AMS494 AMS | Alldatasheet

Document overview

  • Manufacturer or author: pROVIDED bY alldatasheet.com(free datasheet download site)
  • PDF pages: 7

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 AMS494 is used for the control circuit of the PWM switching regulator. The AMS494 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. Internal Block Diagram PIN CONFIGURATION (Top View) 8 9 COM E AMS494 Advanced Monolithic Systems http://www.ams-semitech.com

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 V CC + 0.3 V Power Dissipation (T A = 25°C) P D 1 (AMS494CN) 0.9 (AMS494CD) W Operating Temperature Range T OPR 0 ~ +70 °C Storage Temperature Range T STG -65 ~ + 150 °C http://www.tc-ic.com AMS494 Advanced Monolithic Systems http://www.ams-semitech.com

Electrical Characteristics

= 20V , f = 10KHz, T A = 0°C to + 70°C, unless otherwise specified) Parameter Symbol Conditions Min. Typ. Max. Unit REFERENCE SECTION Reference Output Voltage V REF I REF = 1mA 4.75 5.0 5.25 V Line Regulation ∆V REF V CC = 7V to 40V - 2.0 25 mV Temperature Coefficient of V REF REF /∆TT A Load Regulation ∆V REF I REF = 1mA to 10mA - 1.0 15 mV Short-Circuit Output Currnet I SC V REF = 0V 10 35 50 mA OSCILLATOR SECTION Oscillation Frequency f C T = 0.01µF, R T = 12KΩ -1 0- K H z Frequency Change with Temperature ∆f/∆TC T = 0.01µF, R T = 12KΩ --2 % DEAD TIME CONTROL SECTION Input Bias Current I BIAS V CC = 15V, 0V≤V Maximum Duty Cycle D (MAX) V CC = 15V, V = 0V O.C Pin = V REF 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 V = 2.5V - 2.0 10 mV Input Offset Current I IO V = 2.5V - 25 250 mA Input Bias Current I BIAS V Common Mode Input Voltage V CM 7V ≤ V CC ≤ 40V -0.3 - V CC V Open-Loop Voltage Gain G VO 0.5V ≤ V ≤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 V OUTPUT SECTION Output Saturation Voltage Common Emitter V CE(SAT) V E = 0, I C = 200mA - 1.1 1.3 V Common Collector V CC(SAT) V C = 15V, I E = -200mA - 1.5 2.5 Collector Off-State Currnet I C(OFF) V CC = 40V, V CE = 40V - 2 100 µA Emitter Off-State Current I E(OFF) V CC = V C = 40V, V E = 0 - - -100 TOTAL DEVICE Supply Current I CC Pin 6 = V REF , V CC = 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 AMS494 Advanced Monolithic Systems http://www.ams-semitech.com

Pulse Width Modulated Step-down Converter AMS494 http://www.tc-ic.com AMS494 Advanced Monolithic Systems http://www.ams-semitech.com

#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 AMS494 Advanced Monolithic Systems http://www.ams-semitech.com

(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 -0.05 0.406 0.004 -0.002 0.016 16-SOP http://www.tc-ic.com AMS494 Advanced Monolithic Systems http://www.ams-semitech.com

Ordering Information

Product Number Package Operating Temperature AMS494CN 16 DIP 0 ~ + 70°C AMS494CD 16 SOP AMS494 Advanced Monolithic Systems http://www.ams-semitech.com