RF Quadrature Transceiver / RF Quadrature Receiver
CMX991/CMX992
Supply to C-BUS circuits
Control line to enable/disable Rx LNA
Supply to IF integer N PLL
Reference frequency input
IF PLL charge pump output
IF PLL VCO positive input
IF PLL VCO negative input
Bandgap generated bias voltage – measurement
43
VBIAS
VBIAS
O/P
output
I/P
CMX991: TxQ positive input
TXQP
44
NC
CMX992: Do not connect to this pin, reserved for
(Note 2)
NC
future use
I/P
CMX991: TxQ negative input
TXQN
45
NC
CMX992: Do not connect to this pin, reserved for
(Note 2)
NC
future use
I/P
CMX991: TxI negative input
46
TXIN
NC
CMX992: Do not connect to this pin, reserved for
NC
future use
I/P
CMX991: TxI positive input
47
TXIP
NC
CMX992: Do not connect to this pin, reserved for
NC
future use
O/P
CMX991: Tx IF output
48
TXIFOUT
NC
CMX992: Do not connect to this pin, reserved for
NC
future use
E
XPOSED
The exposed metal pad must be electrically
AGND
AGND
Power
M
ETAL
P
AD
connected to analogue ground
Total = 49 Pins (48 pins and central, exposed metal ground pad)
Table 1 Pin List
Notes:
1) I/P = Input
T/S = 3-state
O/P = Output
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.
Package
Q3
Pin No.
36
37
38
39
40
41
42
Pin Name
(CMX991)
VDDIO
LNAON
VCCSYNTH
FREF
DOIF
VCOP
VCON
Pin Name
(CMX992)
VDDIO
LNAON
VCCSYNTH
FREF
DOIF
VCOP
VCON
Signal
Type
Power
O/P
Power
I/P
O/P
I/P
I/P
Description
3.1
Signal Definitions
Signal Name
AV
DD
DV
DD
V
DD
IO
V
BIAS
Pins
VCCIF, VCCRF, VCCSYNTH
DVDD
VDDIO
VBIAS
Usage
Power supply for analogue circuits.
Power supply for digital circuits.
Power supply voltage for digital interface
(C-BUS).
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 V
BIAS
and AV
SS
.
Ground for digital circuits.
Ground for analogue circuits.
DV
SS
AV
SS
DGND
AGND
Table 2 Definition of Power Supply and Reference Voltages
2012 CML Microsystems Plc
9
D/991_992/18
CMLMICRO [ CML MICROCIRCUITS ]
