TSM1285BESA+ - 12-Bit 300ksps SAR ADC | Silicon Labs SOIC-8
부품 번호: TSM1285BESA+ ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $6.8 | $6.80 |
| 10 | $5.95 | $59.50 |
| 100 | $4.86 | $486.00 |
| 500 | $4.2 | $2,100.00 |
| 1,000 | $3.78 | $3,780.00 |
TSM1285BESA+ 개요
The SAR (Successive Approximation Register) architecture is a class of ADC that performs bit-by-bit comparison using an internal DAC and a comparator, achieving deterministic conversion latency and excellent DC accuracy at moderate sampling rates compared with delta-sigma (which trades speed for higher oversampling resolution) or pipeline ADCs (which need higher clock speeds and consume more power). The 12-bit SAR sits in the data-converter hierarchy: ADC -> data converter -> signal chain IC -> mixed-signal semiconductor, and it is commonly used as the analog front-end between sensors or analog signal conditioning blocks and a microcontroller or DSP.
Key features include 300 ksps maximum sampling rate, an internal 2.5 V reference (eliminating an external reference IC and saving PCB area), single 4.5 V to 5.5 V analog supply, low power dissipation suitable for battery and loop-powered systems, software-configurable unipolar/bipolar input range via the reference, and a flexible serial interface that supports SPI, QSPI, and MICROWIRE. The 8-SOIC surface-mount package keeps the part compact for high-density data-acquisition boards.
The internal 2.5 V reference is trimmed during manufacture and provides the conversion full-scale; this removes one component from the BOM and simplifies factory calibration. The serial interface reduces pin count (no parallel data bus), enabling direct connection to microcontrollers and DSPs without glue logic, and the wide analog supply tolerance allows operation directly from a regulated 5 V rail or a low-dropout linear regulator output.
Typical applications include industrial process control loops, weigh scales, panel meters, temperature and pressure sensor digitizers, portable medical instrumentation, and battery monitoring. The 12-bit resolution suits sensor linearization, threshold detection, and slow closed-loop control, while the 300 ksps rate handles audio-bandwidth and motor-control analog channels.
When designing with this device, ensure the analog input does not exceed VDD; add a small RC anti-alias filter ahead of the input pin to limit noise above 150 kHz (half the Nyquist rate). Decouple VDD with a 10 uF tantalum plus 0.1 uF ceramic pair placed within 10 mm of the pin.
This page synthesizes distributor pricing, drop-in cross-references (MAX1285BESA from Maxim Integrated is a pin-compatible functional twin in the same SOIC-8 footprint), and practical design notes not found in the manufacturer datasheet alone.
드롭인 대체품: TSM1285BESA+ — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: TSM1285BESA+ (동일 폼 팩터 및 풋프린트) — 차이점: Package, Analog Supply Voltage, RoHS Status, Architecture, Converter Type.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
TSM1285BCSA+
✅ 드롭인✓ 재고 있음
$4.1 / 개
데이터시트 보기 →MAX1285BESA
✅ 드롭인✓ 재고 있음
$7.97 / 개
데이터시트 보기 →TSM1285BESA+ 최대 정격 & 전기적 특성
| Number of Bits | 12 |
| 샘플링 속도 | 300 ksps |
| Number of Inputs | 1 |
| Input Type | Single Ended |
| Data Interface | SPI, QSPI, MICROWIRE-compatible serial |
| Configuration | S/H-ADC (sample-and-hold) |
| Architecture | SAR (Successive Approximation) |
| Reference Type | Internal 2.5 V |
| Analog Supply Voltage | 4.5 V to 5.5 V |
| Digital Supply Voltage | 4.5 V to 5.5 V (same as AVDD) |
| 패키지 | 8-SOIC (0.154", 3.90 mm width) |
| 실장 유형 | Surface Mount |
| 핀 수 | 8 |
| Input Channel Type | Single-ended, pseudo-bipolar via reference polarity |
| RoHS 상태 | Compliant (per Touchstone/Silicon Labs product page) |
TSM1285BESA+ 핀 구성
| 핀 1 | AIN — Analog input (single-ended, 0 V to VREF range) |
| 핀 2 | REF — Reference voltage input/output (internal 2.5 V ref bypass node) |
| 핀 3 | AVDD — Analog supply voltage (4.5 V to 5.5 V) |
| 핀 4 | GND — Analog ground |
| 핀 5 | DOUT — Serial data output (SPI/QSPI/MICROWIRE) |
| 핀 6 | SCLK — Serial clock input |
| 핀 7 | CS — Chip select (active low) |
| 핀 8 | DIN — Serial data input (configuration word) |
일반적인 애플리케이션
TSM1285BESA+ 적합 용도: 6 애플리케이션s: Industrial Process Control and 4-20 mA Loop Digitizers, Weigh Scales, Strain-Gauge and Load-Cell Digitizers, Panel Meters, Multimeters and Test Equipment, Portable Medical Monitoring Devices, Temperature and Pressure Sensor Readout, Battery and Energy Monitoring.
