Nokia 9110 Service Manual
PAMS
Technical Documentation
RAE–2
BS1
Page 5 – 20
Section 02/99
Functional Description
Power Unit
Figure 3.
PDA Power distribution diagram
PWRGOOD
PMI
NMI
Am486 CPU
Lid Switch
XIP
RFD
RESETx
PWRU
IOR
ADD(2:0)
DATA (6:0)
VBB
BA
TTDET
MMC_SWITCH
PMI
V17_EN
V28_1
MMC
V28_3
V28_2
IrDA
Backupbattery
VBACK
Charging
HF–
power amp.
VPDA
VPDA
VBATT
Flash
Flashes
NMI
VBA
TT
DRAM
V28
VSYS
VBB
V17
V28_1
Interm.voltages 1–4
VPDA
VPDA
BS1
BS2
BS8
V28_EN
XIP
RFD
Write protect
CS3x
IOW
PWRGOOD
VSYS
VPP
VSYS
VSYS
VPP
VPP
FRAME CONNECT
OR
TESTPADS
RESETx
RESETx
VSYS
Battery voltage is supplied from the BS8 module through a board to board
connector. In the BS1 module the battery voltage is filtered and then sup-
plied to the Phaser, IR–transceiver circuit, BS2 module, and PHF–speak-
er circuitry.
connector. In the BS1 module the battery voltage is filtered and then sup-
plied to the Phaser, IR–transceiver circuit, BS2 module, and PHF–speak-
er circuitry.
The phaser generates internally the system voltage V28, switched volt-
ages V28_1 ,V28_2, V28_3, the LCD bias voltage V17, the LCD inter-
mediate voltages V17_ix, x=1–4 and the backup battery charging voltage
VBACK.
ages V28_1 ,V28_2, V28_3, the LCD bias voltage V17, the LCD inter-
mediate voltages V17_ix, x=1–4 and the backup battery charging voltage
VBACK.
When the battery voltage level is adequate, the PWRU switches V28 on
and after a certain time releases the reset–signal for the CPU. The CPU
and after a certain time releases the reset–signal for the CPU. The CPU