ADS7804U - 12-Bit 100 kSPS SAR ADC | Texas Instruments
MPN： ADS7804U ✓ 啟用中ADS7804U 概覽
An ADC is a data-conversion IC that transforms an analog voltage into a digital code for processing, storage, measurement, or control. The ADS7804U belongs to the SAR ADC hierarchy, which successively tests each bit of the result. Compared with flash and sigma-delta converters, a SAR ADC combines a straightforward conversion process, parallel data interface, and deterministic sampling behavior, making it suitable for instrumentation and control systems.
Key specifications include 12-bit resolution, 100 kSPS minimum sampling, 72 dB minimum SINAD with a 45 kHz input, and ±0.45 LSB maximum integral nonlinearity. The converter offers no missing codes and uses a full parallel output for direct interface with parallel digital buses or latches. Its specified operating-temperature range is -40 °C to +85 °C, and maximum power dissipation is 100 mW.
The ADS7804 is electrically pin-compatible with the 16-bit ADS7805, allowing engineers to reuse a board layout when the required conversion resolution changes. Its ±10 V input capability also permits bipolar analog signals to be measured from a single +5 V supply. The manufacturer datasheet discusses offset and full-scale error adjustment with fixed resistors, along with internal offset and gain adjustment for external trimming.
Typical uses include industrial process measurement, laboratory data acquisition, industrial control loops, embedded instrumentation, and digital panel systems. In each case, the 10 µs conversion time permits 100 kSPS sampling, while the 12-bit output provides 4096 digital codes across the ±10 V input range.
PCB design should prioritize short, shielded analog-input routing, adequate reference bypassing, and a clean digital return path. Because the ADS7804U uses a parallel interface, its 12 output bits can introduce switching activity next to the analog input, making grounding and component placement important. Designers should also verify supply tolerances and external-reference requirements against the system measurement accuracy.
This product page consolidates manufacturer specifications, current distributor pricing, verified drop-in alternatives, and practical engineering guidance. It also distinguishes true pin-compatible replacements from through-hole or function-only alternatives so engineers can make PCB-level decisions without assuming that a similar converter is electrically interchangeable.
直接替換替代品，適用於 ADS7804U — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ADS7804U （相同外形與佔位） — 差異在於 Package, Reference, Resolution, Operating Temperature, Analog Input Range.
ADS7804UB
✅ 直接替換📋 參考替代品（不在目錄中）
ADS7805PB
✅ 直接替換聯絡詢價
查看資料表 →ADS8504IDW
✅ 直接替換📋 參考替代品（不在目錄中）
ADS7804U 最大額定值與電氣特性
| ADC Type | 12-bit successive-approximation ADC |
| Number of Input Channels | 1 channel |
| 解析度 | 12 bits |
| Conversion Time | 10 µs |
| 取樣率 | 100 kSPS minimum |
| Analog Input Range | ±10 V |
| Signal-to-Noise and Distortion | 72 dB minimum SINAD with a 45 kHz input |
| Integral Nonlinearity | ±0.45 LSB maximum |
| Differential Nonlinearity | No missing codes |
| 供應電壓 | Single +5 V operation |
| Power Dissipation | 100 mW maximum |
| Output Interface | Full parallel data output |
| Reference | Internal or external reference |
| Integrated Functions | Sample-and-hold amplifier, reference, and clock |
| 工作溫度 | -40 °C to +85 °C |
| 封裝 | 28-pin SOIC (DW) |
| Package Width | 0.3 inch body width |
| Pin Compatibility | Pin-compatible with the 16-bit ADS7805 |
ADS7804U 0.3 inch body width 腳位配置指南
ADS7804U（0.3 inch body width 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： ADS7804U.
請參閱 資料表 以查看完整腳位配置。
典型應用
ADS7804U 適用於 6 應用s: Industrial Process Measurement, Laboratory Data Acquisition, Industrial Control Loops, Embedded Instrumentation, Digital Panel Meter, Signal-Conditioning Interface.
Industrial Process Measurement
The ADS7804U fits industrial process-measurement front ends that must acquire bipolar sensor signals up to ±10 V while operating from a single +5 V supply. Its 12-bit resolution provides 4096 codes, while the specified 100 kSPS minimum sampling rate and 10 µs conversion time allow comparatively rapid loop updates. The 72 dB minimum SINAD with a 45 kHz input supports general-purpose monitoring where higher precision is unnecessary. In a controller, the parallel output can feed latches or digital acquisition logic, although the 12-bit bus requires careful grounding and layout to prevent switching activity from coupling into the analog input.
推薦
Laboratory Data Acquisition
The ADS7804U is suitable for laboratory data-acquisition systems that need accurate bipolar sampling at a moderate rate without a complex serial interface. A 10 µs conversion time supports sampling at up to the specified 100 kSPS minimum rate, while the full parallel output permits direct capture by suitable FPGA or digital logic. Its ±0.45 LSB maximum integral nonlinearity and no-missing-code behavior help preserve continuity across the 12-bit code range. For laboratory use, the reference and input networks should be placed close to the device, and the system should verify its own noise, grounding, and calibration performance rather than relying only on converter specifications.
