TL494M PULSE-WIDTH-MODULATION CONTROL CIRCUIT

Size: px

Start display at page:

Download "TL494M PULSE-WIDTH-MODULATION CONTROL CIRCUIT"

Tamsin Page
5 years ago
Views:

1 Complete PWM Power Control Circuitry Uncommitted Outputs for 00-mA 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 5-V Reference Supply With 5% Tolerance Circuit Architecture Allows Easy Synchronization ERROR IN+ AMP IN DEAD-TIME CTRL C T R T GND C J PACKAGE (TOP VIEW) FK PACKAGE (TOP VIEW) IN+ IN ERROR AMP OUTPUT CTRL V CC C E E description The TL9M incorporates on a single monolithic chip all functions required in the construction of a pulse-width-modulation controlled system. Designed primarily for power supply control, these devices offer the systems engineer the flexibility to tailor the power supply control circuitry to a specific application. The TL9M contains two error amplifiers, an on-chip adjustable oscillator, a dead-time control comparator, a pulse-steering control flip-flop, a 5-V 5%-precision regulator, and output-control circuits. The error amplifiers exhibit a common-mode voltage range from 0.3 V to V CC V. The dead-time control comparator has a fixed offset that provides approximately 5% dead time when externally altered. The on-chip oscillator can be bypassed by terminating R T to the reference output and providing a sawtooth input to C T, or it can be used to drive the common circuits in synchronous multiple-rail power supplies. DEAD-TIME CTRL NC C T R T NC No internal connection INPUT OUTPUT CTRL VI = GND VI = IN IN+ NC IN+ IN GND C NC E E OUTPUT CTRL NC V CC C The uncommitted output transistors provide either common-emitter or emitter-follower output capability. Each device provides for push-pull or single-ended output operation, which can be selected through the output-control function. The architecture of these devices prohibits the possibility of either output being pulsed twice during push-pull operation. The TL9M is characterized for operation from 55 C to 5 C. ERROR AMP ERROR AMP FUNCTION TABLE OUTPUT FUNCTION Single-ended or parallel output Normal push-pull operation PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright 993, Texas Instruments Incorporated On products compliant to MIL-STD-883, Class B, all parameters are tested unless otherwise noted. On all other products, production processing does not necessarily include testing of all parameters. POST OFFICE BOX DALLAS, TEXAS 755

2 functional block diagram RT CT DEAD-TIME CTRL 5 0. V Oscillator Dead-Time-Control Comparator D OUTPUT CTRL (see Function Table) 3 C Q 8 9 C E IN + IN Error Amplifier + PWM Comparator Pulse-Steering Flip-Flop Q 0 C E IN + IN 5 Error Amplifier + Reference Regulator VCC ma 7 GND Pin numbers shown are for J package. POST OFFICE BOX DALLAS, TEXAS 755

3 absolute maximum ratings over operating free-air temperature range (unless otherwise noted) NOTES: Supply voltage, V CC (see Note ) V Amplifier input voltage, V I V CC V Collector output voltage V Collector output current ma Continuous total dissipation (see Note ) mw Operating free-air temperature range C to 5 C Storage temperature range C to 50 C Case temperature for 0 seconds: FK package C Lead temperature, mm (/ inch) from case for 0 seconds: J package C. All voltage values, except differential voltages, are with respect to the network GND.. For operation above 5 C free-air temperature, derate linearly to 75 mw at the rate of mw/ C. recommended operating conditions MIN MAX UNIT Supply voltage, VCC 7 0 V Amplifier input voltage, VI 0.3 VCC V Collector output voltage, VO 0 V Collector output current (each transistor) 00 ma Current into 0.3 ma Timing capacitor, CT nf Timing resistor, RT kω Oscillator frequency, fosc 300 khz Operating free-air temperature, TA 55 5 C POST OFFICE BOX DALLAS, TEXAS 755 3

4 electrical characteristics over recommended operating free-air temperature range, V CC = 5 V, f = 0 khz (unless otherwise noted) reference section Output voltage, IO = ma V Input regulation VCC = 7 V to 0 V 5 mv Output regulation IO = ma to 0 ma 5 mv Output voltage change with temperature TA = MIN to MAX 0.% 3%* Short-circuit output current = 0 5 ma oscillator section, C T = 0.0 µf, R T = kω (see Figure ) Frequency 0 khz Standard deviation of frequency All values of VCC, CT, RT, and TA constant 0% Frequency change with voltage VCC = 7 V to 0 V, TA = 5 C 0.% Frequency change with temperature# TA = MIN to MAX %* error amplifier section (see Figure ) Input offset voltage VO () =.5 V 0 mv Input offset current VO () =.5 V 5 50 na Input bias current VO () =.5 V 0. µa Common-mode input voltage range VCC = 7 V to 0 V 0.3 to VCC Open-loop voltage amplification VO = 3 V, RL = kω, VO = 0.5 V to 3.5 V db Unity-gain bandwidth VO = 0.5 V to 3.5 V, RL = kω 800 khz Common-mode rejection ratio VO = 0 V, TA = 5 C 5 80 db Output sink current, VID = 5 mv to 5 V, V () = 0.7 V ma Output source current, VID = 5 mv to 5 V, V () = 3.5 V ma * This parameter is not production tested. All typical values except for parameter changes with temperature are at TA = 5 C. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. N Duration of the short circuit should not exceed one second. (x n X) Standard deviation is a measure of the statistical distribution about the mean as derived from the formula: # n Temperature coefficient of the timing capacitor and timing resistor is not taken into account. N V POST OFFICE BOX DALLAS, TEXAS 755

