Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 General Description Features The AZ3842/3/4/5 are high performance fixed frequency current-mode PWM controller series. · These integrated circuits are optimized for off-line and DC-DC converter applications with minimum external components. They feature under-voltage lockout (UVLO) circuit for low start-up current, trimmed oscillator for precise duty cycle control, current sense comparator providing maximum current limiting and a totem pole output stage for increasing output current. In addition, these ICs also feature accurate protection against over-temperature, over-current and maximal output power. · · · · · · The AZ3842 and AZ3844 have UVLO thresholds of 15.5V(on) and 10V(off); The corresponding thresholds for AZ3843 and AZ3845 are 8.4 V(on) and 7.8V(off). Applications · · · · · · The AZ3842 and AZ3843 can operate approaching 100% duty cycle; AZ3844 and AZ3845 can operate from zero to 50% duty cycle. These ICs are available in 3 packages: SOIC-8, DIP-8 and SOIC-14. SOIC-8 Robust VREF Line/Load Regulation Low Line Regulation : 4mV Low Load Regulation : 4mV High Stability of Reference Voltage over a Full Temperature Range: 0.2mV/ oC Operating Frequency up to 500KHz High PWM Frequency Stability over a Full Temperature Range: 2.5% High PWM Frequency Stability under a Full Supply Voltage Range: 0.2% Accurate Over-temperature Protection with Hysteresis UVLO with Hysteresis DIP-8 Off-line Converter DC-DC Converter Voltage Adapter CRT Monitor Power Supply Desktop Power Supply DVD/STB Power Supply SOIC-14 Figure 1. Package Types of AZ3842/3/4/5 March 2003 1 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Pin Configuration M Package (SOIC-14) P/M Package (DIP-8/SOIC-8) COMP 1 14 VREF COMP 1 8 VREF N/C 2 13 N/C VFB 2 7 VCC VFB 3 12 VCC ISENSE 3 6 OUTPUT N/C 4 11 PWR VC RT/CT 4 5 GND ISENSE 5 10 OUTPUT N/C 6 9 GND RT/CT 7 8 PWR GND Figure 2. Pin Configuration of AZ3842/3/4/5 (Top View) Pin Description Pin Number 8-pin 14-pin Pin Name 1 1 COMP 2 3 VFB The inverting input of the Error Amplifier. It is normally connected to the switching power supply output through a resistor divider. 3 5 ISENSE A voltage proportional to inductor current is connected to this input. The PWM uses this information to terminate the output switch conduction. 4 7 RT/CT The Oscillator frequency and maximum Output duty cycle are programmed by connecting resistor RT to VREF and capacitor CT to ground. Operation to 500 kHz is possible. GND The combined control circuitry and power ground. 5 Function This pin is the Error Amplifier output and is made available for loop compensation. 6 10 OUTPUT 7 12 VCC The positive supply of the control IC. 8 14 VREF This is the reference output. It provides charging current for capacitor CT through resistor RT. 8 PWR GND This pin is a separate power ground return that is connected back to the power source. It is used to reduce the effects of switching transient noise on the control circuitry. 