MAXREFDES9#: 15V @ 300mA, 3.3 ~ 15V in, Boost

Summary

The Oceanside design (MAXREFDES9#) uses a step-up controller (MAX668), a 36V H-bridge transformer driver (MAX13256), and a pair of low dropout (LDO) linear regulators (MAX1659 x2) to create a ±15V (±12V) output isolated power supply from a wide range of input voltages.

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.

The Oceanside subsystem reference design operates from a 3.3V to 15V DC power source. The MAX668 high-efficiency step-up controller boosts the input voltage to 16V and connects to the input of the H-bridge transformer driver. The MAX13256 H-bridge transformer driver switches at 425 kHz and drives the primary side of the 1:1 turns ratio, with the use of TGMR-501V6LF transformers from Halo® Electronics. The full-wave bridge rectifiers convert the AC outputs of the Halo transformers’ secondary coils into DC outputs. The LDOs regulate the voltages to ±15V. The Zener diodes (D3 and D4) protect the LDOs by keeping their input voltages below 16.5V.

Specifications

Manufacturer	Analog Devices Inc./Maxim Integrated
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Single Output
Eval Board Part Number	MAXREFDES9#-ND
Eval Board Supplier	Analog Devices Inc./Maxim Integrated
Eval Board	Normally In Stock
Topology	Step Up
Outputs and Type	1 Isolated
Voltage Out: Factory Set	±15 V
Current Out	300 mA
Voltage In	3.3 ~ 15 V
Efficiency @ Conditions	>86%, 15V in, ±15V @ 90 mA >83%, 12V in, ±15V @ 85 mA >79%, 5V in, ±15V @ 70 mA >78%, 3.3V in, ±15V @ 65 mA
Voltage Out Range	1.25 ~ 16 V
Features	Current Limit (Adj. or Fixed) Reverse Polarity Protection Short Circuit Protection Shutdown, Enable, Standby Thermal Protection
Switching Frequency	425 kHz
Standby Current [Typical]	- Not Given
Quiescent Current [Typical]	- Not Given
Component Count + Extras	39 + 9
Internal Switch	No
Design Author	Maxim Integrated Products
Application / Target Market	Factory Automation Medical Power: Industrial Power Smart Building Controls
Standby Current [Maximum]	- Not Given
Quiescent Current [Maximum]	- Not Given
Main I.C. Base Part	MAX13256 MAX1659 MAX668
Date Created By Author	2012-10
Date Added To Library	2014-01