AD7687BCPZ - 16-Bit 250kSPS PulSAR ADC | Analog Devices
MPN: AD7687BCPZ ✓ Hoạt độngAD7687BCPZ Tóm tắt
An ADC (analog-to-digital converter) is an electronic component that converts continuous analog signals into discrete digital numbers. The AD7687 is a SAR ADC, which uses a successive approximation register algorithm to perform conversions with high speed and accuracy. SAR ADCs are widely used in data acquisition systems, industrial process control, and medical instrumentation due to their excellent balance of speed, resolution, and power consumption. The AD7687 belongs to the PulSAR family, known for its low power and high precision.
Key features of the AD7687BCPZ include 16-bit resolution with 1.5 LSB INL (integral nonlinearity), a maximum sampling rate of 250 kSPS, and a differential input range of ±VREF. The device offers a serial SPI-compatible interface with daisy-chain capability and an optional BUSY indicator via the SDI pin. Power consumption scales linearly with throughput, enabling low-power operation in battery-powered systems. The ADC also features a pseudo-differential input option and a dedicated VIO pin for flexible logic-level interfacing.
Technically, the AD7687 uses a charge-redistribution capacitive DAC architecture, which provides inherent sample-and-hold functionality and excellent linearity. The device includes an internal reference buffer, but an external reference voltage (VREF) is required, typically ranging from 0.5 V to VDD. The ADC achieves a signal-to-noise ratio (SNR) of 92 dB and a total harmonic distortion (THD) of -108 dB, making it suitable for high-precision measurement applications. The LFCSP package offers a small footprint with an exposed pad for improved thermal performance.
Typical applications include portable instrumentation, battery-powered data loggers, medical devices such as patient monitors, and industrial process control. The AD7687's low power consumption (typically 4.5 mW at 250 kSPS) and small package make it ideal for these applications. The SPI interface simplifies connection to microcontrollers and DSPs, and the daisy-chain feature allows multiple ADCs to share a single bus.
When designing with the AD7687, ensure that the reference voltage is stable and well-decoupled, as it directly affects conversion accuracy. The VIO pin must be connected to the appropriate logic supply to match the host interface voltage. Proper PCB layout with separate analog and digital ground planes is recommended to minimize noise and achieve optimal performance.
Bộ thay thế dễ dàng lắp đặt cho AD7687BCPZ — 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 AD7687BCPZ (cùng hình factor và footprint) — khác nhau ở Architecture, Interface, Package, Resolution, Input Type.
AD7687BCPZ-R2
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Xem tài liệu →AD7687BCPZRL7
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7687BCPZ Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 16 bit |
| Tỷ lệ lấy mẫu | 250 kSPS |
| Number of Input Channels | 1 |
| Input Type | Differential |
| Giao diện | SPI |
| Architecture | SAR |
| Điện áp cung cấp | 2.3 V to 5.5 V |
| Logic Supply Voltage (VIO) | 1.8 V to 5.5 V |
| INL (Bất định tích hợp) | ±1.5 LSB |
| SNR (Signal-to-Noise Ratio) | 92 dB |
| THD (Total Harmonic Distortion) | -108 dB |
| Power Consumption | 4.5 mW at 250 kSPS |
| Khoảng nhiệt độ hoạt động | -40°C to +85°C |
| Hộp | 10-LFCSP-WD (3x3 mm) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
Cấu hình chân AD7687BCPZ
| Chân 1 | IN+ — Positive differential analog input |
| Chân 2 | IN- — Negative differential analog input |
| Chân 3 | GND — Ground |
| Chân 4 | VREF — Reference voltage input |
| Chân 5 | VDD — Power supply |
| Chân 6 | VIO — Digital interface supply |
| Chân 7 | SDI — Serial data input (also BUSY indicator) |
| Chân 8 | SDO — Serial data output |
| Chân 9 | SCK — Serial clock input |
| Chân 10 | CNV — Convert input |
Ứng dụng tiêu biểu
AD7687BCPZ phù hợp cho 6 Áp dụngs: Portable Instrumentation, Medical Devices, Industrial Process Control, Data Acquisition Systems, Battery-Powered Devices, Audio and Vibration Analysis.
Portable Instrumentation
The AD7687BCPZ is ideal for portable instruments due to its low power consumption of 4.5 mW at 250 kSPS and small 3x3 mm LFCSP package. Its 16-bit resolution and 92 dB SNR ensure accurate measurements in battery-powered devices like handheld multimeters and data loggers. The SPI interface simplifies connection to low-power microcontrollers, and the wide supply range (2.3 V to 5.5 V) accommodates various battery chemistries. The differential input rejects common-mode noise, improving measurement accuracy in field environments.
Được đề xuất
Medical Devices
In medical devices such as patient monitors and diagnostic equipment, the AD7687BCPZ provides high precision with 16-bit resolution and 1.5 LSB INL. Its low power consumption is critical for battery-operated devices, and the small package allows for compact designs. The differential input is suitable for biopotential measurements like ECG and EEG, where common-mode rejection is essential. The SPI interface enables easy integration with medical-grade microcontrollers, and the industrial temperature range (-40°C to +85°C) ensures reliability in clinical environments.
