User Guide

RAE-6/RA-4

Nokia Customer Care 6 - Baseband Description and Troubleshooting

20 COMPANY CONFIDENTIAL Issue 1 12/04

■ CMT EM

UEMEK includes following blocks:

• Baseband regulators (8 different LDOs)

• RF regulators (6 different 2.78V LDOs, 4.75V LDO and two current regulators)

• Power up/down logic (state machine).

• Charger switch and control

LM3820

(=Zocus-C) is the current measurement chip used for phone and charging current

measurement. It can be used to estimate the battery charge level presented as battery bars on

the display. Results are read with CBUS interface to the StUF.

■ APE EM

APE side EM HW consists of several discrete regulators (listed shortly below):

• One DC/DC converters for generating 1.57V to OMAP1510.

• One linear regulator for 2.8V APE side logic, NAND, etc.

• One 3.0V linear regulator for powering of MMC card.

• One 3.3V linear regulator for powering the USB block of OMAP1510.

• One 1.8V linear regulator for powering the SDRAM.

LM3819

UEM

Charger

Battery

PWB track

sense resistor

Cbus

To UPP

VBAT

UEMEK

LM3820

To StUF

GND