LTC2754 LINER [Linear Technology], LTC2754 Datasheet - Page 12

• Manufacturer Part Number: LTC2754
• Description: Quad 12-/16-Bit SoftSpan IOUT DACs
• Manufacturer: LINER [Linear Technology]

TIMING DIAGRAMS
LTC2754
OPERATION
Output Ranges
The LTC2754 is a quad, current-output, serial-input preci-
sion multiplying DAC with selectable output ranges. Ranges
can either be programmed in software for maximum
fl exibility—each of the four DACs can be programmed
to any one of six output ranges—or hardwired through
pin-strapping. Two unipolar ranges are available (0V to 5V
and 0V to 10V), and four bipolar ranges (±2.5V, ±5V, ±10V
and –2.5V to 7.5V). These ranges are obtained when an
external precision 5V reference is used. When a reference
voltage of 2V is used, the ranges become: 0V to 2V, 0V to
4V, ±1V, ±2V, ±4V and –1V to 3V. The output ranges are
linearly scaled for other reference voltages.
Manual Span Confi guration
Multiple output ranges are not needed in some applica-
tions. To confi gure the LTC2754 to operate in a single span
without additional operational overhead, tie the M-SPAN
pin directly to V
DACs is then set via hardware pin strapping of pins S2,
S1 and S0 (rather than through the SPI port); and Write
and Update commands have no effect on the active output
span. See Figure 1 and Table 3.
Tie the M-SPAN pin to ground for normal SoftSpan
operation.
12
CS/LD
LDAC
SRO
SCK
SDI
DD
. The active output range for all four
Hi-Z
t
5
t
7
t
1
t
2
1
t
9
t
2
3
t
4
Figure 1. Using M-SPAN to Confi gure the LTC2754
for Single-Span Operation (±10V Range Shown).
LTC2754-16
M-SPAN
S2
S1
S0
CS/LD SDI
V
V
DD
DD
SCK
31
DAC A
DAC B
DAC C
DAC D
LSB
2754 F01
LSB
32
t
6
–
+
–
+
–
+
–
+
t
8
t
11
2754 TD
±10V
±10V
±10V
±10V
2754f