INTELLIGENT VOLTAGE MODE PWM IC

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INTELLIGENT VOLTAGE MODE PWM IC KA/D GENERAL DESCRIPTION The KA/D is a fixed-frequency improvedperformance pulse-width modulation control circuit with complete housekeeping circuitry for use in the

1 INTELLIGENT VOLTAGE MODE PWM IC KA/D GENERAL DESCRIPTION The KA/D is a fixed-frequency improvedperformance pulse-width modulation control circuit with complete housekeeping circuitry for use in the secondary side of SMPS (Switched mode power supply). It contains various functions, which are precision voltage reference, over voltage protection, under voltage protection, remote on/off control, power good signal generator and etc. -DIP- / -SOP- OVP (Over voltage protection) section It has OVP functions for +.V,+V,+V and PT outputs. The circuit is made up of a comparator with four detecting inputs and without hysteresis voltage. Especially, PT (Pin6) is prepared for an extra OVP input or another protection signal. UVP (Under voltage protection) section It also has UVP functions for +.V, +V, +V outputs. The block is made up of a comparator with three detecting inputs and without hysteresis voltage. Remote on/off section Remote on/off section is used to control SMPS externally. If a high signal is supplied to the remote on/ off input, PWM signal becomes a high state and all secondary outputs are grounded. The remote on/off signal is transferred with some on-delay and off-delay time of 8ms, ms respectively. Precision reference section The reference voltage trimmed to ± % (.9V Vref.V) PG (Power good signal generator) section Power good signal generator is to monitor the voltage level of power supply for safe operation of a microprocessor. KA requires few external components to accomplish a complete housekeeping circuits for SMPS. The KA is available in a -pin dual in-line package. ORDERING INFORMATION Device Package Operating Temperature KA DIP - C ~ 8 C KAD SOP - C ~ 8 C FEATURES Complete PWM control and house keeping circuitry Few external components Precision voltage reference trimmed to % Dual output for push-pull operation Each output TR for ma sink current Variable duty cycle by dead time control Soft start capability by using dead time control Double pulse suppression logic Over voltage protection for.v / V / V Under voltage protection for.v / V / V One more external input for various protection (PT) Remote on/off control function (PS-ON) Latch function controlled by remote and protection input Power good signal generator with hysteresis

2 KA/D INTELLIGENT VOLTAGE MODE PWM BLOCK DIAGRAM V V R T C T COMP 7 8 OSCILLATOR PWM CONTROL D CK Q Q C C E E/A(-) E/A(+) DEAD TIME CONTROL VREF V CC 9 VREF V.V Start Up INTERNAL BIAS.V COMP DEAD TIME CONTROLLER Ichag VREF V Q R S PG GENERATOR DELAY CONTROLLER VREF OVP COMP.V REMOTE ON/OFF.V 6 6 T REM REM (PS-ON) PG PT V V V. DET 9 COMP COMP.8V.6V.8V.6V.V UVP COMP.V T PG.uF T UVP.uF 7 8 GND

3 INTELLIGENT VOLTAGE MODE PWM IC KA/D PIN DESCRIPTION : KA C E C DTC GND TUVP PT V V V. Vref # # KA # # V CC COMP E/A(-) EA(+) TREM REM RT CT DET TPG PG Pin No. Name I/O Function Pin No. Name I/O Function V CC I Supply voltage Vref O Precision reference VTG COMP O E/A output V. I OVP, UVP input for.v E/A(-) I E/A (-) input V I OVP, UVP input for V E/A(+) I E/A (+) input V I OVP, UVP input for V TREM Remote on/off delay 6 PT I Extra protection input 6 REM I Remote on/off input 7 T UVP UVP delay 7 RT Oscillation freq. setting R 8 GND Signal ground 8 CT Oscillation freq. setting C 9 DTC I Deadtime control input 9 DET I Detect input C O Output T PG PG delay E Power ground PG O Power good signal output C O Output

