, this device can be switched into Standby Burst Mode. This is also possible without standby control signal (for adapter application). Additionally, the start up current is very low. To avoid switching stresses of the power devices, the power transistor is always switched on at minimum voltage. The device has several protection functions: VCC overand undervoltage, mains undervoltage and current limiting. Regulation can be done by using the internal error amplifier or an opto coupler feedback. The output driver is ideally suited for driving a power MOSFET. The ICE1QS01 is suited for TV-sets, DVD- sets, SAT- receivers and other consumer applications in the power range from 0 to app. 300 W. Type ICE1QS01 ICE1QS01G Version 1.4 Ordering Code Q67040-S4558 Q67040-S4559 3 Package P-DIP-8 P-DSO-8 27 Apr 2004 ICE1QS01 Block Diagram VCC Overvoltage 20V - Foldback Point Corr. Protection + PCS UVLO + - - + SRC + Burst-Mode 1.5V Reference Voltage and Current + 5V - - 2V + 1V Ringing Suppression Time + 4.8V 5V - 20k + 4.5V Start 5V + 3.5V - 50µs Timer 50ms Timer 50mV Latch Primary Regulation + RZI Digital Processing - ZC-Counter UP/DO-Counter 5.7V Power Driver S SET OUT Q 1V OFC R CLR Q + + D 1V SET Q - L CLR Q GND Version 1.4 4 27 Apr 2004 ICE1QS01 Pinning Pin Symbol Function 1 N.C. 2 PCS Primary Current Simulation 3 RZI Regulation and Zero Crossing Input 4 SRC Soft-Start and Regulation Capacitor 5 OFC Overvoltage Fault Comparator 6 GND Ground 7 OUT Output 8 VCC Supply Voltage Pin Configuration (top view) 1 N.C. VCC 8 1 2 PCS OUT 7 2 3 RZI GND 6 4 SRC OFC 5 Version 1.4 5 VCC 8 PCS OUT 7 3 RZI GND 6 4 SRC OFC 5 27 Apr 2004 ICE1QS01 Functional Description Start up An internal start up diode is connected between pin PCS and pin VCC. Start up current is provided via this diode if VPCS is higher than VCC + VBE (VBE = Base-Emitter-Voltage). During start up the internal reference of the IC is shut off and current consumption is about 60 µA. There is only the start up circuitry working which determines the VCCon threshold. Gate driver OUT is switched to low. An active shut down circuitry ensures that OUT is held below the MOS gate threshold when the IC is in start up mode. Block Diagram: Start Up VCC PCS UVLO OUT ICE1QS01 Version 1.4 6 27 Apr 2004 ICE1QS01 Soft start The internal reference of the IC is switched on when VCC exceeds the VCCon threshold. The IC begins to work with soft start mode. Soft start is realized with an internal soft start resistor, an internal current sink, a current source and the external feedback capacitor connected at pin SRC. The internal resistor is connected between the internal voltage reference and pin SRC. The current sink is connected between pin SRC and GND. The value of the current is set with a timer. Immediately after the IC is switched on the capacitor CSRC is charged with a current source up to 2.5V. This current source is switched off 12 µsec after beginning of soft start. The current value of the current sink is set with a timer. Every three msec the current of the current sink is reduced and so VSRC can increase stepwise. The soft start is finished 24 msec after the IC is switched on. At the end of the soft start the current sink is switched off. Figure: Soft Start VCC 2.5V ICE1QS01 5V 500 VCCon timer t=12us t timer tp=3ms timer t=24ms up down counter D/A 20k current sink VSRC pin SRC VSRC2 VSRC1 ton tp1 tp2 t PCS (primary current simulation) A voltage proportional to the current of the power transistor is generated at Pin PCS by the RC-combination R2, C2. The voltage at Pin PCS is forced to 1.5V when the power transistor is switched off and during its switch on time C2 is charged by R2 from the rectified mains. The relation of VPCS and Version 1.4 7 27 Apr 2004 ICE1QS01 the current in the power transistor (Iprimary) is: × IprimaryVPCS = 1, 5V + Lprimary ------------------------------------------------------R2 × C2 Lprimary: Primary inductance of the transformer The advantage of primary