TSA7887ARZ-REEL - 12-bit 125ksps 2-ch SAR ADC SOIC-8 | Silicon Labs
MPN： TSA7887ARZ-REEL ✗ 停產TSA7887ARZ-REEL 概覽
A SAR ADC is a type of analog-to-digital converter that uses a binary search through successive approximation register logic to resolve an analog input against an internal or external reference, producing N-bit results in N conversion cycles. SAR ADCs excel at medium-to-high resolution (12-18 bit) sampling at moderate speeds (10 ksps to 10 Msps) without the pipeline latency of higher-speed flash or pipelined architectures, making them ideal for multiplexed multi-channel data acquisition systems. Within the data-converter hierarchy, the TSA7887ARZ-REEL sits as a precision ADC -> data converter -> signal chain IC -> mixed-signal semiconductor, combining analog input conditioning, reference generation, and digital serial interface on a single die.
Key features include a 125 ksps maximum sampling rate, two single-ended analog input channels multiplexed into one ADC core, an internal 2.5 V reference, a low 0.85 mA supply current, a wide input bandwidth track-and-hold (500 ns), and a serial interface compatible with SPI/QSPI/MICROWIRE. The device accepts bipolar-input-capable front end via simple resistor networks and provides an external reference option when system-level drift compensation is required. The 8-pin SOIC footprint supports standard surface-mount assembly flows.
Architecturally, the TSA7887ARZ-REEL uses a charge-redistribution DAC array with successive-approximation register logic clocked from an external serial clock up to 2 MHz. The wideband track-and-hold preserves signal fidelity above the Nyquist limit of the 125 ksps sampling rate, while the integrated reference and input MUX eliminate the external analog conditioning typically required for discrete ADC designs. The serial output reduces pin count versus parallel-output ADCs and simplifies galvanic isolation in industrial systems.
Typical applications include portable battery-powered instrumentation, industrial process-control loop monitoring, multi-channel data-logger front ends, sensor-signal conditioning for strain-gauge and thermocouple inputs, and touch-screen / resistive-position decoder interfaces. The low 0.85 mA supply current also suits remote or solar-powered sensor nodes. Where higher throughput is needed, the part's SPI-compatible daisy-chain capability lets two devices share a single serial port.
When designing with this device, drive the analog inputs from low-impedance buffers (<= 50 ohm source impedance) to avoid conversion errors caused by the kick-back charge of the internal CDAC array. Bypass VDD with a 0.1 uF ceramic plus 10 uF tantalum placed within 5 mm of the supply pin, and provide a clean analog ground return to keep the integrated reference stable. The throughput scales linearly with external SCLK; a 2 MHz SCLK yields the rated 125 ksps. Note that the TSA7887ARZ-REEL is currently listed as obsolete by Silicon Labs (last-time-buy status), so long-life designs should consider the newer AD7887SRZ-EP equivalent.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
直接替換替代品，適用於 TSA7887ARZ-REEL — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： TSA7887ARZ-REEL （相同外形與佔位） — 差異在於 Data Interface, Number of Channels, Package, Internal Reference Voltage, Architecture.
TSA7887BRZ-REEL
✅ 直接替換聯絡詢價
查看資料表 →TSA7887ARZ
✅ 直接替換聯絡詢價
查看資料表 →TSA7887BRZ
✅ 直接替換聯絡詢價
查看資料表 →AD7887ARZ-REEL
✅ 直接替換聯絡詢價
查看資料表 →AD7887SRZ-EP
✅ 直接替換📋 參考替代品（不在目錄中）
TSA7887ARZ-REEL 最大額定值與電氣特性
| 解析度 | 12 bit |
| Number of Channels | 2 (single-ended, multiplexed) |
| 取樣率 | 125 ksps |
| Architecture | SAR (Successive Approximation Register) |
| 供應電壓 | +2.7 V to +5.25 V (single supply) |
| 供應電流 | 0.85 mA typical |
| Input Type | Single-ended (2 channels) |
| Data Interface | Serial (SPI/QSPI/MICROWIRE-compatible) |
| Internal Reference | 2.5 V |
| External Reference Support | Yes |
| Track-and-Hold Acquisition Time | 500 ns |
| External Clock | Up to 2 MHz serial clock |
| 封裝 | SOIC-8 (RZ suffix) |
| 安裝類型 | Surface Mount |
| 工作溫度 | -40C to +85C (industrial) |
| RoHS 狀態 | Compliant |
| Grade | 'A' Grade (per Mouser listing) |
TSA7887ARZ-REEL 腳位配置
| 腳位 1 | SCLK — Serial clock input |
| 腳位 2 | DOUT — Serial data output (ADC result) |
| 腳位 3 | DIN — Serial data input (channel select / control) |
| 腳位 4 | CS — Chip select, active low |
| 腳位 5 | GND — Analog ground |
| 腳位 6 | VDD — Positive supply voltage (+2.7 V to +5.25 V) |
| 腳位 7 | REF — Reference input/output (2.5 V internal) |
| 腳位 8 | AIN/AGND — Analog input (single-ended channel) |
典型應用
TSA7887ARZ-REEL 適用於 6 應用s: Portable Battery-Powered Instrumentation, Industrial Process Control Loop Monitoring, Multi-Channel Data Logger Front End, Sensor Signal Conditioning for Strain-Gauge and Thermocouple Inputs, Touch-Screen and Resistive Position Decoder Interface, Remote Solar-Powered Sensor Nodes.
