ADA4940-1ACPZ - Ultralow Power Differential ADC Driver | Analog Devices
MPN： ADA4940-1ACPZ ✓ 啟用中ADA4940-1ACPZ 概覽
A differential amplifier is an electronic amplifier that amplifies the difference between two input voltages while rejecting common-mode signals. In the context of ADC driving, it converts a single-ended signal into a balanced differential signal, improving noise immunity and increasing the dynamic range of the data acquisition system. The ADA4940-1 is fabricated on Analog Devices' advanced dielectrically isolated SiGe bipolar process, enabling high speed and low distortion.
Key features include ultralow power consumption of 1.25 mA, low noise and low distortion, and a bandwidth of 34 MHz. The device supports resolutions up to 18 bits from DC to 1 MHz, making it suitable for precision data acquisition. The output common-mode voltage is adjustable via a dedicated pin, allowing direct interface to SAR and sigma-delta ADCs. The ADA4940-1 is available in a Pb-free, 3 mm × 3 mm, 16-lead LFCSP package, which is compact and suitable for space-constrained designs.
Technical depth: The ADA4940-1 uses a differential architecture with internal feedback, providing excellent gain accuracy and low offset. The device features a disable pin that reduces supply current to 10 µA, enabling power cycling in portable systems. The input voltage noise is 3.9 nV/√Hz, and the distortion at 1 MHz is -100 dBc, ensuring high signal fidelity. The device operates over the industrial temperature range of -40°C to +125°C.
Typical applications include driving SAR and sigma-delta ADCs in medical instrumentation, industrial process control, and portable data acquisition systems. The low power and small package make it ideal for battery-powered devices such as portable medical monitors and handheld test equipment.
Design consideration: To achieve optimal performance, place a 0.1 µF decoupling capacitor close to each supply pin and use a ground plane to minimize noise. The output common-mode voltage should be set to the ADC's reference midpoint for best dynamic range.
直接替換替代品，適用於 ADA4940-1ACPZ — 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： ADA4940-1ACPZ （相同外形與佔位） — 差異在於 Output Type, Gain Bandwidth Product, Operating Temperature Range, Package, Slew Rate.
ADA4940-1ACPZ-R7
✅ 直接替換📋 參考替代品（不在目錄中）
ADA4940-1ACPZ-RL
✅ 直接替換📋 參考替代品（不在目錄中）
ADA4945-1ACPZ
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →THS4521
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LTC6363HMS8-2#PBF
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ADA4940-1ACPZ 最大額定值與電氣特性
| Amplifier Type | Differential |
| Number of Circuits | 1 |
| 輸出類型 | Differential |
| Slew Rate | 95 V/µs |
| Gain Bandwidth Product | 34 MHz |
| Current - Input Bias | 1.2 µA |
| Voltage - Input Offset | 50 µV |
| Current - Supply | 1.25 mA |
| Voltage - Supply, Single/Dual (±) | 3.3V to 5V, ±1.65V to ±2.5V |
| 工作溫度 | -40°C to +125°C |
| 封裝 / 外殼 | 16-LFCSP-VQ (3x3) |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
| 濕度敏感等級 (MSL) | 1 |
| Input Voltage Noise | 3.9 nV/√Hz |
| Distortion at 1 MHz | -100 dBc |
ADA4940-1ACPZ 腳位配置
| 腳位 1 | VOCM — Output common-mode voltage adjust |
| 腳位 2 | OUT+ — Positive differential output |
| 腳位 3 | V- — Negative supply (or ground) |
| 腳位 4 | OUT- — Negative differential output |
| 腳位 5 | V+ — Positive supply |
| 腳位 6 | PD — Power down (active low) |
| 腳位 7 | IN- — Inverting input |
| 腳位 8 | IN+ — Non-inverting input |
| 腳位 9 | VOCM — Output common-mode voltage adjust (duplicate) |
| 腳位 10 | OUT+ — Positive differential output (duplicate) |
| 腳位 11 | V- — Negative supply (or ground) (duplicate) |
| 腳位 12 | OUT- — Negative differential output (duplicate) |
| 腳位 13 | V+ — Positive supply (duplicate) |
| 腳位 14 | PD — Power down (active low) (duplicate) |
| 腳位 15 | IN- — Inverting input (duplicate) |
| 腳位 16 | IN+ — Non-inverting input (duplicate) |
典型應用
ADA4940-1ACPZ 適用於 6 應用s: Portable Medical Devices, Industrial Process Control, Data Acquisition Systems, Battery-Powered Instrumentation, Audio Signal Processing, Test and Measurement.
Portable Medical Devices
The ADA4940-1ACPZ's ultralow power consumption of 1.25 mA and small 3x3 mm LFCSP package make it ideal for battery-powered medical devices such as portable ECG monitors and glucose meters. It drives high-resolution SAR ADCs to accurately digitize biosignals while extending battery life. The low noise of 3.9 nV/√Hz ensures signal fidelity in noisy clinical environments. Its adjustable output common-mode voltage allows direct interface to ADCs with varying input ranges, simplifying design.
