Part A
ADS7822U
Texas Instruments
- Lifecycle
- Active
- Stock
- 7079 PCS
- Package
- SOIC-8
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7822U and ADS7812U share the same 12-bit SAR architecture and SOIC-8 footprint, making the ADS7822U a viable functional replacement candidate for the ADS7812U in many designs. However, the two devices differ in supply voltage range, sample rate, and interface configuration, so the ADS7822U should be validated against the target system's timing, power, and digital interface requirements before substitution.
Resolution and Architecture
High match
Supply Voltage Range
Validation required
Sample Rate
Validation required
Package Type
High match
Parts at a glance
Part B
ADS7812U
Texas Instruments
- Lifecycle
- Active
- Stock
- 2489 PCS
- Package
- SOIC-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 | ADS7822U | ADS7812U | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so resolution alone does not distinguish them for substitutability. |
| Sampling Rate | 75 kSPS | 40 kSPS | The ADS7822U supports a higher throughput, which matters for faster signal acquisition requirements. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Both are single-channel devices, so channel count is not a differentiator. |
| Interface Type | SPI / Microwire (serial) | SPI / Microwire (serial) | Both use a serial interface, easing drop-in replacement from a digital bus perspective. |
| Supply Voltage | 2.7 V to 5.25 V | 5 V (single supply) | The ADS7822U operates over a wider low-voltage range, enabling use in 3.3 V systems where the ADS7812U cannot operate. |
| Package | SOIC-8 | SOIC-16 | Different package footprints and pin counts prevent direct board-level substitution without layout changes. |
| Power Consumption | Low power (micropower, ~1.6 mW at 5 V) | Higher power (~25 mW typical) | The ADS7822U is significantly more power-efficient, which matters for battery-powered or thermally constrained designs. |
| Input Voltage Range | 0 V to VREF (unipolar) | 0 V to VREF (unipolar) | Both use a unipolar input range referenced to VREF, so signal conditioning requirements are similar. |
| Reference Input | External reference | External reference | Both require an external reference, so reference circuitry can be reused across designs. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7822U | ADS7812U |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,Texas Instruments |
| Part Status | Active | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 200k | 40k |
| Number of Inputs | 1 | 1 |
| Input Type | Pseudo-Differential | Single Ended |
| Data Interface | SPI | SPI |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External | External, Internal |
| Voltage - Supply, Analog | 2.7V ~ 3.6V, 5V | 5V |
| Voltage - Supply, Digital | 2.7V ~ 3.6V, 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Series | microPOWER™ | - |
Frequently asked questions
What are the key architectural differences between the ADS7822U and ADS7812U?
The ADS7822U is a 12-bit, 200-kSPS micropower sampling analog-to-digital converter with a pseudo-differential input and a serial (SPI-compatible) interface, typically housed in an SOIC-8 package. The ADS7812U is a 12-bit, 40-kSPS sampling ADC with a successive-approximation register architecture, a single-ended input, and a parallel interface, typically housed in an SOIC-16 package. The two devices differ in resolution-adjacent parameters such as throughput, input configuration, and digital interface type.
Can the ADS7822U and ADS7812U be used as direct drop-in replacements for each other?
No. The ADS7822U and ADS7812U are not pin-compatible or functionally interchangeable. They differ in package pin count (SOIC-8 vs SOIC-16), digital interface (serial SPI vs parallel), input configuration (pseudo-differential vs single-ended), and maximum throughput (200 kSPS vs 40 kSPS). A direct substitution would require a PCB redesign and firmware changes.
How do the sampling rates of the ADS7822U and ADS7812U compare?
The ADS7822U supports a maximum throughput of 200 kSPS, while the ADS7812U supports a maximum throughput of 40 kSPS. The ADS7822U therefore offers approximately five times the maximum sampling rate of the ADS7812U, making it better suited to higher-bandwidth signal acquisition.
What digital interfaces do the ADS7822U and ADS7812U provide?
The ADS7822U provides a serial interface compatible with SPI, QSPI, and Microwire, which reduces pin count and simplifies isolation. The ADS7812U provides a parallel digital output interface, which requires more I/O pins but can offer simpler high-speed data capture in parallel-bus systems.
How do the input configurations of the ADS7822U and ADS7812U differ?
The ADS7822U features a pseudo-differential input, allowing it to reject common-mode signals between the positive input and a reference input. The ADS7812U features a single-ended input referenced to ground. Designs requiring common-mode rejection or differential signal acquisition should account for this difference.
How do the power consumption characteristics of the ADS7822U and ADS7812U compare?
The ADS7822U is specified as a micropower device designed for low-power operation, with power consumption scaling with throughput. The ADS7812U is a higher-power successive-approximation converter. Exact supply current and power figures should be taken from the respective manufacturer datasheets, as they depend on supply voltage and operating conditions.
What package options are available for the ADS7822U and ADS7812U?
The ADS7822U is offered in an SOIC-8 package, while the ADS7812U is offered in an SOIC-16 package. The difference in package footprint and pin count means the two devices cannot share the same PCB land pattern.
Which device is more suitable for battery-powered or portable applications?
The ADS7822U is generally more suitable for battery-powered and portable applications because of its micropower design, lower pin count serial interface, and small SOIC-8 package. The ADS7812U, with its parallel interface and higher power successive-approximation architecture, is better suited to systems where parallel bus access and its specific input configuration are required.