PULSE-WIDTH-MODULATION CONTROL CIRCUITS General Description. Features

Transcription

1 查询 M 供应商 捷多邦, 专业 PCB 打样工厂,24 小时加急出货 General Description The 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 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 V CC -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 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 is characterized for operation from -40 o C to 85 o C. Features 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 SOIC-16 DIP-16 Figure 1. Package Types of 1

2 Pin Configuration M Package / P Package (SOIC-16 / DIP-16) 1IN IN + 1IN IN - FEEDBACK 3 14 REF DTC 4 13 OUTPUT CTRL CT 5 12 V CC RT 6 11 C2 GND 7 10 E2 C1 8 9 E1 Top View Figure 2. Pin Configuration of Function Table Input To Output Control V I = GND V I = V ref Output Function Single-ended or parallel output Normal push-pull operation Functional Block Diagram Output CTRL see Function Table RT CT DTC 1IN + 1IN - 2IN + 2IN - FEEDBACK V Error Amplifier 1 Error Amplifier 2 Oscillator Dead-Time Control Comparator PWM Comparator 0.7mA Pulse-Steering Flip-Flop D CK Reference Regulator 13 8 Q Q C1 E1 C2 E2 V CC REF GND Figure 3. Functional Block Diagram of 2

3 Ordering Information Package Temperature Range Part Number Marking ID Packing Type SOIC o C~85 o C M M Tube DIP-16 P P Tube Absolute Maximum Ratings (Note 1) Parameter Symbol Value Unit Supply Voltage (Note 2) V CC 40 V Amplifier Input Voltage V I -0.3 to V CC V Collector Output Voltage V O 40 V Collector Output Current I O 250 ma Package Thermal Impedance (Note 3) θ JA M Package 73 o C/W P Package 67 Lead Temperature 1.6mm from case for 10 seconds 260 o C Storage Temperature Range T STG -65 to 150 o C ESD rating (Machine Model) 200 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 T J (max), θ JA and T A. The maximum allowable power dissipation at any allowable ambient temperature is P D = ( T J (max) - T A ) / θ JA. Operating at the absolute maximum T J of 150 o C can affect reliability. 3

4 Recommended Operating Conditions Parameter Symbol Min Max Unit Supply Voltage V CC 7 36 V Amplifier Input Voltage V I -0.3 V CC - 2 V Collector Output Voltage V O 36 V Collector Output Current (Each Transistor) 200 ma Current Into Feedback Terminal 0.3 ma Oscillator Frequency f osc 300 KHz Timing Capacitor C T nf Timing Resistor R T KΩ Operating Free-Air Temperature T A o C 4

5 Electrical Characteristics All typical values, except for parameter changes with temperature, are at T A = 25 o C. Vcc=15V, f=10khz unless otherwise noted. Parameter Symbol Conditions (Note 4) Min Typ Max Unit Reference Section Output Voltage (REF) V ref I O =1mA V Line Regulation V CC = 7V to 36V 2 25 mv Load Regulation I O =1mA to 10mA 1 15 mv Output Voltage Change with Temperature T A = MIN to MAX 2 10 mv/v Short-Circuit Output Current (Note 5) I SC REF = 0V 25 ma Oscillator Section, C T = 0.01µF, R T = 12KΩ (See Figure 4) Frequency f osc 10 KHz Standard Deviation of Frequency (Note 6) All values of V CC, C T, R T and T A constant 100 Hz/KHz Frequency Change with Voltage V CC =7V to 36V, T A = 25 o C 1 Hz/KHz Frequency Change with Temperature T A = MIN to MAX 10 Hz/KHz (Note 7) Error-Amplifier Section (See Figure 5) Input Offset Voltage V OS V O (FEEDBACK) = 2.5V 2 10 mv Input Offset Current I OS V O (FEEDBACK) = 2.5V na Input Bias Current I BIAS V O (FEEDBACK) = 2.5V µa Common-Mode Input Voltage Range V CC =7V to 36V -0.3 to V CC -2 V Large-Signal Open-Loop Voltage Gain A VO V O = 3V, R L =2KΩ, V O =0.5V to 3.5V db Large-Signal Unity-Gain Bandwidth GB V O =0.5V to 3.5V, R L =2KΩ 800 KHz Common-Mode Rejection Ratio CMRR V O = 36V, T A = 25 o C db Output Sink Current (FEEDBACK) I SINK V ID = -15mV to -5V, V(FEEDBACK) = 0.7V Output Source Current (FEEDBACK) I SOURCE V ID = 15mV to 5V, V(FEED- BACK) = 3.5V ma -2 ma Output Section Collector Off-State Current I C, OFF V CE = 36V, V CC =36V µa Emitter Off-State Current I E, OFF V CC = V C = 36V, V E = µa Collector-Emitter Saturation Voltage Common Emitter Emitter Follower V E = 0, I C =200mA V V O (C1 or C2) = 15V, I E = -200mA

