DC1238B: 5V @ 500mA, 7.5 ~ 36V in

Summary

Demonstration circuit 1238B features the LTM8021, a 36 V, 500 mA step-down µModule regulator. The output has been preset to 5 V by a single resistor within the LTM8021’s output voltage range of 0.8 to 5 V. An adjustable soft-start period may be implemented with the addition of a capacitor at C3. The input voltage range is from 7.5 to 36 V for the default operating conditions. The LTM8021 may need more input voltage to start up than to run steady state.

The data sheet gives a complete description of the part, operation, and applications information. The LTM8021 data sheet must be read in conjunction with this demo manual prior to working on or modifying demo circuit DC1238B.

Specifications

Manufacturer	Analog Devices Inc.
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Single Output
Eval Board Part Number	DC1238B-ND
Eval Board Supplier	Analog Devices Inc.
Eval Board	Normally In Stock
Topology	Step Down
Outputs and Type	1 Non-Isolated
Voltage Out: Factory Set	5 V
Current Out	500 mA
Voltage In	7.5 ~ 36 V
Efficiency @ Conditions	>85%, 12V in, 5V @ 100 ~ 500 mA >81%, 24V in, 5V @ 150 ~ 500 mA >75%, 36V in, 5V @ 150 ~ 500 mA
Voltage Out Range	0.8 ~ 5 V
Features	Current Limit (Adj. or Fixed) Frequency Foldback PFM or PWM Short Circuit Protection Shutdown, Enable, Standby Soft Start
Switching Frequency	1.1 MHz
Standby Current [Typical]	100 nA
Quiescent Current [Typical]	1.5 mA
Component Count + Extras	6 + 8
Internal Switch	Yes
Design Author	Linear Technology
Application / Target Market	Automotive Portable Devices Power: AC Adapters Power: Auxiliary Power Supply Power: Industrial Power
Standby Current [Maximum]	1 µA
Quiescent Current [Maximum]	2.5 mA
Main I.C. Base Part	LTM8021
Date Created By Author	2012-06
Date Added To Library	2014-01