1 Introduction

The MPC5643L microcontroller is based on the Power

Architecture® and targets electric power steering, chassis, and

safety applications that require a high safety integrity level.

The host processor core of the device is a member of the

e200z4 Power Architecture compatible core family.

For more details, see MPC5643LRM: MPC5643L Reference

Manual and MPC5643L Data Sheet, available on

freescale.com

2 Power supplies

The on-chip voltage regulator module provides the following

features:

• Single high-supply requires nominal 3.3 V.

• An external ballast transistor is used to reduce

dissipation capacity at high temperature but an

embedded transistor can be used if power dissipation is

maintained within package dissipation capacity (lower

frequency of operation).

• All I/Os are at same voltage as external supply (3.3 V

nominal).

• The core voltage supplies are not under user control.

The core supplies are generated by the on-chip voltage

regulator.

Freescale Semiconductor

Document Number: AN4623

Application Note

Rev 1, 10/2013

MPC5643L Hardware

Requirements

by: Anita Maliverney, Masato Oshima, and Eugenio Fortanely

Contents

1 Introduction................................................................1

2 Power supplies...........................................................1

3 Voltage regulator operating

configurations...........................................................4

4 Recommendations on external

components................................................................6

5 /RESET pin and power-up......................................18

6 External oscillator (XOSC).....................................19

7 Unused system pin termination...............................19

8 References...............................................................20

9 Revision history......................................................20

For details on the power supply pin numbers and recommended operating voltage conditions, see MPC5643L Data Sheet,

available on freescale.com.

2.1 Power management unit (PMU) overview

The PMU generates the 1.2 V core logic supply from a 3.3 V (nominal) input supply by means of a linear voltage regulator

driving an external NPN bipolar transistor (emitter-follower configuration) or an internal pMOSFET.

The PMU always starts up using the internal ballast transistor. It then executes an automatic procedure that detects (during

the system reset phase) whether an external ballast transistor is operational. If a functional external ballast transistor is

detected, the power is supplied to the system through the external transistor only. The information whether the internal or the

external ballast transistor is used is available via Configuration Status Bits of the PMUCTRL status register

(PMUCTRL_STATUS[CTB]).

The operating voltages are monitored by a set of on-chip supervisory circuits to ensure that this device works within the

correct voltage range. These circuits are:

• Low-Voltage Detector (LVD)

• High-Voltage Detector (HVD)

• Comparators

Main digital low- and high-voltage monitoring circuits are tested by integrated self-test circuitry. The Voltage Regulator, IO

and flash-dedicated low-voltage monitoring circuitries which are called LVD_MAIN1, LVD_MAIN2, and LVD_MAIN3 are

redundant in order to improve the safety coverage. The LVDs and the comparators provide their output signals to the Reset

Generation Module (MC_RGM) and to the Fault Collection and Control Unit (FCCU).

See MPC5643LRM: MPC5643L Reference Manual and MPC5643L Data Sheet, available on freescale.com, for more details

on the PMU Voltage Architecture.

The 3.3 V supply domains are called High-Voltage (HV) domains, while the 1.2 V supply domains are called Low-Voltage

(LV) domains.

Power supplies

MPC5643L Hardware Requirements, Rev 1, 10/2013

2 Freescale Semiconductor, Inc.