Kirisun DP485 User Manual

DP485 Service Manual
9
3C: Transistor X500 (12.8M TCXO)
5T: RF Pre-drive Amplifier Circuit Q502 (2SC5108), Q503 (2SC3356)
DC-DC: PMU IC1 (HS8851), U500 (RDA1846S)
4.7.IC Description
4.7.1.Features of AT1846S
a. Integrated CMOS RF front-end
b. High linearity low-noise amplifier and mixer
c. Low IF receiver path
⚫ Automatic DC offset calibration circuit
⚫ High performance analogue/digital converter and digital/analogue converter
⚫ Fully-integrated receiver filter
⚫ Digital AGC
⚫ Modulation and demodulation technique based on digital signal processing technology
d. TX path of direct frequency synthesis
⚫ Modulation method of direct frequency synthesis
⚫ TX filter based on digital signal processing technology
⚫ TX modulation gain number is adjustable
⚫ Digital voice activates TX control
e. High-performance fractional PLL frequency synthesizer
⚫ Fully-integrated in-chip RF VCO
⚫ Fully-integrated internal loop filter
⚫ Low phase noise
⚫ Fast lock of phase
⚫ High-frequency resolution with random frequency adjustable
⚫ Built-in transistor frequency error calibration circuit
f. Sleep mode of ultra-low loss
g. Three wire serial digital interface control

Kirisun DP485 Specifications

General

Frequency	136~174 MHz, 400~470 MHz
Channel Capacity	256 channels
Channel Spacing	25 kHz/12.5kHz
Antenna Impedance	50Ω
Operating Voltage	7.4V
Rated Power	1W 16Ω
Transmitting Power	4W/1W@7.4V DC
Current Consumption	≤1.5A@ 7.4V DC
Working Temperature	-25℃~ +55℃
Microphone Impedance	2.2kΩ
Battery	Lithium-ion battery DC 7.4V , 2000mAh
Receiving Sensitivity (12dB SINAD )	-120dBm
Squelch Sensitivity (3-level)	≤-120dBm
Selectivity of Adjacent Channels	70dB@25KHz /60dB@12.5KHz
Intermodulation Immunity	65dB@25KHz/12.5 KHz
Blocking	84dB
Frequency Stability	≤±2.5ppm
Maximum Modulation Offset	±5kHz@25KHz /±2.5kHz@12.5KHz
Modulation Distortion	≤3%
Spurious Emission	≤-36dBm