Chargers; Battery; Back-Up Battery And Real Time Clock; Baseband Measurement A/D Converter - Nokia RH-47 Series Description

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Chargers

RH-47 BB supports a standard charger (two wires), chargers ACP-8 and ACP-12, ciga-
rette charger LCH-8 and LCH-12 are supported.

Battery

RH-47 uses a detachable, semi-fixed lithium-Ion BL-6C battery. Nominal voltage is 3.7 V
(max charging voltage 4.2 V).
The interface consists of three pins: VBAT, GND and BSI. Pull-down resistor inside the
batteries (BSI signal) recognizes the battery types. Voltage level at BSI line is measured
using UEM's AD-converter.

Back-up battery and real time clock

Real time clock (RTC), crystal oscillator and back-up battery circuitry reside in the UEM.
A register in the UEM controls back-up battery charging. Charging is possible only in the
POWER_ON state.

Baseband measurement A/D converter

The UEM contains 11 channels A/D converter, which is used for different baseband mea-
surement purposes. The resolution of A/D converter is 10 bits. Converter uses the CBUS
interface clock signal for the conversion. An interrupt is given to the MCU at the end of
the measurements. The converter is used for following purposes.
• Battery voltage measurement A/D channel (Internal)
• Charger voltage measurement A/D channel (Internal)
• Charger current measurement A/D channel (Internal)
• Battery temperature measurement A/D channel (External)
• Battery size measurement A/D channel (External)
• LED temperature measurement A/D channel (External)
There is also auxiliary AD converter in the UEM, which is used to monitor RF functions.

ZOCUS

The ZOCUS device is a current sensor used for the battery bar display and for determining
whether the phone is in a high current consuming mode. The ZOCUS device measures the
voltage drop across a sense resistor in the battery voltage line. This sense resistor is
formed from a PWB track and is on an internal layer of the PWB. The nominal value of
the sense resistor is 3.3 mohm. ZOCUS reports the current measurement to UPP_WD2 via
the Cbus interface.
Issue 1 05/04
Company Confidential
6 - Baseband Description and Troubleshooting
Copyright © 2004 Nokia Corporation
Company Confidential
RH-47
Page 13