AS1538-BTSU - 12-Bit 8-Ch 50kSPS I2C ADC | ams | TSSOP-16
部品番号: AS1538-BTSU ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $5.42 | $5.42 |
| 10 | $4.88 | $48.80 |
| 100 | $4.35 | $435.00 |
| 500 | $3.91 | $1,955.00 |
| 1,000 | $3.49 | $3,490.00 |
AS1538-BTSU 概要
An analog-to-digital converter (ADC) is a mixed-signal data-acquisition component that converts real-world analog signals into discrete digital codes for processing by a microcontroller, DSP, or FPGA. The AS1538 belongs to the SAR (Successive Approximation Register) ADC family, a category well suited for multiplexed multi-channel low-power applications where deterministic latency and compact code size outweigh the highest sampling rates. SAR ADCs sit hierarchically below Nyquist-rate ADCs and above slower integrating ADCs in the data-converter taxonomy, and they are most commonly used in sensor multiplexing, instrumentation, and industrial monitoring front-ends.
Key features of the AS1538-BTSU include eight single-ended input channels (software-selectable via the multiplexer), true 12-bit no-missing-code performance, an I2C-compatible 2-wire serial interface that simplifies MCU interconnection, a low quiescent supply current suitable for battery-powered designs, an internal reference (with external-reference option via full-scale adjustment), and an operating temperature range rated for industrial environments. Together, these features make the device attractive for space-constrained, multi-sensor systems.
Internally, the architecture combines an input multiplexer, a sample-and-hold front-end, an internal asynchronous clock that removes the need for an external high-frequency master clock, a SAR conversion engine, and a precision internal reference. The combination of internal clocking and a digital serial interface reduces MCU pin count and PCB area while preserving deterministic per-channel conversion timing.
Typical applications include multi-channel sensor monitoring (temperature, pressure, strain-gauge bridges), portable and battery-powered instrumentation, industrial process control front-ends, patient-monitoring and point-of-care medical devices, power-supply telemetry (rail voltage / current sensing), and consumer appliance control boards. The wide analog supply range (2.7 V to 5.25 V) supports both 3.3 V and 5 V system rails.
When designing with this part, ensure that the I2C bus pull-ups are sized for the chosen clock rate and that the analog and digital grounds are tied to a single point to minimize digital-noise coupling into the analog inputs. Designers should also budget adequate acquisition time per channel and avoid channel switching during the conversion phase to prevent settling errors.
This page synthesizes distributor pricing from DigiKey, Mouser, Octopart and Win Source, cross-references for drop-in compatible alternatives, and practical design notes not consolidated in the manufacturer datasheet.
ドロップイン代替品: AS1538-BTSU — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: AS1538-BTSU （同一形状・フットプリント） — 相違点: Analog Supply Voltage, Data Interface, Input Type, Packaging, RoHS Status.
クイック比較ツール — 並列比較する代替部品を選択:
AS1540-BTSU
✅ ドロップイン📋 参考代替品（カタログ未掲載）
AS1538-BQFP
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
AS1538-BSOT
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
AS1538-BTSU 最大定格＆電気的特性
| 分解能 | 12 bits |
| Number of Input Channels | 8 (single-ended) |
| Converter Architecture | SAR (Successive Approximation) |
| サンプリングレート | 50 ksamples/sec |
| Data Interface | I2C (2-wire, serial) |
| Analog Supply Voltage | 2.7 V to 5.25 V (single supply) |
| Digital Supply Voltage | 2.7 V to 5.25 V |
| 基準電圧 | Internal (with external input option) |
| Input Type | Single-ended, multiplexed |
| ピン数 | 16 |
| パッケージ | 16-TSSOP (4.40 mm body width) |
| 実装タイプ | Surface Mount |
| Packaging | Tube (shipping suffix "U" = Tape & Reel per AS1538-BTSU part code) |
| Internal Clock | Yes (asynchronous, no external clock required) |
| RoHS ステータス | Compliant (per distributor listings) |
AS1538-BTSU ピン構成
| ピン 1 | CH0 — Analog input channel 0 |
| ピン 2 | CH1 — Analog input channel 1 |
| ピン 3 | CH2 — Analog input channel 2 |
| ピン 4 | CH3 — Analog input channel 3 |
| ピン 5 | CH4 — Analog input channel 4 |
| ピン 6 | CH5 — Analog input channel 5 |
| ピン 7 | CH6 — Analog input channel 6 |
| ピン 8 | CH7 — Analog input channel 7 |
| ピン 9 | GND — Analog and digital ground |
| ピン 10 | REF — Reference / FS-adjust input |
| ピン 11 | AVDD — Analog supply voltage (2.7 V to 5.25 V) |
| ピン 12 | SCL — I2C serial clock input |
| ピン 13 | SDA — I2C serial data (bidirectional) |
| ピン 14 | A0 — I2C address select bit 0 |
| ピン 15 | DVDD — Digital supply voltage (tied to AVDD) |
| ピン 16 | CS — Chip select / conversion start |
主な用途
AS1538-BTSU の用途: 6 件s: Multi-Channel Sensor Monitoring, Portable Battery-Powered Instrumentation, Industrial Process Control Front-End, Patient Monitoring & Point-of-Care Devices, Power-Supply Voltage & Current Telemetry, Consumer Appliance Control Boards.