Được đề xuất
Industrial Process Control
The AD7687BCPZ is well-suited for industrial process control systems that require accurate analog-to-digital conversion of sensor signals. Its 250 kSPS sampling rate and 16-bit resolution enable real-time monitoring of temperature, pressure, and flow. The differential input rejects noise from industrial environments, and the wide supply voltage range allows operation from 24 V industrial supplies with appropriate regulation. The SPI interface with daisy-chain capability simplifies wiring in multi-channel systems, reducing cost and complexity. The device's robust performance over -40°C to +85°C ensures reliable operation in harsh factory conditions.
Được đề xuất
Data Acquisition Systems
The AD7687BCPZ is a key component in data acquisition systems (DAQ) for test and measurement applications. Its 16-bit resolution and 250 kSPS sampling rate provide a good balance between speed and accuracy for capturing dynamic signals. The low power consumption makes it suitable for USB-powered or battery-operated DAQ modules. The SPI interface allows easy connection to FPGAs or microcontrollers, and the daisy-chain feature enables expansion to multiple channels. The device's excellent SNR (92 dB) and THD (-108 dB) ensure high-fidelity signal capture for applications like vibration analysis and audio testing.
Được đề xuất
Battery-Powered Devices
The AD7687BCPZ is optimized for battery-powered devices due to its low power consumption and wide supply voltage range. It operates from 2.3 V to 5.5 V, allowing direct connection to lithium-ion or alkaline batteries. The power consumption scales linearly with throughput, so reducing the sampling rate extends battery life. The small 3x3 mm package is ideal for compact wearable devices and IoT sensors. The SPI interface with 1.8 V logic capability enables direct connection to low-power microcontrollers, reducing overall system power. The device's high accuracy ensures reliable data collection in remote monitoring applications.
Được đề xuất
Audio and Vibration Analysis
The AD7687BCPZ's high SNR (92 dB) and low THD (-108 dB) make it suitable for audio and vibration analysis applications. Its 16-bit resolution captures fine details in acoustic signals, while the 250 kSPS sampling rate allows analysis of frequencies up to 125 kHz. The differential input reduces common-mode interference, which is beneficial in noisy environments. The low power consumption enables portable audio analyzers and vibration monitors. The SPI interface allows easy integration with digital signal processors (DSPs) for real-time analysis. The device's small package is ideal for embedded systems in industrial and automotive applications.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho AD7687BCPZ — 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 | AD7687BCPZ-R2 | AD7687BCPZRL7 | AD7682BCPZ | AD7690BCPZ |
|---|---|---|---|---|---|
| Package | 10-LFCSP-WD (3x3 mm) | 10-LFCSP-WD (3x3 mm) - same | 10-LFCSP-WD (3x3 mm) - same | 20-LFCSP-WD (4x4 mm) - different | 10-MSOP - different |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit |
| Sampling Rate | 250 kSPS | 250 kSPS | 250 kSPS | 250 kSPS | 400 kSPS |
| Number of Channels | 1 | 1 | 1 | 4 | 1 |
| Input Type | Differential | Differential | Differential | Differential | Differential |
| Supply Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
| Power Consumption | 4.5 mW at 250 kSPS | 4.5 mW at 250 kSPS | 4.5 mW at 250 kSPS | 4.5 mW at 250 kSPS | 7.5 mW at 400 kSPS |
Bảo phân biệt quan trọng
- Low power consumption (vsAD7690BCPZ)
- Small package size (vsAD7682BCPZ)
- Single-channel simplicity (vsAD7682BCPZ)
Ghi chú thiết kế
The AD7687BCPZ operates from a 2.3 V to 5.5 V supply. For optimal performance, use a low-noise LDO regulator to supply VDD and VIO. Decouple each supply pin with a 0.1 µF ceramic capacitor placed as close to the pin as possible, and a 10 µF bulk capacitor for lower frequencies. The VIO supply should match the host interface logic level to avoid signal integrity issues.
For best performance, use a solid ground plane and separate analog and digital ground areas, connecting them at a single point near the ADC. Place the reference decoupling capacitor (0.1 µF) close to the VREF pin. Keep analog input traces short and shielded to minimize noise pickup. The exposed pad on the LFCSP package should be soldered to the ground plane for thermal and electrical performance.
Ensure the reference voltage (VREF) is stable and within the specified range (0.5 V to VDD). An unstable reference will directly degrade conversion accuracy. Also, avoid driving the analog inputs beyond the supply rails, as this can cause latch-up or damage. Use a series resistor (e.g., 100 Ω) to limit input current if overvoltage is possible. The CNV pin must be low during conversion to avoid glitches.
Thông tin tuân thủ
RoHS compliance is indicated by the 'Z' in the part number (AD7687BCPZ). Other compliance details not specified in the provided data.