11 PWR VC The Output high state (VOH) is set by the voltage applied to this pin. With a separate power source connection, it can reduce the effects of switching transient noise on the control circuitry. 9 GND This pin is the control circuitry ground return and is connected back to the power source ground. 2,4,6,13 N/C No connection. These pins are not internally connected. March 2003 This output directly drives the gate of a power MOSFET. Peak currents up to 1.0 A are sourced and sunk by this pin. 2 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Functional Block Diagram VCC 7(12) 34V GND S/R 5(9) 5V REF OSC T COMP ISENSE VREF 6(10) OUTPUT (Note) OVER TEMP PROTECT VFB 8(14) INTERNAL BIAS VREF GOOD LOGIC 4(7) VCC (PWR VC) UVLO 2.50V RT/CT 7(11) ERROR AMP 5(8) S 2R 2(3) R 1(1) R 3(5) GND (PWR GND) 1V CURRENT SENSE COMPARATOR PWN LATCH Note: Toggle flip-flop used for 3844/45 only A(B) A for 8-pin B for 14-pin Figure 3. Functional Block Diagram of AZ3842/3/4/5 Ordering Information Package Temperature Range Part Number Marking ID Packing Type SOIC-8 DIP-8 SOIC-14 -40oC~85oC AZ3842/3/4/5M AZ3842/3/4/5P AZ3842/3/4/5MM 3842/3/4/5M AZ3842/3/4/5P AZ3842/3/4/5MM Tape/Reel/Tube Tube Tape/Reel March 2003 3 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Absolute Maximum Ratings (Note 1, 2) Parameter Symbol Value Unit Supply Voltage Vcc 30 V Output Current Io 土1 A V(ANA) -0.3 to 6.3 V Error Amp Output Sink Current ISINK(E.A) 10 mA Power Dissipation at TA< 25 oC (DIP-8) PD (Note 3) 1000 mW Power Dissipation at TA<25 oC (SOIC-8) PD (Note 3) 460 mW Power Dissipation at TA<25 oC (SOIC-14) PD (Note 3) 725 mW TSTG -65 ~+150 oC TLEAD +300 oC Analog Inputs (8-pin: pin2,3, 14-pin: pin3,5) Storage Temperature Range Lead Temperature (Soldering, 10sec) Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum Ratings" for extended periods may affect device reliability. Note 2: All voltages are with respect to pin 5 and all currents are positive into specified terminal. Note 3: Board thickness 1.6mm, board dimension 90mm x 90mm. Recommended Operating Conditions Parameter Oscillation Frequency Ambient Temperature March 2003 Symbol Min f -40 TA 4 Max Unit 500 KHz 85 o C Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Electrical Characteristics (VCC=15V, RT=10kΩ CT=3.3nF, TA= -40oC to +85oC, unless otherwise specified.) Parameter Symbol Conditions Min Typ Max Unit 4.90 5.00 5.10 V 4 15 mV 4 15 mV -100 -180 mA 0.2 0.4 mV/oC µV 5 25 mV 52 57 KHz 0.2 1 % REFERENCE SECTION Reference Output Voltage VREF Line Regulation ∆VREF TJ=25oC, IREF=1mA 12V ≤ VCC ≤25V Load Regulation ∆VREF 1mA ≤ IREF ≤20mA Short Circuit Output Current ISC TA=25oC Temperature Stability Output Noise Voltage (Note 6) Long Term Stability TA=85oC, 50 1000 hours OSCILLATOR SECTION Oscillation Frequency Frequency Change with Voltage Oscillator Amplitude f ∆f/f VOSC Temperature Stability TJ=25oC 12V ≤ VCC ≤ 25V 47 Pin 4, peak to peak (Note 6) 1.7 V (Note 6) 2.5 % (Note 6) -0.1 -2 µA 2.42 2.50 2.58 V ERROR AMPLIFIER SECTION Input Bias Current Input Voltage IBIAS VI Vpin 1=2.5V Open Loop Voltage Gain AVOL 2V ≤ VO ≤ 4V 65 90 dB Power Supply Rejection Ratio