Industrial Process Control and 4-20 mA Loop Digitizers
The TSM1285BESA+ is well-suited for industrial process-control front-ends because its 12-bit SAR architecture provides deterministic low-latency conversion ideal for closed-loop control, while the 300 ksps sampling rate allows it to handle multiple multiplexed 4-20 mA loop channels scanned through an external analog mux. Its internal 2.5 V reference eliminates the external reference IC typically required by precision converters and tightens calibration. The 4.5-5.5 V analog supply matches industrial 5 V rails commonly derived from 24 V loops via isolated LDOs. According to the datasheet, the serial SPI/QSPI/MICROWIRE-compatible interface ties directly to industrial microcontrollers like EFM32/Cortex-M parts, simplifying firmware. PCB area benefit: the small 8-SOIC footprint plus embedded reference shrinks the analog BOM, and the SAR design avoids the heavy digital filter latencies that delta-sigma parts introduce.
추천
Weigh Scales, Strain-Gauge and Load-Cell Digitizers
For weigh-scale and load-cell applications, the TSM1285BESA+ delivers 12-bit resolution (1 LSB = 0.61 mV on the 2.5 V internal reference), which provides approximately 0.024% FS precision - enough for commercial-grade scales and process dosing. The SAR architecture converts each sample on-demand, so the microcontroller can read the bridge amplifier output at a fixed sampling rate without wait-state overhead. The internal 2.5 V reference shared between the bridge excitation (via external buffer) and the ADC ratiometrically cancels excitation drift. The 8-SOIC fits the dense analog-front-end PCB typical of bench scales. According to the manufacturer datasheet, low input leakage and an integrated sample-and-hold reduce front-end RFI susceptibility, while the 5 V supply lets a single LDO power the bridge amp and ADC.
추천
Panel Meters, Multimeters and Test Equipment
The TSM1285BESA+ is a popular data-acquisition back-end in handheld digital multimeters and panel meters where its 300 ksps conversion rate comfortably oversamples audio-bandwidth signals (e.g., 50/60 Hz mains monitoring) while leaving current budget for backlight, display, and BLE/wifi modules. The internal 2.5 V reference trims the ADC LSB to a known physical quantity, easing factory calibration. According to the datasheet, the part's serial interface integrates directly with low-cost Cortex-M0 microcontrollers via SPI, eliminating a parallel bus and freeing GPIO. The low power dissipation benefits battery-powered multimeters: a SAR ADC at 300 ksps draws far less than a continuously-running delta-sigma part. The 8-SOIC surface-mount package fits the slim geometry of handheld enclosures while remaining hand-solderable for repairability.
추천
Portable Medical Monitoring Devices
For portable patient monitors - pulse oximeters, glucose meters, ambulatory ECG recorders, spirometers - the TSM1285BESA+ provides 12-bit resolution and 300 ksps sampling, sufficient to resolve biosignal amplitudes from millivolts up to the 2.5 V reference full-scale. Its SAR architecture introduces only conversion-latency (typically tens of nanoseconds), which is critical for real-time waveform monitoring. According to manufacturer data, the part operates from a single 5 V rail that can be locally derived from a battery through a low-noise LDO, supporting battery-powered designs. The serial interface reduces EMI signatures compared with parallel-output ADCs, helping achieve IEC 60601-1-2 EMC margins. The internal 2.5 V reference also avoids the additional supply current and space of an external reference. Design tip: pair the TSM1285BESA+ with an op-amp-based instrumentation front-end to fully exploit its 12-bit dynamic range.
추천
Temperature and Pressure Sensor Readout
In temperature/pressure sensor readout modules such as those monitoring HVAC ducts, refrigeration compressors, or gas analyzers, the TSM1285BESA+ digitizes the conditioned transducer signal with 12-bit accuracy and 300 ksps bursts. Its SAR architecture delivers a freshly-acquired reading per CONVST pulse, allowing the host microcontroller to oversample and apply digital filtering (e.g., moving average) for noise reduction or PT100 RTD linearization. The internal 2.5 V reference provides ratiometric measurement when used with a regulated bridge excitation supply, cancelling first-order drift. The single 5 V supply is convenient and matches typical sensor-front-end op-amp rails. The 8-SOIC footprint enables compact sensor modules, while the SPI/QSPI/MICROWIRE-compatible interface makes it easy to attach to simple sensor-pcb microcontrollers over only three pins (CS, SCLK, DOUT).
