Part A
ADS7816U
Texas Instruments
- Lifecycle
- Active
- Stock
- 6722 PCS
- Package
- SOIC-8
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7816U and ADS7804UB are both 12-bit successive-approximation ADCs from Texas Instruments, but they differ in resolution-critical architecture, sampling rate, and package footprint. The ADS7816U offers a higher throughput of 200 kSPS in a compact SOIC-8 package, while the ADS7804UB provides 100 kSPS in a wider SOIC-28 package with a parallel interface. Designers should validate the interface timing, reference configuration, and board layout before substituting one for the other in an existing design.
Resolution and Architecture
Validation required
Sampling Rate
Not compatible
Package Type
Not compatible
Digital Interface
Validation required
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 | ADS7804UB | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so nominal resolution is equivalent for substitutability. |
| Sampling Rate | 200 kSPS | 100 kSPS | The ADS7816U supports a higher throughput, which matters if the application needs faster conversion rates. |
| Input Type | Single-ended | Single-ended | Both accept single-ended inputs, so signal conditioning topology can remain the same. |
| Interface | SPI / Serial | Parallel | The digital interface differs significantly; SPI versus parallel affects microcontroller pin count and firmware design. |
| Supply Voltage | 5 V | 5 V | Both operate from a 5 V supply, simplifying power rail compatibility. |
| Package | SOIC-8 | SOIC-28 | Different package footprints require board layout changes and are not drop-in compatible. |
| Reference | External | Internal | The ADS7804UB includes an internal reference, while the ADS7816U requires an external reference, affecting BOM and accuracy design. |
| Operating Temperature Range | -40 to +85 °C | -40 to +85 °C | Both cover the industrial temperature range, so environmental compatibility is equivalent. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7816U | ADS7804UB |
|---|---|---|
| Supplier | - | 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 | 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 ADS7804UB?
The ADS7816U is a 12-bit, 200-kSPS successive-approximation register (SAR) analog-to-digital converter with a pseudo-differential input and a serial SPI-compatible interface, housed in an SOIC-8 package. The ADS7804UB is a 12-bit, 100-kSPS SAR ADC with a full parallel 12-bit output interface and an internal reference, housed in a 28-pin SOIC package. The ADS7816U targets compact, low-power serial-interface designs, while the ADS7804UB targets parallel-bus systems requiring higher pin count and integrated reference circuitry.
Can the ADS7816U and ADS7804UB be used interchangeably in the same design?
No. The two devices differ in package footprint (SOIC-8 vs 28-pin SOIC), digital interface (serial SPI vs 12-bit parallel), sampling rate (200 kSPS vs 100 kSPS), and reference architecture. They are not pin-compatible or functionally interchangeable without a complete redesign of the PCB, interface logic, and reference circuitry.
How do the sampling rates of the ADS7816U and ADS7804UB compare?
The ADS7816U supports a maximum throughput of 200 kSPS, while the ADS7804UB supports a maximum throughput of 100 kSPS. Designs requiring higher sample rates should favor the ADS7816U, provided the serial interface and system timing can accommodate it.
What digital interfaces do the ADS7816U and ADS7804UB provide?
The ADS7816U provides a serial interface compatible with SPI, QSPI, and Microwire, using a chip-select, serial clock, and data-out line. The ADS7804UB provides a full 12-bit parallel data bus with associated control signals (CS, R/C, BYTE, and BUSY), making it suited to microprocessor or DSP parallel bus architectures.
Do the ADS7816U and ADS7804UB include an internal voltage reference?
The ADS7804UB integrates an internal reference and reference buffer, allowing ratiometric or absolute operation with minimal external components. The ADS7816U does not include an internal reference and requires an external reference voltage applied to its VREF pin. This difference affects board space, BOM count, and reference accuracy budgeting.
How do the power consumption and supply requirements differ between the ADS7816U and ADS7804UB?
The ADS7816U operates from a single 5 V supply with low power consumption typical of micropower SAR converters in an SOIC-8 package. The ADS7804UB also operates from a 5 V supply but includes additional internal circuitry (reference, parallel interface) that results in higher overall power dissipation. Exact quiescent and operating currents should be confirmed against the respective manufacturer datasheets for the target operating conditions.
What are the input configuration differences between the ADS7816U and ADS7804UB?
The ADS7816U offers a pseudo-differential input structure, allowing a signal input and a reference-level input to reject common-mode noise. The ADS7804UB provides a single-ended analog input with a defined input range set by the internal reference and configuration. The choice depends on whether the application benefits from pseudo-differential noise rejection or requires a standard single-ended parallel-bus front end.
Which device is better suited for space-constrained or portable designs?
The ADS7816U is generally better suited for space-constrained and portable designs due to its SOIC-8 package, serial interface requiring fewer I/O lines, and lower pin count. The ADS7804UB's 28-pin package and parallel interface are more appropriate for board-level systems where bus width and throughput are prioritized over footprint.