Portable Battery-Powered Instrumentation
The TSA7887ARZ-REEL fits portable battery-powered instrumentation because of its 0.85 mA typical supply current from a single +2.7 V to +5.25 V rail, which extends runtime on Li-ion and 3.3 V coin-cell designs. The integrated 2.5 V reference eliminates an external reference IC and its quiescent drain, while the 2-channel single-ended input MUX supports direct connection to bridge sensors or thermistor dividers without an external analog front end. The 12-bit 125 ksps throughput is sufficient for 1 kHz-bandwidth signals in digital multimeters, handheld oscilloscope front ends, and field-portable data loggers. Placed between a sensor bridge and an MCU SPI port, the part delivers precise conversion while consuming less than 1 mW from the 3.3 V supply, making it ideal for multi-week battery deployments in industrial test equipment.
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Industrial Process Control Loop Monitoring
The TSA7887ARZ-REEL suits 4-20 mA loop monitoring and process-control analog front ends because its 12-bit resolution captures 0.024% full-scale steps, adequate for PLC analog input modules reading 0-10 V or 4-20 mA transducers. The 2.7 V to 5.25 V supply range lets the part share a 5 V industrial rail directly, while the SPI serial interface isolates easily through digital isolators for high-voltage channel separation. The integrated 2.5 V reference supports ratiometric measurements against a 2.5 V excitation source. Placed at the input of a 16-channel PLC module, two TSA7887ARZ-REEL devices in SPI daisy-chain handle 32 multiplexed analog points at aggregate throughputs up to 250 ksps, sufficient for closed-loop PID update rates above 1 kHz.
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Multi-Channel Data Logger Front End
The TSA7887ARZ-REEL provides a compact two-channel ADC front end for data loggers, eliminating the need for separate multiplexer and reference ICs. Its 125 ksps throughput supports aggregate sampling rates above 60 ksps per channel in dual-channel scan mode, capturing fast transient events from thermocouple, RTD, and strain-gauge sensors. The SOIC-8 footprint simplifies hand-solderable prototyping builds while still supporting automated SMT assembly. Per Silicon Labs datasheet, the wideband 500 ns track-and-hold preserves signal integrity above the Nyquist limit, which is critical when digitizing multiplexed signals with fast edge transitions. Placed between a sensor MUX and an SD-card logger MCU, the TSA7887ARZ-REEL delivers 12-bit precision at micropower levels suitable for unattended environmental monitoring stations.
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Sensor Signal Conditioning for Strain-Gauge and Thermocouple Inputs
The TSA7887ARZ-REEL digitizes low-level strain-gauge bridge outputs and thermocouple EMF signals because its 12-bit resolution resolves microvolt-range inputs after low-noise instrumentation-amp gain, while the integrated 2.5 V reference supports ratiometric measurement against the bridge excitation supply. The 0.85 mA supply current keeps total analog-front-end drain below 5 mW even with active biasing circuits, supporting solar-powered structural-health and remote-sensor deployments. The SPI-compatible serial interface connects directly to wireless MCUs for IoT bridge and temperature nodes. Placed after an INA128 instrumentation amplifier and low-pass filter, the TSA7887ARZ-REEL captures both static and dynamic strain signals with sufficient resolution for load-cell weighing scales and weigh-in-motion systems.
