ADS1255 — Datasheet Summary, Specs & Alternatives

01 — Overview

This Texas Instruments datasheet covers the ADS1255 and ADS1256, which are 24-bit, very low-noise analog-to-digital converters designed for high-resolution measurements. The document defines their electrical characteristics, including a 24-bit resolution with no missing codes across all data rates and programmable gain amplifier settings. Key performance parameters include up to 30kSPS data output rates, differential input impedance of 80 MΩ when the buffer is on, and power dissipation as low as 38mW in normal mode. The chips feature a chopper-stabilized input buffer, self-calibration capabilities, and an SPI-compatible serial interface. Applications span scientific instrumentation, industrial process control, medical equipment, and weigh scales.

02 — Key specifications

Datasheet parameters

Parameter	Min	Typ	Max	Conditions
supply voltage range	500 mV	2.5 V	2.6 V	VREF≡ VREFP– VREFN
input offset voltage drift	—	100 nV/°C	—	PGA = 1
cmrr	95 dB	110 dB	—	fCM(4) = 60Hz, fDATA = 30kSPS(5)
operating temperature	-40 °C	—	105 °C
power dissipation	—	38 mW	57 mW	Normal mode, PGA = 1, Buffer off, DVDD = 3.3V; mW
propagation delay	—	—	50 ns
psrr	60 dB	70 dB	—	±5% Δ in AVDD
adc resolution	—	24 bit	—
output voltage high	800 mV	—	—	IOH = 5mA
output voltage low	—	200 mV	—	IOL = 5mA
sample rate	—	30 kHz	—
settling time	210 µs	—	400 ms
channel count	—	2	—

03 — Alternatives

Closest matches to ADS1255

ADS131M02 6.1× lower power dissipation, 3.0× higher input offset voltage drift, 1.3× higher operating temperature

ADS131M02IPWR 6.1× lower power dissipation, 3.0× higher input offset voltage drift, 2.1× higher sample rate

PCM1808 2.0× higher supply voltage range, 1.6× higher power dissipation, 1.6× higher sample rate

ADS1114 2.2× higher supply voltage range, 1.5× lower adc resolution, 1.3× lower output voltage low

AD7124-8BBCPZ 6.2× lower supply voltage range, 4.8× lower settling time, 1.6× lower sample rate

AD7682BCBZ-RL7 8.3× higher sample rate, 3.0× lower power dissipation, 1.6× higher supply voltage range

MCP3002 6.7× higher sample rate, 5.1× higher output voltage high, 2.4× lower adc resolution

MCP3004 6.7× higher sample rate, 5.1× higher output voltage high, 2.4× lower adc resolution

04 — FAQ

Frequently asked questions

What is the ADC resolution of the ADS1255?

The ADC resolution is 24 bit.

How many channels does the ADS1255 have?

The ADS1255 has a channel count of 2.

What is the CMRR when fCM(4) = 60Hz and fDATA = 30kSPS(5)?

The CMRR is 110 dB.

What is the input offset voltage drift when the PGA is set to 1?

The input offset voltage drift is 100 nV/°C when the PGA is set to 1.

What is the maximum operating temperature for the ADS1255?

The maximum operating temperature is 105 °C.

What is the output voltage high when IOH = 5mA?

The output voltage high is 800 mV when IOH = 5mA.

What is the maximum output voltage low when IOL = 5mA?

The output voltage low is 200 mV when IOL = 5mA.

What is the power dissipation of the ADS1255 in Normal mode with PGA = 1, Buffer off, and DVDD = 3.3V?

The power dissipation is 38 mW.