ADA4940-1ACPZ - Ultralow Power Differential ADC Driver | Analog Devices
MPN: ADA4940-1ACPZ ✓ Hoạt độngADA4940-1ACPZ Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho ADA4940-1ACPZ — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với ADA4940-1ACPZ (cùng hình factor và footprint) — khác nhau ở Output Type, Gain Bandwidth Product, Operating Temperature Range, Package, Slew Rate.
ADA4940-1ACPZ-R7
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADA4940-1ACPZ-RL
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADA4945-1ACPZ
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →THS4521
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LTC6363HMS8-2#PBF
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →ADA4940-1ACPZ Tỷ lệ tối đa & tính chất điện
| Amplifier Type | Differential |
| Number of Circuits | 1 |
| Kiểu đầu ra | 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 |
| Nhiệt độ hoạt động | -40°C to +125°C |
| Hộp / Vỏ | 16-LFCSP-VQ (3x3) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
| Cấp độ độ ẩm nhạy cảm (MSL) | 1 |
| Input Voltage Noise | 3.9 nV/√Hz |
| Distortion at 1 MHz | -100 dBc |
Cấu hình chân ADA4940-1ACPZ
| Chân 1 | VOCM — Output common-mode voltage adjust |
| Chân 2 | OUT+ — Positive differential output |
| Chân 3 | V- — Negative supply (or ground) |
| Chân 4 | OUT- — Negative differential output |
| Chân 5 | V+ — Positive supply |
| Chân 6 | PD — Power down (active low) |
| Chân 7 | IN- — Inverting input |
| Chân 8 | IN+ — Non-inverting input |
| Chân 9 | VOCM — Output common-mode voltage adjust (duplicate) |
| Chân 10 | OUT+ — Positive differential output (duplicate) |
| Chân 11 | V- — Negative supply (or ground) (duplicate) |
| Chân 12 | OUT- — Negative differential output (duplicate) |
| Chân 13 | V+ — Positive supply (duplicate) |
| Chân 14 | PD — Power down (active low) (duplicate) |
| Chân 15 | IN- — Inverting input (duplicate) |
| Chân 16 | IN+ — Non-inverting input (duplicate) |
Ứng dụng tiêu biểu
ADA4940-1ACPZ phù hợp cho 6 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ADA4940-1ACPZ — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | 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 |
Bảo phân biệt quan trọng
- Ultralow power consumption (vsTHS4521)
- Low noise and distortion (vsTHS4521)
- Pin compatible with ADA4945-1 (vsADA4945-1ACPZ)
Ghi chú thiết kế
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.
Thông tin tuân thủ
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified.