4 KA/D INTELLIGENT VOLTAGE MODE PWM PIN DESCRIPTION : KAD # C E C DTC GND TUVP PT V V V. Vref NC # KAD # # Vcc COMP E/A(-) EA(+) TREM REM RT CT DET TPG PG NC Pin No. Name I/O Function Pin No. Name I/O Function V CC I Supply voltage NC - NC COMP O E/A output Vref O Precision reference VTG E/A(-) I E/A (-) input V. I OVP, UVP input for.v E/A(+) I E/A (+) input 6 V I OVP, UVP input for V TREM Remote on/off delay 7 V I OVP, UVP input for V 6 REM I Remote on/off input 8 PT I Extra protection input 7 RT Oscillation freq. setting R 9 T UVP UVP delay 8 CT Oscillation freq. setting C GND Signal ground 9 DET I Detect input DTC I Deadtime control input T PG PG delay C O Output PG O Power good signal output E Power ground NC - NC C O Output

5 INTELLIGENT VOLTAGE MODE PWM IC KA/D Pin No. Name Function V CC Supply voltage. Operating range is V~V. V CC =V, Ta= C at test. COMP Error amplifier output. It is connect to non-inverting input of pulse width modulator comparator. E/A(-) Error amplifier inverting input. Its reference voltage is always.v. E/A(+) Error amplifier non-inverting input feedback voltage.this pin may be used to sense power supply output voltage. TREM Remote on/off delay. Ton/Toff=8ms/ms (Typ.) with C=.uF. Its high/low threshold voltage is.8v/.6v. 6 REM Remote on/off input. It is TTL operation and its threshold voltage is.v. Voltage at this pin can reach normal.6v, with absolutely maximum voltage,.v. If REM = Low, PWM = Low. That means the main SMPS is operational. When REM = High, then PWM = High and the main SMPS is turned-off. 7 RT Oscillation frequency setting R. (Test Condition RT=kΩ) 8 CT Oscillation frequency setting C. (Test Condition CT=.uF) 9 DET Under-voltage detect pin. Its threshold voltage is.v Typ. T PG PG delay. Td=ms (Typ) with CPG=.uF. The high/low threshold voltage are.8v/.6v and the voltage of Pin is clamped at.9v for noise margin. PG Power good output signal. PG = High means that the power is Good for operation and PG = Low means Power fail. () Vref Precision voltage reference trimmed to %. (Typical Value =.V) () V. Over voltage protection for output.v. (Typical Value =.V) (6) V Over voltage protection for output V. (Typical Value = 6.V) (7) V Over voltage protection for output V. (Typical Value =.V) 6(8) PT This is prepared for an extra OVP input or another protection signal. (Typical Value =.V) 7(9) T UVP Timing pin for under voltage protection blank-out time. Its threshold voltage is.8v and clamped at.9v after full charging. Target of delay time is ms and it is realized through external (C=.uF). 8() GND Signal ground. 9() DTC Deadtime control input. The dead-time control comparator has an effective mv input offset which limits the minimum output dead time. Dead time may be imposed on the output by setting the dead time control input to a fixed voltage, ranging between V to.v. () C Output drive pin for push-pull operation. () E Power ground. () C Output drive pin for push-pull operation.

6 KA/D INTELLIGENT VOLTAGE MODE PWM ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Value Unit Supply voltage V CC V Collector output voltage V C, V C V Collector output current I C, I C ma Power dissipation(kad) P D.8 W Power dissipation(ka) P D. W Operating temperature T OPR to 8 C Storage temperature T STG 6 to C TEMPERATURE CHARACTERISTICS Value Characteristic Symbol Min. Typ. Max. Unit Temperature coefficient of Vref (- C Ta 8 C) Vref/ T. %/ C