PSRR 12V ≤ VCC ≤ 25V 60 70 dB Output Sink Current ISINK Vpin2=2.7V, Vpin1=1.1V 2 4 mA -0.5 -0.8 mA 5 6 V Output Source Current ISOURCE Vpin2=2.3V, Vpin1=5V High Output Voltage VOH Vpin2=2.3V, RL=15kΩ to GND Low Output Voltage VOL Vpin2=2.7V, RL=15kΩ to Pin 8 GV (Note 4, 5) Vpin1=5V(Note 4) 0.8 1.1 V 2.85 3 3.15 V/V 0.9 1 1.1 V CURRENT SENSE SECTION Gain Maximum Input Signal VI(MAX) Power Supply Rejection Ratio PSRR Input Bias Current IBIAS Delay to Output 12V ≤ VCC ≤ 25V (Note 4, 6) 70 dB -3 -10 µA Vpin3 = 0 to 2V (Note 6) 150 300 ns ISINK = 20mA 0.1 0.4 V ISINK = 200mA 1.4 2.2 V OUTPUT SECTION Low Output Voltage High Output Voltage Rise Time March 2003 VOL VOH tR ISOURCE = 20mA 13 14 V ISOURCE = 200mA 12 13 V TJ=25oC, CL=1nF (Note 6) 5 50 150 ns Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Electrical Characteristics (Continued) Parameter Symbol Fall Time Conditions tF TJ=25oC, CL=1nF (Note 6) UNDER -VOLTAGE LOCKOUT SECTION Start Threshold VTH(ST) Min. Operation Voltage (After Turn On) Min AZ3842/AZ3844 14.5 Typ Max Unit 50 150 ns 15.5 16.5 V AZ3843/AZ3845 7.8 8.4 9.0 V VOPR (Min.) AZ3842/AZ3844 8.5 10.0 11.5 V AZ3843/AZ3845 7.0 7.6 8.2 V D(Max.) AZ3842/AZ3843 93 95 100 % D(Max.) AZ3844/AZ3845 46 48 50 % 0 % 0.6 1 mA 10 14 mA PWM SECTION Max. Duty Cycle Min. Duty Cycle D(Min.) TOTAL STANDBY CURRENT SECTION Start-Up Current IST ICC(OPR) Operating Supply Current Zener Voltage Vpin3=Vpin2=0V ICC=25mA VZ 30 34 V OVER-TEMPERATURE PROTECT SECTION Shutdown Temperature TSHUT (Note 6) 165 oC Temperature Hysteresis THYS (Note 6) 25 oC Note 4: Parameters are tested at trip point of latch with Vpin2 = 0. Note 5: Here gain is defined as: ∆VPin 1 A= , 0 ≤ Vpin3 ≤ 0.8V ∆VPin 3 Note 6: These parameters, although guaranteed, are not 100% tested in production. VREF 4.7k RT 2N2222 A COMP 1k ERROR AMP ADJUST AZ3842 8 VREF 7 VCC VCC 100k VFB 2 0.1µf 5k 4.7k 1 ISENSE ADJUST ISENSE RT/CT 3 6 OUTPUT 4 5 GND CT 1K 1W OUTPUT 0.1µf GND Figure 4. Basic Test Circuit March 2003 6 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Electrical Characteristics (Continued) Figure 4 is the basic test circuit for AZ384x. In testing, the high peak currents associated with capacitive loads necessitate careful grounding techniques. Timing and bypass capacitors should be connected close to pin 5 in a single point ground. The transistor and 5k potentiometer are used to sample the oscillator waveform and apply an adjustable ramp to pin 3. Typical Performance Characteristics 100k 30 50K n =1 RT (Ω) CT CT 3 F 1 F 0n =1 n 00 =1 10k CT Dead Time (µs) 10 F 5K 0.3 1 2.2 4.7 10 22 100 100 47 1k 10k 1M Figure 6. Timing Resistor vs. Frequency Figure 5. Oscillator Dead Time vs. Timing Capacitor 1.0 5.015 5.010 100k Frequency (Hz) Timing Capacitor (nF) VCC=15V, IO=1mA 0.9 Start Up Current (mA) Reference Voltage (V) AZ3842 5.005 5.000 4.995 4.990 0.8 0.7 0.6 0.5 4.985 0.4 4.980 -40 -20 0 20 40 60 80 100 120 -40 o Ambient Temperature ( C) 0 20 40 60 80 100 120 o Ambient Temperature ( C) Figure 7. Reference Voltage vs. Ambient Temperature March 2003 -20 Figure 8. Start-up