Icom IC-FR3000 Service Manual page 75

• LOGIC UNIT
Top view
OFF-HOOK CTRL
(IC47: LC73701M,
IC50: TC4W53)
CTCSS decoder
(IC29: FX805)
Splatter filter
(IC4: NJM2902V)
D/A converter
(IC25: M62364)
Mic mix amplifier
(IC2: NJM2902V)
Mic amplifier
(IC1: NJM2902V)
Mic mute
(IC13: BU4066)
Bottom view
RESET
(IC34: S-80842C)
Hipass filter,
De-emphasis
(IC9: NJM2902V)
2 - 2
Ringer detect circuit
(IC33: HD64F2238F)
DTMF decoder
(IC30: TC4W53,
IC31: LC738M)
EEPROM
(IC39: BU4094)
CPU
(IC33: HD64F2238F)
Temperature switching
(IC32: TC4W53)
LED current CTRL
(Q18, Q19, Q20: XP1114)
ON-HOOK signal output
(IC45: LM567M)
MIC amplifier, Limitter
(IC3: NJM2902V)