
DAC7800, 7801, 7802
4
SBAS005A
www.ti.com
DATA
CS
CLK
t
1
t
5
UPD A
UPD B
t
3
t
7
CLR
t
6
t
8
t
4
0V
5V
0V
NOTES: (1) All input signal rise and fall times are measured from 10% to 90% of +5V. t = t = 5ns.
(2) Timing measurement reference level is V + V
2
F
R
IH
IL
.
t
2
PARAMETER
MINIMUM
t1 — Data Setup Time
15ns
t2 — Data Hold Time
15ns
t3 — Chip Select to CLK,
15ns
Update, Data Setup Time
t4 — Chip Select to CLK,
40ns
Update, Data Hold Time
t5 — CLK Pulse Width
40ns
t6 — Clear Pulse Width
40ns
t7 — Update Pulse Width
40ns
t8 — CLK Edge to UPD A
15ns
or UPD B
TIMING CHARACTERISTICS
VDD = +5V, VREF A = VREF B = +10V, TA = –40°C to +85°C.
Data In
Bit 0
Bit 23
Bit 22
Bit 21
Bit 20
Bit 19
Bit 18
Bit 17
Bit 16
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
LSB
DAC A
MSB
DAC A
LSB
DAC B
MSB
DAC B
DAC7800 Data Input Sequence
DAC7800 Digital Interface Block Diagram
24-Bit
Shift Register
DAC A Register
UPD A
Data In
CLK
UPD B
LSB
MSB
DAC B Register
LSB
MSB
Bit
23
Bit
12
Bit
11
Bit
0
CLK
DATA INPUT FORMAT
DAC7800 (Cont.)