MAX1248ACEE - 10-Bit 4-Ch 133ksps SAR ADC | Maxim Integrated
부품 번호: MAX1248ACEE ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $9.95 | $9.95 |
| 10 | $8.95 | $89.50 |
| 100 | $7.45 | $745.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $4.95 | $4,950.00 |
MAX1248ACEE 개요
An ADC (analog-to-digital converter) is a data-acquisition component that converts a continuous analog input voltage into a discrete digital code; the MAX1248ACEE belongs to the SAR ADC family, which uses a successive-approximation register and an internal capacitive DAC to perform a binary search on the input voltage in one conversion cycle. In the broader hierarchy, SAR ADCs sit under Nyquist-rate ADCs, which sit under data converters, which are a sub-category of mixed-signal ICs alongside DACs and codecs. The 10-bit resolution and 4-channel input multiplexer make the MAX1248ACEE well suited to medium-accuracy multi-sensor systems where cost, channel count, and serial-interface simplicity outweigh absolute precision.
Key features include a single +2.7V to +5.25V analog/digital supply, a true differential analog input, an internal track-and-hold amplifier with 4 MHz bandwidth, software- and hardware-controllable shutdown modes that reduce supply current to under 10 µA between conversions, and a hard-wired active-low SHDN pin. The reference-buffer amplifier provides a ±1.5% voltage adjustment range for system-level calibration. The serial interface supports both external-clock and internal-clock modes, allowing the host microcontroller to offload bit-streaming at clock rates up to the QSPI specification.
The architecture combines a 4-input analog multiplexer, a high-bandwidth track/hold, and a charge-redistribution SAR DAC on a single die. The internal 2.5V reference (used by the MAX1248; the MAX1249 variant uses an external reference) is trimmed for low drift and feeds the reference buffer, which can also drive an external load up to the datasheet-specified limit. Hardware and software shutdown, plus automatic end-of-conversion power-down, allow system quiescent current to drop an order of magnitude between sample bursts.
Typical applications include portable data loggers, patient-monitoring front ends, 4-20 mA loop-powered sensor digitizers, pen-digitizer tablets, and factory-floor PLC analog input modules. Designers also deploy the part in HVAC thermistor arrays and battery-powered instrumentation where the 1.5 mA active supply current and sub-10 µA shutdown current extend operating life.
When designing with the MAX1248ACEE, ensure REF bypass capacitance per the datasheet and route AVDD/DVDD separately if PCB noise is a concern. The internal 2.5V reference cannot source large external loads - if the system requires reference sharing, add a unity-gain buffer. Layout should keep analog and digital grounds joined only at the IC's GND pin to avoid digital switching currents corrupting the sample-and-hold.
This page synthesizes distributor pricing, drop-in same-family alternatives, and practical design guidance not found in the manufacturer datasheet alone, giving engineers a single source for selection, layout, and sourcing decisions.
