Part A
ADS7809U
Texas Dụng cụ
- Lifecycle
- Active
- Stock
- 6471 PCS
- Package
- SOIC-20
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7804UE4 is a functionally compatible replacement candidate for the ADS7809U, sharing the same 12-bit SAR architecture, 5V supply, and 28-pin SOIC footprint. Designers should validate the serial interface configuration and timing before substitution, as the two devices differ in their digital I/O interface implementation.
Resolution and Architecture
High match
Package Type
High match
Digital Interface
Validation required
Supply Voltage
High match
Parts at a glance
Part B
ADS7804UE4
Texas Dụng cụ
- Lifecycle
- Active
- Stock
- 4392 PCS
- Package
- SOIC-28
- Series
- Data Acquisition - 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 | ADS7809U | ADS7804UE4 | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Resolution determines the smallest analog signal change the ADC can distinguish; a 16-bit device offers far finer quantization than a 12-bit device, so they are not functionally interchangeable in precision applications. |
| Sampling Rate | 100 kSPS | 100 kSPS | The maximum conversion throughput must meet the system's signal bandwidth requirements; matching rates simplify timing design but do not compensate for resolution differences. |
| Input Type | Single-ended | Single-ended | Single-ended inputs simplify front-end design but offer less common-mode noise rejection than differential inputs; both parts share the same input topology here. |
| Supply Voltage | 5 V | 5 V | Supply voltage must match the system rail; both devices operate from a single 5 V supply, easing power-rail compatibility. |
| Interface | Parallel | Parallel | The digital interface must match the host controller's bus; both use a parallel interface, but the data word width differs due to resolution. |
| Package / Mounting | 28-SOIC (surface mount) | 28-SOIC (surface mount) | Package and footprint compatibility determine whether a part can be dropped into an existing board layout without redesign. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range must cover the application environment; identical industrial ranges mean both suit the same operating conditions. |
| Reference Type | Internal | Internal | An internal reference reduces external component count and board space; both parts integrate the reference, simplifying the analog front end. |
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 | ADS7809U | ADS7804UE4 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,Texas Instruments |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 12 |
| Sampling Rate(Per Second) | 100k | 100k |
| Number of Inputs | 1 | 1 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI, DSP | 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, Internal | 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 ADS7809U and ADS7804UE4?
The ADS7809U is a 16-bit successive-approximation ADC with a serial (SPI-compatible) interface, while the ADS7804UE4 is a 12-bit successive-approximation ADC with a parallel interface. The ADS7809U offers higher resolution (16-bit vs 12-bit) and a serial output, whereas the ADS7804UE4 provides a parallel data bus. Both are single-channel, bipolar-input ADCs from Texas Instruments in a 28-pin SOIC package.
Are the ADS7809U and ADS7804UE4 pin-compatible?
No. Although both devices are housed in a 28-pin SOIC (DW) package, their pin functions differ because the ADS7809U uses a serial interface and the ADS7804UE4 uses a parallel interface. The digital I/O pins are not interchangeable, so they cannot be treated as drop-in replacements without verifying the pinout against the respective datasheets.
What is the resolution and sampling rate of each device?
The ADS7809U provides 16-bit resolution with a maximum sampling rate of 100 kSPS. The ADS7804UE4 provides 12-bit resolution with a maximum sampling rate of 100 kSPS. Both operate at the same throughput but differ in resolution and output format.
What input voltage range do these ADCs support?
Both the ADS7809U and ADS7804UE4 are bipolar-input ADCs supporting a ±10 V input range. The full-scale input span is 20 V (±10 V), making them suitable for industrial and instrumentation applications requiring wide bipolar signal acquisition.
What digital interface does each device use?
The ADS7809U uses a serial interface compatible with SPI and similar synchronous serial protocols, outputting data on a single serial data line. The ADS7804UE4 uses a parallel interface with a 12-bit-wide data bus plus control signals. The interface choice is a primary selection criterion between the two parts.
Do both devices operate from the same supply voltage?
Both the ADS7809U and ADS7804UE4 operate from a single +5 V analog supply for their analog and digital circuitry, consistent with the ADS780x family. Designers should confirm exact supply and reference requirements against the respective manufacturer datasheets before finalizing a design.
Can the ADS7809U directly replace the ADS7804UE4 in an existing design?
No, not directly. Because the ADS7809U uses a serial interface and the ADS7804UE4 uses a parallel interface, the host processor interface, PCB routing, and firmware would need to be redesigned. Additionally, the resolution differs (16-bit vs 12-bit), so system-level accuracy and data-handling requirements must be revalidated.
Are both parts available in the same package type?
Yes. Both the ADS7809U and ADS7804UE4 are offered in a 28-pin SOIC (DW) package. However, identical package outline does not imply pin-for-pin compatibility, since the pin assignments differ between the serial and parallel interface variants.