User Guide

NSM–3
System Module
PAMS Technical Documentation
Page 14
Issue 1 12/1999
 Nokia Mobile Phones Ltd.
The voltage limit (VLIM1 or VLIM2) is selected by logic LOW or logic
HIGH on the CHAPS (N101) VLIM input pin. In NSM–3 VLIM is fixed low
in HW.
When the switch in output overvoltage situation has once turned OFF, it
stays OFF until the the battery voltage falls below VLIM and PWM = LOW
is detected. The switch can be turned on again by setting PWM = HIGH.
PWM (1 Hz)
VOUT
VLIM
t
SWITCH
ON OFF
VCH
t
VCH<VOUT
ON