Figure 8-27. Mnus4000A/C/E 700-800 Mhz Receiver Front End Circuit - Motorola APX 7000 Detailed Service Manual

8-48
DC_LIN_1_8V_A
IN
CTRL_RX_78_LNA_A = 3V (HIGH), LNA'S TURN ON
CTRL_RX_78_LNA_A
IN
CTRL_RX_78_SW2 = 0V, 800 PATH SELECTED
CTRL_RX_78_SW1 = 0V, 700 PATH SELECTED
CTRL_RX_78_SW2
C402
TL_RX_78
33PF
IN
C404 C406
33PF 33PF
CTRL_RX_78_SW2
C405 C407
33PF 33PF
DC_LIN_3V
IN
U408
U408
NC7WZ04
VCC
NC7WZ04
GND
3
CTRL_RX_78_SW1 CTRL_RX_78_SW2
U408
NC7WZ04
1 6
IN
Q401
MUN5212T
22K
1
SW1 AND SW2 HAVE TO BE OPPOSITE
L407
7.5NH
C408
0
U402
AS211334
C412
4 3 1
V1 J2
FL401
15PF
5 2 1 B4232 7 2
IN1 OUT1
J1 GND
3 5
IN2 OUT2
6 1 3
V2 J3
CTRL_RX_78_SW1 CTRL_RX_78_SW1
C409
C413
0
47PF
L408
10NH
C410 C414
0 0
U403
AS211334
4 3 1
V1 J2
FL402
5 2 1 B4232 7 2
J1 GND IN1 OUT1
3 5
IN2 OUT2
6 1 3
V2 J3
C415
0
CTRL_RX_78_SW1 CTRL_RX_78_SW1
C411
0
4
NC
E401
1 2
R403 R404
3.3K
68
R401
22K
3
C424 C427
Q402
5 2
33PF 4.7UF
BC858CD
BC858CD
Q402
R413
R402 2.7
82K
C421 C422
L402
4.7UF 33PF
12NH
R406
L401
CTRL_RX_78_SW2
U404
12NH
AS211334
C425
6
J3 V2 3PF
C423
C426
6.8PF
5 1 1PF
GND J1 U406
BFR380F
4
J2 V1
R405
L403
10
2.4NH
C416 C418
33PF 33PF
U405 CTRL_RX_78_SW2
AS211334
6
J3 V2
5
GND J1
4
J2 V1
C417 C419
33PF 33PF
Schematics, Boards Overlays, and Parts Lists: Transceiver (RF) Boards: UHF1/700–800 MHz
2.7
E402
1 2
R409 R410
68
3.3K
R407
22K
BC858CD
Q403
Q403
2 5
BC858CD
R408
82K
C428 C429
4.7UF 33PF
L405
12NH
L404
12NH
C430
6.8PF
1 U407
BFR380F
L406
4.7NH
Figure 8-27. MNUS4000A/C/E 700–800 MHz Receiver Front End Circuit
C431 C434
33PF 4.7UF
C432
R412
RF_RX_FE_B2_OUT
3PF
2.7
OUT
C433
.5PF
R411
10