current simulation is the elimination of the leading edge spike, which is generated when the power transistor is switched on. RZI (zero crossing input and primary regulation) Zero current counter Every time when the falling voltage ramp of VRZI crosses the 50 mV threshold a pulse is sent to the zero-current-counter and increases the counter by one. If zero-current-counter and up-down-counter are equal the gate drive OUT is switched to high. Up-down counter is influenced via SRC voltage as described below. If VRZI is greater than 50 mV gate drive OUT is always switched low. Figure: Zero Crossing Switching Behaviour V VSRC VPCS 1.5V t VRZI OUT Version 1.4 status up-down counter = 0001: switch on at first zero crossing status up-down counter = 0010: switch on at second zero crossing t ton ton t toff 8 toff 27 Apr 2004 ICE1QS01 Ringing suppression When VPCS reaches the feedback voltage VSRC the gate drive OUT is set to low and the ringing suppression timer is started. This timer ensures that the gate drive cannot be switched on until this ringing suppression time is passed. Duration of ringing suppression time depends on the VRZI voltage. Suppression time is 3 µsec if VRZI > 1V and it is 30 µsec if VRZI < 1V. Figure: Ringing Suppression up-down-counter =1 up-down-counter =1 VRZI 1V VSRC 1.5V VPCS OUT ringing suppression time 3 µs Version 1.4 30 us 9 27 Apr 2004 ICE1QS01 Primary regulation Primary regulation is achieved by activating the internal current sink. The current sink is connected between pin SRC and ground. If VRZI exceeds the 5V threshold the current sink is switched on. It is switched off when VRZI falls below 5V. The current sink discharges the CSRC capacitor. CSRC is charged via the internal 20k resistor. If VRZI exceeds the 4.4V threshold a flip-flop is set and the resistor is switched off when VRZI falls below 50 mV. The resistor is switched on again with the falling slope of gate drive OUT. Diagram Primary Regulation VRZI zero current counter = 0010 5V 4.5V OUT OUT 5V start R Q stop S Q 0.05 V R Q S Q + 20k - 20K resistor R Q on 4.5 V RZI + - SRC S Q off + 5V current sink - ICE1QS01 on current sink off VSRC t Version 1.4 10 27 Apr 2004 ICE1QS01 SRC (Regulation and soft start capacitor) The feedback capacitor is connected to pin SRC. The feedback voltage VSRC has two main functions. Function I (MOS FET on time): VSRC provides the switch off reference voltage. If VPCS (which contains the primary current information) exceeds the VSRC voltage the external MOS transistor is switched off. Function II (MOS FET off time for frequency reduction): At low load the frequency is reduced by ignoring zero crossing signals after the transformer demagnetization. VSRC determines the action of the 4-bit up-down-counter which contains the number of zero crossings to be ignored. The content of the up-down-counter is compared with the number of zero-current crossings of VRZI. If the number of zero-current crossings in each period after the transformer demagnetization is equal to the up-down-counter content the MOS is switched on. At low load conditions when VSRC is below 3.5V the counter is increased by one every 50 msec. The result is that the MOS transistor off-time increases and duty cycle decreases. At high load conditions when VSRC is higher than 4.4V the counter content is reduced by one every 50msec. So MOS transistor off-time will be reduced. With this off-time regulation switching jitter can be eliminated. The up-down-counter is immediately set to 0001 if a load jump occurs and VSRC exceeds 4.8 V. This ensures that full power can be provided instantaneously. The following table shows the SRC voltage range and the corresponding up-down counter action. SRC voltage range up-down-counter action 1: VSRC< 3.5V count forward 2: 3.5<VSRC<4.4 stop count 3: VSRC>4.4 count backward 4: VSRC> 4.8 set up-down-counter to1 The information provided by VSRC is stored in two independent flip flops. An internal timer creates a trigger