LTC1854/LTC1855/LTC1856
8-Channel, ±10V Input
12-/14-/16-Bit, 100ksps ADC
Converters with Shutdown
DescripTion
The LTC®1854/LTC1855/LTC1856 are 8-channel, low
power, 12-/14-/16-bit, 100ksps, analog-to-digital con-
verters (ADCs). These ADCs operate from a single 5V
supplyandthe8-channelmultiplexercanbeprogrammed
for single-ended inputs, pairs of differential inputs, or
combinations of both. In addition, all channels are fault
protectedto±±0V.Afaultconditiononanychannelwillnot
affect the conversion result of the selected channel.
FeaTures
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Single 5V Supply
Sample Rate: 100ksps
8-Channel Multiplexer with 30V Protection
10V Bipolar ꢀnput Range
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Single Ended or Differential
3ꢁSB ꢀIꢁ for the ꢁTC1856, 1ꢂ5ꢁSB ꢀIꢁ for the
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ꢁTC1855, 1ꢁSB ꢀIꢁ for the ꢁTC1854
Power Dissipation: 40mW (Typ)
SPꢀ/MꢀCROWꢀRE™ Compatible Serial ꢀ/O
Power Shutdown: Nap and Sleep
SINAD: 87dꢀ (LTC1856)
Operates with Internal or External Reference
Internal Synchronized Clock
28-Pin SSOP Package
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An onboard precision reference minimizes external com-
ponents.Powerdissipationis40mWat100kspsandlower
intwopowershutdownmodes(27.5mWinNapmodeand
40µW in Sleep mode.) DC specifications include ±±LSꢀ
INL for the LTC1856, ±1.5LSꢀ INL for the LTC1855 and
±1LSꢀ for the LTC1854.
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Theinternalclockistrimmedfor5µsmaximumconversion
time and the sampling rate is guaranteed at 100ksps. A
separate convert start input and data ready signal (BUSY)
ease connections to FIFOs, DSPs and microprocessors.
applicaTions
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Industrial Process Control
Multiplexed Data Acquisition Systems
High Speed Data Acquisition for PCs
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L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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Digital Signal Processing
Typical applicaTion
100kHz, 12-Bit/14-/16-Bit Sampling ADC
ꢁTC1856 Typical ꢀIꢁ Curve
2.0
COM
CH0
CONVST
RD
1.5
1.0
0.5
0
LTC1854/
CH1 LTC1855/ SCK
LTC1856
µP
CONTROL
LINES
CH2
SDI
DGND
SDO
SOFTWARE-PROGRAMMABLE
SINGLE-ENDED OR
CH3
CH4
DIFFERENTIAL INPUTS
10V BIPOLAR INPUT RANGE
CH5
BUSY
3V TO 5V
–0.5
CH6
CH7
MUXOUT
MUXOUT
ADC
OV
DV
AV
AGND3
AGND2
DD
DD
DD
5V
+
–
5V
–1.0
0.1µF
10µF
10µF
0.1µF
10µF
0.1µF
+
–1.5
–
ADC
AGND1
REFCOMP
–2.0
V
2.5V
–32768
–16384
0
16384
32767
REF
1µF
10µF
0.1µF
CODE
185456 G01
1854565af
1