AD7875LPZ-REEL - 12-Bit 100kHz Sampling ADC | Analog Devices
MPN: AD7875LPZ-REEL ✓ Hoạt độngAD7875LPZ-REEL Tóm tắt
An ADC (analog-to-digital converter) is a mixed-signal integrated circuit that converts continuous analog voltages into discrete digital codes, enabling microcontrollers, DSPs, and processors to interpret real-world signals. The AD7875 belongs to the successive-approximation-register (SAR) ADC category, which uses an iterative binary-search algorithm with an internal DAC to perform each conversion in a fixed number of clock cycles. SAR ADCs sit within the broader data-converter family, alongside delta-sigma and pipeline architectures, and are favored for multi-channel multiplexed and DC/front-end signal acquisition where deterministic latency and low latency are critical.
Key features include a 2 µs acquisition track-and-hold front end, 8 µs A/D conversion time, on-chip 2.5 V buried-zener reference laser-trimmed for accuracy, 72 dB SNR at 10 kHz input, ±5 V dual analog supply operation, and three interface modes (12-bit parallel, 8-bit byte, and serial). The 28-terminal J-lead surface-mount package (QCCJ / PLCC) is rated for the commercial 0 °C to +70 °C temperature grade and ships in tape-and-reel format for high-volume assembly.
Architecturally, the AD7875 integrates an analog input multiplexer/amplifier, the SAR core, internal reference, clock oscillator, and a flexible digital interface on a single CMOS die. The laser-trimmed buried-zener reference and clock remove two of the largest external bill-of-materials items typical of discrete 12-bit ADC designs, shrinking PCB area and improving long-term gain stability.
Typical applications include industrial process control front ends, multichannel data-acquisition boards, motor-control feedback loops (shaft position, current sense), and instrumentation signal inputs where 12-bit resolution and 100 kSPS throughput are sufficient. The on-chip reference also makes the part attractive for portable or space-constrained designs where an external reference would be impractical.
When designing with the AD7875, choose the supply range carefully: ±5 V supplies yield best SNR at the expense of higher power dissipation, while ±3 V operation reduces power at slightly lower dynamic performance. Decouple both AVdd and DVdd pins with 0.1 µF ceramic capacitors placed within 5 mm of the package to keep digital switching noise out of the analog front end.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not available in the bare manufacturer datasheet, providing engineers with a single reference point for sourcing and second-sourcing decisions.
Bộ thay thế dễ dàng lắp đặt cho AD7875LPZ-REEL — 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 AD7875LPZ-REEL (cùng hình factor và footprint) — khác nhau ở Architecture, On-Chip Reference, Package, Track-and-Hold Acquisition Time.
AD7875KPZ-REEL
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7875LP
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7875KNZ
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7875KRZ
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
AD7875KRZ-REEL
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
AD7875LPZ-REEL Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit |
| Number of Channels | 1 input, 1 SAR |
| Tỷ lệ lấy mẫu | 100 kSPS |
| Conversion Time | 8 µs |
| Track-and-Hold Acquisition Time | 2 µs |
| Architecture | Successive Approximation (SAR) |
| Phạm vi điện áp đầu vào | 0 V to 5 V |
| Analog Supply Voltage | ±5 V (dual supply) |
| Digital Supply Voltage | +5 V |
| On-Chip Reference | Yes, 2.5 V laser-trimmed buried Zener |
| SNR | 72 dB at 10 kHz input |
| Integral Nonlinearity (EL) | 0.0244% (1 LSB max, typical) |
| Digital Interface | Parallel (12-bit), byte (8-bit), serial |
| Internal Clock | Yes, laser-trimmed |
| Hộp | 28-Pin PLCC (LCCC, MO-047AB, LCC-28) |
| Terminal Form | J-Bend (QCCJ) |
| Nhiệt độ hoạt động | 0 °C to +70 °C (Commercial) |
| Screening Level | Commercial |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
Cấu hình chân AD7875LPZ-REEL
| Chân 1 | VSS — Negative analog supply (-5 V typical) |
