Nokia 8260 Manual Do Serviço

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Loopset LPS-3 

PAMS Technical Documentation

Page  7

 Nokia Mobile Phones Ltd.

Issue 1 12/99

When there is no call going, AUXOUT is in high impedance state and XMIC
is pulled up. When loopset is connected, XMIC is pulled down. XMIC is
connected to HeadsetInt line (in MAD), so an interrupt is given due to both
connection and disconnection.

During a call there is bias voltage (1.5 V) in AUXOUT. The state of HeadsetInt
can’t be sure. It is better to disable loopset interrupt during a call and poll from
EAD line (AD converter in CCONT) to see if loopset is disconnected. Actually
disconnection of a headset without remote control switch could be seen in
HookInt, but headset with the switch could not.

Connection resistance must be under 3m

Ω.

The magnet field is based on the IEC 118–4 and BS 6083 part 4 stan-
dard.

Impedance

100k ohm +/– 5 %  at 1 kHz

Frequency responce

See figure 1

Magnetic field

100mA/m (RMS) 

3dB ref.

1kHz=0dB
400mA/m +12dB,125 ms RMS–
peaks

The strength of the magnetic
field measured next to the
ear. (or measured in the hor-
izontal plate and 170mm trip
from the curve of the loop.)

Loop Current

700mA(RMS) 

3dB ref. 1kHz

=>0dB   
2,8A (RMS), 125 ms RMS
peaks     =>+12dB

Automatis Gain Control

Response time <35 ms
Resetting  time 0,5–5dB/s

Signal to Noise Ratio

855 dB

nominal level (122 mVrms)/
1kHz

Determined as defined by IEC 268 using signal limited to frequency range
300 ... 3400 Hz.