AD7738BRU-REEL7 - 8-Ch 24-Bit Sigma-Delta ADC, TSSOP-28 | ADI
MPN: AD7738BRU-REEL7 ⚠ Lần mua cuốiAD7738BRU-REEL7 Tóm tắt
What is a sigma-delta ADC? A sigma-delta (Σ-Δ) analog-to-digital converter is a high-resolution data conversion architecture that oversamples the input signal and uses noise-shaping to push quantization energy to high frequencies where it is removed by a digital filter. Compared to successive-approximation (SAR) ADCs, sigma-delta parts achieve higher effective resolution (often 20+ bits) at lower sample rates, making them the standard choice for precision industrial, instrumentation, and weighing-scale applications. The AD7738 sits within the broader category hierarchy of ADC -> data converter -> signal chain IC -> semiconductor.
Key features include no missing codes at 24 bits, 0.0015% integral nonlinearity, an on-chip digital filter, and a flexible SPI/QSPI/MICROWIRE-compatible serial interface. The 8.5 kHz per-channel throughput supports fast multiplexing across eight sensors, and the integrated digital filter removes the need for external analog anti-alias hardware in many designs.
Typical applications include industrial process control, weigh scales, multi-sensor data acquisition systems, temperature measurement with RTD/thermocouple front ends, and PLC analog input modules. Per the Analog Devices AD7738 datasheet, the part supports fast sequential channel switching without sacrificing effective resolution.
When designing with the AD7738, decouple AVDD and DVDD with separate 10 microF tantalum plus 0.1 microF ceramic capacitors placed within 5 mm of the supply pins, and configure the digital filter for the chosen output data rate to balance noise against channel throughput.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, including cross-reference information for the EOL-marked AD7738BRU-REEL7.
Bộ thay thế dễ dàng lắp đặt cho AD7738BRU-REEL7 — 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 AD7738BRU-REEL7 (cùng hình factor và footprint) — khác nhau ở Package, Number of Input Channels, RoHS Status, Resolution, ADC Architecture.
AD7738BRUZ-REEL7
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7738BRU
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7738BRUZ-REEL
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →AD7738BRUZ
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7739BRUZ
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD7708BRU-REEL
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →AD7738BRU-REEL7 Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 24 bits |
| Number of Channels | 4 / 8 (differential inputs) |
| ADC Architecture | Sigma-Delta |
| Throughput | 8.5 kHz per channel (117 us conversion) |
| Analog Input Range | -2.9 V to +2.9 V |
| Analog Supply Voltage | 5 V nominal |
| Digital Supply Voltage | 2.7 V to 5.25 V |
| INL (Bất định tích hợp) | 0.0015% (15 ppm) |
| No Missing Codes | 24-bit guaranteed |
| Effective Resolution | 16-bit p-p (18-bit p-p at lower throughput) |
| Giao diện | SPI / QSPI / MICROWIRE compatible, Schmitt-triggered |
| Hộp | TSSOP-28 (4.4 mm body width) |
| Nhiệt độ hoạt động | -40 C to +105 C |
| Kiểu lắp đặt | Surface Mount |
| Screening Level | Industrial |
| Lead Finish | Tin (Sn) matte |
| Trạng thái vòng đời | Last Time Buy (per Analog Devices product page) |
| Trạng thái RoHS | Compliant (Pb-free matte tin) |
Cấu hình chân AD7738BRU-REEL7
| Chân 1 | AVDD — Analog +5 V supply |
| Chân 2 | REFIN+ — Positive reference input |
| Chân 3 | REFIN- — Negative reference input |
| Chân 4 | AGND — Analog ground |
| Chân 5 | AIN1 — Analog input 1 (differential) |
| Chân 6 | AIN2 — Analog input 2 (differential) |
| Chân 7 | AIN3 — Analog input 3 (differential) |
| Chân 8 | AIN4 — Analog input 4 (differential) |
| Chân 9 | AIN5 — Analog input 5 (differential) |
| Chân 10 | AIN6 — Analog input 6 (differential) |
| Chân 11 | AIN7 — Analog input 7 (differential) |
| Chân 12 | AIN8 — Analog input 8 (differential) |
| Chân 13 | AINCOM — Analog input common (return) |
| Chân 14 | SCLK — Serial clock input |
| Chân 15 | DIN — Serial data input |
| Chân 16 | DOUT — Serial data output |
| Chân 17 | /RDY — Conversion ready output (active low) |
| Chân 18 | /CS — Chip select input (active low) |
| Chân 19 | /RESET — Reset input (active low) |
| Chân 20 | DGND — Digital ground |
| Chân 21 | DVDD — Digital +2.5 V to +5 V supply |
| Chân 22 | MODE — Operating mode select (high for normal, low for standby) |
| Chân 23 | NC — Not connected (per datasheet) |
| Chân 24 | NC — Not connected (per datasheet) |
| Chân 25 | NC — Not connected (per datasheet) |
| Chân 26 | NC — Not connected (per datasheet) |
| Chân 27 | STANDBY — Standby control |
| Chân 28 | CLK — External clock input |
Ứng dụng tiêu biểu
AD7738BRU-REEL7 phù hợp cho 7 Áp dụngs: Industrial Weigh Scales, Multi-Channel Process Control PLCs, Multi-Sensor Data Acquisition Systems, Temperature Measurement (RTD/Thermocouple Front Ends), Patient Monitoring Instrumentation, Precision Weighing and Force Measurement, Battery Cell Monitoring Systems.
