MCP6S21-I/MS - 1-Ch SPI PGA, 12 MHz, 8-MSOP | Microchip
부품 번호: MCP6S21-I/MS ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.45 | $14.50 |
| 100 | $1.21 | $121.00 |
| 500 | $1.05 | $525.00 |
| 1,000 | $0.92 | $920.00 |
MCP6S21-I/MS 개요
A Programmable Gain Amplifier (PGA) is an analog amplifier whose closed-loop gain is digitally selectable rather than fixed by external resistors. PGAs sit between a sensor or transducer and the rest of the signal chain, allowing a microcontroller to adjust dynamic range on the fly. Within the broader taxonomy, the MCP6S21 belongs to the family of variable-gain amplifiers (VGAs) and instrumentation-style building blocks, all of which fall under the wider class of operational amplifiers and analog front-end (AFE) ICs. By replacing mechanical gain-switch relays or precision resistor networks with an SPI-programmable block, the MCP6S21 reduces BOM count, board area, and software-driven calibration latency.
Key features include 12 MHz gain-bandwidth, 1 mA typical supply current, low 1.35 mV input-offset voltage (max 4.5 mV over temperature), 8 discrete gain steps up to 32 V/V, hardware and software shutdown modes, and daisy-chainable SPI interface. The MSOP-8 surface-mount package makes the part a strong fit for dense sensor-conditioning boards where board real estate is at a premium.
The MCP6S21 uses a CMOS input stage with rail-to-rail input common-mode range and rail-to-rail output drive, allowing it to digitize signals near either supply rail with no dead zone. Its SPI interface lets the host microcontroller change gain on a sample-by-sample basis without external switching components, and the serial interface supports daisy-chaining for multi-PGA boards. The architecture is specified from -40 °C to +85 °C (industrial grade, indicated by the -I suffix).
Typical applications include multi-range sensor signal conditioning (strain-gauge bridges, thermocouples, photodiodes), AGC loops in audio and instrumentation, automotive sensor interfaces, and industrial process-control front ends. The SPI programmability also suits software-defined radio (SDR) IF stages and gain-trimmed ADC drivers where dynamic range must be tuned per channel.
Designers should keep the input common-mode voltage within the rail-to-rail range and bypass VDD with a 0.1 µF ceramic capacitor placed close to the supply pin. The shutdown pin (SHDN, active-low) must be driven logic-high for normal operation and can be tied to VDD through a pull-up if unused; the latch-up immunity exceeds 100 mA per JESD78.
This page synthesizes distributor pricing, drop-in alternatives in the same MSOP-8 footprint, and practical design notes not found in the manufacturer datasheet.
드롭인 대체품: MCP6S21-I/MS — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MCP6S22T-I/MS
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MCP6S21-I/SN
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MCP6S91T-E/MS
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MCP6S92T-E/MSVAO
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MCP6S28-I/SO
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MCP6S21-I/MS 최대 정격 & 전기적 특성
| Amplifier Type | Programmable Gain Amplifier (PGA), single channel |
| Number of Channels | 1 |
| Number of Gain Steps | 8 (G = 1, 2, 4, 5, 8, 10, 16, 32 V/V) |
| Gain Range | 1 V/V to 32 V/V |
| 인터페이스 | SPI (10 MHz max, daisy-chainable) |
| Supply Voltage Range | 2.5 V to 5.5 V |
| Quiescent Current (typical) | 1.0 mA |
| 셧다운 전류 | 0.5 µA typical |
| -3 dB Bandwidth (G = 1) | 12 MHz |
| Input Offset Voltage (max) | 1.35 mV (4.5 mV over temperature) |
| Input Common-Mode Range | Rail-to-rail |
| Output Swing | Rail-to-rail |
| 동작 온도 범위 | -40 °C to +85 °C (industrial) |
| 패키지 | 8-pin MSOP (MS) |
| 실장 유형 | Surface Mount |
| Latch-up Immunity | ≥ 100 mA per JESD78 |
| RoHS 상태 | Compliant |
| MSL 레벨 | 1 |
MCP6S21-I/MS 핀 구성
| 핀 1 | CS — SPI chip-select input (active low) |
| 핀 2 | SCK — SPI serial-clock input |
| 핀 3 | SI — SPI serial-data input |
| 핀 4 | SO — SPI serial-data output (daisy-chain) |
| 핀 5 | GND — Ground reference |
| 핀 6 | VDD — Positive supply (2.5 V to 5.5 V) |
| 핀 7 | SHDN — Shutdown input (active low) |
| 핀 8 | CH0 — Analog input channel 0 |
일반적인 애플리케이션
MCP6S21-I/MS 적합 용도: 6 애플리케이션s: Multi-Range Sensor Signal Conditioning, Automatic Gain Control (AGC) Loops, Industrial Process-Control Front Ends, Photodiode Transimpedance Amplifier with Adjustable Gain, Software-Defined Radio IF Stage, Battery-Powered Portable Instrumentation.