7 INTELLIGENT VOLTAGE MODE PWM IC KA/D ELECTRICAL CHARACTERISTICS (V CC =V, T A = C) Value Characteristic Symbol Test Condition Min. Typ. Max. Unit REFERENCE SECTION Reference output voltage Vref Iref=mA.9. V Line regulation Vref. LINE V V CC V. mv Load regulation Vref. LOAD ma Iref ma. mv Temperature coefficient of Vref () Vref/ T - C Ta 8 C. %/ C Short-circuit output current I SC Vref= 7 ma OSCILLATOR SECTION Oscillation frequency fosc C T =.uf, R T =k khz Frequency change with temperature () fosc/t C T =.uf, R T =k % DEAD TIME CONTROL SECTION Input bias current I B(DT) -. - ua Maximum duty voltage DC MAX Pin9 (DTC)=V 8 % Input threshold voltage V TH(DT) Zero Duty Cycle.. V Max. Duty Cycle ERROR AMP SECTION Inverting reference voltage Vref(EA)... V Input bias current I B(EA) V COMP =.V ua Open-loop voltage gain () G VO.V V COMP.V 7 9 db Unit-gain bandwidth () BW 6 khz Output sink current I SINK V COMP =.7V..9 ma Output source current I SOURCE V COMP =.V ma PWM COMPARATOR SECTION Input threshold voltage V TH(PWM) Zero Duty Cycle. V OUTPUT SECTION Output saturation voltage V CE(SAT) I C =ma.. V Collector off-state current I C(off) V CC =V C =V, V E =V ua Rising time T R ns Falling time T F ns PROTECTION SECTION Over voltage protection for.v V OVP.8.. V

8 KA/D INTELLIGENT VOLTAGE MODE PWM ELECTRICAL CHARACTERISTICS (continued) Value Characteristic Symbol Test Condition Min. Typ. Max. Unit Over voltage protection for V V OVP V Over voltage protection for V V OVP... V Input threshold voltage for PT V PT... V Under voltage protection for.v V UVP... V Under voltage protection for V V UVP.7.. V Under voltage protection for V V UVP 9..8 V Charging current for UVP delay I CHG.UVP C=.uF, V TH =.8V ua UVP Delay Time T D.UVP C=.uF 6 ms REMOTE ON/OFF SECTION REM on input voltage V REMH I REM = ua. V REM off input voltage V REML.8 V REM off input bias voltage I REML V REM =.V.6 ma REM on open voltage V REM(OPEN).. V REM on delay time Ton C=.uF 8 ms REM off delay time Toff C=.uF 6 ms REMOTE ON/OFF SECTION () Detecting input voltage V IN(DET)... V Detecting V voltage V (DET)... V Hysteresis voltage HY COMP, 8 mv Hysteresis voltage HY COMP.6. V PG output load resistor R PG. kω Charging current for PG delay I CHG.PG C=.uF, V TH =.8V ua PG delay time T D.PG C=.uF 6 ms PG output saturation voltage V SAT(PG) I PG =ma.. V TOTAL DEVICE Stanby supply current I CC ma Notes:. These Parameters, although guaranteed over their recommended operating conditions are not % tested in production.. REM on delay time (Pin6 REM: L H ), REM off delay time (Pin6 REM: H L )

9 INTELLIGENT VOLTAGE MODE PWM IC KA/D APPLICATION INFORMATIONS K K VCC=V I O - OSCILLATOR FREQUENCY K K.µF.µF CT=.µF.µF K K K K K K K K K M R T. TIMING RESISTANCE(Ω) Figure. Oscillator Frequency vs. Timing Resistance Feedback Ct Dead-time control Ck Q Q Output Q Output Q Figure. Operating Waveform

10 KA/D INTELLIGENT VOLTAGE MODE PWM HOUSEKEEPING CIRCUIT kω(w) kω(w) Standby Supply V CC =V VCC C V V kω COMP E kω kω.uf E/A(-) C.8kΩ.uF kω + Micom 6 7 E/A(+) T REM REM RT K A DTC GND T UVP PT uF + kω.uf + 8 CT V V 9 DET V V T PG V. V.uF + PG PG Vref uf + Note) The KA requires few external components to accomplish a complete housekeeping circuits for SMPS.