pulse with a period of 50 msec. Every time the pulse occures the up-down counter checks the status flip flops and acts depending on the flip flop information. After this pulse the flip flops are reset. So change of voltage range is noticed by the logic only once during the 50 ms period. In the diagram below the behaviour of the up-down counter is depicted in more detail. D ia g r a m 1 tim e r p u ls e tp VSRC tp tp 50 m sec tp tp tp tp tp tp tp n + 1 n + 1 n + 1 n n - 1 n - 2 n - 3 4 .5 V 3 .5 V s ta tu s o f u p -d o w n c o u n te r Version 1.4 n n + 1 n + 1 11 27 Apr 2004 ICE1QS01 Burst mode 12 µsec after beginning of softstart the burst mode comparator is activated. If VSRC falls below 2V after activating the comparator the gate drive OUT is switched to low and the VCCoff threshold is changed to 14.5 V. VCC decreases because gate drive is held low. If VCC reaches the VCCoff threshold the IC is going into start-up mode. At VCCon threshold the IC is switched on again starting with soft start modus. VCCoff threshold is set to the normal 9V. Figure: Burst Mode Secondary load high low VSRC 2V OUT Vcc 15V 14.5V VCCOFF 9V Vsec normal mode Version 1.4 burst mode 12 soft start t 27 Apr 2004 ICE1QS01 Restart timer If voltage VRZI is lower than 50 mV and gate drive OUT is low an internally created restart pulse will switch gate drive OUT high every 50 µs and the minimum switching frequency is about 20 kHz. Restart pulse is inhibited if VRZI is higher than 50 mV. So the MOS transistor cannot be switched on until the transformer is discharged. VCC overvoltage protection If VCC exceeds the VCCD threshold a latch is set and the gate is disabled. Reset of latch occurs when VCC is falling below VCCon- VCCBHY. Overvoltage fault comparator (OFC) With an external sense resistor connected to pin OFC primary current can be sensed directly. If the sensed current exceeds the internal VOFC threshold a latch is set and gate is disabled. Reset of latch occurs when VCC is falling below VCCon- VCCBHY. Notice: If this comparator is not used pin OFC has to be connected to ground. Mains undervoltage Power supplies must be shut down when mains voltage is below a certain limit to avoid too long ontime of MOS-FET switch, which would lead to a switching frequency in audible spheres. Mains undervoltage is sensed during the off-time of the MOS-FET switch. If the current flowing into pin PCS is smaller than 100 uA, then the output is latched and cannot be switched to high state. Diagram Mains Undervoltage Lockout Current 130 120 Ipcs/µA 110 100 90 80 70 60 50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Temp./°C Version 1.4 13 27 Apr 2004 ICE1QS01 Fold back point correction With increasing mains voltage the switch on time becomes shorter and so the frequency becomes higher. With higher frequency also the maximal possible output power becomes higher. With higher power the danger in case of failure increases. To avoid this, the foldback point correction circuit senses main voltage to reduce the on-time of the switch. Mains voltage is sensed at the supply coil of VCC voltage via a resistor connected to pin RZI. During on-time of the MOS-FET switch current is pulled out from pin RZI. When this current is higher than 500 µA, one fifth of the current higher than this threshold is driven into pin PCS to increase the voltage slope charging the capacitor connected to this pin. IRZI – 0, 5mA IPCSFO = --------------------------------- ,( IRZI > 500uA ) 5 Figure: Fold Back Point Correction Vpcs with fold back point correction Pmax without fold back point correction Vpcs at high mains voltage 5V Vpcs Pmax Vpcs at low mains voltage t0 t1 t2 Pmax with fold back point correction t3 Vmains t Version 1.4 14 27 Apr 2004 ICE1QS01 Absolute Maximum Ratings Parameter Symbol Min Max Unit Remark Charge Current into Pin2 IPCS 500 uA During start up Voltage at Pin 2 VPCS -0.3 21 V Current into Pin 3 IRZI IRZI -10 10 mA mA VRZI>VRZICH VRZI<VRZICL Voltage at Pin 4 