Multi-Range Sensor Signal Conditioning
The MCP6S21-I/MS is well suited to multi-range sensor signal conditioning where a single MCU must digitize outputs spanning more than one decade of amplitude. Its 8 SPI-selectable gain steps from 1 V/V to 32 V/V let the host select coarse sensitivity for strain-gauge bridges, thermocouples, or photodiode TIA stages on a sample-by-sample basis, replacing external resistor networks and analog switches. With 12 MHz -3 dB bandwidth at G=1 and rail-to-rail input common-mode, the MCP6S21 preserves dynamic range for both low-level (sub-millivolt) and large (multi-volt) sensor outputs, while 1 mA quiescent current keeps portable and battery-powered budgets in check.
추천
Automatic Gain Control (AGC) Loops
In AGC loops, the MCP6S21-I/MS gives an MCU direct digital control of analog gain, enabling closed-loop AGC without a dedicated AGC chip. Per the Microchip datasheet, the SPI interface can rewrite the gain register in microseconds, so the host can measure output amplitude, recompute gain, and reload the register between ADC samples. With 1.35 mV maximum input offset and rail-to-rail output, the part is appropriate for audio-band instrumentation AGC; designers typically place the MCP6S21 between a transducer pre-amp and the ADC driver. The shutdown pin further reduces current to 0.5 µA when AGC is disabled, preserving battery life.
추천
Industrial Process-Control Front Ends
Industrial process-control front ends commonly multiplex several 4-20 mA or 0-10 V transducers into a single ADC channel; the MCP6S21-I/MS handles dynamic gain ranging for these mixed-range signals. Its industrial -40 °C to +85 °C operating range and rail-to-rail I/O tolerates the wide common-mode swings typical of grounded and floating transducer outputs, while SPI programmability lets a PLC reprogram gain per channel scan. The 8-pin MSOP package supports compact PLC analog-input modules, and the part's CMOS input stage draws negligible bias current, preserving accuracy on high-impedance sources such as pH or conductivity probes.
추천
Photodiode Transimpedance Amplifier with Adjustable Gain
When paired with a transimpedance front-end, the MCP6S21-I/MS functions as an adjustable second-stage gain block, allowing software calibration of overall responsivity without swapping feedback resistors. The 12 MHz bandwidth at G=1 and rail-to-rail output let the part drive a high-speed ADC directly, while 8 discrete gain steps give 30 dB of dynamic range adjustment in 5 dB increments typical of optical sensing applications. SPI control makes the MCP6S21 well matched to ambient-light sensors, optical encoders, and pulse oximetry front ends where channel-to-channel gain must be tuned at production.
추천
Software-Defined Radio IF Stage
In software-defined radio (SDR) receiver IF stages, the MCP6S21-I/MS serves as a digitally controlled gain block between the mixer and the ADC. Its 12 MHz -3 dB bandwidth covers low-IF and baseband sample rates, and SPI-controlled gain steps allow the host DSP to optimize the ADC's input range per channel, improving SNR under varying signal conditions. The rail-to-rail input common-mode and CMOS input stage keep the noise contribution low, while the small MSOP-8 footprint suits dense SDR front-end boards. Designers typically combine the MCP6S21 with a fixed-gain LNA in front and a high-speed ADC behind.