推薦
Industrial Control Loops
The ADS7804U can serve as the feedback converter in an industrial control loop where the measured control variable spans a bipolar ±10 V range. Its 100 kSPS minimum sampling rate gives designers substantially more acquisition headroom than a slow control loop generally consumes, while the 12-bit result provides 4096 digital steps for controller processing. The single +5 V supply simplifies power distribution, and the -40 °C to +85 °C operating range supports industrial temperature requirements. Because the parallel interface transitions can disturb sensitive analog nodes, route the input and reference paths away from output buses and maintain a low-impedance return between the converter and surrounding circuitry.
推薦
Embedded Instrumentation
The ADS7804U is appropriate for embedded instrumentation that acquires external analog measurements and presents them through a parallel digital subsystem. Its 10 µs conversion time and 100 kSPS sampling capability allow the instrument to measure successive sensor values quickly, while the 12-bit resolution balances information content against implementation complexity. The internal-or-external-reference choice gives designers flexibility: internal reference simplifies the design, whereas an external reference can support system-level calibration or a shared precision source. Firmware must account for calibration, polarity, and code interpretation, and the PCB must keep clock and digital-output activity away from the high-impedance analog input.
推薦
Digital Panel Meter
The ADS7804U can acquire the input of a digital panel meter that must display a bipolar analog measurement. A 12-bit result gives 4096 code levels, and the specified ±0.45 LSB maximum integral nonlinearity is suitable for many non-critical panel indications. The +5 V single-supply operation aligns with common embedded panel electronics, while the parallel interface allows direct connection to display-driver or processing logic. The actual display resolution must not be overstated: sensor accuracy, reference accuracy, analog-front-end noise, and calibration usually limit the complete instrument more than the ADC itself. A shielded analog section and stable reference are therefore essential for repeatable readings.
推薦
Signal-Conditioning Interface
The ADS7804U is useful as the conversion stage in a wider signal-conditioning interface that accepts ±10 V signals and produces a parallel digital measurement. Its 72 dB minimum SINAD with a 45 kHz input provides a defined AC performance basis, and the 100 kSPS minimum sampling rate gives sufficient margin for many monitoring and feedback functions. The manufacturer datasheet specifically addresses offset and full-scale error adjustment using fixed resistors, making the converter relevant to systems requiring calibration. Designers should use those documented adjustment methods and validate the complete analog front end, because input noise, reference drift, and resistor tolerance can dominate final measurement uncertainty.
推薦
推薦產品摘要
工程參考資料，適用於 ADS7804U — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ADS7804UB | ADS7805 | ADS8504IDW |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-pin SOIC (DW) | 28-pin SOIC (DW) | 28-pin SOIC (DW) | 28-pin SOIC (DW) |
主要差異化特點
- Direct higher-resolution family upgrade path (對比ADS7805)
- Closest verified same-footprint orderable alternative (對比ADS7804UB)
- Single-supply bipolar input capability (對比ADS8504IDW)
設計說明
Route the analog input, reference, and ground paths away from the 12 parallel output lines and associated clock signals. Place input and reference components close to their corresponding device pins, use a continuous ground reference beneath the analog section, and avoid switching-current paths beneath the input node. Parallel-output transition activity can couple into a high-impedance analog circuit even when the converter itself has low power dissipation. Validate the completed layout with a system noise test rather than inferring isolation solely from the 72 dB SINAD specification.
Use the manufacturer's single +5 V supply arrangement and provide local high-frequency decoupling at the supply pins. The datasheet identifies 100 mW as the maximum power dissipation, but actual converter energy is affected by supply voltage, conversion activity, reference implementation, and digital-output loading. Do not select local capacitors solely by nominal capacitance; check effective capacitance, DC bias behavior, dielectric class, and placement. Confirm the power budget under worst-case conversion rate and output-state combinations before releasing the board.
Do not equate the 12-bit nominal resolution with 12-bit measurement accuracy. The complete error budget also includes offset, full-scale error, integral and differential nonlinearity, reference error, input noise, analog-front-end error, and calibration residuals. The manufacturer datasheet addresses offset and gain adjustment using fixed resistors and describes external trimming. Follow those documented procedures, retain calibration records, and avoid assuming that the ±0.45 LSB INL limit accounts for every error contribution in the finished instrument.
Treat the parallel data bus as a potentially noisy digital interface. Keep traces short where possible, use an appropriate termination or buffer strategy when longer routing is unavoidable, and sequence or isolate digital outputs during sensitive acquisition periods. Maintain a low-impedance reference and analog ground at the converter. Because the supplied source set does not expose the complete pin table, verify every signal, supply, and no-connect position against revision A of the official Texas Instruments ADS7804 datasheet before fabrication.
合規資訊
The supplied sources identify the product as a green RoHS-compliant Texas Instruments component, but they do not provide a specific compliance declaration for the remaining environmental or automotive categories. ADS7804U is an analog-to-digital converter rather than an AEC-Q100-qualified automotive device.