DC1280A: +12V @ 0.3A, -12V @ 0.2A, 4.5 ~ 10V in

Summary

Demonstration circuit 1280A is a dual output converter featuring the LT3471EDD in Boost and Inverter configurations. Both converters are powered from the same 4.5V to 10V input source. The Boost converter puts out 12V at 300mA and the Inverter -12V at 200mA. The demo circuit demonstrates small size and low component count.

The LT3471 operates with inputs as high as 16V but in this demo board the input is limited by the magnitude of the Boost output. In a Boost converter the input needs to be less than the output.

The DC1280A is designed so that the Inverting converter can easily be configured as a Boost. Instructions are included in the schematic.

Both circuits are designed to demonstrate the soft start feature, advantages of the 1.2MHz switching frequency and the internal 42V/1.3A switches.

Both outputs on this demo board can be modified for higher voltages. These circuits are intended for space-conscious applications such as digital cameras, cellular phones, palmtop computers PC cards, miniature disk drives, xDSL power supplies, flash memory products, local 5V or 12V supplies and LCD displays.

Specifications

Manufacturer	Analog Devices Inc.
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Multi Output
Eval Board Part Number	DC1280A-ND
Eval Board Supplier	Analog Devices Inc.
Topology	Step Up Inverting
Outputs and Type	2 Non-Isolated
Output Voltage: Factory Set	±12 V
Current Out	200 mA 300 mA
Voltage In	4.5 ~ 10 V
Efficiency @ Conditions	>84%, 4.5 Vin, 12 V @ 60 ~ 300 mA >74%, 4.5 Vin, -12V @ 41 ~ 200 mA
Voltage Out Range	11.64 ~ 12.36 V, -11.64 ~ -12.36 V
Features	Current Limit (Adj. or Fixed) PWM Interface Shutdown, Enable, Standby Soft Start
Switching Frequency	1.2 MHz
Standby Current [Typical]	10 nA
Quiescent Current [Typical]	2.5 mA
Component Count + Extras	22 + 12
Internal Switch	Yes
Design Author	Linear Technology
Application / Target Market	Cellular Phone Digital Cameras LCD and OLED Bias Supplies Medical Point of Load (PoL)
Main I.C. Base Part	LT3471
Standby Current [Maximum]	1 µA
Quiescent Current [Maximum]	4 mA
Date Created By Author	2007-08
Date Added To Library	2015-08