Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS General Description Features The AZ494 incorporates on a single chip all the functions required in the construction of a pulse-widthmodulation (PWM) control circuit. Designed primarily for power supply control, this device offers the flexibility to tailor the power supply control circuitry to a specific application. · · The AZ494 contains two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC) comparator, a pulse-steering control flip-flop, a 5V regulator, and output control circuits. The error amplifiers exhibit a common-mode voltage range from -0.3V to VCC-2V. The dead-time control comparator has a fixed offset that provides approximately 5% dead time. The on-chip oscillator can be bypassed by terminating the RT pin to the reference output and providing a sawtooth input to the CT pin, or it can drive the common circuits in synchronous multiple-rail power supplies. The uncommitted output transistors can be configured in either common-emitter or emitter-follower output topology. The AZ494 provides for push-pull or singleended output operation, which can be selected through the output control function. The architecture of this device prohibits the possibility of either output being pulsed twice during push-pull operation. The AZ494 is characterized for operation from -40oC to 85oC. · · · · · AZ494 Complete PWM power-control circuitry Uncommitted outputs for 200mA sink or source current Output control selects single-ended or push-pull operation Internal circuitry prohibits double pulse at either output Variable dead time provides control over total range Internal regulator provides a stable 5V reference supply with 5% tolerance Circuit architecture allows easy synchronization Applications · · SMPS Back Light Inverter DIP-16 SOIC-16 Figure 1. Package Types of AZ494 March. 2003 1 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Pin Configuration M Package / P Package (SOIC-16 / DIP-16) 1IN + 1 16 2IN + 1IN - 2 15 2IN - FEEDBACK 3 14 REF DTC 4 13 OUTPUT CTRL CT 5 12 VCC RT 6 11 C2 GND 7 10 E2 C1 8 9 E1 Top View Figure 2. Pin Configuration of AZ494 Function Table Input To Output Control Output Function VI = GND Single-ended or parallel output VI = Vref Normal push-pull operation Functional Block Diagram Output CTRL see Function Table RT CT 6 5 Pulse-Steering Flip-Flop Dead-Time Control Comparator DTC 9 11 Q2 1 10 PWM Comparator 2IN - FEEDBACK E2 2 12 2IN + E1 C2 CK Error Amplifier 1 1IN - C1 Q1 D 4 0.12V 1IN + 8 13 Oscillator 16 Error Amplifier 2 Reference Regulator 15 0.7mA 14 7 V CC REF GND 3 Figure 3. Functional Block Diagram of AZ494 March. 2003 2 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Ordering Information Package SOIC-16 Temperature Range o o -40 C~85 C DIP-16 Part Number Marking ID Packing Type AZ494M AZ494M Tube AZ494P AZ494P Tube Absolute Maximum Ratings (Note 1) Parameter Symbol Value Unit 40 V Supply Voltage (Note 2) VCC Amplifier Input Voltage VI -0.3 to VCC + 0.3 V Collector Output Voltage VO 40 V Collector Output Current IO 250 mA Package Thermal Impedance (Note 3) θJA M Package 73 P Package 67 Lead Temperature 1.6mm from case for 10 seconds Storage Temperature Range 260 TSTG -65 to 150 ESD rating (Machine Model) 200 oC/W oC oC V 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 Operation Ratings" is not implied. Exposure to "Absolute Maximum Ratings"for extended periods may affect device reliability. Note 2: All voltage values are with respect to the network ground terminal. Note 3: Maximum power dissipation is a function of TJ(max), θJA and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = ( TJ(max) - TA ) / θJA. Operating at the absolute maximum TJ of 150oC can affect reliability. March. 