1999 Oct 08

4

Philips Semiconductors

Product specification

Wideband differential digital controlled

variable gain amplifier

TDA9901

PINNING

SYMBOL

PIN

DESCRIPTION

GRAY0

1

digital control signal bit 0 input

(LSB)

TE

2

transparent enable input

CLK

3

clock input for gain control setting

CLKN

4

inverting clock input for gain

control setting (active low)

CMVGA

5

regulator output common mode

VGA input

IN

6

non-inverting analog input

INN

7

inverting analog input (active low)

n.c.

8

not connected

n.c.

9

not connected

n.c.

10

not connected

11

analog supply voltage

12

analog ground

n.c.

13

not connected

OUTN

14

inverting analog output (active low)

OUT

15

non-inverting analog output

CMADC

16

regulator output common mode

ADC input

17

digital ground

18

digital supply voltage

GRAY2

19

digital control signal bit 2 input

(MSB)

GRAY1

20

digital control signal bit 1 input

handbook, halfpage

GRAY0

TE

CLK

CLKN

CMVGA

IN

INN

n.c.

n.c.

n.c.

GRAY1

GRAY2

VDDD

VSSD

OUT

OUTN

CMADC

n.c.

VSSA

VDDA

1

2

3

4

5

6

7

8

9

10

11

12

20

19

18

17

16

15

14

13

TDA9901TS

MGM963

Fig.2 Pin configuration.

FUNCTIONAL DESCRIPTION

The TDA9901 provides a digitally controlled variable gain function for high-frequency applications.

The TDA9901 can be operated in two different modes, depending on the value at pin TE. When TE is at logic 1, the gain

can be instantly controlled when the clock signal is HIGH (transparent mode). The gain is fixed during the LOW period

of the clock. When TE is at logic 0 the gain of the TDA9901 is changed at the rising edge of the clock signal.