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 ADS7825UB/1K are not drop-in replacements for one another. The ADS7816U is a single-channel 12-bit SAR ADC in a small SOIC-8 package, while the ADS7825UB/1K is a four-channel 16-bit SAR ADC in a wider SOIC-28 package with a different serial interface and reference architecture. Designers must account for differences in resolution, channel count, package footprint, and digital interface before considering any substitution.
Different resolution
Different channel count
Different package footprint
Different digital interface
Parts at a glance
Part B
ADS7825UB/1K
Texas Instruments
- Lifecycle
- Active
- Stock
- 4144 PCS
- Package
- SOIC-28
- 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 | ADS7825UB/1K | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 16 bit | Higher resolution provides finer measurement granularity; a 16-bit ADC resolves 16x more levels than a 12-bit device, affecting precision-critical designs. |
| Number of Input Channels | 1 (single-ended) | 4 (single-ended) | Channel count determines how many analog signals can be digitized; the 4-channel device supports multiplexed multi-signal acquisition without external muxing. |
| Sampling Rate | 200 kSPS | 40 kSPS | Maximum throughput dictates the highest signal bandwidth that can be captured; the faster device suits higher-frequency signals while the slower one suits precision low-speed measurements. |
| Interface Type | SPI (serial) | Parallel | The digital interface must match the host controller; SPI uses fewer pins while parallel offers higher data throughput and simpler timing for some processors. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply, analog and digital) | Supply requirements determine power-rail compatibility; both operate from 5 V, but the multi-channel device may draw more current due to parallel output drivers. |
| Package / Mounting | 8-pin SOIC (surface mount) | 28-pin SOIC (surface mount) | Footprint and pin count affect PCB layout and board space; the two parts are not drop-in compatible and require different land patterns. |
| Input Configuration | Pseudo-differential (single-ended) | Single-ended, 4-channel multiplexed | Input topology affects how signals are referenced and multiplexed; the multi-channel part enables sequential sampling of several sources with one converter. |
| Reference Input | External reference | External reference | Both require an external voltage reference, so accuracy depends on the chosen reference; this is a shared design consideration rather than a differentiator. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7816U | ADS7825UB/1K |
|---|---|---|
| Supplier | - | Texas Instruments,Rochester Electronics, LLC |
| Part Status | Active | Active |
| Number of Bits | 12 | 16 |
| Sampling Rate(Per Second) | 200k | 40k |
| Number of Inputs | 1 | 4 |
| Input Type | Differential | Single Ended |
| Data Interface | SPI | SPI, Parallel |
| 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 architectural differences between the ADS7816U and the ADS7825UB/1K?
The ADS7816U is a 12-bit, 200-kSPS successive-approximation register (SAR) analog-to-digital converter with a single pseudo-differential input, housed in an SOIC-8 package. The ADS7825UB/1K is a 16-bit, 40-kSPS SAR ADC featuring four single-ended or two pseudo-differential input channels, an on-chip sample-and-hold, and a parallel interface, housed in an SOIC-28 package. The ADS7825UB/1K offers higher resolution and multi-channel capability, while the ADS7816U provides a higher sampling rate in a much smaller footprint.
Can the ADS7816U be used as a drop-in replacement for the ADS7825UB/1K?
No. The two devices are not pin-compatible or package-compatible. The ADS7816U is an 8-pin SOIC device with a serial SPI/QSPI/MICROWIRE-compatible interface, whereas the ADS7825UB/1K is a 28-pin SOIC device with a parallel interface and multiple analog input channels. A direct substitution is not possible without a complete PCB redesign and interface rework.
How do the sampling rates and resolution of these two ADCs compare?
The ADS7816U provides 12-bit resolution at a throughput rate of up to 200 kSPS. The ADS7825UB/1K provides 16-bit resolution at a throughput rate of up to 40 kSPS. The ADS7816U is therefore better suited to higher-speed, lower-resolution acquisition, while the ADS7825UB/1K targets higher-precision, lower-speed measurement applications.
What analog input configurations does each device support?
The ADS7816U has a single pseudo-differential input pair (IN+ and IN-), allowing one analog channel to be measured. The ADS7825UB/1K provides four single-ended inputs or two pseudo-differential input pairs, selectable via its input multiplexer. This makes the ADS7825UB/1K suitable for multi-channel systems, whereas the ADS7816U is limited to a single channel.
What digital interfaces do the ADS7816U and ADS7825UB/1K use?
The ADS7816U uses a serial interface compatible with SPI, QSPI, and MICROWIRE protocols, requiring few I/O lines and suiting space-constrained or isolated designs. The ADS7825UB/1K uses a parallel microprocessor interface with a full data bus and control lines, which is appropriate for systems with a parallel host bus but requires more PCB routing and pins.
How do the power supply requirements and power consumption differ?
The ADS7816U operates from a single 5 V supply and typically consumes a low operating current, making it suitable for power-sensitive designs. The ADS7825UB/1K operates from a 5 V supply with separate analog and digital supplies and includes a power-down mode; its higher resolution and multi-channel architecture result in higher overall power consumption than the ADS7816U. Designers should consult the respective datasheets for exact supply current and power-down specifications.
In which application scenarios would each device be preferred?
The ADS7816U is preferred for compact, cost-sensitive, single-channel data acquisition with moderate resolution and higher sampling rates, such as portable instruments, sensor interfaces, and battery-powered monitoring. The ADS7825UB/1K is preferred for multi-channel, high-precision measurement systems requiring 16-bit accuracy, such as industrial process control, instrumentation, and data acquisition systems where a parallel host interface is available.