Multi-Channel Sensor Monitoring
The AS1538-BTSU is well suited for multi-channel sensor monitoring because it integrates an 8-channel input multiplexer with a 12-bit SAR ADC and an I2C interface. With 50 ksps throughput and a single 2.7-5.25 V supply, it can digitize up to eight thermocouple, RTD-conditioned, or strain-gauge signals sequentially through one ADC. Place 100 nF decoupling near the supply pin and route analog/digital grounds to a single star point. The 16-TSSOP keeps the BOM area small, and the I2C bus needs only two MCU pins.
おすすめ
Portable Battery-Powered Instrumentation
Battery-powered data loggers and handheld instruments benefit from the AS1538-BTSU's low quiescent current and 2.7 V minimum supply. The 12-bit / 50 ksps performance is adequate for temperature, pressure, and humidity sensor digitization in environmental monitors. The I2C interface pairs with low-power MCUs without wasting GPIO. Unlike an audio-grade or high-speed ADC, the SAR architecture offers deterministic conversion latency, which simplifies duty-cycled sampling in energy-harvesting designs.
おすすめ
Industrial Process Control Front-End
Industrial process-control front-ends route 4-20 mA current loops and 0-10 V process signals through signal conditioning into an ADC. The AS1538-BTSU handles up to eight conditioned channels with 12-bit resolution and I2C connectivity to industrial MCUs. Its industrial-grade supply range and surface-mount TSSOP footprint suit DIN-rail I/O modules. Compared to higher-cost isolation ADCs, the AS1538 keeps the bill of materials competitive for non-isolated control loops.
おすすめ
Patient Monitoring & Point-of-Care Devices
Point-of-care medical devices digitize multiple biosignals - SpO2, temperature, blood-pressure cuff pressure - using a shared ADC. The AS1538-BTSU's 12-bit resolution, 8 channels, and I2C interface fit compact wearable designs. Single-supply operation removes the need for charge pumps or negative rails, easing IEC 60601-1 compliance design. Use the internal reference for absolute measurements, or switch to an external reference for ratiometric photodiode front-ends.
おすすめ
Power-Supply Voltage & Current Telemetry
Multi-rail power supplies need telemetry to monitor each rail's voltage and current. The AS1538-BTSU can sample up to eight shunt-resistor drops or voltage-divider outputs through its multiplexer and report the data via I2C to a supervisory MCU. The 50 ksps sampling rate tracks fast load transients better than slower integrating ADCs. Use software averaging across multiple conversions to improve noise performance on heavily-switched rails.
おすすめ
Consumer Appliance Control Boards
Washing machines, dishwashers, and HVAC controllers integrate temperature, humidity, water-level, and motor-current sensors. The AS1538-BTSU aggregates these analog signals with a single ADC, reducing board space and MCU pin count. The 2.7-5.25 V supply aligns with 3.3 V and 5 V system rails common in appliance MCUs. Cost-sensitive consumer designs benefit from the 16-TSSOP's small footprint and the part's compatibility with widely-available I2C host firmware stacks.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: AS1538-BTSU — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | AS1540-BTSU | AS1538-BQFP | ADS7824UB |
|---|---|---|---|---|
| Brand | ams | ams | ams | Texas Instruments |
| Package | 16-TSSOP | 16-TSSOP - same | 16-TSSOP - same | 20-SOIC - different |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits |
| Input Channels | 8 single-ended | 4 single-ended (-50%) | 8 single-ended | 4 single-ended (-50%) |
| Sampling Rate | 50 ksps | 50 ksps | 50 ksps | 25 ksps |
| Data Interface | I2C | I2C | I2C | I2C |
| 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 |
| Internal Reference | Yes | Yes | Yes | Yes |
主な差別化要因
- 8 single-ended input channels in a 16-TSSOP （vs AS1540-BTSU)
- 50 ksps throughput vs 25 ksps for ADI equivalents （vs ADS7824UB)
- Internal asynchronous clock - no MCU clock required （vs ADS7825UE4)
設計ノート
Place a 100 nF X7R ceramic decoupling capacitor within 2-3 mm of the AVDD pin and a bulk 1-10 uF tantalum or ceramic capacitor on the same net. Keep analog input traces short and away from digital switching traces (SDA/SCL, MCU clock). Use a single star-ground tie-point where the AGND pin joins the system ground; avoid running analog ground currents through digital return paths. Reference: ams AS1538-BTSU datasheet layout recommendation.
I2C pull-up resistor selection must balance rise-time and bus capacitance. For 100 kHz Standard-mode, 4.7 kohm is typical; for 400 kHz Fast-mode, 2.2-3.3 kohm is recommended. Keep total bus capacitance below 400 pF to meet the I2C spec rise time of 1 us at Fast-mode. Series resistors of 100 ohm near the AS1538 SDA/SCL pins can dampen ringing on long bus stubs.
Do not switch the input multiplexer during an active conversion, or settling errors will corrupt the result. The input acquisition time per channel must exceed the datasheet-specified minimum to settle to 12-bit accuracy; software pacing must respect this. Verify I2C address selection via the A0 pin to avoid bus conflicts when multiple AS1538 devices (or I2C peripherals) share the same bus.
コンプライアンス情報
RoHS and lead-free status confirmed via ams product page and DigiKey listing. AEC-Q100 not qualified - the AS1538-BTSU is not specified for automotive applications. Halogen-free status not explicitly published in the verified web data and is left as 'unknown'.