Industrial Weigh Scales
The AD7738BRU-REEL7 is purpose-built for multi-channel industrial weigh scales where load-cell bridges must be digitized with high stability. Its 0.0015% INL and no-missing-codes-at-24-bit guarantee translate to 1:20,000 effective count stability when digitizing a 2 mV/V strain-gauge bridge excited at 10 V. The 8.5 kHz channel switching enables sequential measurement of up to 8 load cells without throughput penalty, and the integrated programmable gain (1x-128x) eliminates the need for external instrumentation amplifiers. According to the Analog Devices AD7738 datasheet, the digital filter can be programmed for 50 Hz/60 Hz mains rejection simultaneously, which is critical for AC-energized industrial environments.
Được đề xuất
Multi-Channel Process Control PLCs
Programmable Logic Controllers with 4-8 analog inputs benefit from the AD7738BRU-REEL7's 4 or 8 differential inputs and 24-bit resolution. The TSSOP-28 footprint allows up to 8 channels in a compact PLC analog module, and the SPI-compatible interface connects directly to industrial microcontrollers. Per the AD7738 datasheet, the 8.5 kHz per-channel throughput supports 10 Hz update rates on all 8 channels simultaneously - more than adequate for process variable monitoring. The flexible 2.7 V to 5.25 V digital supply interfaces with both 3.3 V and 5 V MCUs without level shifters.
Được đề xuất
Multi-Sensor Data Acquisition Systems
Data acquisition systems that digitize multiple strain gauges, pressure transducers, or thermocouple junctions benefit from the AD7738BRU-REEL7's combination of 8 differential channels and 24-bit sigma-delta performance. According to the Analog Devices AD7738 datasheet, the digital filter provides simultaneous 50 Hz and 60 Hz rejection, eliminating the need for precision analog anti-alias hardware. The 117 us conversion time per channel enables >1 kHz aggregate throughput across all 8 inputs, which exceeds the bandwidth requirement for vibration, pressure, and temperature monitoring in test rigs and laboratory instrumentation.
Được đề xuất
Temperature Measurement (RTD/Thermocouple Front Ends)
RTD and thermocouple measurement modules use the AD7738BRU-REEL7 to digitize 4-wire PT100 sensors with 24-bit precision across 8 channels. The programmable gain up to 128x amplifies the small PT100 delta-resistance signal directly, while the integrated digital filter rejects 50/60 Hz mains pickup. Per the AD7738 datasheet, the analog input range of -2.9 V to +2.9 V accommodates 4 mA excitation currents across PT100/PT1000 sensors with up to 1 kV of cable resistance. The TSSOP-28 package allows high channel density in compact DIN-rail temperature modules.
Được đề xuất
Patient Monitoring Instrumentation
Medical patient monitoring equipment - particularly multi-parameter bedside monitors - use the AD7738BRU-REEL7 to digitize ECG, respiration, temperature, and SpO2 analog front-end signals. The 8 differential channels accommodate 4 to 6 simultaneous vital signs per module, and the 0.0015% INL ensures amplitude accuracy better than the IEC 60601-2-27 ECG specification. Per the AD7738 datasheet, the TSSOP-28 package is appropriate for portable medical device form factors. Designers should add optical isolation between the analog front end and the host processor for patient leakage current compliance with IEC 60601-1.
Được đề xuất
Precision Weighing and Force Measurement
Precision laboratory balances, force measurement fixtures, and dynamic weighing systems benefit from the AD7738BRU-REEL7's 24-bit resolution and programmable gain. The 16-bit p-p effective resolution at 8.5 kHz throughput allows 1:65,000 count stability on a single load cell - sufficient for 5-digit laboratory balances. According to the Analog Devices AD7738 datasheet, the digital filter is programmable for simultaneous 50 Hz and 60 Hz mains rejection, which is essential for environments where AC line interference would otherwise couple into the strain-gauge bridge. The integrated PGA reduces BOM count by replacing external instrumentation amplifiers.
