MAX1243AEPA - 10-Bit Serial ADC, 73ksps, DIP-8 | Maxim Integrated
料号： MAX1243AEPA ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.2 | $620.00 |
| 500 | $5.1 | $2,550.00 |
| 1,000 | $4.35 | $4,350.00 |
MAX1243AEPA 概述
A successive-approximation ADC is a converter architecture that uses a binary-search algorithm with an internal DAC to compare the sampled input voltage against successively halved reference voltages, converging on a digital code in N conversion cycles for an N-bit converter. SAR ADCs are prized for low-latency conversions, deterministic throughput, and excellent DC accuracy, making them the preferred choice for multiplexed data-acquisition systems, sensor readouts, and instrumentation loops where the signal is bandwidth-limited but high precision is required.
Key features of the MAX1243AEPA include a low 3mA (max) operating supply current, an automatic power-down mode that drops supply current to 2uA between conversions (controlled by the CS pin), an external reference input (REF) that allows the full-scale range to be scaled to any value between 0V and VDD, and a unipolar single-ended analog input. The MAX1243AEPA accepts a 0 to VREF input range, providing flexibility for ratiometric and absolute measurements alike.
The MAX1243AEPA is built on a low-power CMOS process and integrates the sample/hold, clock, and reference buffer internally, which simplifies PCB design by removing the need for an external precision clock. The 3-wire serial interface reduces GPIO overhead on the host microcontroller, allowing multiple ADCs to share a single bus by staggered CS lines. Combined with the 2.7V minimum supply, the part is well suited for 3.3V and 5V microcontrollers, including industrial 16-bit MCUs lacking integrated ADCs.
Typical applications include portable instrumentation, battery-powered data loggers, process control signal conditioning, isolated sensor front-ends, and HVAC monitoring. The 73 ksps throughput is high enough to handle multi-channel scanning via an external mux, yet low enough that the 3mA supply current keeps total system power budgets modest.
When designing with the MAX1243AEPA, place the 0.1uF VDD bypass capacitor within 2-3mm of the VDD pin and keep REF and AIN traces short, guarded by a ground pour to limit digital coupling into the analog path. The CS pin can be tied to a GPIO to invoke the 2uA power-down mode between conversions for power-sensitive designs.
This page combines distributor pricing, drop-in alternative cross-references, and applied design notes that go beyond what appears in the manufacturer datasheet, giving engineers a single source for sourcing the MAX1243AEPA confidently.
直接替换替代料： MAX1243AEPA ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： MAX1243AEPA （相同外形与封装尺寸） ——差异在于 Package, Conversion Time, Input Type, Reference Type, RoHS Status.
快速对比工具——选择替代料号进行并排对比：
MAX1243ACPA
✅ 直接替换✓ 有现货
$5.92 / 个
查看数据手册 →MAX1243ACPA+
✅ 直接替换📋 参考替代料（不在目录中）
MAX1243BCPA+
✅ 直接替换📋 参考替代料（不在目录中）
MAX1243BEPA
✅ 直接替换✓ 有现货
$2.05 / 个
查看数据手册 →MAX1242BCPA
✅ 直接替换✓ 有现货
$7.55 / 个
查看数据手册 →MAX1241AEPA
✅ 直接替换📋 参考替代料（不在目录中）
MAX1243AEPA 最大额定值与电气特性
| 分辨率 | 10 bits |
| Number of Channels | 1 |
| 采样率 | 73 ksps (max) |
| Architecture | SAR (Successive Approximation) |
| Conversion Time | 7.5 us (typ) |
| Track-and-Hold Acquisition Time | 1.5 us (typ) |
| Supply Voltage (VDD) | +2.7 V to +5.25 V |
| Supply Current (Operating) | 3 mA (max) |
| Supply Current (Power-Down) | 2 uA (typ, via CS de-assertion) |
| Reference Type | External (REF input) |
| Input Type | Single-ended, unipolar |
| 输入电压范围 | 0 V to VREF |
| Digital Interface | 3-wire SPI / QSPI / MICROWIRE |
| Configuration | S/H-ADC, ratio 1:1 |
| 工作温度 | -40 C to +85 C (industrial) |
| 封装 | PDIP-8 (0.3 inch, plastic DIP) |
| 安装类型 | Through-Hole |
| MSL 等级 | 1 (through-hole, no MSL seal requirement) |
MAX1243AEPA 引脚配置
| 引脚 1 | VDD — +2.7V to +5.25V supply input |
| 引脚 2 | AIN — Analog input (single-ended, 0 to VREF) |
| 引脚 3 | REF — External voltage reference input (sets full-scale) |
| 引脚 4 | GND — Ground |
| 引脚 5 | DOUT — Serial data output (MSB-first, clocked on SCLK falling edge) |
| 引脚 6 | SCLK — Serial clock input |
| 引脚 7 | CS — Chip select, active low; tie high to enter 2uA shutdown |
| 引脚 8 | NC — Not connected (per datasheet) |
典型应用
MAX1243AEPA 适用于 6 应用s: Portable Battery-Powered Data Loggers, Industrial Process-Control Signal Conditioning, Isolated Sensor Front-Ends, HVAC Environmental Monitoring, Handheld Digital Multimeter / Test Equipment, Automotive Sensor-Node Telematics.