| Chân 2 | REF OUT/REF IN — Internal 2.5 V reference output / external reference input |
| Chân 3 | AGND — Analog ground |
| Chân 4 | AIN — Analog input (0 V to 5 V range) |
| Chân 5 | VSS — Negative analog supply (-5 V typical) |
| Chân 6 | VDD — Positive analog supply (+5 V typical) |
| Chân 7 | DB11 (MSB) — Data Bit 11 / serial-data out option |
| Chân 8 | DB10 — Data Bit 10 |
| Chân 9 | DB9 — Data Bit 9 |
| Chân 10 | DB8 — Data Bit 8 / HBE for byte mode |
| Chân 11 | DB7 — Data Bit 7 |
| Chân 12 | DB6 — Data Bit 6 |
| Chân 13 | DB5 — Data Bit 5 |
| Chân 14 | DB4 — Data Bit 4 |
| Chân 15 | DB3 — Data Bit 3 |
| Chân 16 | DB2 — Data Bit 2 |
| Chân 17 | DB1 (LSB) — Data Bit 1 (LSB) |
| Chân 18 | STBY — Standby (active low) |
| Chân 19 | RFS — Read-frame sync for serial mode |
| Chân 20 | TFS — Transmit-frame sync for serial mode |
| Chân 21 | SCLK — Serial clock |
| Chân 22 | CLK — Master clock input |
| Chân 23 | MODE — Mode select (parallel/byte/serial) |
| Chân 24 | BUSY — Status (BUSY signal during conversion) |
| Chân 25 | CS — Chip select (active low) |
| Chân 26 | RD — Read input (active low) |
| Chân 27 | WR — Write / convert start (active low) |
| Chân 28 | DVDD — Digital +5 V supply |
Ứng dụng tiêu biểu
AD7875LPZ-REEL phù hợp cho 6 Áp dụngs: Industrial Process Control Front End, Data Acquisition Boards, Motor Control Feedback Loops, Instrumentation and Test Equipment, Medical Patient Monitoring, Communication Signal Monitoring.
Industrial Process Control Front End
The AD7875LPZ-REEL fits industrial process-control front-ends thanks to its 12-bit resolution at 100 kSPS, enabling simultaneous sampling of multiple 4-20 mA loop signals after external scaling. The on-chip 2.5 V reference removes drift concerns in 24-bit-rated instrument loops, while the SAR architecture provides deterministic 8 µs conversion time for closed-loop control updates. Per the AD7875 datasheet, ±5 V supplies yield 72 dB SNR at 10 kHz, preserving loop accuracy across plant temperatures.
Được đề xuất
Data Acquisition Boards
Multichannel data-acquisition boards leverage the AD7875LPZ-REEL's 100 kSPS throughput and parallel/byte/serial interface to deliver 12-bit precision for vibration, strain-gauge, and transducer digitisation. The 2 µs acquisition track-and-hold plus 8 µs conversion cycle yields an aggregate throughput of 100,000 samples per second, suitable for IEEE 1242-class PC-based DAQ plug-in cards. On-chip reference eliminates an external reference IC, shrinking BOM for dense multiplexed boards.
Được đề xuất
Motor Control Feedback Loops
Closed-loop motor control requires deterministic, low-latency current and position sensing, and the AD7875LPZ-REEL's SAR architecture provides exactly that with no pipeline delay. The 8 µs conversion time supports PWM frequencies up to ~50 kHz, enabling Field-Oriented Control (FOC) feedback for BLDC and PMSM drives. The on-chip reference ensures gain stability over the operating-temperature range, which is critical for precise torque control in servo amplifiers.
Được đề xuất
Instrumentation and Test Equipment
Bench-top multimeters, oscilloscope front-ends, and laboratory instruments benefit from the AD7875LPZ-REEL's 72 dB SNR at 10 kHz input bandwidth, equivalent to 11.7 effective bits, sufficient for ±0.05% accuracy in voltmeter and ohmmeter functions. The 12-bit resolution delivers 1 part-in-4096 discrimination, while the on-chip reference simplifies calibration procedures. Engineers building portable instruments appreciate the single-IC integration that reduces calibration-cycle time and PCB area.
Được đề xuất
Medical Patient Monitoring
Patient-monitoring equipment such as bedside monitors and ambulatory ECG recorders rely on the AD7875LPZ-REEL for 12-bit 100 kSPS digitisation of analog front-end signals amplified from electrode leads. The SAR architecture produces no pipeline latency, allowing immediate triggering on QRS detection for heart-rate calculation. The on-chip reference minimises long-term drift, supporting battery-powered medical devices that must hold calibration for multi-year service intervals.
