VOLTAGE CHART
SST-442
25
REF
PIN TX
RX
SB
DESCRIPTION
IC303
1
2.4
2.4
*
Audio processing
2
2.4
2.4
*
3
2.4
2.4
*
4
5.0
5.0
*
5
2.4
2.4
*
6
2.4
2.4
*
7
2.4
2.4
*
8
2.4
2.4
*
9
2.4
2.4
*
10
2.4
2.4
*
11
GND GND GND
12
2.4
2.4
*
13
2.4
2.4
*
14
2.4
2.4
*
IC304
1
0.0
0.0
*
Audio signal switching
2
2.4
2.4
*
3
2.4
2.4
*
4
2.4
2.4
*
5
0.0
2.5
*
6
GND GND GND
7
GND GND GND
8
GND GND GND
9
5.0
0.0
0.0
10
5.0
0.0
0.0
11
5.0
0.0
0.0
12
2.4
2.4
*
13
NC
NC
NC
14
0.0
2.4
*
15
0.0
2.4
*
16
5.0
5.0
5.0
IC305
1
2.4
2.4
*
Audio processing
2
2.4
2.4
*
3
2.4
2.4
*
4
GND GND GND
5
2.4
2.4
*
6
2.4
2.4
*
7
2.4
2.4
*
8
5.0
5.0
*
IC306
1
2.0
2.0
*
Audio signal level
2
NC
NC
NC
control
3
GND GND GND
4
0.0
2.5
*
5
2.4
2.4
*
6
2.4
2.4
*
7
2.4
2.4
*
8
0.0
0.0
*
9
5.0
5.0
*
10 GND GND GND
11
NC
NC
NC
12
0.0
0.0
*
13
2.4
2.4
*
14
2.4
2.4
*
15
2.4
2.4
*
16
2.4
2.4
*
17
2.4
2.4
*
18
NC
NC
NC
19
5.0
5.0
*
20
5.0
5.0
*
IC307
1 NC
NC
NC
Audio
amplifier
2
0.0
0.0
0.0
3 GND GND GND
4 GND GND GND
5
0.0
3.7
0.0
6
0.0
7.5
0.0
7
0.0
3.7
0.0
8 NC
NC
NC
REF
PIN TX
RX
SB
DESCRIPTION
IC308
1
2.4
2.4
*
Tone low pass filter
2
2.4
2.4
*
3
GND GND GND
4
5.0
5.0
*
5
2.4
2.4
*
6
2.4
2.4
*
7
5.0
5.0
*
8
3.2
3.2
*
IC309
1
7.5
7.5
7.5
+5 VDC voltage
2
GND GND GND
regulator
3 7.5
7.5
7.5
4
NC
NC
NC
5
5.0
5.0
5.0
IC401
1
→
→
→
→
3.6 MHz clock signal
2
5.0
5.0
*
Frequency synthesizer
3
NC
NC
NC
4
NC
NC
NC
5
5.0
5.0
5.0
6
→
→
*
→
1.5 – 4.5 VDC VCO
7
GND GND GND
tuning voltage
8
2.2
2.2
*
9
NC
NC
NC
10
2.4
2.4
*
11
2.4
2.4
*
12
5.0
5.0
*
13
NC
NC
NC
14
5.0
5.0
5.0
15
0.0
0.0
*
16
NC
NC
NC
17
5.0
5.0
5.0
18
5.0
5.0
*
19
0.0
0.0
*
20
2.2
→
2.2
→
*
→
14.4 MHz reference
Q 101
1
5.0
4.3
*
RX +V switching
2
5.0
5.0
*
3
0.0
4.7
*
Q 102
1
0.0
0.7
*
RX RF amplifier
2
GND GND GND
3
0.0
3.0
*
Q 103
1
0.0
4.7
*
RX mixer
2
0.0
0.0
*
3
0.0
1.8
*
Q 104
1
0.0
0.7
*
RX IF amplifier
2
GND GND GND
3
0.0
1.2
*
Q 105
1
0.0
0.7
*
RX 2
nd
LO
2
GND GND GND
multiplier/amp
3
0.0
4.6
*
Q 201
1
6.8
7.5
7.5
TX +V switching
2
7.5
7.5
7.5
3
7.0
0.0
0.0
Q 202
1
5.0
0.0
0.0
TX +V switching
2
4.3
0.0
0.0
3
6.8
7.5
7.5
Q 203
1
0.7
0.0
0.0
TX RF amplifier
2
GND GND GND
3
5.6
0.0
0.0