TSA7887ARMZ-REEL - 12-bit 125ksps 2-ch SAR ADC | Silicon Labs
MPN: TSA7887ARMZ-REEL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.95 | $3.95 |
| 10 | $3.55 | $35.50 |
| 100 | $3.15 | $315.00 |
| 500 | $2.85 | $1,425.00 |
| 1,000 | $2.55 | $2,550.00 |
TSA7887ARMZ-REEL Overview
A SAR ADC is a successive-approximation-register analog-to-digital converter, a converter topology that uses a binary-search algorithm and a capacitive charge-redistribution DAC to resolve each conversion in N clock cycles for an N-bit result. SAR converters sit in the data-converter hierarchy between flash converters (fastest, lowest resolution) and sigma-delta converters (highest resolution, slowest). They are valued for deterministic latency, low power consumption, and the ability to drive them directly from a microcontroller or DSP serial port without an external reference or high-speed clock.
Key features include a 500 ns input track-and-hold acquisition time, an internal +2.5V reference that eliminates external reference components, and a single-ended analog input structure that supports one or two channels multiplexed to the ADC core. Throughput scales with the external serial clock up to 125 ksps at 2 MHz SCLK. The wide supply range allows direct interfacing to 3.3V and 5V microcontrollers, while the small MSOP-8 footprint suits space-constrained sensor readouts and portable instrumentation.
Typical applications include transducer and sensor signal conditioning, battery-powered data loggers, industrial process control loops with 4-20 mA interfaces, and portable medical or instrumentation front-ends. The combination of low power, internal reference, and small footprint also suits loop-powered 4-20 mA smart transmitters where every milliwatt and square millimeter matters.
When designing with this device, ensure the analog input stays within the input common-mode range specified by the supply, and add a small RC anti-alias filter on each input to limit out-of-band noise folding into the conversion result.
Drop-in alternatives for TSA7887ARMZ-REEL — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TSA7887ARMZ-REEL (same form factor and footprint) — differing in Number of Channels, Package, Data Interface, Grade, Input Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TSA7887ARZ-REEL
✅ Drop-In✓ In Stock
$2.48 / Unit
View Datasheet →TSA7887BRMZ-REEL
✅ Drop-In📋 Reference alternative (not in catalog)
AD7887ARMZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD7887BRMZ
✅ Drop-In📋 Reference alternative (not in catalog)
TSA7887ARMZ-REEL Maximum Ratings & Electrical Characteristics
| Number of Bits | 12 |
| Sampling Rate | 125 ksps |
| Number of Channels | 2 (single-ended, multiplexed) |
| Supply Voltage | +2.7 V to +5.25 V (single supply) |
| Supply Current | 0.85 mA typical at full throughput |
| Architecture | SAR (Successive Approximation Register) |
| Input Track-and-Hold Acquisition Time | 500 ns |
| Internal Reference Voltage | +2.5 V |
| Data Interface | SPI, MICROWIRE, QSPI, DSP-compatible serial |
| External Serial Clock | 2 MHz maximum |
| Analog Input Type | Single-ended (one or two inputs) |
| Package | MSOP-8 (RM) |
| Mounting Type | Surface Mount |
| Operating Temperature Grade | Automotive (xIND / extended industrial, per Silabs marking) |
| Pin Count | 8 |
| RoHS Status | Compliant |
TSA7887ARMZ-REEL Pin Configuration
| Pin 1 | VDD — Analog +2.7V to +5.25V supply input; decouple with 100nF to GND |
| Pin 2 | REF — Internal +2.5V reference output; bypass with 1uF to GND or overdrive with external reference |
| Pin 3 | GND — Analog and digital ground |
| Pin 4 | AIN1 — Analog input channel 1, single-ended |
| Pin 5 | AIN2 — Analog input channel 2, single-ended |
| Pin 6 | CS — Chip-select (active low) for SPI serial interface |
| Pin 7 | SCLK — Serial clock input, up to 2 MHz |
| Pin 8 | DOUT — Serial data output (SPI/MICROWIRE/QSPI/DSP-compatible) |
Typical Applications
TSA7887ARMZ-REEL is suitable for 6 applications: Battery-Powered Sensor Data Logger, 4-20 mA Loop-Powered Smart Transmitter, Industrial Process Control Analog Input Module, Portable Medical Instrumentation Front-End, Automotive Sensor Interface (xIND Grade), Digital Control Loop Position Feedback.
