MC33998 Datasheet, PDF (1/20 Pages) Freescale Semiconductor, Inc – Switching Power Supply with Linear Regulators

Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Document order number: MC33998/D
Rev 1.0, 03/2003
Advance Information
Switching Power Supply with Linear
Regulators
The 33998 is a medium-power, multi-output power supply integrated circuit
that is capable of operating over a wide input voltage range, from 6.0 V up to
26.5 V with 40 V transient capability. It incorporates a sensorless current
mode control step-down switching controller regulating directly to 5.0 V. The
2.6 V linear regulator uses an external pass transistor to reduce the 33998
power dissipation. The 33998 also provides a 2.6 V linear standby regulator
and two 5.0 V sensor supply outputs protected by internal low-resistance
LDMOS transistors.
There are two separate enable pins for the main and sensor supply outputs
and standard supervisory functions such as resets with power-up reset delay.
The 33998 provides proper power supply sequencing for advanced
microprocessor architectures such as the Motorola MPC5xx and 683xx
microprocessor families.
Features
• Operating Voltage Range 6.0 V up to 26.5 V (40 V transient)
• Step-Down Switching Regulator Output V_DDH = 5.0 V @ 1400 mA (total)
• Linear Regulator with External Pass Transistor V_DDL = 2.6 V @ 400 mA
• Low-Power Standby Linear Regulator V_KAM = 2.6 V @ 10 mA
• Two 5.0 V @ 200 mA (typical) Sensor Supplies V_REF Protected Against
Short-to-Battery and Short-to-Ground with Retry Capability
• Undervoltage Shutdown on the V_DDL, V_DDH Outputs with Retry Capability
• Reset Signals
• Power-Up Delay
• Enable Pins for Main Supplies (EN) and Sensor Supplies (SNSEN)
• Power Sequencing for Advanced Microprocessor Architectures
• SOIC-24WB Package
33998
POWER SUPPLY
INTEGRATED CIRCUIT
DW SUFFIX
24-LEAD SOICW
CASE 751E
ORDERING INFORMATION
Device
Temperature
Range (T_A)
Package
MC33998DW/R2 ^{-40°C to 125°C}
24 SOICW
5.0 V
5.0 V
33998 Simplified Application Diagram
33998
KA_VPW _R VSW
VDDH
VPW _R
5.0 V
VRE _F1
VDDH
DRV L
VRE _F2
FBL
MCU
VDDL
2.6 V
EN
VKAM
SNSEN
GND ^PWROK
VKAMOK
VKAM
2.6 V
This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Motorola, Inc. 2003
For More Information On This Product,
Go to: www.freescale.com