LinearTechnology Corporation announces the H-grade version of the LTC3803-3,a current mode flyback DC/DC controller in a tiny 6-pin ThinSOTpackage. This H-grade device is guaranteed up to +150C operatingjunction temperature and is ideal for automotive and industrialapplications subjected to high ambient temperatures. The LTC3803H-3 canbe powered from an input voltage ranging from 9V to 75V through aseries resistor clamped with the device's internal shunt regulator. Thecontroller is well suited for 4:1 input voltage range isolatedapplications commonly found in 12V and 42V automotive requirements.
The constant 300kHz operating frequency is maintained down tolight loads, minimizing low frequency noise generation over a widerange of load current. With adjustable slope compensation, anLTC3803H-3 based power supply achieves fast transient response withminimum output capacitance. An integrated soft-start function reducesinrush current and output voltage overshoot. A 100mV current sensethreshold allows the use of a very small current sense resistor even athigh power levels to maintain high efficiency. An LTC3803H-3-baseddesign does not require a minimum load on the output for stableoperation, and the output voltage is determined by the selection ofexternal components. With a 40uA start-up and 240uA quiescent current,the IC maintains high efficiency at light loads, allowing the use of ahigh-value input resistor for low power dissipation and quick powersupply start-up.
The LTC3803H-3 operates and is guaranteed over an operating junctiontemperature of -40°C to 150°C. Pricing starts at $1.63 each in1,000-piece quantities. For more information, visit www.linear.com