ADS1245 24-Bit Low-Power ADC With High-Z Input Buffer | TI.com

ADS1245 (ACTIVE)

24-Bit Low-Power ADC With High-Z Input Buffer

 

Description

The ADS1245 is a 24-bit, delta-sigma analog-to-digital converter (ADC). It offers excellent performance and very low power in an MSOP-10 package and is well suited for demanding high-resolution measurements, especially in portable and other space- and power-constrained systems.

The buffered input presents an impedance of 3G, minimizing measurement errors when using high-impedance sources. The ADS1245 is compatible with ADS1244 and offers a direct upgrade path for designs requiring higher input impedance.

A third-order delta-sigma () modulator and digital filter form the basis of the ADC. The analog modulator has a ±2.5V differential input range. The digital filter rejects both 50Hz and 60Hz signals, completely settles in one cycle, and outputs data at 15 samples per second (SPS).

A simple, two-wire serial interface provides all the necessary control. Data retrieval, self-calibration, and Sleep mode are handled with a few simple waveforms. When only single conversions are needed, the ADS1245 can be shut down (Sleep mode) while idle between measurements to dramatically reduce the overall power dissipation. Multiple ADS1245s can be connected together to create a synchronously sampling multichannel measurement system. The ADS1245 is designed to easily connect to microcontrollers, such as the MSP430.

The ADS1245 supports 2.5V to 5.25V analog supplies and 1.8V to 3.6V digital supplies. Power is typically less than 470µW in normal operation and less than 1µW during Sleep mode.

Features

  • 20-Bit Effective Resolution
  • High-Impedance Buffered Input
  • ±2.5V Differential Input Range
  • Pin-Compatible with ADS1244
  • 0.0006% INL (typ), 0.0015% INL (max)
  • Simple Two-Wire Serial Interface
  • Simultaneous 50Hz and 60Hz Rejection
  • Single Conversions with Sleep Mode
  • Single-Cycle Settling
  • Self-Calibration
  • Well Suited for Multi-Channel Systems
  • Easily Connects to the MSP430
  • Current Consumption: 158µA
  • Analog Supply: 2.5V to 5.25V
  • Digital Supply: 1.8V to 3.6V
  • APPLICATIONS
    • Hand-Held Instrumentation
    • Portable Medical Equipment
    • Industrial Process Control
    • Test and Measurement Systems

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Parametrics Compare all products in Precision ADCs (<=10MSPS)

 
Resolution (Bits)
Sample Rate (Max) (kSPS)
Number of input channels
Interface
Operating temperature range (C)
Package Group
Approx. price (US$)
Power consumption (Typ) (mW)
Package size: mm2:W x L (PKG)
Architecture
Input type
Multi-channel configuration
Reference mode
Features
Input range (Max) (V)
Input range (Min) (V)
Analog voltage AVDD (Min) (V)
Analog voltage AVDD (Max) (V)
Digital supply (Min) (V)
Digital supply (Max) (V)
INL (Max) (+/-LSB)
Rating
ADS1245 ADS1244
24     24    
0.015     0.03    
1     1    
SPI     SPI    
-40 to 85     -40 to 85    
VSSOP | 10     VSSOP | 10    
5.41 | 1ku     4.08 | 1ku    
0.27     0.27    
10VSSOP: 9 mm2: 3 x 3 (VSSOP | 10)     10VSSOP: 9 mm2: 3 x 3 (VSSOP | 10)    
Delta-Sigma     Delta-Sigma    
Differential
Single-Ended    
Differential
Single-Ended    
   
   
Ext     Ext    
50/60 Hz Rejection     50/60 Hz Rejection    
4     5.25    
0     0    
2.5     2.5    
5.25     5.25    
1.8     1.8    
3.6     3.6    
251.7     134.2    
Catalog     Catalog