Kenwood NX-740H Service Manual page 18

Pin Port Name I/O
No.
129 NC O No connection
130 VSS - GND
131 VDD - 33MD
132 NC O No connection
133 SWO O SWO for SWD
134 SRST O SRST for SWD
135 BLULED O Blue LED
136 GRNLED O Green LED
137 REDLED O Red LED
138 BOOT_0
139 IGN I Ignition Sense
140 POWKEY I Power Key Input
141 BATT_INT I MCU Stop
142 CML_IRQ I Baseband IC IRQ (CML_pin8)
143 Power On I 33MD
Reset
144 VDD - 33MD
2.6 COMPONENTS DESCRIPTION
2.6.1 Display Unit (X54-3890-20)
Ref. No. Part Name
IC1 IC
Q1, Q2 Transistor
Q3, Q4 Transistor
Q5, Q9 Transistor
Q6 Transistor
Q7, Q8 Transistor
D1~D5 LED
D20 Diode
D22 LED
D23 LED
D33 Zener diode
D37 LED
2.6.2 TX-RX Unit (XC1-0010-XX)
Ref. No. Part Name
IC2 IC
IC3 IC
IC301 IC
IC500 IC
IC501 IC
IC502 IC
IC503 IC
IC700 IC
IC701 IC
IC702 IC
1-18 (No.RA010<Rev.001>)
Function
Test Point to enable Bootloader
Description
LED driver
TX/RX indication LED switch
KEY backlight control switch
LED dimmer control switch
Indication LED switch
TX/Busy indication LED switch
KEY backlight
Voltage protection
Indication
TX/Busy indication
Surge protection
LED display
Description
PLL IC
Assist Filter
APC DC amplifier
DETAF amplifier
FM IC
Voltage regulator (33MS)
RF BPF DC amplifier
I2C level shifter
3.3V level shifter
(RXDO/CTSO)
IO expander
Ref. No. Part Name
IC703 IC
IC704 IC
IC705 IC
IC706 IC
IC709 IC
IC710 IC
IC713 IC
IC714 IC
IC715 IC
IC716 IC
IC717 IC
IC718 IC
IC720 IC
IC721 IC
IC722 IC
IC723 IC
IC724 IC
IC725 IC
IC726 IC
Q2 Transistor
Q3, Q4 FET
Q5 FET
Q6 FET
Q7 FET
Q9 Transistor
Q10 Transistor
Q11 Transistor
Q12 Transistor
Q300 FET
Q500 Transistor
Q501 Transistor
Q502 Transistor
Q503 FET
Q504 Transistor
Q505 Transistor
Q506 FET
Q700 FET
Q701 Transistor
Q702 Transistor
Q703 FET
Q704 Transistor
Q705 FET
Q706 Transistor
Q707 Transistor
Q708 Transistor
Q709 Transistor
Description
5V level shifter (TXDO/RTSO)
RS-232C driver
5V level shifter (TXD2)
MIC/AFO amplifier
Baseband IC
Voltage regulator (33BD)
19.2MHz amplifier
MCU
Evol/DAC
EEPROM
Voltage regulator (9R)
Voltage regulator (33MD)
Voltage regulator (33MA)
Voltage regulator (5M)
Voltage detection (INT)
Voltage detection (Reset)
5V level shifter (MKEY/PTT)
3.3V level shifter (MKEY/PTT)
Voltage regulator (33C)
PLL Fin amplifier
Assist filter control switch
RX VCO
TX/RX VCO switch
TX VCO
TX/RX VCO switch
Ripple filter
VCO buffer amp
VCO common amp
Drive amp
RX 2nd local amp
1st IF amp
Squelch amp
Mixer
Squelch input switch
Squelch input control switch
Front-end LNA
MIC mute switch
MIC mute switch
Horn alert control switch
Horn alert switch
DETO amp
MOD2 switch
Ignition sense control switch
9R control switch
9T control switch
9R switch