드롭인 대체품: MAX1248ACEE — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MAX1248ACEE+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX1248BCEE+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX1248BEEE+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX1249ACEE+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX1248ACEE 최대 정격 & 전기적 특성
| 분해능 | 10 bit |
| Number of Inputs | 2 / 4 (single-ended or differential) |
| 샘플링 속도 | 133 ksps |
| Architecture | SAR (Successive Approximation) |
| Input Type | Differential, Single-Ended |
| Data Interface | SPI / QSPI / MICROWIRE-compatible serial |
| Configuration | MUX-S/H-ADC (1:1 ratio) |
| Number of ADCs | 1 |
| Reference Type | Internal 2.5V |
| Reference Buffer Trim | ±1.5% adjustment range |
| Analog Supply Voltage | 2.7 V to 5.25 V |
| Digital Supply Voltage | 2.7 V to 5.25 V |
| Supply Current (Active) | 1.5 mA (typ) |
| Supply Current (Shutdown) | < 10 µA |
| Track-and-Hold Bandwidth | 4 MHz |
| Shutdown Modes | Hardware SHDN pin and software auto-shutdown |
| 패키지 | 16-pin QSOP |
| Operating Temperature Range (Commercial) | 0°C to +70°C |
| 실장 유형 | Surface Mount |
MAX1248ACEE 핀 구성
| 핀 1 | AIN1 — Analog input channel 1 |
| 핀 2 | AIN2 — Analog input channel 2 |
| 핀 3 | AIN3 — Analog input channel 3 |
| 핀 4 | AIN4 — Analog input channel 4 |
| 핀 5 | GND — Ground |
| 핀 6 | REF — Reference input/output (internal 2.5V) |
| 핀 7 | REFADJ — Reference buffer adjust (±1.5%) |
| 핀 8 | AVDD — Analog supply voltage (2.7V to 5.25V) |
| 핀 9 | DVDD — Digital supply voltage (2.7V to 5.25V) |
| 핀 10 | DGND — Digital ground |
| 핀 11 | SCLK — Serial clock input |
| 핀 12 | DOUT — Serial data output |
| 핀 13 | DIN — Serial data input |
| 핀 14 | CS — Active-low chip select |
| 핀 15 | SHDN — Active-low shutdown control |
| 핀 16 | NC — Not connected (per datasheet) |
일반적인 애플리케이션
MAX1248ACEE 적합 용도: 6 애플리케이션s: Portable Data Loggers, Patient Monitoring Front End, 4-20 mA Loop-Powered Sensor Digitizers, Pen-Digitizer Tablets and Touch Panels, PLC Analog Input Modules, HVAC Thermistor Array Digitizers.
Portable Data Loggers
The MAX1248ACEE's 1.5 mA active supply current and sub-10 µA shutdown current make it a strong fit for battery-powered multi-channel data loggers where four sensor inputs (temperature, pressure, humidity, flow) must be digitized with reasonable accuracy. The internal 2.5V reference eliminates an external reference IC, saving PCB area and quiescent draw, while the 4 MHz track/hold bandwidth comfortably captures transducer signals with millisecond-scale time constants. Power-cycling between bursts via the SHDN pin extends coin-cell life into months.
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Patient Monitoring Front End
In patient-monitoring designs (pulse oximetry, body-temperature patches, ECG leads) the MAX1248ACEE delivers 10-bit resolution across four bioelectric channels while drawing only 1.5 mA from a 3.3V rail. The differential input mode rejects 50/60 Hz mains pickup on long electrode leads, and the SPI-compatible interface streams cleanly to low-power MCUs. The internal reference and small QSOP-16 footprint ease compliance with IEC 60601-1 PCB creepage/clearance layouts for patient-connected circuits.
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4-20 mA Loop-Powered Sensor Digitizers
Industrial 4-20 mA loop-powered transmitters benefit from the MAX1248ACEE's wide 2.7V-5.25V supply range and true differential inputs, which connect directly to a current-sense resistor without instrumentation-amp front ends. The 133 ksps throughput oversamples the 4-20 mA signal so that averaging can suppress loop noise. Hardware SHDN plus software auto-shutdown drop quiescent current below 10 µA between updates, satisfying the 3.5 mA loop budget. The QSOP-16 package fits inside a standard DIN-43700 field-mount head.
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Pen-Digitizer Tablets and Touch Panels
Digitizer tablets sample multiple analog axes (X, Y, pressure, tilt) at rates well below the MAX1248ACEE's 133 ksps ceiling, but the device's 4-channel input mux lets one ADC serve all axes sequentially. The internal 2.5V reference tolerates the noisy LCD backlight inverter supply on the same PCB, and the SPI/QSPI serial interface synchronizes easily with touch-controller timing. Active-low SHDN allows the host MCU to power-gate the ADC between stylus polling cycles to extend battery life.
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PLC Analog Input Modules
Programmable logic controller (PLC) analog input modules digitize 4-20 mA, 0-10V, RTD, and thermocouple signals using the MAX1248ACEE's 4-channel mux to reduce per-channel BOM cost. The single 2.7V-5.25V supply simplifies 24V-to-5V field-bus power design, and the SPI-compatible serial interface streams to industrial MCUs at QSPI rates. The internal 2.5V reference provides adequate stability for ±0.5% full-scale readings typical of process-control modules, and the QSOP-16 footprint packs four channels into a 5 mm x 6 mm PCB area.
