10A+ Switch-Mode Power
Supply with LDO Regulator
Document Number: MC34703
Rev. 5.0, 8/2006
The 34703 integrated power supply IC is designed to support the
PowerQUICC™ family of MCUs as well as other MCUs and DSPs
requiring a high current core supply. The 34703 incorporates a high-
performance switching regulator for the microprocessor’s core
supply, and a low-dropout (LDO) linear regulator control circuit to
provide I/O and bus voltage.
The switching regulator is an efficient synchronous buck converter
with integrated low RDS(ON) high side and low side FETs.
Temperature and current sensing is built in and provides protection
for the IC as well as the external circuitry.
The 34703 incorporates specific advanced protection features for
use with high power processors and controllers, including power-up
and power-down sequencing of the I/O and core supply voltages in
relation to each other.
INTEGRATED POWER SUPPLY IC
Wide input Operating Voltage Range: 2.8 V to 13.5 V
Adjustable Output Voltages
Continuous Core Voltage Supply Currents up to 10 A (with
infrequent excursions to 12 A permitted)
Selectable Power Sequencing
Programmable Watchdog Timer
Voltage Margining via I2C Bus
Reset with Programmable Power-ON Delay
MC34703PNB/R2 -40 to 85°C
2.8 to 13.5 V
Figure 1. MC34703 Simplified Application Diagram
* This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2006. All rights reserved.