MC33397DW

Overview

The MC33397DW is a multi-output power supply integrated circuit designed for automotive applications, featuring a step-down switching controller and multiple linear regulators. It operates within an input voltage range of 6.0 V to 26.5 V, with transient capability up to 40 V. The device provides a 5.0 V output at 1400 mA from the switching regulator, a 3.3 V output at 400 mA via a linear regulator with an external pass transistor, and two 5.0 V sensor supplies at 200 mA each. It includes undervoltage shutdown, reset signals, and power sequencing features in a 24-SOIC package.

Feature Summary

• Integrates a sensorless current mode control step-down switching controller for efficient main power regulation.
• Provides dedicated linear regulators for low-power standby and auxiliary sensor supplies with short-to-battery protection.
• Includes advanced power management features such as undervoltage shutdown with retry and configurable power sequencing.

Applications

• Automotive electronic control units requiring robust multi-rail power distribution
• Microprocessor power architectures needing precise power-up sequencing
• Sensor interface circuits requiring protected 5.0 V supply rails

Procurement Notes

Verify component authenticity through authorized NXP or Freescale distributors due to legacy status. Confirm package marking and date codes against official datasheets. Check for RoHS compliance variations across production lots. Ensure storage conditions meet moisture sensitivity level requirements before reflow soldering.

Selection Notes

Select this IC when a single solution is needed for combined switching and linear regulation in automotive environments. Consider the need for external pass transistors for the 3.3 V rail to manage thermal dissipation. Evaluate if the fixed 5.0 V outputs align with system voltage requirements without additional post-regulation.

Part Context

Part of the MC3399x series of power system basis chips developed by Freescale Semiconductor (now NXP). Designed specifically for harsh automotive electrical environments, offering high reliability and integration compared to discrete solutions. Shares functional similarities with other members of the family but differs in specific output configurations and control interfaces.

Replacement Considerations

MC33997DWR2 offers identical functionality in a tape-and-reel packaging format suitable for automated assembly processes.

FAQ

How is the 3.3 V linear regulator output achieved?

The 3.3 V linear regulator requires an external pass transistor to handle the current load and reduce internal power dissipation within the IC.

What protection features are available for the sensor supplies?

The two 5.0 V sensor supplies are protected against short-to-battery and short-to-ground conditions with automatic retry capability.