RF Quadrature Transceiver / RF Quadrature Receiver
CMX991/CMX992
Package
Pin Name
(CMX991)
Pin Name
(CMX992)
Signal
Type
Q3
Pin No.
36
Description
VDDIO
LNAON
VCCSYNTH
FREF
VDDIO
LNAON
VCCSYNTH
FREF
Power Supply to C-BUS circuits
O/P
Power Supply to IF integer N PLL
I/P
O/P
I/P
37
38
39
40
41
42
Control line to enable/disable Rx LNA
Reference frequency input
IF PLL charge pump output
IF PLL VCO positive input
IF PLL VCO negative input
DOIF
VCOP
VCON
DOIF
VCOP
VCON
I/P
Bandgap generated bias voltage – measurement
output
CMX991: TxQ positive input
CMX992: Do not connect to this pin, reserved for
future use
CMX991: TxQ negative input
CMX992: Do not connect to this pin, reserved for
future use
CMX991: TxI negative input
CMX992: Do not connect to this pin, reserved for
future use
CMX991: TxI positive input
CMX992: Do not connect to this pin, reserved for
future use
CMX991: Tx IF output
CMX992: Do not connect to this pin, reserved for
future use
43
VBIAS
VBIAS
O/P
I/P
TXQP
(Note 2)
44
NC
NC
I/P
TXQN
(Note 2)
45
46
47
48
NC
NC
NC
NC
I/P
TXIN
TXIP
NC
I/P
NC
O/P
NC
TXIFOUT
AGND
NC
EXPOSED
METAL PAD
The exposed metal pad must be electrically
connected to analogue ground
AGND
Power
Total = 49 Pins (48 pins and central, exposed metal ground pad)
Table 1 Pin List
Notes:
1) I/P = Input
O/P = Output
T/S = 3-state
NC = Not Connected
2) In versions of the datasheet before D/991_992/13 these pins were incorrectly referenced as pin
44 = TXQN and pin 45 = TXQP causing a spectrum inversion at the modulator output.
3.1
Signal Definitions
Signal Name
AVDD
DVDD
Pins
Usage
VCCIF, VCCRF, VCCSYNTH
DVDD
VDDIO
Power supply for analogue circuits.
Power supply for digital circuits.
Power supply voltage for digital interface
(C-BUS).
VDDIO
VBIAS
VBIAS
Bandgap generated bias voltage used
as a reference for differential amplifier
stages. Decoupling is optional but, if
used, a capacitor of >200nF should be
connected between VBIAS and AVSS.
Ground for digital circuits.
DVSS
AVSS
DGND
AGND
Ground for analogue circuits.
Table 2 Definition of Power Supply and Reference Voltages
2012 CML Microsystems Plc
9
D/991_992/18
CMLMICRO [ CML MICROCIRCUITS ]
