CMX991 Datasheet, PDF (24/56 Pages) CML Microcircuits – Two-mode demodulator

RF Quadrature Transceiver / RF Quadrature Receiver
CMX991/CMX992
5.5 V_BIAS
The VBIAS pin provides a 1.6V bandgap reference-derived bias voltage (V_BIAS) that may be used as a
reference voltage for differential amplifier stages (e.g. in the receiver output). The VBIAS pin can be
decoupled to ground but a capacitor greater than 200nF should be used to ensure stability.
5.6 Data Interface
The CMX991/CMX992 is controlled via a three wire C-BUS. A fourth pin (RDATA) is required if register
read-back is to be used. A further pin (RESETN) is provided which, when ‘low’, generates a reset signal
(see section for 6.1 further details). The pin should be pulled to the V_DDIO supply with a suitable resistor if
not used.
The data interface can run at a lower voltage than the rest of the IC by setting the V_DDIO supply to the
required interface voltage, in the range 1.6V to 3.6V.
Full details of the control register structure are given in section 6.
 2015 CML Microsystems Plc
24
D/991_992/20