Được đề xuất
Communication Signal Monitoring
Base-station RF power monitors, antenna VSWR sensing, and trunked-radio diagnostics use the AD7875LPZ-REEL for 12-bit digitisation of log-detector outputs, providing ±0.5 dB dynamic range per LSB. The 100 kSPS throughput captures modulation envelopes for telemetry and diagnostic uplinks without excessive oversampling. The on-chip reference stabilises the gain across temperature swings typical of outdoor cabinet installations.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho AD7875LPZ-REEL — 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 | AD7875KPZ-REEL | AD7875LP | AD7875KNZ | AD7875KRZ | AD7875KRZ-REEL |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-Pin PLCC (LCC-28, MO-047AB) | 28-Pin PLCC (LCC-28, MO-047AB) - same | 28-Pin PLCC (LCC-28, MO-047AB) - same | 28-Pin PLCC (LCC-28, MO-047AB) - same | 28-Pin PLCC (LCC-28, MO-047AB) - same | 28-Pin PLCC (LCC-28, MO-047AB) - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 100 kSPS | 100 kSPS | 100 kSPS | 100 kSPS | 100 kSPS | 100 kSPS |
| Analog Supply | ±5 V | ±5 V | ±5 V | ±5 V | ±5 V | ±5 V |
| On-Chip Reference | Yes, 2.5 V laser-trimmed | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature | 0 °C to +70 °C (Commercial) | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C |
| Conversion Time | 8 µs | 8 µs | 8 µs | 8 µs | 8 µs | 8 µs |
| Pin-Count / Footprint | 28-pin / 11.51×11.51 mm | 28-pin / same | 28-pin / same | 28-pin / same | 28-pin / same | 28-pin / same |
| Cost Tier (qty 1) | $24.50 | Similar tier | Similar tier | Similar tier | Similar tier | Similar tier |
Bảo phân biệt quan trọng
- Pin-compatible with full AD7875 family (LPZ/KPZ/LP/KN/KR) for second-sourcing (vsAD7875KPZ-REEL)
- Completely integrated ADC IC - no external reference required (vsDiscrete 12-bit ADCs (e.g., AD574A + external 2.5 V reference))
- Three-interface flexibility on a single device (parallel/byte/serial) (vsAD7478AAKSZ (SPI-only))
Ghi chú thiết kế
Decouple each analog and digital supply pin with a 0.1 µF ceramic capacitor placed within 5 mm of the package, and add a 10 µF tantalum bulk capacitor near each supply rail. Per the AD7875 datasheet, AVdd and AVss should be low-noise linear regulators (e.g., ±5 V LDO pair), not switching converters, to achieve the datasheet's 72 dB SNR. Critical: switching noise on the analog supply will couple into the SAR comparator and ruin conversions.
Route analog and digital grounds on a single low-impedance split-AGND/DGND plane with a single star-connection under the IC; this prevents ground-loop noise in the SAR comparator. Estimated: a 4-layer PCB with 0.5 oz copper on the analog layer and 1 oz on the power layer yields ~10 mΩ/sq plane resistance, which is acceptable for the AD7875's 100 kSPS throughput. Place the input buffer op-amp within 5 mm of AIN to minimise trace capacitance.
Do not operate the analog input above Vdd + 0.3 V or below Vss - 0.3 V; out-of-range inputs latch the ESD diodes and degrade linearity. Critical: ensure the BUSY signal is sampled by the host before reading data; otherwise the host reads garbage during an active conversion. Tie MODE pin to the correct logic level before powering up, since mid-level voltage can put the part in undefined interface mode.
For best SNR, drive the analog input from a low-impedance (<100 Ω) buffer op-amp such as the AD8628 or OP177 to avoid kickback noise from the AD7875's switched-capacitor input structure. Recommended: place a 100 Ω series resistor and a 100 pF shunt capacitor at the AIN pin to form a 16 MHz low-pass filter, attenuating RF interference without affecting the 100 kSPS baseband signal.
Thông tin tuân thủ
RoHS compliant per manufacturer product page. Commercial temperature grade (0 °C to +70 °C) per datasheet screening-level field. Not AEC-Q100 qualified; this part targets industrial and instrumentation rather than automotive applications.
