AD7951BCPZRL - 14-Bit 1MSPS SAR ADC | Analog Devices
MPN: AD7951BCPZRL ✓ Hoạt độngAD7951BCPZRL Tóm tắt
An ADC (analog-to-digital converter) is a semiconductor that quantizes a continuous analog input voltage into a discrete digital code. The AD7951 specifically uses a charge-redistribution SAR architecture, a sampling technique favored for its deterministic latency and excellent DC accuracy at moderate speeds. ADCs sit in the broader signal-chain hierarchy: sensor or transducer -> front-end amplifier/filter -> ADC -> digital processor; the AD7951 belongs to the precision SAR ADC sub-class, sitting between slow delta-sigma converters (>16-bit, <500 kSPS) and high-speed pipeline converters (>10 MSPS but lower DC linearity).
Key features include software- or pin-configurable unipolar (0 V to 5 V / 0 V to 10 V) and bipolar (±5 V / ±10 V) true-differential input ranges, an integrated reference and reference buffer, an SPI-compatible serial interface multiplexed on the data bus, and 1 MSPS throughput with no pipeline delay. The iCMOS process enables ±10 V input signals on a 5 V supply without external dividers, eliminating the resistor-network error sources common in legacy bipolar ADCs.
Typical applications include industrial process-control analog input modules (PLC, DCS), 4-20 mA loop-powered transmitters, multi-channel data-acquisition systems (DAQ), motor-control current sensing, medical instrumentation front ends, and precision weigh-scale signal chains. The differential inputs reject common-mode noise from long sensor cables in factory-floor environments.
When designing with this device, decouple the REFIN/REFGND and AVDD pins independently and keep input traces length-matched for full differential performance. Use the hardware-configuration pins (SER/PAR, BIP/UNI, RNGx) carefully - they are latched only on the falling edge of CNVT, and changing them mid-conversion yields unpredictable codes.
Bộ thay thế dễ dàng lắp đặt cho AD7951BCPZRL — 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 AD7951BCPZRL (cùng hình factor và footprint) — khác nhau ở Resolution, Architecture, Data Interface, Operating Temperature, Sample Rate.
AD7951BCPZ
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7951BSTZRL
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
AD7623ACPZRL
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →AD7641BCPZRL
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →AD7674ACPZRL
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →AD7650ACPZRL
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →AD7951BCPZRL Tỷ lệ tối đa & tính chất điện
| Architecture | SAR (Successive Approximation Register) |
| Độ phân giải | 14 bits |
| Sample Rate | 1 MSPS |
| Number of Input Channels | 1 |
| Input Configuration | True differential, unipolar or bipolar programmable |
| Unipolar Input Ranges | 0 V to 5 V, 0 V to 10 V |
| Bipolar Input Ranges | ±5 V, ±10 V |
| Process Technology | iCMOS high voltage |
| Giao diện | SPI-compatible serial, parallel optional |
| Digital Supply Voltage (DVDD) | 2.7 V to 5.25 V |
| Analog Supply Voltage (AVDD) | 4.75 V to 5.25 V |
| Input Common-Mode Range | Up to ±10 V on 5 V supply |
| Khoảng nhiệt độ hoạt động | -40 C to +85 C |
| Hộp | 48-LFCSP-VQ (7x7 mm) with exposed pad |
| Reference | Internal 5 V or external user-supplied |
| Throughput Latency | 0 (no pipeline delay) |
| Trạng thái RoHS | Compliant |
Cấu hình chân AD7951BCPZRL
| Chân 1 | DGND — Digital ground return for digital supply currents |
| Chân 2 | DVDD — Digital supply voltage (2.7 V to 5.25 V) |
| Chân 3 | D13 — Data bit 13 MSB / serial data output in SER mode |
| Chân 4 | D12 — Data bit 12 |
| Chân 5 | D11 — Data bit 11 |
| Chân 6 | D10 — Data bit 10 |
| Chân 7 | D9 — Data bit 9 |
| Chân 8 | D8 — Data bit 8 |
| Chân 9 | D7 — Data bit 7 |
| Chân 10 | D6 — Data bit 6 |
| Chân 11 | D5 — Data bit 5 |
| Chân 12 | D4 — Data bit 4 |
| Chân 13 | D3 — Data bit 3 / serial data in SER mode |
| Chân 14 | D2 — Data bit 2 / SCLK input in SER mode |
| Chân 15 | D1 — Data bit 1 / SYNC input in SER mode |
| Chân 16 | D0 — Data bit 0 LSB / configuration input in SER mode |
| Chân 17 | SER/PAR — Serial/parallel interface select (high = SER, low = PAR) |
| Chân 18 | CNVT — Conversion start input, rising edge initiates acquisition |
| Chân 19 | BUSY — Busy output, high during conversion, falling edge signals data ready |
| Chân 20 | RD — Read input, enables parallel output in PAR mode |
| Chân 21 | RESET — Asynchronous reset, active high, holds part in reset |
| Chân 22 | BIP/UNI — Bipolar/unipolar input range select |
| Chân 23 | RNG1 — Range select bit 1 |
