Philips Semiconductors Linear Products

Product specification

AM6012

12-Bit multiplying D/A converter

August 31, 1994

783

Figure 3. Interfacing Circuits for ECL, CMOS, HTL Logic Inputs

NOTE:

1. Set the voltage ‘A’ to the desired logic input switching threshold.

2. Allowable range of logic threshold is typically –5V to +13.5V when operating the DAC on

±15V supplies.

V+

“A”

TO PIN 13

2N3904

2N3904

400

µA

20k

Ω

20k

Ω

3k

Ω

VLC

R

–5.2V

“A”

TO PIN 13

2N3904

2N3904

6.2k

Ω

13k

Ω

39k

Ω

3k

Ω

VLC

CMOS, HTL

ECL

ACCOMMODATING BIPOLAR REFERENCE

NOTE:

VREF(+) Must be above peak positive swing of VIN.

NOTE:

IREF > Peak negative swing of IIN.

VREF(+)

RREF

RIN

AM6012

14

15

18

19

VIN

IIN

IREF

IO

IO

IREF > PEAK NEGATIVE SWING OF IIN

14

15

18

19

AM6012

IO

IO

VIN

RREF = R15

VREF(+) RREF

R15

(OPTIONAL)

HIGH INPUT

IMPEDANCE

VREF MUST BE ABOVE PEAK POSITIVE SWING OF VIN

BASIC NEGATIVE REFERENCE OPERATION

NOTE:

I

FS [

V

REF(

* )

R

REF

x 4

14

15

18

19

R15

AM6012

IO

IO

VREF(–)

RREF

RECOMMENDED FULL-SCALE ADJUSTMENT

CIRCUIT

VREF+ MUST BE ABOVE PEAK POSITIVE SWING OF VIN

14

15

18

19

R15

(OPTIONAL)

HIGH INPUT

IMPEDANCE

AM6012

IO

IO

VIN

RREF = R15

VREF(+) RREF