2003 3 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Recommended Operating Conditions Parameter Symbol Min Max Unit Supply Voltage VCC 7 36 V Amplifier Input Voltage VI VCC - 2 V Collector Output Voltage VO 36 V 200 mA 0.3 mA 300 KHz -0.3 Collector Output Current (Each Transistor) Current Into Feedback Terminal Oscillator Frequency fosc Timing Capacitor CT 0.47 10000 nF Timing Resistor RT 1.8 500 KΩ Operating Free-Air Temperature TA -40 85 oC March. 2003 4 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Electrical Characteristics All typical values, except for parameter changes with temperature, are at TA = 25oC. Vcc=15V, f=10KHz unless otherwise noted. Parameter Symbol Conditions (Note 4) Min Typ Max Unit IO=1mA 4.75 5 5.25 V Reference Section Output Voltage (REF) Vref Line Regulation VCC = 7V to 36V 2 25 mV Load Regulation IO=1mA to 10mA 1 15 mV Output Voltage Change with Temperature ∆TA = MIN to MAX 2 10 mV/V REF = 0V 25 mA 10 KHz 100 Hz/KHz 1 Hz/KHz Short-Circuit Output Current (Note 5) ISC Oscillator Section, CT = 0.01µF, RT = 12KΩ (See Figure 4) Frequency fosc Standard Deviation of Frequency (Note 6) All values of VCC, CT, RT and TA constant Frequency Change with Voltage VCC=7V to 36V, TA = 25oC Frequency Change with Temperature (Note 7) ∆TA= MIN to MAX 10 Hz/KHz Error-Amplifier Section (See Figure 5) Input Offset Voltage VOS VO (FEEDBACK) = 2.5V 2 10 mV Input Offset Current IOS VO (FEEDBACK) = 2.5V 25 250 nA Input Bias Current IBIAS VO (FEEDBACK) = 2.5V 0.2 1 µA VCC=7V to 36V Common-Mode Input Voltage Range Large-Signal Open-Loop Voltage Gain AVO ∆VO = 3V, RL =2KΩ, VO =0.5V to 3.5V Large-Signal Unity-Gain Bandwidth GB VO =0.5V to 3.5V, RL =2KΩ Common-Mode Rejection Ratio Output Sink Current (FEEDBACK) Output Source Current (FEEDBACK) V -0.3 to VCC-2 70 95 dB 800 KHz CMRR ∆VO = 36V, TA = 25oC 65 80 dB ISINK VID = -15mV to -5V, V(FEEDBACK) = 0.7V 0.3 0.7 mA VID = 15mV to 5V, V(FEEDBACK) = 3.5V -2 ISOURCE mA Output Section Collector Off-State Current IC, OFF VCE = 36V, VCC=36V Emitter Off-State Current IE, OFF VCC = VC = 36V, VE = 0 Collector-Emitter Saturation Voltage March. 2003 2 100 µA -100 µA V Common Emitter VE = 0, IC =200mA 1.1 1.3 Emitter Follower VO (C1 or C2) = 15V, IE = -200mA 1.5 2.5 5 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Electrical Characteristics (Continued) Parameter Symbol Conditions Min Typ VI = Vref Output Control Input Current Max Unit 3.5 mA -10 µA Dead-Time Control Section Input Bias Current VI = 0 to 5.25V -2 Maximum Duty Cycle, Each Output VI (DEAD-TIME CTRL) = 0, CT =0.01µF, RT =12KΩ 45 Input Threshold Voltage Zero Duty Cycle 3 3.3 V 4 4.5 V Maximum Duty Cycle % 0 PWM Comparator Section (See Figure 4) Input Threshold Voltage (FEEDBACK) Zero duty cycle Input Sink Current (FEEDBACK) V(FEEDBACK) = 0.7V 0.3 0.7 mA Total Device Standby Supply Current ISTDBY Average Supply Current RT=Vref, All other VCC = 15V inputs and outputs V = 36V CC open 6 10 9 15 mA VI (DEAD-TIME-CTRL) =2V See Figure 4. 