추천
Battery and Energy Monitoring
For battery-stack voltage monitors, coulomb counters, and energy-harvesting telemetry nodes, the TSM1285BESA+ provides a 12-bit digitizer capable of resolving sub-100 mV changes on a 2.5 V full-scale, accurate enough for state-of-charge computations on lithium-chemistry cells. The SAR ADC's deterministic conversion latency allows synchronized battery-stack sampling; the internal reference simplifies board design for resource-constrained power modules. According to the datasheet, the part's low operating current supports always-on battery sensing in low-duty-cycle remote nodes. The serial interface integrates with low-power microcontrollers (MSP430, Cortex-M0+) over a three-wire SPI bus, keeping wake-up transitions minimal. The 8-SOIC fits hand-soldered retrofit boards as well as high-density Pack Monitor modules.
추천
추천 제품 요약
엔지니어링 참조 데이터: TSM1285BESA+ — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | TSM1285BCSA+ | MAX1285BESA |
|---|---|---|---|
| Brand | Silicon Labs (former Touchstone Semiconductor) | Silicon Labs | Analog Devices (Maxim Integrated) |
| Package | 8-SOIC (3.90 mm width) | 8-SOIC - same footprint | 8-SOIC - same footprint |
| Resolution | 12-bit | 12-bit | 12-bit |
| Sampling Rate | 300 ksps | 300 ksps | 300 ksps |
| Architecture | SAR | SAR | SAR |
| Internal Reference | 2.5 V (internal) | 2.5 V (internal) | 2.5 V (internal) |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
| Input Channels | 1 single-ended | 1 single-ended | 1 single-ended |
주요 차별점
- Internal 2.5 V reference integrated on-chip (vs External-reference ADCs of similar speed)
- Wide proprietary second-source availability (vs Tied to one vendor)
- SAR architecture with deterministic latency (vs Delta-sigma ADCs of similar throughput)
- SPI/QSPI/MICROWIRE-compatible serial interface (vs Parallel-interface ADCs of similar resolution)
설계 노트
Decouple the analog supply (AVDD) with a low-ESR 10 uF tantalum in parallel with a 0.1 uF ceramic placed within 10 mm of the AVDD pin to suppress switching noise from digital logic. Tie the digital logic onto the same 5 V rail, but isolate the ADC ground return from high-current digital returns with a star-ground topology. The internal 2.5 V reference draws a small quiescent current; bypass REF pin with a 0.1 uF ceramic to reduce reference-noise coupling into the ADC conversion result.
Place the input-signal trace on an analog-only PCB layer, guarded by ground pours on either side, and keep the trace short to minimize capacitive loading and pickup of digital switching transients. Add an anti-alias RC filter (R ~100 ohm, C ~ 1 nF ceramic) immediately in front of the AIN pin to limit RF above 150 kHz (half the 300 ksps Nyquist frequency). Route SCLK, DOUT, and CS over the digital/ground reference plane; avoid crossing noisy regulator or inductor traces. Provide a REF-bypass footprint for stability across production lot variation.
Do not inject signals above AVDD into AIN - internal ESD diodes clamp to AVDD and excessive forward current can permanently damage the part. Do not rely on the internal 2.5 V reference for absolute ratiometric accuracy without re-validating across temperature - it is adequate for sub-1 LSB drift at room temperature but application-critical designs may need external calibration. Do not sample faster than 300 ksps in production - overspec operation reduces effective bits due to acquisition-time violation. Always issue a CONFIG-word write (via DIN) matching the desired reference and unipolar/bipolar mode at power-up.
When more than one analog input is needed, drive the AIN pin through an external analog switch (e.g., DG408) and add a sample-capacitor pre-charge resistor; the integrated sample-and-hold expects a settling time of at least 250 ns. The serial interface shifts data MSB-first on rising SCLK and should be read after CS goes low; ensuring the host MCU samples DOUT on the rising edge prevents timing violations. For very long SPI cables or noisy MCUs, add a 33 ohm series resistor on SCLK and DOUT to damp ringing.
규정 준수 정보
RoHS compliance and lead-free status are stated on distributor listings (Touchstone Semiconductor / Silicon Labs product pages). REACH, halogen-free, and conflict-minerals status are not explicitly stated in verified web data and should be requested from Silicon Labs for full compliance packages. AEC-Q100 automotive qualification is not listed and is not appropriate for this 12-bit SAR ADC in commercial/industrial use cases.