6 Electrical Characteristics (Continued) Parameter Symbol Conditions Min Typ Max Unit Output Control Input Current V I = V ref 3.5 ma Dead-Time Control Section Input Bias Current V I = 0 to 5.25V µa Maximum Duty Cycle, Each Output V I (DEAD-TIME CTRL) = 0, C T =0.01µF, R T =12KΩ 45 % Input Threshold Voltage Zero Duty Cycle V Maximum Duty Cycle 0 PWM Comparator Section (See Figure 4) Input Threshold Voltage (FEEDBACK) Zero duty cycle V Input Sink Current (FEEDBACK) V(FEEDBACK) = 0.7V ma Total Device Standby Supply Current I STDBY RT=V ref, All other V CC = 15V 6 10 ma inputs and outputs open V CC = 36V 9 15 Average Supply Current V I (DEAD-TIME-CTRL) =2V See Figure ma Switching Characteristics Rise Time t r Common-emitter Configuration ns Fall Time t f See Figure ns Rise Time t r Emitter-follower Configuration ns Fall Time t f See Figure ns 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. 6

7 Parameter Measurement Information V CC = 15V Test Inputs KΩ uF V CC DTC FEEDBACK RT CT 1IN+ 1IN- 2IN+ 2IN- C1 E1 C2 E Ω 2W 150Ω 2W Output 1 Output 2 50KΩ 13 OUTPUT CTRL GND 7 REF 14 Test Circuit Voltage at C1 V CC 0V Voltage at C2 V CC 0V Voltage at CT DTC Threshold Voltage 0V FEEDBACK Threshold Voltage 0.7V Duty Cycle 0% MAX 0% Voltage Waveforms Figure 4. Operational Test Circuit and Waveforms 7

8 Parameter Measurement Information V I Amplifier Under Test FEEDBACK V ref Other Amplifier Figure 5. Error Amplifier Characteristics 15V 68Ω 2W t f t r Each Output Circuit Output 90% 90% C L = 15pF (See Note A) 10% 10% Note A: C L includes probe and jig capacitance. Figure 6. Common-Emitter Configuration 15V Each Output Circuit 90% 90% C L = 15pF (See Note A) 68Ω 2W Output 10% t r 10% t f Note A: C L includes probe and jig capacitance. Figure 7. Emitter-Follower Configuration 8

9 Typical Characteristics 100k Vcc=15V T A =25 o C Oscillator Frequency-Hz 10k 1k uF C T =1uF 0.01uF 0.001uF 10 1k 10k 100k 1M Timing Resistance-Ω Figure 8. Oscillator Frequency vs. Timing Resistance 100 Voltage Gain-dB Vcc=15V Vo=3V T A =25 o C k 10k 100k 1M Frequency-Hz Figure 9. Error Amplifier Small-Signal Voltage Gain vs. Frequency 9

10 Mechanical Dimensions SOIC B A 20:1 0.55± φ2.0 Depth 0.06~ R ±2 R (0.20min) ± B 20:1 C-C 50:1 C Sφ ± A C 10

11 Mechanical Dimensions (Continued) DIP ± ± ±0.15 φ3 0.10± ~ R ±

12 USA: 1510 Montague Expressway, San Jose, CA 95131, USA Tel: , Fax: China: 8th Floor, Zone B, 900 Yi Shan Road, Shanghai , China Tel: , Fax: Taiwan: Room 2210, 22nd Fl, 333, Keelung Road, Secretary 1, Taipei, Taiwan Tel: , Fax: IMPORTANT NOTICE 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. does not assume any responsibility for use of any circuitry described other than the circuitry embodied in ' products. The company makes no representation that circuitry described herein is free from patent infringement or other rights of Advanced Analog Circuits Corporation.