Part A
ADS7816U
Texas Instruments
- Lifecycle
- Active
- Stock
- 6722 PCS
- Package
- SOIC-8
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Not a drop-in replacement
The ADS7816U and ADS7808U/1K are not drop-in replacements for each other. Although both are 12-bit successive-approximation ADCs from Texas Instruments, they differ in resolution-critical architecture, package footprint, and interface timing, so the ADS7808U/1K cannot be substituted directly for the ADS7816U without a board redesign and interface revalidation.
Different package footprint
Different sampling architecture
Different interface timing
Different supply configuration
Parts at a glance
Part B
ADS7808U/1K
Texas Instruments
- Lifecycle
- Active
- Stock
- 9730 PCS
- Package
- SOIC-20
- 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 | ADS7816U | ADS7808U/1K | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both converters provide 12-bit resolution, so quantization step size is equivalent for a given reference. |
| Sampling Rate | 200 kSPS | 100 kSPS | The ADS7816U can sample twice as fast, which matters for higher-bandwidth or multiplexed signal acquisition. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Both are single-channel devices, so channel count does not differentiate them for multi-signal systems. |
| Input Type | Single-ended | Single-ended | Identical input configuration means the same signal conditioning front-end can be reused. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply) | Matching supply requirements allow drop-in use in the same 5 V system rail. |
| Interface | SPI / serial | Parallel | The interface differs fundamentally: ADS7816U uses a serial bus while ADS7808U/1K uses a parallel bus, requiring different microcontroller pinouts and firmware. |
| Package | SOIC-8 | SOIC-28 | Different package footprints and pin counts prevent direct PCB substitution without layout changes. |
| Reference | External | Internal | ADS7816U requires an external reference while ADS7808U/1K includes an internal reference, affecting accuracy budget and BOM complexity. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings mean both suit the same industrial ambient conditions. |
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 | ADS7816U | ADS7808U/1K |
|---|---|---|
| Supplier | - | Texas Instruments,Rochester Electronics, LLC |
| Part Status | Active | Active |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 200k | 100k |
| Number of Inputs | 1 | 1 |
| Input Type | Differential | Single Ended |
| Data Interface | SPI | SPI, DSP |
| 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 | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the ADS7816U and the ADS7808U/1K?
The ADS7816U is a 12-bit, 200-kSPS micropower sampling analog-to-digital converter with a serial (SPI-compatible) interface, offered in a small SOIC-8 package. The ADS7808U/1K is a 12-bit, 100-kSPS sampling ADC with a parallel 8-bit bus interface, offered in a wider SOIC-28 package. They differ in resolution-adjacent architecture, sampling rate, interface type, package footprint, and power consumption, so they are not pin- or function-compatible substitutes.
Are the ADS7816U and ADS7808U/1K pin-compatible or footprint-compatible?
No. The ADS7816U is supplied in an 8-pin SOIC (SOIC-8) package, while the ADS7808U/1K is supplied in a 28-pin SOIC (SOIC-28) package. The pin counts, pin functions, and PCB land patterns differ, so neither part can be dropped into the other's footprint without a board redesign.
How do the digital interfaces of the ADS7816U and ADS7808U/1K differ?
The ADS7816U uses a serial interface compatible with SPI, QSPI, and Microwire, requiring only a few I/O lines (CS, SCLK, DOUT, and typically a conversion-start signal). The ADS7808U/1K provides a parallel 8-bit data bus with associated control signals (CS, R/C, BYTE, and BUSY), which requires more host I/O pins but allows direct connection to parallel-bus microcontrollers or DSPs.
What are the sampling rates and resolution of each device?
Both devices are 12-bit successive-approximation ADCs. The ADS7816U has a specified sampling rate of 200 kSPS, while the ADS7808U/1K has a specified sampling rate of 100 kSPS. The ADS7816U therefore offers twice the throughput of the ADS7808U/1K at the same 12-bit resolution.
How do the power consumption and supply requirements compare?
The ADS7816U is a micropower device operating from a single 5 V supply with very low power consumption (typically in the low milliwatt range at full rate, and it features automatic power-down between conversions). The ADS7808U/1K also operates from a 5 V supply but draws higher supply current due to its parallel interface and larger die, resulting in higher overall power dissipation. For battery-powered or power-sensitive designs, the ADS7816U is generally the lower-power choice.
What are the analog input configurations of the ADS7816U and ADS7808U/1K?
The ADS7816U provides a single pseudo-differential analog input (one input channel) with a 0 V to VREF input range. The ADS7808U/1K provides a single-ended analog input channel with a 0 V to 5 V input range (using its internal or external reference). Designers should confirm the exact input range and reference configuration against the respective manufacturer datasheets for their specific grade and operating conditions.
Can the ADS7816U directly replace the ADS7808U/1K in an existing design?
No. Because the two devices differ in package (SOIC-8 vs SOIC-28), interface (serial vs parallel 8-bit), sampling rate (200 kSPS vs 100 kSPS), and pinout, a direct replacement is not possible. Substitution would require a PCB redesign, changes to the host firmware/driver for the different interface, and revalidation of timing, reference, and power budgets against the target design requirements.
Which device is better suited for space-constrained or portable applications?
The ADS7816U is generally better suited for space-constrained and portable applications because it is housed in a compact SOIC-8 package, uses a serial interface that minimizes host I/O and routing, and features micropower operation with automatic power-down. The ADS7808U/1K, with its larger SOIC-28 package and parallel bus, is more appropriate for systems where a parallel interface and higher pin count are acceptable or required.