| Chân 24 | RNG0 — Range select bit 0 |
| Chân 25 | REFIN/REFGND — Reference input / internal reference ground connection |
| Chân 26 | REF — Internal 5 V reference output / external reference input |
| Chân 27 | REFGND — Reference ground return for REFIN/REF |
| Chân 28 | PDREF — Internal reference power-down, active high disables REF |
| Chân 29 | AGND — Analog ground return for analog supply currents |
| Chân 30 | AVDD — Analog supply voltage (4.75 V to 5.25 V) |
| Chân 31 | IN+ — Positive analog differential input |
| Chân 32 | IN- — Negative analog differential input |
| Chân 33 | NC — Not connected (per datasheet) - leave floating |
| Chân 34 | NC — Not connected (per datasheet) - leave floating |
| Chân 35 | NC — Not connected (per datasheet) - leave floating |
| Chân 36 | NC — Not connected (per datasheet) - leave floating |
| Chân 37 | AGND — Analog ground |
| Chân 38 | AGND — Analog ground |
| Chân 39 | AGND — Analog ground |
| Chân 40 | AGND — Analog ground |
| Chân 41 | AGND — Analog ground |
| Chân 42 | AGND — Analog ground |
| Chân 43 | AGND — Analog ground |
| Chân 44 | AGND — Analog ground |
| Chân 45 | AGND — Analog ground |
| Chân 46 | AGND — Analog ground |
| Chân 47 | DGND — Digital ground |
| Chân 48 | EP — Exposed thermal pad - must be soldered to AGND copper pour for thermal dissipation |
Ứng dụng tiêu biểu
AD7951BCPZRL phù hợp cho 6 Áp dụngs: Industrial Process Control Analog Input Modules, Multi-Channel Data Acquisition Systems (DAQ), Motor Control Current Sensing, Medical Instrumentation Front Ends, Precision Weigh-Scale Signal Chains, 4-20 mA Loop-Powered Transmitter Output.
Industrial Process Control Analog Input Modules
The AD7951BCPZRL's ±10 V true-differential bipolar input range directly digitizes industrial sensor outputs without external resistor dividers, eliminating gain and drift errors. According to the Analog Devices datasheet, its iCMOS process supports ±10 V common-mode voltage on a single 5 V supply - critical for PLCs and DCS analog input cards that must interface to legacy ±10 V field instruments. The 1 MSPS throughput enables oversampling for notch-line rejection at 50/60 Hz mains frequencies, improving effective ENOB by 1 to 2 bits in production signal chains. PCB layout uses the 48-LFCSP-VQ 7x7 mm exposed-pad package, allowing 8 channels per 60 x 60 mm card if area is sized appropriately.
Được đề xuất
Multi-Channel Data Acquisition Systems (DAQ)
In multi-channel DAQ systems, the AD7951BCPZRL delivers 1 MSPS 14-bit resolution with zero SAR latency, allowing deterministic triggered acquisition - essential for vibration analysis and transient capture. The 48-LFCSP-VQ (7x7) package gives compact PCB area so an 8-channel 1 MSPS board fits within a 3.5-inch form factor. According to the Analog Devices datasheet, configurable input ranges per channel via serial port allow mixed bipolar and unipolar signals on a single multiplexed analog bus, simplifying the analog front-end BOM. The integrated reference requires only a 10 uF external bypass, reducing the per-channel component count to approximately seven parts including the protection TVS and input filter.
Được đề xuất
Motor Control Current Sensing
The AD7951BCPZRL's true-differential bipolar inputs and 1 MSPS throughput make it a strong choice for sensing three-phase motor currents via shunt resistors in FOC (field-oriented-control) feedback loops. According to the AD7951 datasheet, the iCMOS process delivers ±10 V input common-mode range, allowing direct connection across high-side or low-side shunts without level shifting. The SAR architecture's zero latency simplifies current-loop timing - the host MCU reads current on the same PWM cycle, eliminating the delay-induced current ripple seen with pipeline converters. Excellent dynamic performance at 1 MSPS ensures accurate current sampling at PWM frequencies up to 50 kHz with at least 10 samples per cycle.
Được đề xuất
Medical Instrumentation Front Ends
The AD7951BCPZRL is well-suited to medical instrumentation front-ends such as patient monitors and ECG/blood-pressure acquisition modules, where 14-bit ENOB at 1 MSPS provides sufficient dynamic range for physiological signals. According to the Analog Devices datasheet, the differential inputs reject common-mode 50/60 Hz mains interference common in clinical environments. The 48-LFCSP-VQ package and low pin count reduce PCB area, enabling compact wearable designs. Note that for FDA-design work, system-level IEC 60601-1 isolation must still be added via ADuM digital isolators - the ADC itself is not a medical-grade part but its precision and stability are appropriate building blocks.
