ADS7825UE4 - 16-Bit 4-Ch 40kSPS ADC | Texas Instruments
MPN: ADS7825UE4 ✓ Hoạt độngADS7825UE4 Tóm tắt
An analog-to-digital converter (ADC) is a mixed-signal integrated circuit that converts a continuous-time, continuous-amplitude analog voltage into a discrete-time, discrete-amplitude digital code. Successive-approximation register (SAR) ADCs use a binary-search algorithm against an internal DAC and comparator, achieving 16-bit resolution with low latency and deterministic throughput. Multi-channel ADCs integrate an analog input multiplexer that sequentially routes one of several inputs to the converter core, allowing a single ADC silicon die to digitize many signals - reducing cost, board area, and channel-to-channel timing skew. The ADS7825UE4 belongs to the broader SAR ADC family within TI's precision data-converter portfolio.
Key features include 25 us maximum acquisition-plus-conversion time, +/-2.0 LSB maximum integral nonlinearity, +/-10 V true bipolar input range achieved through laser-trimmed scaling resistors, channel-to-channel matching within +/-0.1%, and a choice of parallel (8/16-bit) or serial data output. The internal 2.5 V reference eliminates an external reference IC in many designs. A continuous-conversion mode allows the device to autonomously cycle through all four input channels without host intervention.
The architecture combines a capacitive-charge-redistribution DAC, a low-noise comparator, and an SAR control logic block. The input MUX is followed by a wide-bandwidth track-and-hold, which preserves the 16-bit accuracy even when the internal multiplexer switches between full-scale +/-10 V signals. The internal reference is buffered to drive the DAC ladder directly, reducing dynamic reference current transients. The combined architecture delivers 86 dB typical SNR and is pin-compatible with the lower-resolution ADS7824.
Typical applications include multi-channel industrial process control, portable or rack-mounted data-logging systems, medical instrumentation signal acquisition, automated test equipment (ATE) front-ends, and general-purpose precision data-acquisition boards requiring bipolar +/-10 V inputs from sensors or transducers.
When designing with this ADC, ensure the input amplifier drive strength and settling time are matched to the 25 us acquisition window, and add anti-alias filtering on each analog input to attenuate out-of-band noise above the Nyquist frequency (20 kHz at 40 kSPS aggregate throughput).
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving engineers a single reference for selecting, sourcing, and qualifying the ADS7825UE4.
Bộ thay thế dễ dàng lắp đặt cho ADS7825UE4 — 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 ADS7825UE4 (cùng hình factor và footprint) — khác nhau ở Package, Data Interface, Number of Input Channels, Resolution, Sampling Rate.
ADS7825U
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7824UB/1KG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7824UB/1KG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7824PG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7822PBG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7825UE4 Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 16 bits |
| Number of Input Channels | 4 (single-ended, multiplexed) |
| Tỷ lệ lấy mẫu | 40 kSPS (max) |
| Acquisition + Conversion Time | 25 us (max) |
| Phạm vi điện áp đầu vào | +/-10 V (bipolar, laser-trimmed scaling) |
| Integral Nonlinearity (INL) | +/-2.0 LSB (max) |
| Channel-to-Channel Matching | +/-0.1% |
| Điện áp cung cấp | +5 V single supply |
| Power Dissipation | 50 mW (max during conversion) |
| Data Interface | Parallel (8/16-bit) or Serial |
| Internal Reference | +2.5 V (on-chip) |
| Nhiệt độ hoạt động | -40C to +85C |
| Hộp | 28-SOIC (DW, 0.295 in / 7.50 mm width) |
| Kiểu lắp đặt | Surface Mount |
| Pin-Compatible With | ADS7824 (12-bit version, same 28-SOIC pinout) |
| Trạng thái RoHS | Compliant |
Cấu hình chân ADS7825UE4
| Chân 1 | CH0 — Analog input channel 0 |
| Chân 2 | CH1 — Analog input channel 1 |
| Chân 3 | CH2 — Analog input channel 2 |
| Chân 4 | CH3 — Analog input channel 3 |
| Chân 5 | AGND — Analog ground |
| Chân 6 | REF — +2.5 V internal reference (bypass to AGND) |
| Chân 7 | VREF — Reference voltage input/output |
| Chân 8 | DGND — Digital ground |
| Chân 9 | DB0 — Parallel data bit 0 (LSB) |
| Chân 10 | DB1 — Parallel data bit 1 |
| Chân 11 | DB2 — Parallel data bit 2 |
| Chân 12 | DB3 — Parallel data bit 3 |
| Chân 13 | DB4 — Parallel data bit 4 |
| Chân 14 | DB5 — Parallel data bit 5 |
| Chân 15 | DB6 — Parallel data bit 6 |
| Chân 16 | DB7 — Parallel data bit 7 |
| Chân 17 | DB8 — Parallel data bit 8 |
| Chân 18 | DB9 — Parallel data bit 9 |
| Chân 19 | DB10 — Parallel data bit 10 |
| Chân 20 | DB11 — Parallel data bit 11 |
| Chân 21 | DB12 — Parallel data bit 12 |
| Chân 22 | DB13 — Parallel data bit 13 |
| Chân 23 | DB14 — Parallel data bit 14 |
| Chân 24 | DB15 — Parallel data bit 15 (MSB) |
| Chân 25 | CS — Chip select (active low) |
| Chân 26 | RD — Read strobe (active low) |
| Chân 27 | CLK — External clock input / serial clock |
| Chân 28 | VDD — +5 V analog/digital supply |
Ứng dụng tiêu biểu
ADS7825UE4 phù hợp cho 6 Áp dụngs: Multi-Channel Industrial Process Control, Portable Data-Logging Systems, Medical Instrumentation Signal Acquisition, Automated Test Equipment (ATE) Front-Ends, Precision Data-Acquisition Boards (PC/104, PXI, USB DAQ), Industrial PLC Analog Input Modules.
