TL494 FAIRCHILD | Alldatasheet

Document overview

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Technical content

Features

  • Internal regulator provides a stable 5V reference supply trimmed to 5%
  • Uncommitted output TR for 200mA sink or source current
  • Output control for push-pull or single-ended operation
  • Variable duty cycle by dead time control (pin 4) Complete PWM control circuit
  • On-chip oscillator with master or slave operation
  • Internal circuit prohibits double pulse at either output

Description

The TL494 is used for the control circuit of the PWM switching regulator. The TL494 consists of 5V reference voltage circuit, two error amplifiers, flip flop, an output con- trol circuit, a PWM comparator, a dead time comparator and an oscillator. This device can be operated in the switching frequency of 1 KHz to 300 KHz. 16-DIP 16-SOP Internal Block Diagram TL494 SMPS Controller

Parameter Symbol Value Unit Supply Voltage V CC 42 V Collector Supply Voltage V C 42 V Output Current I O 250 mA Amplifier Input Voltage V IN VCC + 0.3 V Power Dissipation (TA = 25°C) P D 1 (TL494CN) 0.9 (TL494CD) W Operating Temperature Range T OPR 0 ~ +70 °C Storage Temperature Range T STG -65 ~ + 150 °C

Electrical Characteristics

(VCC = 20V , f = 10KHz, TA = 0°C to + 70°C, unless otherwise specified) Parameter Symbol Conditions Min. Typ. Max. Unit REFERENCE SECTION Reference Output Voltage V REF IREF = 1mA 4.75 5.0 5.25 V Line Regulation ∆VREF VCC = 7V to 40V - 2.0 25 mV Temperature Coefficient of VREF ∆VREF/∆TT A = 0°C to 70°C - 0.01 0.03 %/ °C Load Regulation ∆VREF IREF = 1mA to 10mA - 1.0 15 mV Short-Circuit Output Currnet I SC VREF = 0V 10 35 50 mA OSCILLATOR SECTION Oscillation Frequency f C T = 0.01µF, RT = 12KΩ -1 0- K H z Frequency Change with Temperature ∆f/∆TC T = 0.01µF, RT = 12KΩ --2 % DEAD TIME CONTROL SECTION Input Bias Current I BIAS VCC = 15V, 0V≤V4≤5.25V - -2.0 -10 µA Maximum Duty Cycle D (MAX) VCC = 15V, V4 = 0V O.C Pin = VREF 45 - - % Input Threshold Voltage V ITH Zero Duty Cycle - 3.0 3.3 VMax. Duty Cycle 0 - - ERROR AMP SECTION Input Offset Voltage V IO V3 = 2.5V - 2.0 10 mV Input Offset Current I IO V3 = 2.5V - 25 250 mA Input Bias Current I BIAS V3 = 2.5V - 0.2 1.0 µA Common Mode Input Voltage V CM 7V ≤ VCC ≤ 40V -0.3 - V CC V Open-Loop Voltage Gain G VO 0.5V ≤ V3 ≤3 .5V 70 95 - dB Unit-Gain Bandwidth BW - - 650 - KHz PWM COMPARATOR SECTION Input Threshold Voltage V ITH Zero Duty Cycle - 4 4.5 V Input Sink Currnet I SINK V3=0.7V -0.3 -0.7 - mV OUTPUT SECTION Output Saturation Voltage Common Emitter VCE(SAT) VE = 0, IC = 200mA - 1.1 1.3 V Common Collector V CC(SAT) VC = 15V, IE = -200mA - 1.5 2.5 Collector Off-State Currnet I C(OFF) VCC = 40V, VCE = 40V - 2 100 µA Emitter Off-State Current I E(OFF) VCC = VC = 40V, VE = 0 - - -100 TOTAL DEVICE Supply Current I CC Pin 6 = VREF, VCC = 15V - 6 10 mA OUTPUT SWITCHING CHARACTERISTIC Rise Time t R - ---- Common Emitter - - - 100 200 ns Common Collector - - - 100 200 Fall Time t F - ---- Common Emitter - - - 25 100 ns Common Collector - - - 40 100

Pulse Width Modulated Step-down Converter TL494

#8 #9 #16 6.40 ±0.20 7.62 0.300 2.54 0.100 0.252 ±0.008 0~15° 0.25 +0.10 –0.05 0.010 +0.004 –0.002 3.30 ±0.30 0.130 ±0.012 3.25 ±0.20 0.128 ±0.008 19.40 ±0.20 0.764 ±0.008 19.80 0.780MAX 5.08 0.200 0.38 0.014 MAX MIN 0.81 0.032()0.46 ±0.10 0.018 ±0.004 0.059 ±0.004 1.50 ±0.10 16-DIP

Mechanical Dimensions (Continued) Package 0.70 ±0.20 0.0275 ±0.008 #8 #9 #16 9.90 ±0.20 0.39 ±0.008 1.27 0.050 5.72 0.225 1.55 ±0.10 0.061 ±0.004 0.05 0.002 6.00 ±0.30 0.236 ±0.012 3.95 ±0.20 0.156 ±0.008 10.30 0.405MAX 0~8 0.51 0.020() 1.80 0.071 MAX0.10 MAX0.004 MAX MIN +0.10-0.05 0.20 +0.004-0.002 0.008 +0.10 -0.050.406 +0.004 -0.0020.016 16-SOP

Ordering Information

Product Number Package Operating Temperature TL494CN 16 DIP 0 ~ + 70°C TL494CD 16 SOP

7/12/00 0.0m 001 Stock#DSxxxxxxxx  2000 Fairchild Semiconductor International 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 INTERNATIONAL. As used herein: 1. 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. 2. 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. www.fairchildsemi.com