TLC7226C_15 Datasheet, PDF (8/24 Pages) Texas Instruments – QUADRUPLE 8-BIT DIGITAL-TO-ANALOG CONVERTERS

TLC7226C, TLC7226I, TLC7226M
ą
QUADRUPLE 8ĆBIT DIGITALĆTOĆANALOG CONVERTERS
ą
SLAS060F − JANUARY 1995 − REVISED APRIL 2009
PRINCIPLES OF OPERATION
AGND bias for positive output offset (continued)
VI
AGND
5
Vbias
4 ^Vref
TLC7226†
18 ^VDD
_
DAC A
+
2 OUTA
3
VSS
6
DGND
† _{Digital inputs omitted for clarity.}
Figure 5. AGND Bias Circuit
interface logic information
Address lines A0 and A1 select which DAC accepts data from the input port. Table 2 shows the operations of
the four DACs. Figure 6 shows the input control logic. When the WR signal is low, the input latches of the
selected DAC are transparent and the output responds to activity on the data bus. The data is latched into the
addressed DAC latch on the rising edge of WR. While WR is high, the analog outputs remain at the value
corresponding to the data held in their respective latches.
Table 2. Function Table
CONTROL INPUTS
WR
A1
A0
OPERATION
H
X
X No operation
Device not selected
L
L
L DAC A transparent
↑
L
L DAC A latched
L
L
H DAC B transparent
↑
L
H DAC B latched
L
H
L DAC C transparent
↑
H
L DAC C latched
L
H
H DAC D transparent
↑
H
H DAC D latched
L = low, H = high, X = irrelevant
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