Consumer Microcircuits Limited FX019P, FX019DW Datasheet

1

Features

4 Digitally Controlled Amplifier s
15 Gain/Attenuation Steps
3 Amplifiers, with a ± 3dB Range

in 0.43dB Steps
1 'Volume' Amplifier, with a

± 14dB Range in 2dB Steps

FX019

Brief Description

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 during
development, production/calibration and operation.

Applications include:

(i) Control, adjustment and set-up of communications
equipment by an Intelligent ATE without manual
intervention – eg. Deviation, Microphone and L/S
Levels, 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 FX019 is a low-power, single 5-volt CMOS

device available in plastic DIL and Small Outline
(S.O.I.C.) SMD package versions.

Publication D/019/4 December 1995

8-Bit Serial Data Control
Output Mute Function
Audio and Data Gain Control

Applications
Telecoms, Radio and Industrial

Applications

CML Semiconductor Products

FX019

2

3

3

3

4

4

SERIAL DATA
INPUT

LOAD/LATCH

LOAD/LATCH

CHIP SELECT

1

1

2

2

Ch1

Ch2

Ch4

Ch3

V

DD

V

BIAS

SERIAL CLOCK
INPUT

V

SS

8-BIT SERIAL DATA INPUT

AND

LINE DECODERS

CONTROLLED AUDIO OUTPUT LINES

VOLUME

Digitally Controlled
Quad Amplifier Array

PRODUCT INFORMATION

The FX019 Digitally Adjustable Amplifier Array is
available to replace trimmer potentiometers and
volume controls in Cellular, PMR, Telephony and
Communications applications where d.c., voice or
data signals need adjustment.
The FX019 is a single-chip LSI consisting of four
digitally controlled amplifier stages, each with 15
distinct gain/attenuation steps. Control of each
individual amplifier is by an 8-bit serial data stream.
Three 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 suggested for
volume control applications. Each amplifier includes a
16th 'Off' state which when applied, mutes the output
audio from that channel. This array uses a Chip
Select input to select one of two FX019s in a system.

Fig.1 Functional Block Diagram

2

Pin Number Function

FX019DW

FX019P

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Analogue Inputs :

These individual amplifier inputs are self-biasing, a.c. input
analogue signals must be capacitively coupled to these pins, as
shown in Figure 2.
Note that amplifiers Ch1 to Ch4 are 'inverting amplifiers.'

Controlled Analogue Outputs :

The individual "Gain Controlled" amplifier outputs.
Ch1 to Ch3 range from -3dB to +3dB in 0.43dB steps, Ch4 could be
utilized as a volume control, ranging from -14dB to +14dB in 2.0dB
steps.
In the “OFF” mode there is no output from the selected amplifier.

Serial Clock : This external clock pulse input is used to “clock in” the Control Data. See Figure 4,
Serial Control Data Load Timing. This input has an internal 1MΩ pullup resistor.

Load/Latch : Governs the loading and execution of the control data. During serial data loading
this input should be kept at a logical '0' to ensure that data rippling past the latches has no effect.
When all 8 bits have been loaded, this input should be strobed '0' - '1' - '0' to latch the new data in.
Data is executed on the falling edge of the strobe. If the Load/Latch input is used this pin should
be left open circuit. This input has an internal 1MΩ pullup resistor.

Load/Latch : The inverted Load/Latch input. This function governs the loading and execution of
the control data. During serial data loading this input should be kept at a logical '1' to ensure that
data rippling past the latches has no effect. When all 8 bits have been loaded, this input should be
strobed '1' - '0' - '1' to latch the new data in. Data is executed on the rising edge of the strobe.
If the Load/Latch input is used this pin should be left open circuit. This input has an internal 1MΩ
pulldown resistor.

Ch1 Input :

Ch2 Input :

Ch3 Input :

Ch4 Input :

V

SS

: Negative supply rail (GND).

V

BIAS

: The output of the on-chip bias circuitry, held at VDD/2. This pin should be decoupled to V

SS

as shown in Figure 2.

Ch4 Output :

Ch3 Output :

Ch2 Output :

Ch1 Output :

Chip Select : A logic input to select one of two FX019 microcircuits in a system, see Table 1.

This input has an internal 1MΩ pulldown resistor.

Control Data Input : Operation of the 4 amplifier channels (Ch1 – Ch4) is controlled by the 8 bits
of data entered serially at this pin. The data is entered (bit 7 to bit 0) on the rising edge of the
external Serial Clock. The data format is described in Tables 1, 2 and Figure 4. This input has an
internal 1MΩ pullup resistor.

V

DD

: Positive supply rail. A single +5-volt power supply is required.