AD775JR - 8-Bit 20 MSPS Low-Power ADC | Analog Devices
MPN： AD775JR ✓ 啟用中AD775JR 概覽
An ADC is a data-conversion IC that transforms an analog input voltage into a digital code. The AD775 belongs to the sampling ADC hierarchy, with its 8-bit parallel outputs providing a direct digital interface to a controller, DSP, FPGA, or data-acquisition system. Its flash-based sampling architecture is intended for high-speed signal capture without the complexity of a much higher-resolution converter.
Key features include a sampling rate of 20 MSPS, 11 pF typical input capacitance, 60 mW power dissipation, and +5 V single-supply operation. The converter also specifies 0.3 LSB differential nonlinearity, 1% differential gain, and 0.5 degrees differential phase. Three-state outputs allow the parallel interface to share buses with other devices, while the integrated sampling function simplifies front-end design.
Internally, the AD775 uses a pipelined/ping-pong two-step flash architecture capable of operation up to 35 MHz while maintaining low power consumption. This architecture provides a practical balance between conversion speed, circuit complexity, and power efficiency. The low 11 pF typical input capacitance makes the ADC comparatively easy to drive, reducing the burden on the preceding amplifier or signal source.
Typical applications include industrial control and instrumentation, communications receivers, data-acquisition systems, digital oscilloscopes, and embedded measurement platforms. It is particularly suitable where an 8-bit parallel result and rapid sampling are sufficient, such as waveform capture, feedback monitoring, communications demodulation, and sensor-interface designs.
Designers should account for the ADC input drive requirements, supply bypassing, and digital output timing. Because the outputs are three-state, output-enable control must prevent multiple devices from driving a shared parallel bus simultaneously. The manufacturer datasheet should also be consulted for the complete application circuit, recommended decoupling values, acquisition timing, and input-range configuration before PCB release.
This page consolidates verified manufacturer specifications, current distributor pricing, application guidance, and verified-source limitations into a design-oriented resource. It also explicitly distinguishes documented AD775-family behavior from unverified substitute claims, helping engineers avoid assuming that a converter with a similar resolution and speed is pin-to-pin compatible.
直接替換替代品，適用於 AD775JR — 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。
此產品無可直接替換的替代品。
申請替代品AD775JR 最大額定值與電氣特性
| Converter Type | Sampling analog-to-digital converter |
| 解析度 | 8 bits |
| 取樣率 | 20 MSPS |
| Architecture | Pipelined/ping-pong two-step flash architecture |
| Maximum Clock Rate | Up to 35 MHz |
| 供應電壓 | +5 V single supply |
| Power Dissipation | 60 mW |
| Process Technology | CMOS |
| 輸入電容 | 11 pF typical |
| Differential Nonlinearity | 0.3 LSB |
| Differential Gain | 1% |
| Differential Phase | 0.5 degrees |
| Output Interface | Three-state parallel outputs |
| Integrated Functions | On-chip sampling function and reference bias resistors |
| 封裝 | 24-pin SOIC |
| Commercial Operating Temperature Range | -20°C to +75°C |
| 安裝類型 | Surface mount |
| Price | From $13.3159 as of 2026-10-28 |
AD775JR 24-pin soic 腳位配置指南
AD775JR（24-pin soic 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： AD775JR.
請參閱 資料表 以查看完整腳位配置。
典型應用
AD775JR 適用於 6 應用s: Digital Oscilloscope Acquisition, Communications Receiver, Industrial Process Monitoring, Embedded Data-Acquisition System, Waveform Feedback Control, Portable Measurement Instrument.
Digital Oscilloscope Acquisition
The AD775JR fits digital oscilloscope front ends that require rapid repeated sampling but can represent the measured waveform with 8-bit resolution. Its 20 MSPS conversion rate supports waveform capture, while the three-state parallel outputs can be connected to acquisition logic when bus isolation is controlled. The 11 pF typical input capacitance is also helpful when driving the ADC from a bandwidth-limited amplifier. Designers must still verify analog bandwidth, settling time, and acquisition timing in the complete signal chain, because the converter's sample rate alone does not guarantee oscilloscope accuracy.
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Communications Receiver
The AD775JR can serve as a sampling ADC in communications receiver and demodulation circuits where 20 MSPS sampling and an 8-bit parallel result provide an effective balance between data rate and power. The 60 mW dissipation supports compact receiver hardware, and three-state outputs facilitate controlled connection to digital processors. The low 11 pF typical input capacitance may simplify interface with the preceding RF or IF signal-conditioning stage. Actual receiver suitability depends on the required occupied bandwidth, signal-to-noise ratio, and clocking accuracy, which must be evaluated against the system specification.
