Service Manual

18
When the remote speaker microphone with VOX is inserted into the earpiece jack, Q201 cuts off.
MIC_EN switches from low level to high level and Q202 completes the circuit with R204 and the
external remote speaker microphone simultaneously. Q202 becomes conductive. EXT-PTT
switches from low level to high level, which is detected by MCU as insert of a remote speaker
microphone with VOX. The VOX function is enabled. When the VOX detect level (5 levels available)
meets the preset requirements, the radio transmits and the audio signal goes to the baseband
processing IC AN29160 through the processing path.
If a remote speaker microphone without VOX (remote speaker microphone with PTT) is inserted,
Q201 cuts off. MIC_EN switches from low level to high level but Q202 can not complete the circuit
and keep the cut-off status. EXT-PTT is of low level. MCU detects as the remote speaker
microphone without VOX and the radio returns to the common mode. Press the PTT key on the
remote speaker microphone to transmit.
Semiconductor Data
Pin
No.
Pin Name TC-610 TC-620
I/
O
Description
1 AVcc Vcc Vcc
Power supply pin for A/D, connecting power
supply
2 AVR Vcc Vcc
A/D reference input pin, connecting power
supply
3 PE3/INT13 PTT PTT I
PTT key (connected with pull-up resistor ) (valid
at low level)
4 PE2/INT12 A_KEY A_KEY I
SK1, programmable function key (connected
with pull-up resistor ) (valid at low level)
5 PE1/INT11 EXT-PTT EXT-PTT I
PTT key on the earpiece (connected with
pull-down resistor) (valid at high level)
6 PE0/INT10 B_KEY B_KEY I
SK2, programmable function key (connected
with pull-up resistor ) (valid at low level)
7 P83 ENC3 ENC3 I
8 P82 ENC2 ENC2 I
9 P81 ENC1 ENC1 I
10 P80 ENC0 ENC0 I
Encoder input of channel selector
knob(connected with pull-up resistor )
11 P71/TI0 T/R T/R O Tx-Rx switch control H(R)/L(T)
12 P70/TO0 Reserve Reserve O Reserved
13 MOD
For down
-loading
For down
-loading
I
An operating mode designation pin. When
downloading, this pin is connected with Vcc and
a resistor of 47K is also connected between the