Motorola EP450 Service Manual page 49

6-2
7. Circuit Block Interconnection Legend:
USWB+
5V
5R
5T
RESET
D3_3V
3V
TX_ENA
PWR_SET
DEMOD
BW_SEL
RSSI
IF_IN/OUT
RF_IN/OUT
MOD OUT/IN
16_8_MHZ
SYNTH_CS
SPI_CLK
SPI_DATA_OUT
LOCK
PRESC
V_STEER
V_SF
VCO_MOD
TRB
RX_INJ
TX_INJ
November 24, 2003
VHF Schematic Diagrams, Overlays, and Parts Lists: Introduction
Ref. No. Series
301-400 DC Regulation
401-450 Microprocessor
451-550 Audio
Name
Unswitched Battery Voltage (always on)
5 volts (regulated)
5 volts in RX mode only
5 volts in TX mode only
Low-line reset signal from U320 to uP
Digital 3.3 volts (regulated)
Analog 3 volts (regulated)
Transmit enable signal from uP to transmitter
DC voltage from ASFIC to TX power control
RX audio from backend to ASFIC
Backend filter BW select from ASFIC
RX signal strength indication from IFIC to uP
44.85 MHz from 1st mixer to high IF filter
RX signal from antenna switch to front end
TX modulation from ASFIC to synthesizer
Ref osc signal from synthesizer to ASFIC
Synthesizer chip select from uP
Serial clock from uP
Serial data from uP
Lock detect indication from synth to uP
VCO freq feedback from VCOBIC to synth
Steering line voltage from synth to VCO's
Super-filtered 4.5 volts from synth to VCOBIC
TX modulation from ASFIC to synthesizer
TX/RX control from synth to VCOBIC
Buffered RX VCO output to RX 1st mixer
TX VCO output to transmitter input
Circuit Block
Description
HKLN4216A