Nokia NSE-3 SERIES, Service Manual

Page: 19 / 217

PAMS
Technical Documentation
NSE–3
System Module
Page 3 – 13
Original 11/97
Notes Unit Max Typ Min Name Pin
8 XMIC 2.0 2.2 k
Ω
Input AC impedance
1 Vpp Maximum signal level
1.47 1.55 V Mute (output DC level)
2.5 2.85 V Unmute (output DC level)
100 600
µ
A Bias current
58 490 mV Maximum signal level
HMIC 0 3.2 29.3 mV Microphone signal
Connected to COBBA MIC3P input
9 SGND
47
Ω
Output AC impedance (ref. GND)
10
µ
F Series output capacitance
380
Ω
Resistance to phone ground
10 XEAR 47
Ω
Output AC impedance (ref. GND)
10
µ
F Series output capacitance
16 300
Ω
Load AC impedance to SGND (Head-
set)
4.7 10 k
Ω
Load AC impedance to SGND (Acces-
sory)
1.0 Vpp Maximum output level (no load)
22 626 mV Output signal level
10 k
Ω
Load DC resistance to SGND (Acces-
sory)
16 1500
Ω
Load DC resistance to SGND (Head-
set)
2.8 V DC voltage (47k pull–up to VBB)
HEAR 28 626 mV Earphone signal (HF– HFCM)
Connected to COBBA HF output
11 MBUS 0 logic low 0.8 V Serial bidirectional control bus.
2.0 logic high 2.85
Baud rate 9600 Bit/s
Phone has a 4k7 pullup resistor
12 FBUS_RX 0 logic low 0.8 V Fbus receive. Serial Data
2.0 logic high 2.85
Baud rate 9.6k–230.4kBit/s
Phone has a 220k pulldown resistor
13 FBUS_TX 0 logic low 0.5 V Fbus transmit. Serial Data
2.0 logic high 2.85
Baud rate 9.6k–230.4kBit/s
Phone has a 47k pullup resistor
14 GND 0 0.3 V Supply ground