5 electrical characteristics over recommended operating free-air temperature range, V CC = 5 V, f = 0 khz (unless otherwise noted) output section Collector off-state current VCE = 0 V, VCC = 0 V 00 µa Emitter off-state current VCC = VC = 0 V, VE = 0 00 µa Collector-emitter saturation voltage Common emitter VE = 0, IC = 00 ma..3 Emitter follower VC = 5 V, IE = 00 ma.5.5 Output control input current VI = 3.5 ma dead-time control section (see Figure ) Input bias current, DEAD-TIME CTRL VI = 0 to 5.5 V 0 µa Maximum duty cycle, each output VI (DEAD-TIME CTRL) = 0, CT = 0. µf, RT = kω 5% 50%* Input threshold voltage, DEAD-TIME CTRL pwm comparator section (see Figure ) Zero duty cycle Maximum duty cycle 0* Input threshold voltage, Zero duty cycle.5 V Input sink current, V () = 0.7 V ma total device (see Figure ) Standby supply current RT at, VCC = 5 V All other inputs and outputs open VCC = 0 V 9 Average supply current VI (DEAD-TIME CTRL) = V, See Figure 7.5 ma switching characteristics, T A = 5 C Output voltage rise time, tr Output voltage fall time, tf Common-emitter configuration, See Figure 3 Output voltage rise time, tr Output voltage fall time, tf Emitter-follower configuration, See Figure * This parameter is not production tested. All typical values except for temperature coefficient are at TA = 5 C * 5 00* 00 00* 0 00* V V ma ns ns POST OFFICE BOX DALLAS, TEXAS 755 5

6 PARAMETER MEASUREMENT INFORMATION VCC = 5 V Test Inputs 3 kω µf 5 VCC DEAD-TIME CTRL RT CT IN + IN IN + IN Error Amplifiers 50 Ω, W 50 Ω, W C 8 Output E 9 C Output E 0 50 kω 3 OUTPUT CTRL GND 7 TEST CIRCUIT Voltage at C Voltage at C VCC 0 V VCC 0 V Voltage at CT DEAD-TIME CONTROL Threshold Voltage 0 V Threshold Voltage 0.7 V Duty Cycle 0% MAX 0% VOLTAGE WAVEFORMS Figure. Operational Test Circuit and Waveforms POST OFFICE BOX DALLAS, TEXAS 755

7 PARAMETER MEASUREMENT INFORMATION Amplifier Under Test + VI + Other Amplifier Figure. Amplifier Characteristics 5 V Each Output Circuit 8 Ω, W Output 90% tf tr 90% CL = 5 pf (includes probe and jig capacitance) 0% 0% TEST CIRCUIT OUTPUT VOLTAGE WAVEFORM Figure 3. Common-Emitter Configuration 5 V Each Output Circuit 90% 90% Output 0% 0% CL = 5 pf (includes probe and jig capacitance) 8 Ω, W tr OUTPUT VOLTAGE WAVEFORM tf TEST CIRCUIT Figure. Emitter-Follower Configuration POST OFFICE BOX DALLAS, TEXAS 755 7

8 TYPICAL CHARACTERISTICS Oscillator Frequency Hz 00 k 0 k 0 k k k OSCILLATOR FREQUENCY AND FREQUENCY VARIATION vs TIMING RESISTANCE % % CT = µf 0% 0. µf 0.0 µf VCC = 5 V TA = 5 C 0.00 µf f = % 0 k k 0 k 0 k 00 k 00 k M RT Timing Resistance Ω Frequency variation ( f) is the change in oscillator frequency that occurs over the full temperature range. Figure AMPLIFIER VOLTAGE AMPLIFICATION vs FREQUENCY VCC = 5 V VO = 3 V TA = 5 C Voltage Amplification db k 0 k 00 k M f Frequency Hz Figure Printed 8 in U.S.A. POST OFFICE BOX DALLAS, TEXAS 755 SGLS0A

9 IMPORTANT NOTICE Texas Instruments (TI) reserves the right to make changes to its products or to discontinue any semiconductor product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before placing orders, that the information being relied on is current. TI warrants performance of its semiconductor products and related software to the specifications applicable at the time of sale in accordance with TI s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. Certain applications using semiconductor products may involve potential risks of death, personal injury, or severe property or environmental damage ( Critical Applications ). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. Inclusion of TI products in such applications is understood to be fully at the risk of the customer. Use of TI products in such applications requires the written approval of an appropriate TI officer. Questions concerning potential risk applications should be directed to TI through a local SC sales office. In order to minimize risks associated with the customer s applications, adequate design and operating safeguards should be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or services described herein. Nor does TI warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. Copyright 995, Texas Instruments Incorporated

TL494C, TL494I, TL494M, TL494Y PULSE-WIDTH-MODULATION CONTROL CIRCUITS

TL494C, TL494I, TL494M, TL494Y PULSE-WIDTH-MODULATION CONTROL CIRCUITS Complete PWM Power Control Circuitry Uncommitted Outputs for 00-mA Sink or Source Current Output Control Selects Single-Ended or Push-Pull Operation Internal Circuitry Prohibits Double Pulse at Either