User Guide

NSD-5
3. System Module PAMS Technical Documentation
Page 34 Nokia Corporation Issue 1 05/02
With 2–wire charging, the charger provides constant output current, and the charging is
controlled by the PWMOUT signal from CCONT to CHAPS. PWMOUT signal frequency is
1 Hz, and the charging switch in CHAPS is pulsed on and off at this frequency. The pulse
width of PWMOUT is controlled through the serial data bus.
There is a protection mechanism in CHAPS to protect the phone from over-charging the
phone’s voltage. When a charger is connected to the phone, if VBAT exceeds preset limits
in CHAPS, the switch immediately turns OFF (soft switching is bypassed). There are two
voltage limits: VLIM1 and VLIM2. VLIM input = “0” selects VLIM1; VLIM input = “1”
selects VLIM2.
When the switch turns off due to an overvoltage condition, it stays off until the input
voltage falls below the specified limit (VCH<VBAT). Phone software will stop the charg-
ing as fast as it detects that there is no battery present.
CCONT/MAD4 and CCONT/Others Interface Signals
Table 8 lists all of the inputs and outputs of the Power Management section.
Symbol Parameter Min Typ Max
VLIM1 (V) Output voltage cutoff limit (during transmission or Li-battery) 4.4 4.6 4.8
VLIM2 (V) Output voltage cutoff limit (no transmission or Ni-battery) 4.8 5.0 5.2
Signal To
Signal Level (V)
High Low
Rising
time
Falling
time
Function
MAD4
CLK_EN CCONT > 2.4 < 0.62 16 ns 16 ns Enable VR1 and CAFE
CDMA clock output
CCONTCSX CCONT > 2.4 < 0.62 16 ns 16 ns Serial bus select
UIF_CCONT_SDIO CCONT > 2.4 < 0.62 10 10 Serial bus data
UIF_CCONT_SCLK CCONT > 2.4 < 0.62 10 10 Serial interface clock, also
used for LCD
CCONT_INT MAD > 2.1 < 0.5 25 25 Interrupt signal to MAD
PURX MAD > 2.1 < 0.5 25 25 Power up reset
SLEEPCLK MAD > 2.1 < 0.5 25 25 32 kHz clock
VLIM CHAPS > 2.24 < 0.62
N/S
(a)
N/S
(a)
Chaarge voltage limit
control
CAFE_TX_GATE from MAD > 2.24 < 0.62 16 ns 16 ns
RF
PA_TEMP from TX
N/A
(b)
N/A
(b)
N/A
(b)
N/A
(b)
PA temperature mux’ed
with VCXO_TEMP