Battery-Powered Sensor Data Logger
The TSA7887ARMZ-REEL fits battery-powered sensor data loggers because its 0.85 mA supply current at full throughput and +2.7V to +5.25V supply range let it run directly from Li-ion or 3.3V coin-cell rails. The internal +2.5V reference removes the bulky external reference typical of 12-bit SAR designs, while the 125 ksps throughput captures fast transients from temperature, pressure, and strain sensor front-ends. Place 100 nF decoupling next to the VDD pin and a small RC anti-alias filter at each AIN input to limit out-of-band noise folding into the 12-bit result. The MSOP-8 footprint fits inside sealed IP68 enclosures where PCB area is at a premium.
Recommended
4-20 mA Loop-Powered Smart Transmitter
In a 4-20 mA loop-powered smart transmitter, the TSA7887ARMZ-REEL digitizes the bridge or RTD signal with full 12-bit resolution while drawing only 0.85 mA from the 4 mA quiescent loop budget. The internal +2.5V reference provides the excitation needed for a single 350 ohm ratiometric bridge without external buffering, and the SPI serial output pipes converted data directly to a low-power MCU over 2 MHz SCLK. The single-supply +2.7V to +5.25V operation accommodates loop drops of 12-24V after a series regulator. Designers should add a small input RC and a TVS diode for surge protection against inductive kickback in industrial installations.
Recommended
Industrial Process Control Analog Input Module
The TSA7887ARMZ-REEL is well suited to industrial analog input modules that digitize 0-5V or 0-10V process signals at channel scan rates up to 125 ksps per channel. Two single-ended channels let a PLC backplane read two transducers with one IC, halving board area versus discrete ADC channels, and the SPI/MICROWIRE/QSPI/DSP-compatible serial interface drops straight onto a micro-controller or DSP serial peripheral. The +2.7V to +5.25V supply tolerance accommodates both legacy 5V PLC rails and modern 3.3V logic. Provide input protection (TVS, fuses) and a small isolation barrier if connecting to field wiring in hazardous-area installations.
Recommended
Portable Medical Instrumentation Front-End
Medical instrumentation such as handheld pulse-oximeters, glucose meters, and portable ECG front-ends benefit from the TSA7887ARMZ-REEL's small MSOP-8 footprint, 0.85 mA supply draw, and integrated +2.5V reference, which together shrink the analog front-end BOM. The 500 ns input track-and-hold accurately captures pulse-oximeter photodiode transients without aliasing, and the SPI serial output streams 12-bit samples to a low-power MCU for further DSP. Operate the part from a regulated 3.0V LDO for noise-sensitive measurements; ensure patient-connected circuits meet IEC 60601 isolation and creepage requirements separately.
Recommended
Automotive Sensor Interface (xIND Grade)
The TSA7887ARMZ-REEL carries an automotive/extended-industrial (xIND) temperature grade, suiting it to body-electronics sensor interfaces for throttle position, pedal travel, and HVAC flap position sensing. Two single-ended 12-bit channels cover redundant sensor pairs needed for ASIL-classified inputs, and the +2.7V to +5.25V supply range tolerates load-dump-regulated 5V rails on-board. The small MSOP-8 package simplifies placement near remote sensor connectors. Designers must add reverse-battery and load-dump protection at the supply pin, and verify compliance with the OEM-specific EMC and ESD requirements beyond the datasheet ratings.
