Analog Devices LT8330 | Demoboard DC2018A

Description

Demonstration circuit 2018A features the LT®8330, a lowIQ boost/SEPIC/inverting converter with a 1A, 60V switch.The LT8330 allows higher input and output voltages thancomparable converters and also significantly reduces inputcurrent at light loads and no load. The LT8330 regulateseither positive or negative outputs and has an internallyprogrammed switching frequency of 2MHz.DC2018A consists of two circuits: one circuit is a boostconverter with an operating input voltage range from 10Vto 36V and an output voltage of 48V. With a 12V input,the maximum output current for the boost is 135mA andthe efficiency is 89%. The second circuit is an invertingconverter which demonstrates a negative output. Theoperating input voltage range of the inverting converteris from 4V to 36V and the output voltage is –12V. With a12V input, the maximum output current for the invertingconverter is 270mA and the efficiency is 87%.For each DC2018A circuit, the output voltage is programmedby resistor divider feedback. The voltage divideruses high resistance values that minimize current leakage,and the feedback network also includes a 4.7pF feedforwardcapacitor. Each DC2018A circuit also uses a lowleakage rectifier diode to further minimize input currentat light loads and no load. The input supply for power tothe inductor can be separated from the LT8330 VIN pin toallow operation from two input sources.A resistor divider from the input to the EN/UVLO pinprograms the boost to turn off when the input falls below9V and the inverting converter to turn off when the inputfalls below 3.6V. The position of the EN/UVLO CONTROLjumper either connects the EN/UVLO pin to the input supplythrough a resistor divider, shorts EN/UVLO to ground, orallows the EN/UVLO pin to be driven directly by a signalapplied to the EN/UVLO terminal. A 50V tantalum polymercapacitor protects the input from ringing that may occurwhen the input is hot-plugged using long leads.Low input current at light loads, a high voltage rating andnegative output capability make the LT8330 attractive forbattery-powered and extended voltage range regulatorcircuits. DC2018A features the LT8330ES6 in a small6-lead TSOT-23 package. The LT8330 data sheet mustbe read in conjunction with this demo manual to properlyuse or modify DC2018A.

More information

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• IC product information