Maxim > Design Support > Technical Documents > Reference Designs > Medical > APP 5510

Maxim > Design Support > Technical Documents > Reference Designs > Power-Supply Circuits > APP 5510

Maxim > Design Support > Technical Documents > Reference Designs > Protection and Isolation > APP 5510

electronics, transformer, lakewood, maxrefdes7, industrial, dual supplies, power

REFERENCE DESIGN 5510 INCLUDES:

Tested Circuit

Schematic

BOM

Description

Test Data

Layout

Lakewood (MAXREFDES7#): 3.3V Input, ±12V (±15V)

Output Isolated Power Supply

Nov 06, 2012

Abstract: This document details the Lakewood (MAXREFDES7#) subsystem reference design, a 3.3V input, ±12V

(±15V) output, isolated power supply. The Lakewood reference design includes a 3W primary-side transformer H-

bridge driver for isolated supplies, and two wide input range and adjustable output low dropout (LDO) linear

regulators. Test results and hardware files are included.

Introduction

The Lakewood design (MAXREFDES7#) uses an H-bridge

transformer driver (MAX256) and a pair of low dropout (LDO)

linear regulators (MAX1659 x2) to create a ±12V (±15V)

output isolated power supply from a 3.3V voltage input

(Figure 1). This general-purpose power solution can be used

in many different types of isolated power applications, but is

mainly targeted for industrial sensors, industrial automation,

process control, and medical applications.

More detailed image (PDF, 1.9MB)

Figure 1. The Lakewood subsystem design block diagram.

Features

Applications

Isolated power

±12V (±15V) outputs

Small printed circuit board (PCB) area

Pmod™-compatible form factor

Industrial sensors

Process control

Industrial automation

Medical

Detailed Description of Hardware

The Lakewood subsystem reference design operates from a 3.3V DC power source. The MAX256 H-bridge

transformer driver switches at approximately 475kHz and drives the primary side of the 1:2.6 turns ratio, with the

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