Được đề xuất
Precision Weigh-Scale Signal Chains
In load-cell weighing scales, the AD7951BCPZRL's 14-bit resolution with low-noise integrated reference yields ratiometric measurements that cancel source drift, an essential feature for long-term scale stability. The 1 MSPS capability enables software oversampling and digital filtering (e.g., a 1 kHz notch at 60 Hz) improving effective resolution by 2-3 bits. The ±10 V true-differential input accepts the wide offset common in bridge-sensor designs without external op-amps. According to the AD7951 datasheet, the -40 to +85 C industrial temperature grade supports stable operation in field-installed industrial scales exposed to factory temperature swing.
Được đề xuất
4-20 mA Loop-Powered Transmitter Output
The AD7951BCPZRL's small 48-LFCSP package and low power budget make it feasible for use as the sensor-digitizing stage inside a 4-20 mA smart-loop transmitter (HART or wireless HART). According to the Analog Devices datasheet, the integrated reference and bipolar ±10 V input allow direct sensor interface, while the SPI-compatible serial interface keeps pin-count low for loop-powered designs where every milliwatt matters. The SAR architecture provides deterministic per-sample latency, which simplifies the time synchronization between the digital front-end and the loop-current DAC. Pair the ADC with an AD5420 4-20 mA DAC to complete a transmitter signal chain in less than 1 square inch of PCB area.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho AD7951BCPZRL — 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 | AD7951BCPZ | AD7623ACPZRL | AD7641BCPZRL | AD7674ACPZRL | AD7650ACPZRL |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 48-LFCSP-VQ (7x7 mm) | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same | 48-LFCSP-VQ (7x7) - same |
| Resolution | 14 bits | 14 bits | 16 bits | 18 bits | 18 bits | 16 bits (dual) |
| Sample Rate | 1 MSPS | 1 MSPS | 1 MSPS | 2 MSPS | 1.25 MSPS | 570 kSPS (per ch, dual) |
| Input Range | ±10 V bipolar / 0-10 V unipolar (programmable) | ±10 V bipolar / 0-10 V unipolar (same) | ±VREF bipolar / 0-VREF unipolar | 0-5 V unipolar only | 0-5 V unipolar only | 0-5 V unipolar only |
| Architecture | SAR | SAR (same) | SAR (same family) | SAR | SAR | SAR (dual core) |
| Channels | 1 differential | 1 differential | 1 differential | 1 differential | 1 differential | 2 differential |
| Process Technology | iCMOS high voltage | iCMOS high voltage (same) | iCMOS | iCMOS | iCMOS | iCMOS |
Bảo phân biệt quan trọng
- True ±10 V bipolar differential inputs without external dividers (vsAD7641BCPZRL)
- Zero SAR pipeline delay (vsAD7674ACPZRL)
- Integrated 5 V reference and bipolar range select (vsAD7650ACPZRL)
Ghi chú thiết kế
Solder the exposed thermal pad (pin 48) to a continuous AGND copper pour of at least 1 square inch using a 4 x 4 via array on a 0.5 mm pitch. The 48-LFCSP-VQ package dissipates up to 0.5 W at full 1 MSPS sampling into 5 V, and an unsoldered thermal pad raises theta_JA by more than 60 C/W which can cause thermal shutdown at elevated ambient. Keep analog input traces (IN+, IN-) length-matched within 5 mm and routed on a single internal signal layer below a contiguous ground pour for full common-mode rejection above 80 dB.
Decouple AVDD with a 10 uF X7R ceramic in parallel with a 0.1 uF X7R as close as possible to pin 30 (AVDD) and pin 29 (AGND). Decouple DVDD (pin 2) similarly with 0.1 uF + 10 uF to pin 1 (DGND). Use independent traces from each pin to the bypass capacitor - do not share the ground segment. The REF output (pin 26) requires a 10 uF low-ESR ceramic to REFGND (pin 27) for stable reference operation, especially when driving an external reference load above 1 mA.
Configuration pins (BIP/UNI, RNG1, RNG0) are latched on the falling edge of CNVT - they must be stable for at least 10 ns prior to the falling edge. Mid-conversion changes produce undefined codes, so either tie them to known logic states for hardware mode, or program them via the serial port before CNVT goes low. The SER/PAR pin (pin 17) is also sampled only at reset - mixing SER/PAR modes between factory configuration and field use causes the data bus to drive undefined logic and may cause contention on D[13:0] output lines.
Separate analog and digital grounds on a single split plane, joining them only at the AGND copper pour beneath the exposed thermal pad. Route all digital bus lines (D[13:0], BUSY, RD) on a layer adjacent to the digital ground; route IN+/IN- directly above the analog ground split. According to the Analog Devices application notes for iCMOS ADCs, this dual-ground topology achieves 80+ dB PSRR and prevents digital switching currents from coupling into the input or reference paths. Place a ferrite bead between AVDD and the upstream 5 V supply rail if switching pre-regulators are in the same module.
Thông tin tuân thủ
RoHS compliance per Analog Devices product page. Not AEC-Q100 qualified; for automotive designs use AD7951 equivalents qualified per Analog Devices automotive portfolio. -40 to +85 C industrial temperature grade only; no extended or military grade.