Icom IC-E90 Service Manual

Also see for IC-E90: Instruction manual Service manual

Contents

Icom IC-E90 Service Manual Manual pdf 15 page image

4 - 7LINEHVVCCCPU3+3C+3+10VAFVR3R3VT3DESCRIPTIONThe voltage from the external power supply orattached battery pack.The same voltage as the “HV” line (externalpower supply or battery pack).Common 3 V converted from the “VCC” line byCPU3 regulator IC (LOGIC unit; IC141). The out-put voltage is supplied to the +3C regulator cir-cuits, etc.Common 3 V converted from the “VCC” line bythe +3C regulator circuit (LOGIC unit; Q142 andQ145) using the +3CPU regulator (LOGIC unit;IC141.)Common 3 V converted from the “VCC” line bythe +3 regulator circuit (LOGIC unit; Q8 and Q9)using the +3C regulator (LOGIC unit; Q142 andQ145).Common 10 V converted from the “+3” line bythe +10 regulator circuit(LOGIC unit; IC91, IC92,Q91, D91, D300–D302). The output voltage isapplied to the RF and VCO units.6 V for receiver circuit converted from the “VCC”line by the “AF” regulator circuit (LOGIC unit;Q201, Q202). The output voltage is applied tothe AF amplifier (AF unit; IC252, pin 2).3 V for receiver circuit converted from the “+3”line by the “R3” regulator circuit (RF unit; O353).3 V for the receiver circuit converted from the“VCC” line by the “R3V’ regulator circuit (AF unit;Q208 and Q209).3 V for transmitter circuit converted from the “+3”line by the “T3” regulator circuit (RF unit; Q56and D20). The output voltage is applied to thebuffer amplifier (RF unit; IC51, pin 6).4-4 POWER SUPPLY CIRCUITSVOLTAGE LINEPin Port Descriptionnumber name45671415BSFTB1CB2CB3B4CB5Outputs frequency shift control signalto tuned bandpass filters (RF unit).Outputs 0.5–29.995 MHz band controlsignal.Low: While 0.5–29.995 MHz band isreceiving.Outputs 30–75.995 MHz band controlsignal.Low: While 30–75.995 MHz band isreceiving.Outputs 76–229.995 MHz band con-trol signal.Low: While 76–229.995 MHz band isreceiving.Outputs 230–629.995 MHz band con-trol signal.Low: While 230–629.995 MHz bandis receiving.Outputs 630–999.995 MHz band con-trol signal.Low: While 630–999.995 MHz bandis receiving.Pin Port Descriptionnumber name5611121314Outputs frequnecy setting D/A data tothe reference oscillator (RF unit; X1).Outputs the power amplifier’s outputpower setting data to the APC con-troller (RF unit; IC101).Outputs D/A data to the tuned band-pass filters (RF unit).Outputs the R3 regulator (RF unit;Q353) control signal.High: While receiving.Outputs attenuator control signal.Low: Attenuator is ON.Outputs the drive amplifier’s outputpower setting data to the APC con-troller (RF unit; IC101).FSETPSETTUNERXCATTDSET4-5-2 R3V SWITCH IC (AF UNIT; IC51)4-5 PORT ALLOCATIONS4-5-1 D/A CONVERTOR IC (RF UNIT; IC251)