Part A
ADS7816U
Texas Instruments
- Lifecycle
- Active
- Stock
- 6722 PCS
- Package
- SOIC-8
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Not a drop-in replacement
The ADS7816U and ADS7804UB/1K are not drop-in replacements for each other. The ADS7816U is a 12-bit, 200 kSPS successive-approximation ADC in a small 8-pin SOIC package with a serial interface, while the ADS7804UB/1K is a 12-bit, 100 kSPS sampling ADC in a 28-pin SOIC package with a parallel interface. The differences in resolution-adjacent sampling rate, package footprint, pin count, and digital interface architecture require a full redesign of the host board and firmware, so substitution is not feasible without significant engineering changes.
Different package footprint
Different digital interface
Different sampling rate
Different pin count
Parts at a glance
Part B
ADS7804UB/1K
Texas Instruments
- Lifecycle
- Active
- Stock
- 4479 PCS
- Package
- SOIC-28
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (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 | ADS7804UB/1K | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so digital output word width is equivalent for system integration. |
| Sampling Rate | 200 kSPS | 100 kSPS | The ADS7816U supports a higher throughput, which affects maximum signal bandwidth and timing budget. |
| Input Type | Single-ended | Single-ended | Both accept single-ended analog inputs, simplifying front-end signal conditioning requirements. |
| Number of Input Channels | 1 | 1 | Single-channel architecture means both suit one-signal acquisition paths without multiplexing. |
| Interface | SPI / Serial | Parallel | The interface type determines microcontroller pin count and firmware complexity; these parts are not drop-in compatible. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply) | Both operate from a 5 V rail, so power supply design can remain similar. |
| Reference Type | External | Internal | Internal vs external reference changes accuracy budget and external component count. |
| Package / Mounting | SOIC-8 (surface mount) | SOIC-28 (surface mount) | Different package footprints prevent direct board-level substitution without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent industrial temperature ratings mean both suit similar environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7816U | ADS7804UB/1K |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Obsolete |
| 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 the ADS7804UB/1K?
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/1K is a 12-bit, 100-kSPS SAR ADC with a full 16-bit parallel data bus and an internal reference, offered in a 28-pin SOIC package. The ADS7816U targets compact, low-power serial-interface designs, while the ADS7804UB/1K targets parallel-bus systems requiring higher throughput bus access and an integrated reference.
Can the ADS7816U be used as a drop-in replacement for the ADS7804UB/1K?
No. The two devices differ in package footprint (SOIC-8 versus 28-pin SOIC), digital interface (serial SPI versus 16-bit parallel), sampling rate (200 kSPS versus 100 kSPS), and reference architecture (external reference versus internal reference on the ADS7804UB/1K). A direct drop-in substitution is not possible without a PCB redesign and interface rework.
How do the sampling rates and throughput of the ADS7816U and ADS7804UB/1K compare?
The ADS7816U supports a maximum sampling rate of 200 kSPS, while the ADS7804UB/1K supports a maximum sampling rate of 100 kSPS. The ADS7816U therefore offers twice the throughput of the ADS7804UB/1K, which is relevant for applications requiring faster conversion cycles.
What are the differences in digital interface between the ADS7816U and ADS7804UB/1K?
The ADS7816U provides a serial interface compatible with SPI, QSPI, and Microwire, using a chip-select, serial clock, and serial data output. The ADS7804UB/1K provides a 16-bit parallel data bus with associated control signals (CS, R/C, BYTE, and BUSY). The serial interface of the ADS7816U reduces pin count and simplifies isolation, while the parallel interface of the ADS7804UB/1K suits high-speed bus-connected systems.
Do the ADS7816U and ADS7804UB/1K differ in reference voltage requirements?
Yes. The ADS7816U requires an external reference voltage applied to its VREF pin to define the input full-scale range. The ADS7804UB/1K includes an internal reference and also allows the use of an external reference. Designs using the ADS7816U must therefore provide a stable external reference, whereas the ADS7804UB/1K can operate with its internal reference.
How do the power supply and power consumption of the ADS7816U and ADS7804UB/1K compare?
The ADS7816U operates from a single 5 V supply and is specified for low power consumption, making it suitable for battery-powered and portable systems. The ADS7804UB/1K also operates from a 5 V supply but, as a parallel-interface device with an internal reference, typically dissipates more power than the ADS7816U. Designers should consult the respective datasheets for exact quiescent and operating current specifications.
What are the input configuration differences between the ADS7816U and ADS7804UB/1K?
The ADS7816U provides a pseudo-differential input pair (IN+ and IN−) that allows rejection of common-mode signals within the specified range. The ADS7804UB/1K provides a single-ended analog input with a defined input range set by the reference. The pseudo-differential input of the ADS7816U can be advantageous in noisy environments where common-mode rejection is needed.
Which applications are better suited to the ADS7816U versus the ADS7804UB/1K?
The ADS7816U is well suited to space-constrained, low-power, serial-interface designs such as portable instrumentation, remote sensors, and isolated data acquisition. The ADS7804UB/1K is better suited to systems with a parallel microprocessor bus, higher bus bandwidth requirements, and a need for an integrated reference, such as industrial control and legacy parallel-interface data acquisition cards.