VSRC -0.3 VSRCCL V ISRC=100 µA Voltage at Pin 5 VOFC -0.3 6 V Current into Pin 7 IOUT -500 500 mA Voltage at Pin 8 VCC -0.3 21 V 4000 V ESD Protection Storage Temperature Tstg -50 150 °C Operating Junction Temperature TJ -25 150 °C Thermal Resistance Junction-Ambient RthJA 100 K/W Version 1.4 15 t<1ms MIL STD 883C method 3015.6, 100pF,1500Ω P-DIP-8 27 Apr 2004 ICE1QS01 Characteristics (Unless otherwise stated, -25°C<Tj <150 °C, VCC = 16V) Parameter Symbol min. typ. max. Unit Test Condition VCC start-up circuit Start-up supply current ICCL 60 100 µA VCC=VCCon-0.5V Operating supply current ICCH 8 11 12.5 mA Output low VCC Turn-On threshold VCC ON 14.1 15 15.5 V VCC Turn-Off threshold VCC OFF 8.5 9 9.5 V VCC Hysteresis VCCHY 5.4 6 6.5 V VCC Burst Hysteresis VCCBHY 0.2 0.4 0.6 V VCC Overvoltage VCCD 19 20 21 V 2.40 2.65 2.85 V Ioptocoupler=0 µA Ioptocoupler=0 µA SRC soft start mode Start Voltage VSRC1 Digital voltage step VSRCST 360 mV Step pulse rate tSRCSTR 3 ms Soft start time tST Current source rise time tSTRT 14 µs Current source on time tSTOT 12 µs 19 24 32 ms VSRC=0.2V to 2.0V CSRC=10nF SRC normal mode Source resistor RSRC 17 21 28 kOhm Clamping threshold voltage VSRCCL 4.95 5.1 5.25 V Reset counter to one VSRCR 4.75 4.9 5.05 V Distance clamping to reset VSRCH 150 200 250 mV Threshold downward count VSRCD 4.3 4.5 4.7 V Threshold upward count VSRCSU 3.4 3.5 3.7 V Burst mode latch threshold voltage VSRCB 1.9 2.05 2.2 V Counter time 1) tCOUNT Sink current prim reg mode ISRCS 50 400 500 VPCS=VSRC, OUT switches to Low, ISRC=100µA VSRC <VSRCB: OUT=Low msec 550 µA VRZI > 5V 1) The parameter is not subject to production test - verified by design/characterization Version 1.4 16 27 Apr 2004 ICE1QS01 Parameter Symbol min. typ. max. Unit Test Condition VRZI<VRZIT1: Out=High RZI (regulation and zero crossing input) Zero crossing threshold voltage VRZIT1 25 50 80 mV Time delay switch on tdon 350 440 550 nsec Leakage current IRZIB -1 25 110 µA VRZI=5V Clamping voltage low state VRZICL -0.5 -0.3 -0.2 V IRZI = -1mA Clamping voltage high state VRZICH 5.5 6.0 6.4 V IRZI= 5mA Primary regulation threshold for discharge current VRZIDC 4.95 5.1 5.25 V Primary regulation threshold for charge current VRZICC 4.2 4.4 4.65 V Ringing suppression threshold voltage VRZIT2 0.9 1.0 1.1 V Ringing suppression time tRZIPS tRZIPL 1.5 20 2.5 29 3.2 37 µsec µsec VRZI > VRZIT2 VRZI < VRZIT2 Foldback point correction current threshold IPCSF 250 400 600 µA -25°C<Tj<120°C PCS (primary current simulation) Gate enable threshold voltage VPCSE 0.9 1.0 1.1 V VPCS<VPCSE: Out=Low Basic voltage VPCSB 1.45 1.55 1.65 V gate low Shut down delay tPCS 150 230 nsec Mains undervoltage lockout current 2) IPCS 100 160 µA Voltage drop startup diode VPCSD Discharge current IPCSD 40 0.85 1.6 2.6 3.6 V IPCS=300µA mA VPCS=3V OFC (overcurrent fault comparator) Bias Current IOFCB -1 µA Gate drive disabled threshold voltage VOFC 0.93 Shut Down Delay tOFC 1.0 1.05 V 180 240 ns 2) See diagram mains undervolt. lockout current Version 1.4 17 27 Apr 2004 ICE1QS01 Parameter Symbol min. typ. max. Unit Test Condition tRES 33 42 55 µs VRZI<25mV 0.7 0.8 1.1 1.4 V V IOUT=20mA IOUT=200mA 10.6 10.5 11.0 11.0 V V IOUT=-20mA IOUT=-180mA Output voltage active shut down 1.0 1.35 V VCC=7V IOUT=20mA Rise time 40 100 ns COUT=1nF Fall time 60 120 ns COUT=1nF Restart Timer Restart time Gate Drive Output voltage low Output voltage high Version 1.4 9.5 9.5 18 27 Apr 2004 ICE1QS01 Figure: Circuit Diagram for Standard Application with PFC Version 1.4 19 27 Apr 2004 ICE1QS01 Figure: Circuit Diagram for Application with PFC and Low Voltage Standby Mode Version 1.4 20 27 Apr 2004 ICE1QS01 GPS05121 Plastic Package, P-DSO-8-3 (Plastic Dual Small Outline Package) GPD05025 Plastic Package, P-DIP-8-4 (Plastic Dual In-line Package) Sorts of Packing Package outlines for tubes, trays etc. are contained in our Data Book “Package Information”. SMD = Surface Mounted Device Version 1.4 21 Dimensions in mm 27 Apr 2004