Recommended
Digital Control Loop Position Feedback
Digital control loops in robotics and CNC machinery use the TSA7887ARMZ-REEL to read two potentiometer or Hall-sensor outputs at 12-bit resolution with 125 ksps throughput, providing deterministic SAR latency suitable for PID feedback computation. The internal +2.5V reference avoids the need for a precise external reference on every axis card, and the SPI output streams channel data to a motion controller or DSP at full 2 MHz SCLK. The small MSOP-8 footprint lets designers pack multiple axis-digitizers on a single multi-axis controller board. Use shielded cabling and 0.1 inch pitch input filtering when routing near motor drive FETs.
Recommended
Recommended Products Summary
Engineering reference data for TSA7887ARMZ-REEL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TSA7887ARZ-REEL | TSA7887BRMZ-REEL | AD7887ARMZ | AD7887BRMZ |
|---|---|---|---|---|---|
| Brand | Silicon Labs | Silicon Labs | Silicon Labs | Analog Devices | Analog Devices |
| Package | MSOP-8 (RM) | SOIC-8 - NOT same package, not drop-in | MSOP-8 - same | MSOP-8 - same | MSOP-8 - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | |
| Throughput | 125 ksps | 125 ksps | 125 ksps | 125 ksps | |
| Channels | 2 single-ended | 2 single-ended | 2 single-ended | 2 single-ended | |
| Supply Voltage | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | |
| Supply Current | 0.85 mA typical | 0.85 mA typical | 0.85 mA typical | 0.85 mA typical | |
| Internal Reference | +2.5V | +2.5V | +2.5V | +2.5V | |
| INL / Grade | A grade | B grade (different INL tolerance) | A grade | B grade | |
| Temperature Grade | Automotive / xIND | Automotive / xIND | Industrial | Industrial |
Key Differentiators
- Micropower operation for battery and loop-powered systems (vs MAX187CEWE)
- Integrated +2.5V reference eliminates external reference BOM (vs MAX174AEPI)
- Pin-compatible second source for industry-standard AD7887 (vs AD7887ARMZ)
- Two single-ended channels in MSOP-8 for space-constrained designs (vs MAX174BEPI)
Design Notes
Decouple VDD (pin 1) with a 100 nF X7R ceramic placed within 2 mm of the pin; adding a 1 uF to 10 uF bulk capacitor suppresses the digital current spikes caused by the SAR charge-redistribution DAC. Bypass the internal +2.5V reference at the REF pin (pin 2) with a 1 uF low-leakage ceramic to keep reference noise below the 12-bit LSB. Estimated: at 5V supply and 0.85 mA typical, full-speed dissipation is about 4.25 mW; however, peaks during the SAR bit-trial transitions can momentarily exceed this average by 2-3x.
Use a continuous ground plane under the IC and keep analog (AIN1, AIN2, REF, VDD) traces on one side, digital (CS, SCLK, DOUT) on the other to prevent digital switching noise from coupling into the analog inputs. Keep the REF bypass capacitor trace short and avoid routing high-current digital return paths beneath the reference pin. Place input RC filters (typically 10 ohm + 1 nF) within 5 mm of each AIN pin to limit out-of-band noise that would otherwise alias into the 12-bit result.
Avoid operating VDD above the +5.25V absolute maximum, even briefly during load-dump transients in automotive designs - the part does not include internal TVS protection. When reading signals near VDD or GND rails, account for input common-mode restrictions and add a resistive divider if the source exceeds VDD. Do not clock SCLK above 2 MHz; throughput scales linearly but accuracy drops above the rated clock. If the internal reference must be overdriven by an external source, slew the reference pin to its final value before the first conversion.
Compliance Information
RoHS and REACH compliance per Silicon Labs/Touchstone product page. AEC-Q100 not specifically qualified; the 'xIND' / automotive temperature grade covers extended-industrial but is not equivalent to full automotive certification.
