Nokia RH-18 - Buzzer; Flashlight

CCS Technical Documentation Engine module
Company confidential RH-18/36/38
Issue 1 10/03 Nokia Corporation. Page 21
The RC filter (220 Ω, 4.7µF) is scaled to provide damping at 217 Hz.
Figure 6: Internal electrical microphone interface
Buzzer
The ringing tones are generated by a buzzer, which gives monophonic ringing tones. Fig-
ure below shows the electrical interface of the buzzer..
Figure 7: Electrical interface of buzzer
Flashlight
The flashlight feature can be used to light up for example a keyhole.
Table 15: Flashlight LED currents
Flashlight nominal
current
Temperature Note
20mA 25°C See Figure 8
6mA 85°C See Figure 8
UEM
1k
1k
MIC+
MIC-
4.7uF
MIC1N
MIC1P
MICB1
220
2k2
2k2
1n 1n
MICBCAP
1u
1n
22k
2*33n
Placed near
UEM
Placed near
bottom
connector
2k2
2k2
UEMc
VBATDriv
VSADriv2
Vbat
Buzz0
12pF
56pF
56pF
220nH
220nH
Buzzer
12pF