Fig 2 Uem Charging Circuitry - Nokia RH-9 Series Ccs Technical Documentation

CCS Technical Documentation
Charge Control
In active mode charging is controlled by UEM's digital part. Charging voltage and current
monitoring is used to limit charge into safe area. For that reason UEM has programmable
charging cut-off limits VBATLim
is limited to 1.2 A. Default for VBATLim is 3.6V (used for Initial charging of empty bat-
tery).
VBATLim
1,2L,2H
VBATLim
1,2L,2H
ational mode is done. After voltage has decreased below VBATLim
If VBAT is detected to rise above the programmed limit, the output signal OVV is set to '1'
by CHACON. If charging current limit is reached OVC output is set '1' by CHACON.
Pulse-width-Modulated (PWM) control signals PWM1 and PWM32 are generated by
UEM's digital part to CHACON block.
In principle there are two PWM frequencies in use depending on the type of the charger
(standard charger 1Hz, fast charger 32Hz. Duty cycle range is 0% to 100%), but in RH-9
only the 1Hz mode will be used, as all charger will be treated as standard charges (2-
wire types).
Supported Chargers
Supported chargers are:
• 2-wire chargers: ACP-7, ACP-8 and ACP-12.
• 3-wire chargers: PPH-1, ACP-9,, ACT-1, LCH-8 and LCH-9.
The 3-wire chargers have a 3 wire interface to the phone, 2 power and 1 control. The
control wire carries the 32Hz digital pulse width modulated signal which must be gener-
ated by the phone to control the charger output voltage. In RH-9 the 32Hz PWM for the
charger is connected to GND inside the bottom connector. This sets full charger output
voltage and equals 0% PWM from charger point of view.
Charger Interface Protection
In order to ensure safe operation with all chargers and in misuse/fail situations charger
interface is protected using transient voltage suppressor (TVS) and 1.5A fuse. TVS used in
RH-9 is 16V@175W device.
Issue 1 11/02
1,2L,2H
are designed with hysteresis. When the voltage rises above
+ charging is stopped by turning charging switch OFF. No change in oper-
ãNokia Corporation
(3.6V / 5.0V / 5.25V). Maximum charging current
RH-9
System Module & UI
charging re-starts.
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