TLC7628C, TLC7628E, TLC7628I

DUAL 8-BIT MULTIPLYING

DIGITAL-TO-ANALOG CONVERTERS

SLAS063A – APRIL 1989 – REVISED MAY 1995

7

POST OFFICE BOX 655303

APPLICATION INFORMATION

φ 2

Address

Decoder

Logic

Address Bus

Data Bus

D0 – D7

DB7

DB0

WR

CS

DACA/DACB

TLC7628

VMA

CPU

6800

A8–A15

A

A + 1

NOTE D: A = decoded address for TLC7628 DACA

A + 1 = decoded address for TLC7628 DACB

Figure 5. TLC7628 – 6800 Interface

voltage-mode operation

The current-multiplying DAC in these devices can be operated in a voltage mode. In the voltage mode, a fixed

voltage is placed on the current output terminal. The analog output voltage is then available at the reference

voltage terminal. An example of a current-multiplying DAC operating in voltage mode is shown in Figure 6. The

relationship between the fixed input voltage and the analog output voltage is given by the following equation:

Analog output voltage = fixed input voltage (D/256)

where D = the digital input. In voltage-mode operation, these devices meet the following specification:

LINEARITY ERROR

TEST CONDITIONS

MIN

MAX

UNIT

Analog output voltage for REFA, REFB

VDD = 12 V, OUTA or OUTB at 5 V, TA = 25°C

1

LSB

2R

2R

2R

“0”

“1”

2R

RR

R

R

OUT (Fixed input voltage)

AGND

REF

(Analog output voltage)

Figure 6. Current-Multiplying DAC Operating in Voltage Mode