User Guide

PAMS
System Module DB6
NHB–3
Technical Documentation
Original 26/97
Page 4–22
External Signals and Connections, Outputs
Signal name Signal description To
XRES Master reset ASIC
VL1 Logic supply voltage. Max 150 mA CTRLU,ASIC,
RFI,UIF,DSPU
VL2 Logic supply voltage. Max 150 mA DSPU,ASIC
VA1 Analog supply voltage. Max 40 mA AUDIO,UIF
VA2 Analog supply voltage. Max 80 mA RFI
VREF Reference voltage 4.65 V±2% Max 5 mA CTRLU,RFI
VBATDET Switched VBATT divided by 2 CTRLU
VC Attenuated VCHAR CTRLU
CHRDET Charger detection ASIC
Block Description
The PSL+ IC produces the following supply voltages:
2 * VL 150mA for logic
VA1 40mA for audios
VA2 80mA for RFI
VREF 5mA reference
In addition, it has internal watchdog, voltage detection and charger detection
functions. The watchdog will cut off output voltages if it is not reset once in ev-
ery 1.5 (+/– 0.75) second. The voltage detector resets the phone if the battery
voltage falls below 4.7 V (+/–0.2V). The charger detection starts the phone if it
is in power–off state when the charging voltage is applied.
The charging electronics is controlled by the MCU. When the charging voltage
is applied to the phone and the phone is powered up, the MCU detects it and
starts controlling charging. If MCU detects too high charging voltage (over 14
volts) or current (over 78 A/D bit difference between VC and VBATDET) it will
cut off the charging. The phone will accept charging voltages from 5 to 14 volts.
If the phone is in power–off state, the PSL+ will detect the charging voltage and
turn on the phone. If the battery voltage is high enough the reset will be re-
leased and the MCU will start controlling charging. If the battery voltage is too
low the phone stays in reset state and the charging control circuitry will pass
charging current to the battery. When the battery voltage has reached 5.25 V
(+/– 0.2 V) the reset will be removed and the MCU starts controlling charging.
MCU controls the charging with pulse width modulation output. Charging volt-
age is limited by hardware in normal operation to 8.9 V and during a call to
7.6 V.