Description:
The SA58646 is a BiCMOS integrated circuit that performs all functions from the antenna
to the microcontroller for reception and transmission for both the base station and the
handset in a 902 MHz to 928 MHz full-duplex radio. The IC may be used in a UHF
push-to-talk walkie-talkie or in a UHF to 900 MHz data transceiver. The SA58646 is a
pin-compatible derivative of the UAA3515 with advanced features.
This IC integrates most of the functions required for a half-duplex or full-duplex radio in a
single integrated circuit. Additionally, the programmability implemented reduces
significantly external components count, board space requirements and external
adjustments.
Features
1. RF RX (single frequency conversion FM receiver):
♦ Integrated LNA
♦ Image reject mixer
♦ FM detector at 10.7 MHz including an IF limiter, a wide band PLL demodulator, an
output amplifier and a RSSI output
♦ Carrier detection with programmable threshold
♦ Programmable data amplifier (slicer) phase
2. Synthesizer:
♦ Crystal reference oscillator with integrated tuning capacitor
♦ Reference frequency divider
♦ Narrow band RX PLL including RX VCO with integrated varicaps
♦ Narrow band TX PLL including TX VCO with integrated varicaps
♦ VCO external inductors can be done with printed transmission lines on the PCB
which offers substantial savings
♦ Programmable clock divider with output buffer to drive a microcontroller
3. Baseband RX section:
♦ Programmable RX gain (enable phone volume control)
♦ Expander with output noise level control
♦ Earpiece amplifier with volume control feature
♦ Data amplifier
4. Baseband TX section:
♦ Microphone amplifier
♦ Compressor with automatic level control and hard limiter
♦ Programmable TX gain
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Datasheet