Multi-Channel Industrial Process Control
The ADS7825UE4 fits industrial process-control front-ends because its four-channel input multiplexer accepts true bipolar +/-10 V signals directly from PLC analog outputs and 4-20 mA loop sense resistors, eliminating external level-shifting signal conditioning. With 16-bit resolution, +/-2.0 LSB max INL, and +/-0.1% channel-to-channel matching, the device delivers the precision required for closed-loop PID control loops monitoring temperature, pressure, and flow simultaneously. Its 25 us acquisition-plus-conversion time sustains 40 kSPS aggregate throughput, which is sufficient for sub-millisecond control updates across four sensors. The on-chip +2.5 V reference and single +5 V supply reduce BOM count and simplify UL/IEC 61010-1 isolation design.
Được đề xuất
Portable Data-Logging Systems
Battery-powered multi-channel data loggers benefit from the ADS7825UE4's 50 mW max power dissipation and single +5 V supply, which simplifies power-tree design and extends runtime. The integrated 4-channel MUX lets one ADC digitize four thermocouple, RTD, or strain-gauge signals without a second IC, reducing quiescent current draw. At 40 kSPS aggregate, the part is fast enough for vibration and acoustic emission logging but slow enough to operate in duty-cycled burst mode for further power savings. The internal +2.5 V reference eliminates an extra low-power reference IC, freeing budget for the MCU's sleep current. Industrial -40C to +85C operation supports outdoor and vehicular logging deployments.
Được đề xuất
Medical Instrumentation Signal Acquisition
Medical front-ends for patient monitoring, infusion pumps, and diagnostic analyzers need simultaneous multi-channel digitization of low-amplitude bioelectric and sensor signals. The ADS7825UE4 provides 16-bit resolution and +/-10 V input range, allowing direct connection to amplified ECG, EEG, SpO2, and blood-pressure transducer outputs without additional gain stages. The +/-0.1% channel-to-channel matching ensures that multi-lead measurements remain temporally and gain-aligned across channels. The parallel/serial interface simplifies connection to low-power medical MCUs and DSPs. Designers should add input ESD protection and patient-isolation barriers per IEC 60601-1 in the analog front-end ahead of the ADC.
Được đề xuất
Automated Test Equipment (ATE) Front-Ends
ATE rack-and-stack instruments use the ADS7825UE4 to digitize multiple DUT stimulus or response signals through a single ADC, reducing instrument cost and calibration complexity. With 25 us per conversion and 16-bit resolution, the part supports sub-100 us per-channel test sequences across four channels. The parallel 8/16-bit interface enables fast host-side data transfer to FPGA or DSP-based test controllers, while the serial mode reduces pin count for compact PXI-style modules. The +/-10 V true bipolar input accepts both positive and negative DUT signals without external inversion. On-chip +2.5 V reference minimizes calibration drift between channels.
Được đề xuất
Precision Data-Acquisition Boards (PC/104, PXI, USB DAQ)
Off-the-shelf PC-based DAQ cards often use the ADS7825UE4 to provide 4 simultaneous bipolar channels at 16-bit resolution, supporting laboratory-grade measurements of strain, load, force, and temperature. The part's 86 dB typical SNR and laser-trimmed scaling resistors provide the accuracy needed for transducer-based metrology. The internal MUX simplifies analog input stage design and reduces channel-to-channel crosstalk. Designers commonly pair this ADC with instrumentation amplifiers ahead of each input to provide high common-mode rejection and source impedance buffering for the ADC's resistive input divider.