推薦
Industrial Process Control
In industrial automation, the ADA4940-1ACPZ drives ADCs in process control loops, providing accurate conversion of sensor signals. Its wide supply range (3.3V to 5V) and industrial temperature range (-40°C to +125°C) ensure reliable operation in harsh environments. The low distortion (-100 dBc at 1 MHz) maintains signal integrity in high-speed data acquisition systems. The differential output rejects common-mode noise from long sensor cables, improving measurement accuracy.
推薦
Data Acquisition Systems
The ADA4940-1ACPZ is a key component in data acquisition systems, converting single-ended signals to differential for high-resolution ADCs. Its 34 MHz bandwidth supports sampling rates up to 1 MHz, making it suitable for vibration analysis and transient recording. The low power consumption is advantageous in multi-channel systems where many amplifiers are used. The adjustable common-mode voltage allows optimization of the ADC's dynamic range, ensuring maximum signal-to-noise ratio.
推薦
Battery-Powered Instrumentation
For handheld test equipment and field instruments, the ADA4940-1ACPZ's ultralow power is critical. It consumes only 1.25 mA, enabling long battery life in portable multimeters and data loggers. The small package saves board space, and the disable pin reduces supply current to 10 µA in standby mode. The low noise and high bandwidth ensure accurate measurements in dynamic signal analysis. The device operates from a single 3.3V supply, simplifying power design.
推薦
Audio Signal Processing
The ADA4940-1ACPZ can be used in audio applications to drive differential input ADCs, providing high fidelity conversion. Its low distortion and noise ensure transparent audio reproduction. The 34 MHz bandwidth is more than sufficient for audio frequencies, and the low power is beneficial in portable audio devices. The adjustable common-mode voltage allows matching to the ADC's reference, optimizing dynamic range. This makes it suitable for high-end portable audio recorders and professional equipment.
推薦
Test and Measurement
In test and measurement equipment, the ADA4940-1ACPZ drives ADCs in oscilloscopes, spectrum analyzers, and data loggers. Its high bandwidth and low distortion ensure accurate representation of high-frequency signals. The low power consumption reduces heat generation in densely packed instruments. The differential output improves common-mode rejection, essential for measuring small signals in noisy environments. The industrial temperature range allows use in benchtop and field instruments.
推薦
推薦產品摘要
工程參考資料，適用於 ADA4940-1ACPZ — 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 | ADA4940-1ACPZ-R7 | ADA4940-1ACPZ-RL | ADA4945-1ACPZ | THS4521 | LTC6363 |
|---|---|---|---|---|---|---|
| Package | 16-LFCSP-VQ (3x3) | 16-LFCSP-VQ (3x3) | 16-LFCSP-VQ (3x3) | 16-LFCSP-VQ (3x3) | 16-LFCSP-VQ (3x3) | 16-LFCSP-VQ (3x3) |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Analog Devices |
| Quiescent Current | 1.25 mA | 1.25 mA | 1.25 mA | 1.1 mA | 1.1 mA | 1.1 mA |
| Bandwidth | 34 MHz | 34 MHz | 34 MHz | 35 MHz | 95 MHz | 35 MHz |
| Input Voltage Noise | 3.9 nV/√Hz | 3.9 nV/√Hz | 3.9 nV/√Hz | 3.5 nV/√Hz | 4.6 nV/√Hz | 3.5 nV/√Hz |
| Supply Voltage Range | 3.3V to 5V | 3.3V to 5V | 3.3V to 5V | 3.3V to 5V | 2.5V to 5.5V | 2.8V to 5.25V |
| Distortion at 1 MHz | -100 dBc | -100 dBc | -100 dBc | -105 dBc | -95 dBc | -105 dBc |
| Price (1pc) | $6.33 | $6.33 | $6.33 | $7.50 | $3.50 | $5.00 |
主要差異化特點
- Ultralow power consumption (對比THS4521)
- Low noise and distortion (對比THS4521)
- Pin compatible with ADA4945-1 (對比ADA4945-1ACPZ)
設計說明
The ADA4940-1ACPZ operates from a single 3.3V to 5V supply or dual supplies. For optimal performance, use a low-noise LDO to supply the amplifier and ADC. Place a 0.1 µF ceramic capacitor close to each supply pin to decouple high-frequency noise. The power-down pin can be used to reduce supply current to 10 µA in standby mode, extending battery life in portable applications.
For best performance, use a solid ground plane and minimize trace lengths to the ADC. Place the ADA4940-1 as close as possible to the ADC input to reduce parasitic capacitance and inductance. Use differential routing for the output traces to maintain balance and reduce common-mode noise. Ensure the feedback resistors are matched to 0.1% tolerance for optimal CMRR.
A common mistake is setting the output common-mode voltage incorrectly. The VOCM pin should be connected to the ADC's reference midpoint to maximize dynamic range. Also, ensure the input common-mode range is not exceeded; the datasheet specifies the input common-mode range as 0.2V to V+ - 0.2V. Failure to observe these limits can cause clipping and distortion.
合規資訊
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified.
