| Resolution (Bits) | 24 |
| Number of input channels | 2 |
| Sample rate (Max) (kSPS) | 30 |
| Interface type | SPI |
| Architecture | Delta-Sigma |
| Input type | Differential, Single-Ended |
| Multi-channel configuration | Multiplexed |
| Rating | Catalog |
| Reference mode | Ext |
| Input range (Max) (V) | 5.25 |
| Input range (Min) (V) | 0 |
| Features | 50/60 Hz Rejection, GPIO, PGA |
| Operating temperature range (C) | -40 to 85 |
| Power consumption (Typ) (mW) | 36 |
| Analog voltage AVDD (Min) (V) | 4.75 |
| Analog voltage AVDD (Max) (V) | 5.25 |
| Digital supply (Min) (V) | 1.8 |
| Digital supply (Max) (V) | 3.6 |
- 24 Bits, No Missing Codes
- All Data Rates and PGA Settings
- Up to 23 Bits Noise-Free Resolution
- ±0.0010% Nonlinearity (max)
- Data Output Rates to 30kSPS
- Fast Channel Cycling
- 18.6 Bits Noise-Free (21.3 Effective Bits) at 1.45kHz
- One-Shot Conversions with Single-Cycle Settling
- Flexible Input Multiplexer with Sensor Detect
- Four Differential Inputs (ADS1256 only)
- Eight Single-Ended Inputs (ADS1256 only)
- Chopper-Stabilized Input Buffer
- Low-Noise PGA: 27nV Input-Referred Noise
- Self and System Calibration for All PGA Settings
- 5V Tolerant SPI?-Compatible Serial Interface
- Analog Supply: 5V
- Digital Supply: 1.8V to 3.6V
- Power Dissipation
- As Low as 38mW in Normal Mode
- 0.4mW in Standby Mode
The ADS1255 and ADS1256 are extremely low-noise, 24-bit analog-to-digital (A/D) converters. They provide complete high-resolution measurement solutions for the most demanding applications.
The converter is comprised of a 4th-order, delta-sigma (ΔΣ) modulator followed by a programmable digital filter. A flexible input multiplexer handles differential or single-ended signals and includes circuitry to verify the integrity of the external sensor connected to the inputs. The selectable input buffer greatly increases the input impedance and the low-noise programmable gain amplifier (PGA) provides gains from 1 to 64 in binary steps. The programmable filter allows the user to optimize between resolution of up to 23 bits noise-free and data rate of up to 30k samples per second (SPS). The converters offer fast channel cycling for measuring multiplexed inputs and can also perform one-shot conversions that settle in just a single cycle.
Communication is handled over an SPI-compatible serial interface that can operate with a 2-wire connection. Onboard calibration supports both self and system correction of offset and gain errors for all the PGA settings. Bidirectional digital I/Os and a programmable clock output driver are provided for general use. The ADS1255 is packaged in an SSOP-20, and the ADS1256 in an SSOP-28.