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HVAC Thermistor Array Digitizers
Multi-zone HVAC systems read 4-8 thermistors to control damper and compressor stages; the MAX1248ACEE's 4-channel input mux handles up to four thermistor dividers per chip while the internal 2.5V reference provides a stable excitation rail, eliminating an external reference IC. The 10-bit resolution maps 0-100 °C into 1024 steps (~0.1 °C LSB) - sufficient for zone-temperature control. The QSOP-16 surface-mount package and SPI interface drop into compact thermostat and air-handler control boards.
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추천 제품 요약
엔지니어링 참조 데이터: MAX1248ACEE — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MAX1248ACEE+ | MAX1248BCEE+ | MAX1248BEEE+ | MAX1249ACEE+ |
|---|---|---|---|---|---|
| Package | QSOP-16 | QSOP-16 - same | QSOP-16 - same | QSOP-16 - same | QSOP-16 - same |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 10 bit | 10 bit | 10 bit | 10 bit | 10 bit |
| Sampling Rate | 133 ksps | 133 ksps | Lower (B-grade) | Lower (B-grade) | 133 ksps |
| Number of Input Channels | 2 / 4 (single-ended or differential) | 2 / 4 | 2 / 4 | 2 / 4 | 2 / 4 |
| Internal Reference | 2.5V internal | 2.5V internal | 2.5V internal | 2.5V internal | External required |
| Supply Voltage Range | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V |
| RoHS Status | Non-RoHS (legacy) | RoHS compliant | RoHS compliant | RoHS compliant | RoHS compliant |
주요 차별점
- Integrated internal 2.5V reference saves external reference IC (vs MAX1249ACEE+)
- Higher 133 ksps throughput for time-critical sampling (vs MAX1248BCEE+)
- True differential input rejects common-mode noise (vs MAX1248ACEE+)
설계 노트
Layout should keep analog and digital grounds joined only at the IC's GND pin (star-ground topology) to prevent digital switching currents from corrupting the sample-and-hold acquisition. Place 0.1 µF ceramic bypass capacitors as close as possible to AVDD and DVDD, with a 10 µF tantalum or ceramic bulk capacitor at each supply pin. Reference pin (REF) requires at least 4.7 µF of low-leakage capacitance per the Maxim datasheet; use a COG/NP0 dielectric for best temperature stability.
The MAX1248ACEE draws 1.5 mA in active mode and below 10 µA in shutdown. Use the active-low SHDN pin or software auto-shutdown (auto-shutdown at end of conversion, software-controlled via the serial command word) to drop quiescent current between bursts. Estimated: at 100 Hz sample rate with 1.5 mA active, average supply current is roughly (100 * 1.5 mA / 133000) + 10 µA ≈ 11 µA - ideal for coin-cell data loggers.
Route analog input traces as differential pairs with 50 Ω characteristic impedance, keep them short, and guard them with a ground pour to reduce coupling from the SPI serial traces. The 4 MHz track/hold bandwidth means signals with slew rates above 4 MHz content will be attenuated - add an RC anti-aliasing filter ahead of AINx. Do not run analog traces parallel to DOUT/SCLK traces for more than a few millimeters without a ground guard.
Do not drive the internal 2.5V reference with heavy external loads - the reference buffer is sized for the internal ADC only and will droop if shared. If system design requires an external reference path, choose the MAX1249ACEE+ variant instead. The REFADJ pin provides ±1.5% trim range; leaving REFADJ floating accepts the factory-trimmed accuracy (±5 LSB INL typical). Ensure CS is held low throughout the entire conversion cycle in external-clock mode or data corruption will occur.
규정 준수 정보
The legacy non-'+' suffix indicates non-RoHS lead-finish. Use MAX1248ACEE+ for RoHS-compliant designs. REACH and AEC-Q100 status are not characterized in the 1998-vintage datasheet; verify with Maxim/Analog Devices for automotive applications.
