LTC2451_1 Datasheet, PDF (1/18 Pages) Linear Technology – Ultra-Tiny, 16-Bit DS ADC with I2C Interface

FEATURES
n _{GND to VCC Single-Ended Input Range}
n _{0.02LSB RMS Noise}
n _{2LSB INL, No Missing Codes}
n _{1LSB Offset Error}
n _{4LSB Full-Scale Error}
n _{Programmable 30/60 Conversions per Second}
n _{Single Conversion Settling Time for Multiplexed}
Applications
n _{Single-Cycle Operation with Auto Shutdown}
n _{400μA Supply Current}
n _{0.2μA Sleep Current}
n _{Internal Oscillator—No External Components Required}
n _{Single Supply, 2.7V to 5.5V Operation}
n _{2-Wire I}²_{C Interface}
n _{Ultra-Tiny 3mm × 2mm DFN or TSOT-23 Package}
APPLICATIONS
n _{System Monitoring}
n _{Environmental Monitoring}
n _{Direct Temperature Measurements}
n _{Instrumentation}
n _{Industrial Process Control}
n _{Data Acquisition}
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.
LTC2451
Ultra-Tiny, 16-Bit DS ADC
with I²C Interface
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
includes a proprietary input sampling scheme that reduces
the average input sampling current several orders of
magnitude lower than conventional Δ∑ converters.
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
temperature range. The converter has external REF⁺ and
REF^– pins and the input voltage can range from V_REF– to
V_REF+. If V_REF+ = V_CC and V_REF– = GND, the input voltage
can range from GND to V_CC.
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.
TYPICAL APPLICATION
1k
SENSOR
2.7V TO 5.5V
0.1μF
10μF
REF⁺ VCC _SCL
IN LTC2451
2-WIRE I²C
0.1μF
SDA INTERFACE
REF ^– GND
2451 TA01a
Integral Nonlinearity, V_CC = 3V
3
2
1
0
T_A = 90°C
–1
T_A = – 45°C, 25°C
–2
–3
0
0.5 1 1.5 2 2.5 3
INPUT VOLTAGE (V)
2451 TA01b
2451ff
1