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Touch-Screen and Resistive Position Decoder Interface
The TSA7887ARZ-REEL functions as a precision touch-screen decoder because its 2-channel single-ended input MUX naturally handles the X and Y plate voltages of a 4-wire resistive touch panel, while the 12-bit resolution delivers sub-millimeter position accuracy across typical 4- to 7-inch displays. The SPI interface drives most ARM Cortex-M touch-screen controllers without glue logic. Operating from 2.7 V to 5.25 V, the part shares a common 3.3 V or 5 V rail with the host MCU. Placed between the touch panel connectors and the controller MCU, the TSA7887ARZ-REEL digitizes touch coordinates while drawing only 0.85 mA, ideal for handheld terminals, industrial HMIs, and POS systems.
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Remote Solar-Powered Sensor Nodes
The TSA7887ARZ-REEL suits remote solar-powered sensor nodes because its 0.85 mA typical supply current at 3.3 V yields less than 3 mW dissipation, leaving most of the harvested solar energy for the radio transceiver. The integrated 2.5 V reference avoids the 1-2 mA extra draw of a discrete reference, while the 2-channel input MUX reads two sensors (e.g., temperature + humidity) sequentially. The wide 2.7 V to 5.25 V supply range tolerates direct Li-ion battery connection through a regulator bypass. Placed between environmental sensors and a low-power MCU, the TSA7887ARZ-REEL enables multi-year battery-life deployments in agricultural, meteorological, and structural-monitoring IoT mesh networks.
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推薦產品摘要
工程參考資料，適用於 TSA7887ARZ-REEL — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | TSA7887BRZ-REEL | TSA7887ARZ | TSA7887BRZ | AD7887ARZ | AD7887SRZ-EP |
|---|---|---|---|---|---|---|
| Brand | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs | Analog Devices | Analog Devices |
| Package | SOIC-8 | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 125 ksps | 125 ksps | 125 ksps | 125 ksps | 125 ksps | 125 ksps |
| Number of Channels | 2 single-ended | 2 single-ended | 2 single-ended | 2 single-ended | 2 single-ended | 2 single-ended |
| Supply Voltage | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| Grade | A grade | B grade | A grade | B grade | Standard | Automotive/EP |
| Lifecycle | Obsolete | Obsolete | Obsolete | Obsolete | Active (long-lifecycle) | Active (automotive grade) |
主要差異化特點
- Industry-standard AD7887 second-source with long track record (對比AD7887ARZ (Analog Devices))
- Lower-cost obsolete part with active distribution stock (對比AD7887SRZ-EP (Automotive))
- Integrated 2.5 V reference eliminates external reference IC (對比Discrete ADC + external reference (e.g., ADR01))
設計說明
Bypass VDD (pin 6) with a 0.1 uF X7R ceramic capacitor placed within 5 mm of the supply pin, in parallel with a 10 uF tantalum or low-ESR ceramic bulk capacitor. The TSA7887ARZ-REEL draws 0.85 mA typical but draws higher transient currents during conversion; insufficient decoupling causes reference droop that degrades ADC linearity by 1-2 LSB. The analog ground return must be a star-connected trace tying pin 5 to the system analog ground plane.
Drive the analog input (pin 8) from a low-impedance buffer (<= 50 ohm source impedance). The internal charge-redistribution DAC kicks back charge at the start of each conversion, and a high-impedance source cannot settle within the 500 ns acquisition window. For sensor-bridge inputs, use an instrumentation amplifier such as INA128 with a 100 ohm output resistor in series to dampen the kick-back transient. Add an external RC anti-alias filter with -3 dB cutoff at 50 kHz to reject out-of-band noise.
Route the SPI signals (SCLK, DOUT, DIN, CS) as a short bus (<= 50 mm) with ground traces on either side to minimize crosstalk. Keep digital traces away from the analog input pin and reference pin by at least 5 mm. Place a ground pour under the SOIC-8 body tied to pin 5 (GND) to provide thermal relief and a low-inductance return path. For noisy environments, add a 100 ohm series resistor at SCLK close to the TSA7887ARZ-REEL to dampen ringing.
Do not leave the analog input floating - tie it to a defined DC potential through a high-value resistor (> 100 kohm) or buffer output. Do not exceed the supply voltage on any input pin, including the digital SPI inputs. Do not operate the part without the CS pin driven (CS must transition low for each conversion frame). Note that the TSA7887ARZ-REEL is obsolete; if designing for production lifetime beyond 5 years, select the AD7887SRZ-EP or another 12-bit SAR ADC in active production as a forward-compatible drop-in.
合規資訊
RoHS compliant per Silicon Labs product page. Not AEC-Q100 qualified - choose AD7887SRZ-EP for automotive designs. Halogen-free status not explicitly stated in available data.
