CML Semiconductor Products
PRODUCT INFORMATION
FX009A
Features/Applications
8 Digitally Controlled Low-Noise
Amplifiers
15 Gain/Attenuation Steps
7 Trimmers, with a
±
3dB Range in
0.43dB Steps
1 'Volume' Trimmer, with a
±
14dB
Range in 2.0dB Steps
SERIAL CLOCK INPUT
8 - BIT
SERIAL DATA INPUT
AND
LINE DECODERS
Low-Noise Digitally Controlled
Amplifier Array
Publication D/009A/3 July 1994
8-Bit Serial Data Control
Output Mute/Powersave Function
Audio and Data Gain Control
Applications
Cellular, PMR, PABX Applications
LOAD/LATCH
SERIAL DATA INPUT
V
DD
V
BIAS
16
LOAD/LATCH
7
8
1
2
3
4
5
6
1
16-LINE STEP CONTROLS TO AMPLIFIERS 1 to 8
V
SS
5
Ch1
2
V
BIAS
*
OUTPUT MUTE - POWERSAVE
*
V
BIAS
Ch5
6
Ch2
3
V
BIAS
*
*
V
BIAS
Ch6
7
FX009A
Ch3
V
BIAS
*
*
V
BIAS
Ch7
4
8
Ch4
V
BIAS
*
*
V
BIAS
Ch8
4
3
2
1
5
6
7
8 - VOLUME
CONTROLLED AUDIO OUTPUT LINES
Fig.1 Functional Block Diagram
Brief Description
The FX009A Digitally Adjustable Amplifier Array is
intended to replace trimmer potentiometers and volume
controls in Cellular, PMR, Telephony and
Communications applications where d.c., voice or data
signals need adjustment.
The FX009A is a low-noise single-chip LSI consisting
eight digitally controlled amplifier stages, each with 15
distinct gain/attenuation steps. Control of each
individual amplifier is by an 8-bit serial data stream.
Seven of the amplifier stages offer a +/-3dB range in
steps of 0.43dB, whilst the remaining amplifier offers a
+/-14dB range in steps of 2dB, and is intended for
volume control applications. Each amplifier includes a
16th 'Mute' state which sets the output to bias (V
DD
/2)
and powersaves the entire section. Minimum current
drain may be achieved by muting all eight sections.
1
This product replaces the need for manual trimming of
audible signals by using the host microprocessor to
digitally control the set-up of all audio levels.
Applications include:
(i) Control, adjustment and set-up of communications
equipment by an Intelligent ATE without manual
intervention – eg. Deviation, Microphone and L/S
Level, Rx Audio Level etc.
(ii) Automatic Dynamic Compensation of drift caused
by variations in temperature, linearity, etc.
(iii)Fully automated servicing and re-alignment.
The FX009A is a low-power, single 5-volt CMOS
device available in both 24-pin DIL and SMD package
versions.
CMLMICRO [ CML MICROCIRCUITS ]
