LTC2451
Ultra-Tiny, 16-Bit DS ADC
2
with I C Interface
FEATURES
DESCRIPTION
The LTC®2451 is an ultra-tiny, 16-bit, analog-to-digital
converter. The LTC2451 uses a single 2.7V to 5.5V
supply, accepts a single-ended analog input voltage and
communicates through an I2C interface. The converter
is available in an 8-pin, 3mm × 2mm DFN or TSOT-23
package. It includes an integrated oscillator that does not
require any external components. It uses a delta-sigma
modulator as a converter core and provides single-cycle
settling time for multiplexed applications. The LTC2451
includesaproprietaryinputsamplingschemethatreduces
the average input sampling current several orders of
magnitude lower than conventional Δ∑ converters.
n
GND to V Single-Ended Input Range
CC
n
0.02LSB RMS Noise
n
2LSB INL, No Missing Codes
1LSB Offset Error
4LSB Full-Scale Error
n
n
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Programmable 30/60 Conversions per Second
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Single Conversion Settling Time for Multiplexed
Applications
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Single-Cycle Operation with Auto Shutdown
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400μA Supply Current
0.2μA Sleep Current
n
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Internal Oscillator—No External Components Required
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Single Supply, 2.7V to 5.5V Operation
The LTC2451 is capable of up to 60 conversions per
second and, due to the very large oversampling ratio,
has extremely relaxed antialiasing requirements. In the
30Hz mode, the LTC2451 includes continuous internal
offset calibration algorithms which are transparent to the
user, ensuring accuracy over time and over the operating
2
n
2-Wire I C Interface
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Ultra-Tiny 3mm × 2mm DFN or TSOT-23 Package
APPLICATIONS
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System Monitoring
n
+
Environmental Monitoring
temperature range. The converter has external REF and
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–
–
Direct Temperature Measurements
REF pins and the input voltage can range from V
to
REF
n
+
+
–
Instrumentation
V
. If V
= V and V
= GND, the input voltage
REF
REF
CC
REF
CC
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Industrial Process Control
can range from GND to V .
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Data Acquisition
Following a single conversion, the LTC2451 can auto-
matically enter sleep mode and reduce its power to less
than 0.2μA. If the user reads the ADC once per second,
the LTC2451 consumes an average of less than 50μW
from a 2.7V supply.
n
Embedded ADC Upgrades
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. No Latency Δ∑ and Easy Drive are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners. Protected by U.S.
Patents, including 6208279, 6411242, 7088280, 7164378.
Integral Nonlinearity, VCC = 3V
TYPICAL APPLICATION
3
2
1
0
2.7V TO 5.5V
0.1μF
10μF
+
V
REF
CC
SCL
SDA
1k
T
= 90°C
A
2
2-WIRE I C
INTERFACE
IN LTC2451
–
SENSOR
0.1μF
–1
–2
–3
REF
GND
T
= –45°C, 25°C
A
2451 TA01a
0
1
1.5
2
2.5
3
0.5
2451 TA01b
INPUT VOLTAGE (V)
2451ff
1