Part A
ADS7822U
Texas Instruments
- Lifecycle
- Active
- Stock
- 7079 Stückzahl
- Package
- SOIC-8
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7822U and ADS7817UB/2K5 are both 12-bit micropower SAR analog-to-digital converters in an 8-pin SOIC package, sharing a compatible serial interface and similar supply requirements. While the ADS7817UB/2K5 offers a higher sampling rate and a differential input, the ADS7822U provides a pseudo-differential input with lower power consumption. Designers should validate the input configuration and timing against the target application before substituting one for the other.
Resolution
High match
Package Type
High match
Input Configuration
Validation required
Sampling Rate
Validation required
Parts at a glance
Part B
ADS7817UB/2K5
Texas Instruments
- Lifecycle
- Active
- Stock
- 5649 Stückzahl
- Package
- SOIC-8
- Series
- Datenerfassung mit Analog to Digital Converters (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 | ADS7817UB/2K5 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so nominal resolution is equivalent for substitutability. |
| Sampling Rate | 200 kSPS | 200 kSPS | Maximum throughput determines whether the part meets system timing requirements. |
| Number of Input Channels | 1 (single-ended) | 1 (pseudo-differential) | Input configuration affects how the signal source must be connected and whether common-mode rejection is available. |
| Input Type | Single-ended | Pseudo-differential | Pseudo-differential inputs can reject ground noise, which may matter in noisy environments. |
| Supply Voltage | 2.7 V to 5.25 V | 4.75 V to 5.25 V | The wider supply range of the ADS7822U allows operation at lower voltages, while the ADS7817UB requires a 5 V supply. |
| Interface | SPI / QSPI / Microwire compatible serial | SPI / QSPI / Microwire compatible serial | Both use a compatible serial interface, simplifying digital-side substitution. |
| Package | SOIC-8 | SOIC-8 | Matching package and pinout enables drop-in board replacement. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent temperature ratings ensure both parts suit the same environmental conditions. |
| Reference Type | External | External | Both require an external reference, so the reference design can remain unchanged. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7822U | ADS7817UB/2K5 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 200k | 200k |
| Number of Inputs | 1 | 1 |
| Input Type | Pseudo-Differential | Differential |
| 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 |
| 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 differences between the ADS7822U and ADS7817UB/2K5?
The ADS7822U is a 12-bit, 200-kSPS micropower sampling ADC with a pseudo-differential input, while the ADS7817UB/2K5 is a 12-bit, 200-kSPS micro-power sampling ADC with a true differential input. Both are offered in an SOIC-8 package and operate from a single 2.7 V to 5.25 V supply, but they differ in input configuration and some AC performance specifications.
Are the ADS7822U and ADS7817UB/2K5 pin-compatible?
Both devices are packaged in an 8-pin SOIC (D) package and share a similar pinout, but the analog input pins differ: the ADS7822U uses a pseudo-differential input (+IN and -IN), while the ADS7817UB/2K5 uses a true differential input (+IN and -IN) with different internal sampling architecture. Designers should verify pin functions against the respective datasheets before considering a layout-compatible substitution.
Do both ADCs support the same supply voltage range?
Yes. Both the ADS7822U and ADS7817UB/2K5 are specified for a single supply voltage range of 2.7 V to 5.25 V, making them suitable for low-power, single-supply systems.
What is the maximum sampling rate of each device?
Both the ADS7822U and ADS7817UB/2K5 are specified at a maximum throughput of 200 kSPS (kilo-samples per second) at a 5 V supply.
How do the input configurations differ between the two ADCs?
The ADS7822U features a pseudo-differential input, where the negative input is typically tied to a fixed reference or ground and the positive input is sampled against it. The ADS7817UB/2K5 features a true differential input, allowing both inputs to swing independently, which provides better common-mode rejection and is suited for differential signal sources.
What is the resolution and interface type of these ADCs?
Both the ADS7822U and ADS7817UB/2K5 are 12-bit successive-approximation register (SAR) ADCs with a serial SPI-compatible interface, allowing direct connection to microcontrollers and DSPs.
What are the package and operating temperature specifications?
Both devices are offered in an 8-pin SOIC package. The ADS7822U is specified over the industrial temperature range of -40°C to +85°C, and the ADS7817UB/2K5 is also specified over the industrial temperature range of -40°C to +85°C.
Can the ADS7817UB/2K5 be used as a drop-in replacement for the ADS7822U?
Not without design verification. Although both are 12-bit, 200-kSPS, 8-pin SOIC ADCs with SPI interfaces and similar supply ranges, the input architecture differs (pseudo-differential vs. true differential), and AC performance specifications such as SINAD and THD may differ. The replacement should only be made after confirming input drive requirements, reference configuration, and timing against both datasheets.