7.5 mA Common-emitter Configuration See Figure 6 100 200 ns 25 100 ns Emitter-follower Configuration See Figure 7 100 200 ns 40 100 ns Switching Characteristics Rise Time tr Fall Time tf Rise Time tr Fall Time tf Note 4: For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. Note 5: Duration of the short circuit should not exceed one second. Note 6: Standard deviation is a measure of the statistical distribution about the mean as derived from the formula: Note 7: Temperature coefficient of timing capacitor and timing resistor are not taken into account. March. 2003 6 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Parameter Measurement Information VCC = 15V 12 4 Test Inputs 3 12KΩ 6 5 0.01uF 1 2 16 15 13 50KΩ VCC DTC C1 FEEDBACK E1 RT C2 CT E2 8 150Ω 2W 150Ω 2W Output 1 9 11 Output 2 10 1IN+ 1IN2IN+ 2INOUTPUT CTRL GND REF 14 7 Test Circuit Voltage at C1 VCC Voltage at C2 VCC 0V 0V Voltage at CT Threshold Voltage DTC 0V Threshold Voltage FEEDBACK 0.7V Duty Cycle MAX 0% 0% Voltage Waveforms Figure 4. Operational Test Circuit and Waveforms March. 2003 7 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Parameter Measurement Information Amplifier Under Test VI FEEDBACK Vref Other Amplifier Figure 5. Error Amplifier Characteristics 15V 68Ω 2W Each Output Circuit tf Output tr 90% 90% CL = 15pF (See Note A) 10% 10% Note A: CL includes probe and jig capacitance. Figure 6. Common-Emitter Configuration 15V Each Output Circuit 90% 90% Output CL = 15pF (See Note A) 10% 68Ω 2W 10% tr tf Note A: CL includes probe and jig capacitance. Figure 7. Emitter-Follower Configuration March. 2003 8 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Typical Characteristics 100k Oscillator Frequency-Hz Vcc=15V o TA=25 C 0.001uF 10k 0.01uF 1k 0.1uF CT=1uF 100 10 1k 10k 100k 1M Timing Resistance-Ω Figure 8. Oscillator Frequency vs. Timing Resistance 100 Vcc=15V ∆Vo=3V o TA=25 C 90 Voltage Gain-dB 80 70 60 50 40 30 20 10 0 1 10 100 1k 10k 100k 1M Frequency-Hz Figure 9. Error Amplifier Small-Signal Voltage Gain vs. Frequency March. 2003 9 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Mechanical Dimensions SOIC-16 1.65 0.70 1.00 1.30 7° 7° 0.406 A 20:1 B 0.25 0.55±0.05 10.00 1.27 φ2.0 ±2° 3° Depth 0.06～ 0.10 R0.20 R0.20 0.25(0.20min) 0.20±0.05 6.04 C-C 50:1 B 20:1 8° 9.5° C 0.20 Sφ1.00×0.20 5° ±2° 8° 8° 0.40×45° March. 2003 A 1.00 0.203 3.94 C 10 Rev.1.0 Data Sheet Advanced Analog Circuits PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494 Mechanical Dimensions (Continued) DIP-16 6° 1.524 0.7 6° 4° 4° 3.4±0.15 7.62±0.25 5° 19.0±0.10 3.3 φ3×0.10±0.05 0.254 0.254 8.4～9.0 2.54 6.3±0.10 0.457 R0.75 March. 2003 11 Rev.1.0 Advanced Analog Circuits http://www .aacmicro.com USA: 1510 Montague Expressway, San Jose, CA 95131, USA China: 8th Floor, Zone B, 900 Yi Shan Road ， Shanghai 200233, China Tel: 408-433 9888，Fax: 408-432 9888 Tel: 86-21-6495 9539, Fax: 86-21-6485 9673 Taiwan: Room 2210, 22nd Fl, 333, Keelung Road, Secretary 1, Taipei, Taiwan Tel: 886-2-2564 3699, Fax: 886-2-2564 3770 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.