User Guide

NPM-10 (3595)

System Module CC Technical Documentation

VBATLim

1,2L,2H

are designed with hysteresis. When the voltage rises above

VBATLim

1,2L,2H

+ charging is stopped by turning charging switch OFF. No change in oper-

ational mode occurs. After voltage has decreased below VBATLim

charging restarts.

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 the

digital portion of the UEM to CHACON block.

In principle, there are two PWM frequencies in use — depending on the type of the

charger (standard charger 1 Hz, fast charger 32 Hz. Duty cycle range is 0% to 100%), but

in NPM-10 (3595), only the 1 Hz 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 32 Hz digital pulse width modulated signal, which must be

generated by the phone to control the charger output voltage. The 32 Hz 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, the

charger interface is protected using transient voltage suppressor (TVS) and 1.5 A fuse.

TVS used is a 16 V@175 W device. A Schottky diode is present to protect the charger

input from reverse polarity chargers.

Figure 3: Charger interface

TVS Characteristics

TVS characteristics include the following:

• Breakdown voltage (V

)17.8 Vmin (at I

1.0 mA)

• Reverse standoff voltage (V

) 16 V