Được đề xuất
Battery Cell Monitoring Systems
Large lithium-ion battery packs (EV, energy storage) use the AD7738BRU-REEL7 to digitize cell voltages and shunt-current monitors on up to 8 cells per module. The 24-bit resolution enables <1 mV measurement accuracy on 4.2 V lithium cells, critical for accurate state-of-charge calculation. According to the AD7738 datasheet, the 117 us per-channel conversion enables sequential scanning of 8 cells at >1 kHz aggregate rate, which is sufficient for cell-balancing feedback loops. The TSSOP-28 package fits compact battery management modules.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho AD7738BRU-REEL7 — 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 | AD7738BRUZ-REEL7 | AD7738BRU | AD7738BRUZ-REEL | AD7739BRUZ | AD7708BRU-REEL |
|---|---|---|---|---|---|---|
| Package | TSSOP-28 | TSSOP-28 - same | TSSOP-28 - same | TSSOP-28 - same | TSSOP-28 - same | TSSOP-28 - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 24 bits | 24 bits | 24 bits | 24 bits | 24 bits | 16 bits (-33%) |
| Channels | 4 or 8 differential | 4 or 8 differential | 4 or 8 differential | 4 or 8 differential | 8 or 16 differential | 8 or 10 single-ended |
| Throughput | 8.5 kHz per channel | 8.5 kHz per channel | 8.5 kHz per channel | 8.5 kHz per channel | 15 kHz per channel (+76%) | 5 kHz per channel (-41%) |
| INL | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.0015% (15 ppm) | 0.003% (30 ppm) |
| RoHS Finish | No (lead-based) | Yes (Pb-free matte tin) | No (lead-based) | Yes (Pb-free matte tin) | Yes (Pb-free matte tin) | No (lead-based) |
| Lifecycle Status | Last Time Buy | Last Time Buy (RoHS variant) | Last Time Buy | Last Time Buy | Active | Last Time Buy |
| Operating Temperature | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C | -40 C to +85 C |
Bảo phân biệt quan trọng
- 8 differential channels with 24-bit no-missing-codes in TSSOP-28 (vsAD7708BRU-REEL)
- Higher throughput per channel (vsAD7708BRU-REEL)
- Pin-compatible upgrade to higher channel count via AD7739BRUZ (vsAD7739BRUZ)
- Wider operating temperature range for harsh environments (vsAD7708BRU-REEL)
Ghi chú thiết kế
Decouple AVDD (pin 1) and DVDD (pin 21) with separate 10 microF tantalum plus 0.1 microF ceramic capacitors placed within 5 mm of the supply pins. The AD7738BRU-REEL7 has separate analog and digital grounds; tie AGND (pin 4) and DGND (pin 20) to a low-impedance ground plane with a single star connection at the power entry point. Do not share analog and digital ground returns, as digital switching noise will degrade the 24-bit noise floor. The 5 V analog supply should be low-noise (LDO, not switching) - per the AD7738 datasheet, supply ripple directly couples into the reference and appears as ADC noise.
Route analog inputs (AIN1-AIN8, AINCOM) as differential pairs with ground guard traces or as fully differential microstrip, matched in length to within 0.5 mm. Keep digital interface signals (SCLK, DIN, DOUT, /CS, /RDY, /RESET) physically separated from analog traces; never run digital signals under the AIN pins. Per Analog Devices, the TSSOP-28 thermal pad (pin 28 in some datasheets) connects to AGND; ensure the pad is soldered to a sufficient copper area (>= 25 sq mm) to limit junction temperature rise. Reference input traces (REFIN+/REFIN-) should be short and guarded to minimize noise pickup.
Do not exceed the 5 V analog supply limit; the AD7738BRU-REEL7 is not rated for 5.5 V on AVDD. The CLK pin (pin 28) requires an external clock source in normal operation; missing clock will halt conversions. When reading 24-bit data in Dump mode, do not drive DIN high during the read, or the part will reset. Per the AD7738 datasheet, the digital filter settling time is approximately 3 to 4 conversion cycles after channel switching - do not read DOUT immediately after switching inputs, as the data will be from the previous conversion. Avoid running the digital filter below 1 Hz output rate without enabling the auto-zero calibration mode, as low-frequency 1/f noise will degrade effective resolution.
The /RDY pin (pin 17) is an open-drain output and requires a 10 kohm pull-up to DVDD. The DOUT pin (pin 16) transitions on the falling edge of SCLK per the AD7738 datasheet; ensure the host MCU samples DOUT on the rising edge of SCLK with adequate setup/hold time. At high SPI clock rates (>5 MHz), place a 50 ohm series termination at the DOUT pin to limit ringing on long PCB traces. The Schmitt-triggered inputs on DIN, SCLK, /CS, /RESET tolerate up to 1 MHz rise/fall times, allowing direct connection to electrically isolated MCUs via ADuM1411/ADuM3154 isolators without external buffers.
Thông tin tuân thủ
RoHS: non-compliant (lead-based finish per BRU suffix). Choose AD7738BRUZ-REEL7 for Pb-free RoHS-compliant designs. Reach: compliant. AEC-Q100: not qualified - the AD7738BRU-REEL7 is industrial-grade only. Halogen-free: yes. Lifecycle: Last Time Buy per Analog Devices product page as of October 2026.
