Part A
ADS7809U
Техасские инструменты
- Lifecycle
- Active
- Stock
- 6471 ПКС
- Package
- SOIC-20
- Series
- Сбор данных - аналогово-цифровые преобразователи (ADC)
Replacement verdict
Not a drop-in replacement
The ADS7809U and ADS7800KUG4 are not drop-in replacements for one another. Although both are 12-bit successive-approximation ADCs, they differ in resolution-critical architecture, package footprint, and interface timing, so substituting one for the other requires board-level redesign and firmware validation rather than direct replacement.
Different package footprint
Different interface timing
Different conversion architecture
Different supply configuration
Parts at a glance
Part B
ADS7800KUG4
Техасские инструменты
- Lifecycle
- Active
- Stock
- 2642 ПКС
- Package
- SOIC-24
- Series
- Сбор данных - аналогово-цифровые преобразователи (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 | ADS7800KUG4 | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Resolution determines the smallest analog increment the ADC can distinguish; a 16-bit part offers 16x finer quantization than a 12-bit part, so they are not functionally interchangeable in precision applications. |
| Sampling Rate | 100 kSPS | 333 kSPS | Maximum throughput limits the bandwidth of signals that can be digitized; the ADS7800KUG4 samples over 3x faster, which matters for faster-changing inputs. |
| Input Type | Single-ended | Single-ended | Input configuration affects how the signal source must be connected; both are single-ended, so the same signal conditioning topology can be reused. |
| Supply Voltage | 5 V (single supply) | 5 V and -15 V (dual supply) | Supply requirements dictate board-level power design; the ADS7800KUG4 needs a negative rail while the ADS7809U runs from a single 5 V supply, affecting direct substitution. |
| Interface | Serial (SPI/QSPI compatible) | Parallel | The digital interface must match the host controller; serial vs parallel output requires different pin connections and firmware, preventing drop-in replacement. |
| Package | 28-pin SOIC | 28-pin SOIC | Package footprint determines PCB compatibility; both share the same 28-pin SOIC outline, so the land pattern is reusable. |
| Integral Nonlinearity (INL) | ±2 LSB (max) | ±0.5 LSB (max) | INL measures deviation from an ideal transfer function; tighter INL yields better absolute accuracy, and the values differ between the two parts. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range defines the environments where the part is guaranteed to meet specs; identical ranges mean equivalent environmental suitability. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7809U | ADS7800KUG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Discontinued at Digi-Key |
| Number of Bits | 16 | 12 |
| Sampling Rate(Per Second) | 100k | 333k |
| 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 | Internal |
| Voltage - Supply, Analog | 5V | 5V, -11.4V ~ 16.5V |
| 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 ADS7800KUG4?
The ADS7809U is a 16-bit successive-approximation ADC with a serial interface, while the ADS7800KUG4 is a 12-bit successive-approximation ADC with a parallel interface. The ADS7809U offers higher resolution (16-bit vs 12-bit) and a different digital interface architecture, making them non-interchangeable in most designs.
Do the ADS7809U and ADS7800KUG4 have the same package and pinout?
No. The ADS7809U is supplied in a 28-pin SOIC package, while the ADS7800KUG4 is supplied in a 28-pin SOIC package as well, but the pin functions differ due to the different interface types (serial vs parallel) and control signal assignments. They are not pin-compatible substitutes.
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 ADS7800KUG4 provides 12-bit resolution with a maximum sampling rate of 333 kSPS. The ADS7800KUG4 offers faster throughput at lower resolution, while the ADS7809U prioritizes higher precision.
What digital interfaces do these ADCs use?
The ADS7809U uses a serial interface for data output, which reduces pin count and simplifies isolation. The ADS7800KUG4 uses a parallel interface for data output, providing simultaneous access to all data bits. The interface choice affects microcontroller or FPGA connection requirements and PCB routing.
Are the analog input ranges the same for both parts?
Both devices support bipolar input ranges of ±10 V and ±5 V, as well as a unipolar 0 V to 10 V range, configurable via external connections. The input range configuration differs in pin strapping and reference requirements, so the datasheet for each part must be consulted for exact wiring.
Can the ADS7809U directly replace the ADS7800KUG4 in an existing design?
No. The ADS7809U cannot directly replace the ADS7800KUG4 because the resolution (16-bit vs 12-bit), digital interface (serial vs parallel), and control signal timing differ. A redesign of the digital interface, timing, and data processing is required, and the replacement must be validated against both datasheets.
What are the power supply requirements for each device?
Both the ADS7809U and ADS7800KUG4 operate from a single +5 V analog supply and a +5 V digital supply. The ADS7809U additionally requires an external reference or uses its internal reference, and the ADS7800KUG4 similarly supports internal or external reference operation. Exact supply tolerances and current consumption should be verified from the respective manufacturer datasheets.
Which part is better suited for high-precision measurement applications?
The ADS7809U is better suited for high-precision measurement applications due to its 16-bit resolution, which provides finer quantization steps than the 12-bit ADS7800KUG4. However, the ADS7800KUG4 offers higher sampling throughput, making it preferable for faster, lower-resolution acquisition systems.