LTC2704
Quad 12-, 14- and 16-Bit
Voltage Output SoftSpan
DACs with Readback
FEATURES
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DESCRIPTION
The LTC®2704-16/LTC2704-14/LTC2704-12 are serial
input, 12-, 14- or 16-bit, voltage output SoftSpan™ DACs
that operate from 3V to 5V logic and ±5V to ±15V analog
supplies. SoftSpan offers six output spans—two unipolar
and four bipolar—fully programmable through the 3-wire
SPI serial interface. INL is accurate to 1LSB (2LSB for the
LTC2704-16). DNL is accurate to 1LSB for all versions.
Six Programmable Output Ranges:
Unipolar: 0V to 5V, 0V to 10V
Bipolar: ±5V, ±10V, ±2.5V, –2.5V to 7.5V
Serial Readback of All On-Chip Registers
1LSB INL and DNL Over the Industrial
Temperature Range (LTC2704-14/LTC2704-12)
Force/Sense Outputs Enable Remote Sensing
Glitch Impulse: < 2nV-sec
Outputs Drive ±5mA
Pin Compatible 12-, 14- and 16-Bit Parts
Power-On and Clear to Zero Volts
44-Lead SSOP Package
Readback commands allow verification of any on-chip
register in just one 24- or 32- bit instruction cycle. All other
commands produce a “rolling readback” response from
the LTC2704, dramatically reducing the needed number
of instruction cycles.
A Sleep command allows any combination of DACs to be
powered down. There is also a reset flag and an offset
adjustment pin for each channel.
APPLICATIONS
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Process Control and Industrial Automation
Direct Digital Waveform Generation
Software Controlled Gain Adjustment
Automated Test Equipment
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. SoftSpan is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
BLOCK DIAGRAM
AGND
V+1
32
42
V–
REFM1 REFG1 REF1 REF2 REFG2 REFM2 V+2 1,8,15,22,31,36
24
21
44
2
23
43
25
VOSB 40
LTC2704-16
Integral Nonlinearity (INL)
27 VOSC
28 C1C
C1B 39
RFBB 37
DAC C
DAC B
OUTB 38
1.0
0.8
0.6
30 RFBC
VOSA 4
19 VOSD
C1A 5
INL (LSB)
26 AGNDC
0.2
0
–0.2
18 C1D
–0.4
16 RFBD
–0.6
17 OUTD
RFBA 7
–0.8
DAC D
DAC A
OUTA 6
AGNDA 3
20 AGNDD
33
34
GND VDD
10
13
11
14
CS/LD SCK
SDI
CLR
9
35
12
LDAC RFLAG SRO
ALL 4 DACS
SUPERIMPOSED
0.4
29 OUTC
–1
–1
AGNDB 41
V+/V– = ±15V
VREF = 5V
±10V RANGE
–1.0
0
16384
32768
CODE
49152
65535
2704 BD
2704 TA01b
2704fd
1
