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 1M

Ω 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 1M

Ω 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 1M

Ω

pulldown resistor.

Ch1 Input :

Ch2 Input :

Ch3 Input :

Ch4 Input :

V

Negative supply rail (GND).

V

The output of the on-chip bias circuitry, held at V

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 1M

Ω 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 1M

Ω pullup resistor.

V

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