추천
Battery-Powered Portable Instrumentation
The MCP6S21-I/MS fits battery-powered portable instruments because its 1.0 mA quiescent current and 0.5 µA shutdown current extend runtime, while its 2.5 V to 5.5 V supply range supports both single-cell Li-ion and 3 V coin-cell platforms. SPI gain programmability removes the need for mechanical gain switches, reducing BOM and sealed-enclosure rework. With rail-to-rail I/O the part swings to both rails, maximizing dynamic range on low-voltage ADCs; the MSOP-8 footprint is well suited to handheld multimeter, data-logger, and field-meter enclosures where PCB area is constrained and operating temperature can reach -40 °C to +85 °C.
추천
추천 제품 요약
엔지니어링 참조 데이터: MCP6S21-I/MS — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MCP6S22T-I/MS | MCP6S21-I/SN | MCP6S91T-E/MS | MCP6S92T-E/MSVAO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | MSOP-8 (MS) | MSOP-8 - same | SOIC-8 (different footprint) | MSOP-8 - same | MSOP-8 - same |
| Channels | 1 | 2 | 1 | 1 | 2 |
| Number of Gain Steps | 8 | 8 | 8 | 32 | 32 |
| Gain Range | 1 to 32 V/V | 1 to 32 V/V | 1 to 32 V/V | 1/3 to 32 V/V | 1/3 to 32 V/V |
| -3 dB Bandwidth (G=1) | 12 MHz | 12 MHz | 12 MHz | Higher | Higher |
| Supply Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +125 °C (E grade) | -40 °C to +125 °C (E grade) |
주요 차별점
- 8 discrete SPI-programmable gain steps (1 to 32 V/V) in MSOP-8 (vs MCP6S91T-E/MS)
- Single-channel 8-pin MSOP with rail-to-rail I/O and 12 MHz bandwidth (vs MCP6S22T-I/MS)
- Industrial -40 °C to +85 °C qualification (vs MCP6S21-I/SN)
설계 노트
Bypass VDD (pin 6) with a 0.1 µF low-ESR ceramic capacitor placed within 5 mm of the supply pin, and add a 1 µF to 10 µF bulk capacitor near the chip for transient suppression. Although the MCP6S21-I/MS only draws 1.0 mA quiescent, transient currents during SPI activity can exceed several milliamps; the bulk capacitor prevents the rail from dipping during fast SPI bursts. Drive SHDN (pin 7) logic-high through a 100 kΩ pull-up to VDD if shutdown is not used, and add a 100 kΩ pull-down to ensure a defined low at power-up.
Route the SPI bus (CS, SCK, SI, SO) away from the analog input CH0 (pin 8) and any analog output traces; keep ground return paths separate between digital and analog sections. Use a single-point ground tie at the MCP6S21 GND pin, with the analog ground plane covering CH0 and the digital ground plane covering the SPI pins, joined at the chip. Keep analog input traces short and guarded to reduce capacitive pickup, and place the 0.1 µF VDD bypass capacitor on the same layer as the chip to minimize parasitic inductance.
Estimated: at G=32, the -3 dB bandwidth of the MCP6S21-I/MS drops to roughly 375 kHz (12 MHz / 32) because the gain-bandwidth product is approximately constant; do not use the highest gain step for signals with content above a few hundred kHz. Input common-mode voltage must remain within VSS−0.3 V to VDD+0.3 V; exceeding this range risks input-stage saturation and recovery glitches. The SHDN pin must not be left floating; floating SHDN can leave the part in an undefined state and cause excessive supply current.
규정 준수 정보
RoHS compliant per Microchip product page. AEC-Q100 not qualified; choose -E or -Q grade variants for automotive. Latch-up immunity ≥ 100 mA per JESD78.
