Filter
Top Products
SP200/210 Maxon SP200/210 Radio
Issue 1.0 DETAILED FUNCTIONAL DESCRIPTION
03/01 Page 5-3
5.3.2 Sat Signal Path
ASW4 ASW4 switches between RxSAT (RDIN) and Tx SAT (TXIN) and
routes to the filter.
VSCLPF Seventh order Elliptic Variable Switched Capacitor Low Pass Filter.
Cut-off frequency is variable from 50Hz to 300Hz. Level adjustable in
0.5dB steps from –3dB to +2.5dB. Output is on pin 23 FLT OUT.
SATRIM1 Not used.
SATRIM2 SAT level adjustment. Amplitude is controlled in 0.5dB steps from –
3dB to +2.5dB. Output is on pin 23 FLTOUT.
COM Compares the external reference voltage (COMPPIN-) with the applied
SAT signal which is from FLTOUT to COMPIN+ and it goes to Logic
High and Logic Low at this point. The output COMPOUT (pin 21) goes
to the microcontroller IC406. NB in transmit the SAT is switched into
TXSUM.
5.3.3 Miscellaneous Signals and Controller
ADC / DAC ADC is not used. DACs are 8 bit devices.
CONTROL Control serial interface for control lines.
DATA Operates as output line for a READ instruction and as input line for a
WRITE instruction, Pin 18.
CLOCK This is the synchronous input terminal for communication with the
microcontroller, pin 12.
ENBL With an active low, data read and write is enabled.
AGND.DGND Reference analogue and digital grounds.
Figure 5-1 – ASIC Block Diagram