Part A
ADS1256IDBT
Texas Instruments
- Lifecycle
- Active
- Stock
- 4833 PCS
- Package
- SSOP-28
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS1246IPW and ADS1256IDBT share the same TSSOP-28 footprint and pin-compatible serial interface, making the ADS1256IDBT a viable functional upgrade candidate for the ADS1246IPW in many designs. However, the ADS1256IDBT offers a higher channel count, faster programmable data rate, and a wider input configuration range, so firmware configuration and system-level validation are required before substitution.
Package Type
High match
Resolution
High match
Channel Count
Validation required
Data Rate
Validation required
Parts at a glance
Part B
ADS1246IPW
Texas Instruments
- Lifecycle
- Active
- Stock
- 6549 PCS
- Package
- TSSOP-16
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADS1246IPW | ADS1256IDBT | Why it matters |
|---|---|---|---|
| Resolution (bits) | 24 | 24 | Both are 24-bit delta-sigma ADCs, so resolution alone does not differentiate them for substitutability. |
| Number of input channels | 1 differential / 2 single-ended | 4 differential / 8 single-ended | Channel count determines how many signals can be measured; the ADS1256 supports multiplexed multi-channel systems while the ADS1246 is limited to a single channel. |
| Maximum data rate (SPS) | 2000 | 30000 | Higher throughput enables faster sampling; the ADS1256 is far faster, which matters for high-speed acquisition applications. |
| PGA gain range | 1 to 128 | 1 to 64 | Programmable gain affects the smallest resolvable signal; the ADS1246 offers higher maximum gain for very low-level inputs. |
| Interface | SPI | SPI | Both use SPI, so the host microcontroller interface is compatible between the two parts. |
| Supply voltage (analog) | 2.7 V to 5.25 V | 5 V (4.75 V to 5.25 V) | The ADS1246 supports lower supply voltages, allowing operation in 3.3 V systems where the ADS1256 requires a 5 V analog supply. |
| Package | 16-pin TSSOP | 28-pin TSSOP | Different package footprints and pin counts mean the two parts are not drop-in replacements on the same PCB layout. |
| Internal oscillator | Yes | Yes | Both include an internal oscillator, simplifying clocking requirements and reducing external component count. |
| Operating temperature range | -40 °C to +105 °C | -40 °C to +85 °C | The wider temperature range of the ADS1246 suits harsher environments, while the ADS1256 is limited to standard industrial ranges. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS1256IDBT | ADS1246IPW |
|---|---|---|
| Part Status | Active | Active |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | 30k | 2k |
| Number of Inputs | 4, 8 | 1 |
| Input Type | Differential, Single Ended | Differential, Single Ended |
| Data Interface | SPI | SPI |
| Configuration | MUX-PGA-ADC | MUX-PGA-ADC |
| Number of A/D Converters | 1 | 1 |
| Architecture | Sigma-Delta | Sigma-Delta |
| Reference Type | External | External, Internal |
| Voltage - Supply, Analog | 5V | 2.7V ~ 5.25V |
| Voltage - Supply, Digital | 1.8V ~ 3.6V | 2.7V ~ 5.25V |
| Features | PGA | PGA, Temperature Sensor |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 105°C |
Frequently asked questions
What are the primary differences between the ADS1246IPW and ADS1256IDBT?
The ADS1246IPW is a 24-bit, 2 kSPS delta-sigma ADC with a single differential input (or two single-ended inputs) in a 20-pin TSSOP package. The ADS1256IDBT is a 24-bit, 30 kSPS delta-sigma ADC with an 8-channel multiplexer (4 differential or 8 single-ended inputs) in a 28-pin TSSOP package. The ADS1256 offers higher throughput and more input channels, while the ADS1246 provides a smaller package and lower channel count.
Are the ADS1246IPW and ADS1256IDBT pin-to-pin compatible?
No. The ADS1246IPW uses a 20-pin TSSOP (PW) package, while the ADS1256IDBT uses a 28-pin TSSOP (DBT) package. The pin counts, pin functions, and PCB land patterns differ, so they are not direct drop-in replacements.
What are the maximum data rates of the ADS1246IPW and ADS1256IDBT?
The ADS1246IPW supports programmable data rates up to 2 kSPS. The ADS1256IDBT supports programmable data rates up to 30 kSPS. The higher rate of the ADS1256 makes it suitable for faster-sampling applications.
How many input channels does each device provide?
The ADS1246IPW provides one differential input or two single-ended inputs. The ADS1256IDBT includes an input multiplexer providing four differential inputs or eight single-ended inputs, allowing it to scan multiple sensors without external multiplexing.
Do both devices include a programmable gain amplifier (PGA)?
Yes. Both the ADS1246IPW and ADS1256IDBT integrate a low-noise programmable gain amplifier (PGA) that supports gains from 1 to 128, enabling direct interfacing with low-level sensor signals such as thermocouples and bridge sensors.
What digital interfaces do the ADS1246IPW and ADS1256IDBT use?
Both devices use an SPI-compatible serial interface for configuration and data readout. The interface supports daisy-chaining and is compatible with standard SPI modes, allowing connection to most microcontrollers and DSPs.
What are the supply voltage requirements for these ADCs?
Both the ADS1246IPW and ADS1256IDBT operate from an analog supply (AVDD) of 5 V (range 4.75 V to 5.25 V) and a digital supply (DVDD) of 2.7 V to 5.25 V. Both also require an external reference voltage for accurate conversion.
Which device is better suited for multi-sensor data acquisition systems?
The ADS1256IDBT is better suited for multi-sensor systems because its integrated 8-channel multiplexer (4 differential) allows multiple inputs to be scanned by a single ADC. The ADS1246IPW, with only one differential input, is better suited to single-channel or low-channel-count designs where board space is critical.