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Maxim > Design Support > Technical Documents > Reference Designs > Medical > APP 5512

Maxim > Design Support > Technical Documents > Reference Designs > Power-Supply Circuits > APP 5512

Maxim > Design Support > Technical Documents > Reference Designs > Protection and Isolation > APP 5512

Keywords: power, 15V, 12V, pmod, industrial sensors, process control, industrial automation, medical, industrial

power, halo, transformer, riverside, maxrefdes8, industrial, power

REFERENCE DESIGN 5512 INCLUDES: Tested Circuit Schematic BOM Description Test Data Layout

Riverside (MAXREFDES8#): 3.3V Input, 12V (15V)

Output Isolated Power Supply

Nov 06, 2012

Abstract:

This document

details the Riverside (MAXREFDES8#) subsystem reference design, a 3.3V input, 12V

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

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

regulator. Test results and hardware files are included.

Introduction

The Riverside design (MAXREFDES8#) uses an H-bridge

transformer driver (MAX256) and a low dropout (LDO) linear

regulator (MAX1659) 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 (JPG)

Figure 1. The Riverside subsystem design block diagram.

Features Applications

Isolated power

12V (15V) output

Small printed circuit board (PCB) area

Pmod™-compatible form factor

Industrial sensors

Process control

Industrial automation

Medical

Detailed Description of Hardware

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

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Summary of content (5 pages)

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Maxim > Design Support > Technical Documents > Reference Designs > Medical > APP 5512 Maxim > Design Support > Technical Documents > Reference Designs > Power-Supply Circuits > APP 5512 Maxim > Design Support > Technical Documents > Reference Designs > Protection and Isolation > APP 5512 Keywords: power, 15V, 12V, pmod, industrial sensors, process control, industrial automation, medical, industrial power, halo, transformer, riverside, maxrefdes8, industrial, power REFERENCE DESIGN 5512 INCLUDES: Tested Ci
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transformer driver switches at approximately 475kHz and drives the primary side of the 1:2.6 turns ratio, with the use of a TGM-H281NF transformer from Halo® Electronics. The transformer secondary side is connected to a voltage doubler that rectifies the AC output into DC output. The MAX1659 LDO regulates the voltage to 12V. The Zener diode D3 protects the LDO by keeping its input voltage below 16.1V.
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Figure 2. Power efficiency vs. current load for 12V output. Figure 3. Power efficiency vs. current load for 15V output. The output noise is well below 0.5% of the output voltage. The noise is mainly due to the switching pulses of the MAX256. Figure 4 and Figure 5 display the noise at no load for 12V and 15V outputs, respectively. Figure 6 and Figure 7 display the noise at the maximum loads for 12V and 15V outputs, respectively. Figure 4. Noise at VOUT = 12V, IOUT = 0mA. Figure 5.
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Figure 6. Noise at VOUT = 12V, IOUT = 165mA. Figure 7. Noise at VOUT = 15V, IOUT = 60mA. All Design Files Hardware Files Schematic Bill of materials (BOM) PCB layout PCB Gerber PCB CAD (PADS 9.0) Buy Reference Design Riverside (MAXREFDES8#) Halo is a registered trademark of Halo Electronics, Inc. Pmod is a trademark of Digilent Inc. Related Parts MAX1659 350mA, 16.
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