Datasheet
SLAS063B − APRIL 1989 − REVISED MARCH 2007
7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
φ 2
Address
Decoder
Logic
Address Bus
Data BusD0−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 the TLC7628C 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 V
DD
= 12 V, OUTA or OUTB at 5 V, T
A
= 25°C 1 LSB
2R 2R 2R
“0” “1”
2R
RRR
R
OUT (Fixed input voltage)
AGND
REF
(Analog output voltage)
Figure 6. Current-Multiplying DAC Operating in Voltage Mode