LTC2486 Datasheet, PDF (1/36 Pages) Linear Technology – 16-Bit 2-/4-Channel ΔΣ ADC with PGA and Easy Drive Input Current Cancellation

LTC2486
FEATURES
16-Bit 2-/4-Channel ΔΣ ADC
with PGA and Easy Drive
Input Current Cancellation
DESCRIPTION
■ _{Up to 2 Differential or 4 Single-Ended Inputs}
■ _{Easy Drive Technology Enables Rail-to-Rail Inputs}
with Zero Differential Input Current
■ _{Directly Digitizes High Impedance Sensors with}
Full Accuracy
■ _{600nV RMS Noise}
■ _{Programmable Gain from 1 to 256}
■ _{Integrated High Accuracy Temperature Sensor}
■ _{GND to VCC Input/Reference Common Mode Range}
■ _{Programmable 50Hz, 60Hz, or Simultaneous}
50Hz/60Hz Rejection Mode
■ _{2ppm INL, No Missing Codes}
■ _{1ppm Offset and 15ppm Full-Scale Error}
■ _{2x Speed Mode/Reduced Power Mode (15Hz Using}
Internal Oscillator and 80µA at 7.5Hz Output)
■ _{No Latency: Digital Filter Settles in a Single Cycle,}
Even After a New Channel is Selected
■ _{Single Supply 2.7V to 5.5V Operation (0.8mW)}
■ _{Internal Oscillator}
■ _{Tiny 4mm × 3mm DFN Package}
APPLICATIONS
■ _{Direct Sensor Digitizer}
■ _{Direct Temperature Measurement}
■ _{Instrumentation}
■ _{Industrial Process Control}
The LTC^®2486 is a 4-channel (2-channel differential),
16-bit, No Latency ΔΣ™ ADC with Easy Drive™ technology.
The patented sampling scheme eliminates dynamic input
current errors and the shortcomings of on-chip buffering
through automatic cancellation of differential input current.
This allows large external source impedances and rail-to-
rail input signals to be directly digitized while maintaining
exceptional DC accuracy.
The LTC2486 includes programmable gain, a high accuracy
temperature sensor, and an integrated oscillator. This de-
vice can be configured to measure an external signal (from
combinations of 4 analog input channels operating in single
ended or differential modes) or its internal temperature sen-
sor. It can be programmed to reject line frequencies of 50Hz,
60Hz, or simultaneous 50Hz/60Hz, provide a programmable
gain from 1 to 256 in 8 steps, and configured to double its
output rate. The integrated temperature sensor offers 1/2°C
resolution and 2°C absolute accuracy.
The LTC2486 allows a wide common mode input range
(0V to V_CC), independent of the reference voltage. Any
combination of single-ended or differential inputs can
be selected and the first conversion after a new channel
selection is valid.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
No Latency ∆Σ and Easy Drive are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
TYPICAL APPLICATION
Data Acquisition System with Temperature Compensation
CH0
CH1
4-CHANNEL
MUX
CH2
CH3
COM
TEMPERATURE
SENSOR
2.7V TO 5.5V
V_CC
REF⁺
IN⁺
SDI
16-BIT ∆Σ ADC SCK
WITH EASY-DRIVE SDO
IN^–
CS
REF ^–
F_O
OSC
2486 TA01a
0.1µF
10µF
4-WIRE
SPI INTERFACE
Absolute Temperature Error
5
4
3
2
1
0
–1
–2
–3
–4
–5
–55 –30
–5 20 45 70
TEMPERATURE (°C)
95 120
2486 TA01b
2486f
1