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Industrial Process Monitoring
The AD775JR is appropriate for industrial process-monitoring systems that repeatedly sample a sensor signal and require fast digital conversion without the power cost of a high-resolution converter. Its 20 MSPS sampling rate allows rapid data acquisition, while the 60 mW operating power helps contain thermal load in distributed instrumentation. The single +5 V supply and three-state parallel interface simplify integration with embedded controllers. Engineers should select the external analog front end to preserve the AD775's documented differential nonlinearity, gain, and phase behavior over the complete operating range.
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Embedded Data-Acquisition System
The AD775JR can provide the sampling stage for an embedded data-acquisition system requiring 8-bit data at high throughput. The parallel outputs can feed a controller, DSP, or FPGA when timing and output-enable sequencing are implemented correctly. At 60 mW, the converter is practical for space- and power-conscious instrumentation, and its 11 pF typical input capacitance reduces loading on the source. A complete design must account for acquisition time, source settling, clock jitter, and the lack of a verified published pin list in the supplied excerpts before layout is finalized.
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Waveform Feedback Control
The AD775JR can serve in waveform-feedback and servo-control loops where the controller needs frequent samples of an analog correction signal. Its 20 MSPS conversion capability provides a higher sampling rate than many general-purpose low-resolution converters, and the pipelined/ping-pong two-step flash architecture helps support sustained acquisition. The three-state output feature allows controlled bus sharing when several converters are present. Loop stability and signal fidelity still depend on the complete analog path, controller latency, and output timing, so the AD775 datasheet must guide the timing design.
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Portable Measurement Instrument
The AD775JR is suitable for portable measurement instruments because it combines 20 MSPS sampling with 60 mW power dissipation in a 24-pin SOIC package. A compact sensor interface can use the converter's 11 pF typical input capacitance without imposing a heavy load, while the parallel digital interface can connect to a low-power embedded controller. Its 8-bit resolution is best suited to measurements that do not require finer quantization. Designers should verify battery-rail regulation, analog signal range, thermal behavior, and acquisition timing under the intended enclosure and operating conditions.
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工程參考資料，適用於 AD775JR — 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 |
|---|---|
| Brand | Analog Devices |
| Package | 24-pin SOIC |
| Resolution | 8 bits |
| Sampling Rate | 20 MSPS |
| Supply Voltage | +5 V single supply |
| Power Dissipation | 60 mW |
| Input Capacitance | 11 pF typical |
| Output Interface | Three-state parallel outputs |
| Differential Nonlinearity | 0.3 LSB |
| Differential Gain | 1% |
| Differential Phase | 0.5 degrees |
| Operating Temperature Range | -20°C to +75°C commercial |
主要差異化特點
- High sampling rate with low specified power dissipation (對比Generic 8-bit flash ADC)
- Low input loading for source-driven systems (對比Higher-capacitance conventional flash converter)
- Integrated sampling and reference-bias support (對比Generic 8-bit sampling ADC)
- Three-state parallel interface (對比Converter without bus-output disable)
設計說明
Follow the decoupling and reference-bias configuration shown in the official Analog Devices AD775 datasheet when laying out the board. The verified material identifies on-chip reference bias resistors, but it does not provide the recommended capacitor values or complete return paths in the supplied excerpts. Place required supply and bypass capacitors adjacent to their associated pins, provide a low-impedance analog return, and keep high-current digital output transitions away from sensitive input and reference nodes.
Treat the clock and digital outputs as timing-critical interfaces. The AD775 uses a pipelined/ping-pong architecture, so the external clock quality, output timing, and enable sequencing directly affect valid conversion data. Route clock and data traces with controlled return paths, avoid unnecessary stubs, and use the manufacturer's timing definitions when selecting a controller or FPGA interface. The three-state outputs must never be enabled simultaneously on a shared bus.
Do not select a generic 8-bit, 20 MSPS ADC as a drop-in replacement without checking the complete pinout and interface behavior. Same resolution and sampling rate do not guarantee compatibility of input range, reference pins, clock polarity, output enable logic, or three-state timing. Because no verified replacement was identified for the AD775JR, compare any proposed substitute against the official 24-pin SOIC pinout, acquisition circuit, and digital timing tables before changing the BOM.
Estimated: the AD775JR's specified 60 mW dissipation applies during the documented operating conditions. Actual board-level consumption depends on clock rate, output toggling, supply voltage, and external circuitry, so measure the complete analog and digital rails under the intended load. Keep the 5 V supply stable, use local bypassing, and avoid placing the converter's switching and output activity next to sensitive signal paths.
合規資訊
The supplied verified excerpts do not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. The documented commercial temperature range is -20°C to +75°C, but it does not establish automotive qualification.