Current vs. Ambient Temperature 7 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Typical Performance Characteristics (Continued) 16 4.0 15 3.5 o VCC=15V 13 Saturation Voltage (V) Supply Current (mA) 14 12 11 10 9 VCC=15V, TA=25 C 3.0 2.5 2.0 1.5 1.0 0.5 8 0.0 7 6 -40 -0.5 -20 0 20 40 60 80 100 120 o Ambient Temperature ( C) 0 50 100 150 200 250 300 350 400 450 500 550 600 Output Sink Current (mA) Figure 9. Supply Current vs. Ambient Temperature Figure 10. Output Saturation Characteristics 90 80 o Voltage Gain (dB) 70 VCC=15V, TA=25 C 60 50 40 30 20 10 0 10 100 1k 10k 100k 1M Frequency (Hz) Figure 11. Error Amplifier Open-loop Frequency Response March 2003 8 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Typical Application NTC Bridge Diode 1N4007*4 C2 0.01µ 600V + R2 100k J1 AC 220V C1 50µ C14 100µ/400V R3 39k 2W T D3 8TQ100 L3 45µ C9 2200µ D1 Byv26e R4 100 C10 1000µ + C11 1µ C12 10µ Z2 SA12A + + D2 1N4148 7 R12 500 cc VVCC J2 12V/5A C3 0.1µ VREF 8 R5 1k 2 VFB 1 COMP 5 GND C5 220p RT/CT 4 OUTPUT 6 ISENSE 3 R14 130k U1 AZ3842/3/4/5 R13 15k R11 820 C6 2200p/600V C4 10n R8 39k/2W R6 10 R7 1k R15 100 Q1 IRF820 R16 8.2k D4 Byv26e U3 AZ431 C7 0.01µ Z1 1N5819 C8 0.22µ W1 1k R10 0.51/1W R9 7.5k R18 3.9k R17 2k U2 PS521 Figure 12. Typical Application of AZ3842/3/4/5 March 2003 9 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Mechanical Dimensions 0.2±0.10 7° 0.70±0.025 4.9±0.10 7° 0.22±0.03 1.55±0.20 SOIC-8 0.32 8° 8° D 6.00±0.20 0.90 1.00 3.90±0.10 φ0.8 0.20 D 20:1 ±4° 4° R0.15 R0.15 3° ±2° 0.42±0.09 March 2003 10 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Mechanical Dimensions (Continued) SOIC-14 A 7° 0.38±0.10 ×45° 8° 8° +0.05 0.2-0.10 4° ±4° 0.70 7° 8° 3.90±0.10 1.55±0.20 0.42±0.09 9.5° 0.22±0.03 8.65±0.10 1.27 A 20:1 0.25 (0.20min) R0.20 1.00 6.00±0.20 R0.20 0.55±0.05 0.25 1.30 ±2° 3° φ2.0 Depth 0.06～0.10 March 2003 11 Rev: 1.0 Data Sheet Advanced Analog Circuits CURRENT MODE PWM CONTROLLER AZ3842/3/4/5 Mechanical Dimensions (Continued) DIP-8 7.62±0.25 5° 9.2±0.10 6° 6° 4° 3.30±0.30 1.46±0.31 4° 0.7 φ3×0.15±0.05 0.254 0.457 0.28±0.07 2.54 10.0MAX R0.75 March 2003 6.60±0.50 0.13MIN 12 Rev: 1.0 Advanced Analog Circuits http://www.aacmicro.com USA: 860 Hillview Court, Suite 160, Milpitas, CA 95035, USA China: 8th Floor, Zone B, 900 Yi Shan Road, Shanghai 200233, China Tel: 408-586 8809, Fax: 408-586 8801 Tel: 86-21-6495 9539, Fax: 86-21-6485 9673 Taiwan: Room 2210, 22nd Fl, 333, Keelung Road, Sec. 1, Taipei 110, Taiwan Tel: 886-2-2758 6828, Fax: 886-2-2758 6892 IMPORTANT NOTICE Advanced Analog Circuits Corporation reserves the right to make changes to its products or specifications at any time, without notice, to improve design or performance and to supply the best possible product. Advanced Analog Circuits does not assume any responsibility for use of any circuitry described other than the circuitry embodied in Advanced Analog Circuits' products. The company makes no representation that circuitry described herein is free from patent infringement or other rights of Advanced Analog Circuits Corporation.