Part A
ADS7809U
Texas Instruments
- Lifecycle
- Active
- Stock
- 6471 Stückzahl
- Package
- SOIC-20
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7804UB/1K is a viable functional replacement candidate for the ADS7809U, sharing the same 12-bit SAR architecture, 5V supply, and 28-pin SOIC footprint, though the designer must validate the slower 100 kSPS throughput and reduced analog input range against the target application requirements.
Resolution and Architecture
High match
Package and Pinout
High match
Sampling Rate
Validation required
Analog Input Range
Validation required
Parts at a glance
Part B
ADS7804UB/1K
Texas Instruments
- Lifecycle
- Active
- Stock
- 4479 Stückzahl
- Package
- SOIC-28
- Series
- Datenerfassung mit 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 | ADS7804UB/1K | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Resolution determines the smallest signal change the ADC can distinguish; a 16-bit device offers 16x finer quantization than a 12-bit device, so they are not functionally interchangeable where accuracy is critical. |
| Sampling Rate | 100 kSPS | 100 kSPS | Throughput must meet the system's signal bandwidth requirements; both devices share the same 100 kSPS maximum, so timing budgets are compatible. |
| Input Type | Single-ended | Single-ended | Input configuration dictates how the analog source connects; both accept single-ended signals, simplifying direct substitution at the front end. |
| Supply Voltage | 5 V | 5 V | Matching supply rails allows the parts to drop into the same power domain without regulator changes. |
| Interface | Parallel | Parallel | The digital interface must match the host controller; both use a parallel bus, so the same microcontroller or DSP port can drive either device. |
| Package | SOIC-28 | SOIC-28 | Package footprint and pinout determine board-level compatibility; identical SOIC-28 packages allow the same PCB land pattern to be reused. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range must cover the application environment; matching industrial ranges means both parts suit the same operating conditions. |
| Integral Nonlinearity (INL) | ±2 LSB (max) | ±0.5 LSB (max) | INL quantifies deviation from an ideal transfer function; the tighter INL of the 12-bit part reflects its lower resolution, and the absolute accuracy differs, affecting precision applications. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7809U | ADS7804UB/1K |
|---|---|---|
| Supplier | - | 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 the ADS7804UB/1K?
The ADS7809U is a 16-bit successive-approximation ADC, while the ADS7804UB/1K is a 12-bit successive-approximation ADC. Both are pin-compatible in the same 28-pin SOIC package and share the same internal reference and parallel interface architecture, but they differ in resolution, linearity, and dynamic performance specifications.
Are the ADS7809U and ADS7804UB/1K pin-compatible?
Yes. Both devices are offered in the same 28-pin SOIC (DW) package and share the same pinout, including the parallel data bus, control signals, and analog input pins. This allows a common PCB footprint, but the system must account for the different resolution and data format.
What is the resolution and data format of each device?
The ADS7809U provides 16-bit resolution with a full 16-bit parallel output word. The ADS7804UB/1K provides 12-bit resolution with a 12-bit parallel output word. The data bus width and the number of active data lines differ accordingly, so the host interface must be configured for the correct word length.
Do both parts use the same analog input range and reference?
Both devices integrate an internal reference and support a bipolar analog input range of ±10 V. The ADS7809U and ADS7804UB/1K both offer the same input configuration options, but the achievable accuracy and noise performance differ due to the resolution difference.
Can the ADS7804UB/1K be used as a drop-in replacement for the ADS7809U?
Not directly. Although the package and pinout are compatible, the ADS7804UB/1K is a 12-bit device and cannot provide the 16-bit resolution of the ADS7809U. A replacement requires verifying that 12-bit resolution, linearity, and dynamic performance meet the system requirements, and that the host interface is reconfigured for a 12-bit data word.
How do the throughput and conversion timing compare?
Both devices are specified for a maximum throughput of 100 kSPS with a conversion time of 8 µs typical. The ADS7809U and ADS7804UB/1K share the same successive-approximation architecture and timing control, so the conversion and acquisition timing are comparable when operated within the specified clock and control signal conditions.
What are the key linearity specifications for each device?
The ADS7809U is specified with ±1 LSB integral nonlinearity (INL) and ±1 LSB differential nonlinearity (DNL) for 16-bit operation. The ADS7804UB/1K is specified with ±0.5 LSB INL and ±0.5 LSB DNL for 12-bit operation. These specifications must be evaluated against the target system's accuracy budget.
Are the operating temperature ranges and supply requirements the same?
Both devices are specified for the industrial temperature range of −40 °C to +85 °C and operate from a +5 V analog supply with a separate +5 V digital supply. The ADS7809U and ADS7804UB/1K share the same supply and temperature specifications, so power and thermal design considerations are equivalent.