LTD2261
High-precision, Multi-channel, 40-kSPS, 24-bit, Delta-sigma ADC
Description
The LTD226X family are high-precision, multi-channel, 40-kSPS, delta-sigma (Δ-Σ) analog-to-digital converters (ADCs). Features, for example, programmable gain amplifier
(PGA), precise and low-drift voltage reference, monitors for fault detection, general purpose input output options are included in this highly-integrated chip making it a single-chip solution
to deal with measurements tasks such as weigh scales, resistance temperature detectors (RTDs) and thermalcouple sensors.
The main path of analog-to-digital conversion consists of an input multiplexer (5 channels for LTD2260 and 10 channels for LTD2261), a low-noise PGA, a 24-bit Δ-Σ modulator, a precise and
low-drift voltage reference, and a programmable digital filter. The 1 GΩ high input impedance of the PGA minimizes the error induced by sensor loading. The device provide two individual
current source with programmable supplying current, that simplifies the circuit of RTDs measurements.
The conversion is completed by a fourth-order Δ-Σ modulator combined with a flexible digital filter. The filter supports a simultaneous 50-Hz and 60-Hz rejection mode and single-cycle
settling mode. Associated with internal signal and reference monitors, a temperature sensor and CRC data verification, the output data is more reliable. The LTD226X family are available in 5 mm × 5 mm QFN packages and specified in temperature range from -40℃ to 125℃.
Advantages And Characteristics
High-precision, 24-bit delta-sigma ADC
Low noise: 30 nVRMS (@20 SPS, gain=128)
Linearity: 2 ppm
5 single-ended inputs or 3 differential inputs (LTD2260)
10 single-ended inputs or 5 differential inputs (LTD2261)
PGA gain: 1 to 128
Input voltage range: ±7 mV to ±5 V
Data rate: 2.5 SPS to 40 kSPS
Low drift 2.5 V reference: 2 ppm/℃
Simultaneous 50-Hz and 60-Hz rejection mode
Single-cycle settling mode
PGA voltages and reference monitors
5 V or ±2.5 V supply
Integrated temperature sensor
Cyclic redundancy check
Two individual current source
Sensor burn-out detection
4 GPIOs available
AC excitation for bridge sensors
SPI compatible
Application
Temperature and pressure measurement
Analog input modules in PLC and DCS
Weigh scales and strain-gauge digitizers
Scientific and lab instruments