Power Management AAC242/243 AAC242/243 PRELIMINARY DATA Current Mode PWM Contoller DESCRIPTION The AAC242 and AAC243 are part of AAI's new family of specialty products for Power Management applications. The AAC242 and AAC243 are high performance integrated circuits designed for Off-line or DC to DC converters using peak current mode control. The AAC24X has a current sense of 250mV in comparison to 1V for AAC14X parts. In offline AC designs the startup is improved by the low start-up current of the family. The integrated soft-start function adds to the easy of using the AAC24X parts in offline applications. The AAC242 and AAC243 are identical except for the Under Voltage Lockout. The AAC242 has UVLOon threshold of 16V and off of 10V making it easy to use in offline supplies where startup requirements for energy storage is necessary. For applications using lower supply voltages the AAC243 has UVLOon of 8.4V and UVLOoff of 7.6V. FEATURES * Low Start-up current * Pulse by pulse current limiting * On board voltage reference * * * * * * * * Under Voltage Lockout with hysteresis The greater than 1A output driver is ideal for driving MOSFETs and low power IGBTs. Rise and fall times are typically less that 30ns with a 1000pF load. The improvements in switching speed can provide improvements in efficiency, higher operating frequency and over current protection. * 100ns leading edge current blanking for reduced filtering * 250mV current sense The AAC24X family has a minimum pulse width of 0.4% allowing operation at very low power without pulse skipping or erratic operation. The narrower pulse width capibilities enhances operation at higher frequencies and voltages. View of the AAC24X shown from the top. The AAC24X family is offered in DIP and SMD packages. The packages are industry standards and are ROHS compliant. Extended temperature is standard with the AAC24X family. (c) Copyright 2010- ASIC Advantage, Inc. - Simple oscillator circuit Over Voltage protection zener High current output driver Less than 30ns rise and fall times Operation to over 1MHz Peak Current Mode control Integrated Cycles) Soft-Start Function (~330 Clock PIN CONFIGURATION: 8-Lead DIP and SOIC8 AADS00012 / R127B COMP 1 8 VFB AAC242 ISENSE AAC243 5 Rt/Ct 4 - Preliminary - VREF VCC OUT GND October 2010 1/8 Power Management AAC242/243 BLOCK DIAGRAM 8 Vcc UVLO 34V 5.00VREF 5V REF 5 GND REF OK 2.5V OSC 4 Rt/Ct Error Amp OUTPUT 6 11R 2R + S 2 Vf b Vref 7 DVR - R 1V R + Q Current Sense Comparator 1 COMP 3 Isense Open Loop Test Circuit V+ A Rt 4.7K 100K 1 2N3904 2 1K 3 4 4.7K 5K Vref FB Vcc Isense R/C 0.1uF 8 COMP OUT GND 7 1K/1W 6 OUTPUT 5 0.1uF Ct MAXIMUM RATINGS PARAMETER PARAMETERS UNITS CONDITIONS Low impedance source Supply Voltage (Vcc - Ground) MIN. 0 MAX. 30 V Vfb and Isense Amp Inputs -0.3 5.5 V 1 A 1200 mW DIP 1000 mW SOIC8 150 C Output Current Power Dissipation Operating Junction Temperature Operating Ambient Temperature -40 105 C Operating Ambient Temperature -40 125 C Storage Temperature Range -65 150 C 300 C Lead Temperature (10 Second) (c) Copyright 2010- ASIC Advantage, Inc. - AADS00012 / R127B - Preliminary Extended industrial temp. rated devices Automotive temp. rated devices Soldering - October 2010 2/8 Power Management AAC242/243 ELECTRICAL CHARACTERISTICS Unless otherwise stated, T=25C, Vcc=15V, RT = 10K, CT = 3300pF. PARAMETER PARAMETERS UNITS MIN. TYP. MAX. 4.95 5.00 5.05 V Line Regulation 6 15 mV Load Regulation 3 25 mV CONDITIONS REFERENCE SECTION Output Voltage Temperature Stability Total Output Variation 0.2 4.9 5.1 Long Term Stability Output Short Circuit Current 5 12V