Được đề xuất
Industrial PLC Analog Input Modules
Modular PLC analog input cards digitize 4-8 channels per slot, and the ADS7825UE4 is well matched to that channel density. Its 28-SOIC package allows dense PCB placement with each ADC handling a quad of +/-10 V channels. The 50 mW max power dissipation simplifies thermal design in sealed IP67 enclosures. Channel-to-channel matching within +/-0.1% ensures uniform scaling across the module's input channels, critical for safety-integrity applications per IEC 61508 SIL-2/3 when used in redundant architectures. Industrial -40C to +85C operation supports unconditioned cabinet installations.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ADS7825UE4 — 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 | ADS7825U | ADS7824UB/1KG4 | ADS7824UB | ADS7824PG4 | ADS7822PBG4 |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-SOIC (DW) | 28-SOIC (DW) - same | 28-SOIC (DW) - same | 28-SOIC (DW) - same | 28-PDIP (N) - through-hole variant | 28-PDIP (N) - through-hole variant |
| Resolution | 16 bits | 16 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Input Channels | 4 (multiplexed) | 4 (multiplexed) | 4 (multiplexed) | 4 (multiplexed) | 4 (multiplexed) | 1 (single-channel) |
| Sampling Rate | 40 kSPS | 40 kSPS | 40 kSPS | 40 kSPS | 40 kSPS | 75 kSPS |
| Input Voltage Range | +/-10 V (bipolar) | +/-10 V (bipolar) | +/-10 V (bipolar) | +/-10 V (bipolar) | +/-10 V (bipolar) | +/-5 V or +/-10 V |
| Supply Voltage | +5 V single | +5 V single | +5 V single | +5 V single | +5 V single | +5 V single |
| Internal Reference | +2.5 V (on-chip) | +2.5 V (on-chip) | +2.5 V (on-chip) | +2.5 V (on-chip) | +2.5 V (on-chip) | External reference |
| Pin-Compatible Drop-In | Yes (same family) | Yes - identical | Yes - lower resolution | Yes - lower resolution | DIP only - different package | DIP only - different package |
Bảo phân biệt quan trọng
- Four-channel input multiplexer integrated (vsADS7807PBG4 (single-channel 16-bit ADC))
- True bipolar +/-10 V input range on-chip (vsADS7824UB (12-bit pin-compatible variant))
- Both parallel and serial interface in one part (vsADS7817UBG4 (serial-only 12-bit ADC))
Ghi chú thiết kế
The ADS7825UE4 uses on-chip laser-trimmed scaling resistors that present a fixed source impedance to each analog input. Drive each input through a low-output-impedance buffer amplifier (such as a TI OPA227 or OPA2227) capable of settling to 16-bit accuracy within the 25 us acquisition window. Add a 10 nF X7R ceramic bypass capacitor directly at each ADC input pin to absorb charge-injection transients from the internal MUX and to provide instantaneous charge to the internal sample-and-hold capacitor.
Separate the analog and digital ground planes using a single-point connection (star ground) under or near the AGND pin. Keep the parallel data bus (DB0-DB15) traces short and away from the analog input traces. Place the +5 V supply decoupling (10 uF tantalum + 0.1 uF ceramic) within 5 mm of the VDD pin. The internal reference at the REF pin should be bypassed with a 10 uF tantalum in parallel with a 0.1 uF ceramic to minimize reference noise.
Do not exceed the absolute maximum analog input voltage of +/-25 V. Ensure the ADC's logic-low input voltage (VIL) is met by your host MCU - the ADS7825UE4 uses TTL-compatible thresholds, so 3.3 V microcontrollers may need a level shifter. In serial mode, observe the timing diagram carefully: the CLK-to-DOUT propagation delay is specified in the datasheet and may require wait states at high clock rates. In continuous-conversion mode, ensure the host reads data fast enough to avoid FIFO overrun (the part does not have an internal data buffer).
Estimated: At +5 V supply and maximum 40 kSPS continuous sampling, the ADS7825UE4 draws approximately 10 mA average current, yielding 50 mW total power dissipation (matching the datasheet maximum). For battery-powered designs, use the duty-cycled conversion mode to reduce average supply current proportionally to the sampling duty cycle. Add a ferrite bead in series with the VDD pin to isolate digital switching noise on the +5 V rail from the analog reference ladder.
At 50 mW maximum dissipation in the 28-SOIC package (theta_JA approximately 75 C/W for a standard JEDEC test board), the junction temperature rise is approximately 3.8C above ambient - well within the 125C absolute maximum. No external heatsink is required. For very dense PCBs (>3 ADCs per square inch), verify thermal rise with a prototype, especially in sealed enclosures with limited airflow.
Thông tin tuân thủ
ADS7825UE4 is the lead-free (Pb-free) and RoHS-compliant assembly version of the ADS7825. Per the UE4 ordering code suffix, this part meets RoHS and lead-free requirements. Halogen-free status not explicitly stated in the verified web data - marked unknown. Not AEC-Q100 qualified; the part is targeted at industrial (-40C to +85C) rather than automotive Grade 1/0 environments.
