Document Number: MC33730
Rev. 9.0, 8/2012
Switch Mode Power Supply with
Multiple Linear Regulators
The 33730 is a multiple output power supply integrated circuit for
automotive applications. The integrated circuit (IC) incorporates a
switching regulator, which operates over a wide input voltage range
from 4.5 to 26.5 V.
The step-down switching regulator uses a fixed frequency pulse-
width modulation (PWM) voltage mode control. It has a 3.5 A current
limit (typical) and the slew-rate is adjustable via a control pin to reduce
switching noise. The switching regulator has an adjustable frequency
oscillator, which allows the user to optimize its operation over a wide
range of input voltages and component values.
The linear regulators can be configured either as two Normal mode
regulators (VDD3, VDDL) and one standby regulator (VKAM), or as one
Normal mode linear regulator (VDDL) and two standby regulators (VKAM
and VDD3 Standby). Two protected outputs [VREF (1, 2)] are used to
provide power to external sensors.
• Provides all regulated voltages for Freescale 32-bit
• Adjustable frequency switching buck regulator with slew-rate
• Power sequencing provided
• Programmable voltages VDDL, VDD3 - 3% accuracy
• Programmable standby regulator VKAM - 15% accuracy,
operating down to 4.5 V at the KA_VBAT pin
• VDD3 can be programmed as an optional second standby
regulator with 15% accuracy
• Provides two 5.0 V protected supplies for sensors
• Provides reverse battery protection FET gate drive
• Provides necessary MCU monitoring and fail-safe support
SWITCHING POWER SUPPLY
EK SUFFIX (PB-FREE)
(Add R2 Suffix for
Tape and Reel)
- 40 °C to 125 °C
* Recommended device for all new designs
Figure 1. 33730 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., 2009 - 2012. All rights reserved.