Quadrature Modulator
CMX993/CMX993W
6.2
General Control Register: C-BUS address $02
8-bit write-only
This register controls general features such as powersave.
All bits of this register are cleared to 0 by a General Reset command.
Bit:
7
6
0
5
4
3
2
1
0
0
I/Q Pwr
VREF
Filter
Input
Wideband
Filter
Filter Amp
Gain
Amps Pwr Amps Pwr
Amps Pwr
Reduction
CMX993
only
CMX993W
only
CMX993W
only
General Control Register b7-b1: Select high input gain
These bits control power up/power down of the various blocks of the IC. In all cases,
‘1’ = power up, ‘0’ = power down.
b7
b6
b5
Enable I/Q modulator and local oscillator sections
reserved, set to ‘0’
Enable internal bias circuits and bandgap reference (VREF and BVREF).
CMX993 – Enable filter amplifiers
CMX993W – reserved, set to ‘0’
Enable input amplifiers
CMX993 – reserved, set to ‘0’
CMX993W – Enable wide bandwidth filter amplifiers
reserved, set to ‘0’
b4
b3
b2
b1
General Control Register b0: Filter Amplifier Gain Reduction
CMX993W – Wide bandwidth filter amplifier gain reduction by adding
b0 = 1
1k between output and negative input.
CMX993W – Normal Operation
CMX993 – reserved, set to ‘0’
b0 = 0
b0
6.3
Gain Control Register: C-BUS address $05
8-bit write-only
This register controls the gain of the I/Q modulator.
Bit:
7
0
6
5
4
3
2
0
1
0
0
0
F4
F3
F2
F1
Gain Control Register b2-b0: Reserved for future use, set to '0'.
2013 CML Microsystems Plc
14
D/993/10
CMLMICRO [ CML MICROCIRCUITS ]