11 INTELLIGENT VOLTAGE MODE PWM IC KA/D TYPICAL CHARACTERISTICS V CC -I CC Bandgap Reference Voltage Temperature Characteristic I CC [A].8.6 Vref [V] Supply Voltage [V] TEMP [ C] PIN9(Dead Time Control Voltage)-Duty Cycle OVP for.v Duty Ratio [%].%.8%.8% Deadtime Control Voltage [V] V. [V] OVP for V OVP for V V [V] V [V]

12 KA/D INTELLIGENT VOLTAGE MODE PWM OVP for PT UVP for.v..... Vpt [V] Pin (V.) Voltage [V] UVP for V UVP for V Pin (V) Voltage [V] Pin (V) Voltage [V] Remote ON Charging Current REM ON/OFF Vth Irem [A] Vrem [V]

13 INTELLIGENT VOLTAGE MODE PWM IC KA/D Remote ON Open Voltage Detecting V CC Voltage (DET) Vrem [V] Pin 9 (DET) Voltage [V] Detecting V Voltage Charging Current for PG IPG [V] Pin (V) Voltage [V] Short Circuit Current Hysteresis Voltage -. Iref [A] Pin (TPG) Voltage [V]

14 KA/D INTELLIGENT VOLTAGE MODE PWM Error Amp Sink Current Reference Voltage. Isink & Isource [A] Vref [V] Supply Voltage [V]

15 INTELLIGENT VOLTAGE MODE PWM IC KA/D EXPERIMENTAL RESULT CH : PS-ON CH : +Vdc Output CH : PG Signal Figure. Rising Time of +Vdc Output Voltage CH : PS-ON CH : +Vdc Output CH : PG Signal Figure. PG Signal Delay Time

16 KA/D INTELLIGENT VOLTAGE MODE PWM CH : PS-ON CH : +Vdc Output CH : PG Signal Figure. Power Down Warning CH : +.Vdc Output CH : +Vdc Output CH : +Vdc Output Figure 6. No Load Protection

17 INTELLIGENT VOLTAGE MODE PWM IC KA/D CH : Vcc CH : +Vdc Output CH : PG Signal Figure 7. Vcc, +Vdc Output vs. PG Signal (High) CH : Vcc CH : +Vdc Output CH : PG Signal Figure 8. Vcc, +Vdc Output vs. PG Signal (Low)

18 KA/D INTELLIGENT VOLTAGE MODE PWM APPLICATION CIRCUIT 7K R6 7K R IC Vcc C C VCC COMP E POWER ON K E/A(-) E/A(+) C DTC 9 C R.K OUT REF +.uf 6 7 TREM REM RT GND TUVP PT uF + R 6K + C6 uf 8 9 CT DET V V V OUT V OUT PG +.uf TPG PG V. Vref.V OUT ARX D9 K C6 + VR D9 CT

19 INTELLIGENT VOLTAGE MODE PWM IC KA/D PACKAGE DIMENSION

20 KA/D INTELLIGENT VOLTAGE MODE PWM PACKAGE DIMENSION

21 LIFE SUPPORT POLICY FAIRCHILD S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein:. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user.. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. /8/99.m Stock#DSxxxxxxxx 999 Fairchild Semiconductor Corporation

Power good signal generator is to monitor the voltage level of power supply for safe operation of a microprocessor.

Power good signal generator is to monitor the voltage level of power supply for safe operation of a microprocessor. November,999 AN00 PC POWER SUPPLY DESIGN WITH KA Sang-Tae Im. GENERAL DESCRIPTION The KA is a fixed-frequency improved-performance pulse-width modulation control circuit with complete housekeeping circuitry