Portable Battery-Powered Data Loggers
The MAX1243AEPA fits portable data loggers because its 2.7V minimum supply matches 3.3V coin-cell or Li-ion rails, and its 2uA shutdown current (controlled by CS between conversions) lets the host MCU sample once per second and sleep, extending battery life dramatically. With 10 bits (1 part in 1024) the part gives ~5 mV resolution on a 5V full-scale, which suits thermistor or voltage-divided sensor reads. The 73 ksps sample rate is overkill for slow loggers but provides headroom for faster accelerations during transient capture. Compared to a continuous-mode ADC at 3 mA, the duty-cycled approach here cuts average power by ~100x in a 1 Hz sample regime, directly improving field-deployment longevity.
推荐
Industrial Process-Control Signal Conditioning
In process-control panels the MAX1243AEPA reads conditioned 0-5V or 0-10V transducer signals (after op-amp scaling) and reports them to a 16-bit MCU over SPI. The 10-bit resolution is sufficient for slow loops (loop times 100 ms+) typical of temperature, pressure, and flow regulation. The industrial -40C to +85C temperature range ensures operation in unheated cabinets, and the 3-wire SPI bus allows several MAX1243AEPA chips to be wired in parallel and selected by independent CS lines, allowing one MCU to monitor 8 or 16 channels without external muxes. Total system cost is lower than a discrete instrumentation-amp + external SAR + reference stack.
推荐
Isolated Sensor Front-Ends
Isolated 4-20 mA loops and high-voltage sensor readouts benefit from the MAX1243AEPA's small PDIP-8 footprint and self-contained SAR core: the host MCU sits on the digital side of a digital isolator while a tiny isolated DC-DC module provides +5V to the ADC on the analog side, where it samples and SPI-streams the data across the isolation barrier. With a 7.5 us conversion time the loop latency added by the ADC is negligible compared to the digital isolator's propagation delay. The 2uA shutdown lets the isolated side sleep when not sampling, reducing the load on the bias supply and the heat dissipated in the isolation barrier. This topology is common in medical, motor-control, and grid-monitoring instrumentation.
推荐
HVAC Environmental Monitoring
In HVAC and indoor-air-quality systems the MAX1243AEPA reads thermistor, humidity-sensor voltage dividers, and gas-sensor analog front-ends. Its wide 2.7V-5.25V supply is tolerant of the 3.3V and 5V regulator rails common in building-automation PCBs. Resolution of 10 bits (~5 mV on a 5V full-scale) is sufficient for thermistor temperature reads after Steinhart-Hart linearization, and the SPI interface connects directly to low-cost ARM Cortex-M0+ MCUs. The 2uA shutdown means the ADC only consumes average microwatts during low-duty monitoring - a major consideration for solar- or battery-powered thermostats and wireless sensor nodes.
推荐
Handheld Digital Multimeter / Test Equipment
Handheld digital multimeters, clamp meters, and handheld oscilloscope probes rely on the MAX1243AEPA's 10-bit precision and 73 ksps sample rate to convert the conditioned input voltage into a readable digital value. The auto-shutdown at 2uA keeps battery life long, and the 3-wire SPI minimizes the number of I/O pins on the meter main CPU. The 73 ksps aggregate throughput is sufficient to track slowly-varying AC RMS measurements averaged over multiple cycles. The PDIP-8 package simplifies the through-hole PCB layout typical of rugged, hand-solderable handheld-meter boards.
推荐
Automotive Sensor-Node Telematics
The MAX1243AEPA can be used in non-safety automotive systems (such as infotainment, interior lighting, and telematics modules) to read temperature, battery voltage, and occupant-presence sensors. Its wide supply range accommodates the 12V battery rail after regulation to 5V, and its 8-pin PDIP provides easy rework for prototyping. For safety-critical automotive applications requiring AEC-Q100 qualification, designers should select a qualified part from the same family; the standard MAX1243AEPA is suitable for body-electronics prototyping and development kits, with the production variant being chosen from the same datasheet family in SO-8 / TSSOP packaging.
推荐
推荐产品汇总
工程参考数据： MAX1243AEPA ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | MAX1243ACPA | MAX1243ACPA+ | MAX1243BCPA+ | MAX1243BEPA | MAX1242BCPA | MAX1241AEPA |
|---|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | PDIP-8 (0.3 inch) | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same |
| Resolution | 10 bits | 10 bits | 10 bits | 10 bits | 10 bits | 12 bits | 12 bits |
| Sample Rate | 73 ksps | 73 ksps | 73 ksps | 73 ksps | 73 ksps | 73 ksps | ~55 ksps |
| Supply Voltage | 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 | 2.7V to 5.25V | 2.5V to 5.25V (wider minimum) |
| Operating Current | 3 mA max | 3 mA max | 3 mA max | 3 mA max | 3 mA max | 3 mA max | ~2.5 mA max |
| Reference Type | External | External | External | External | External | External | External |
| Serial Interface | 3-wire SPI | 3-wire SPI | 3-wire SPI | 3-wire SPI | 3-wire SPI | 3-wire SPI | 3-wire SPI |
关键差异点
- Built-in 2 uA auto-shutdown via CS pin （对比 MAX1242BCPA)
- A-grade specification with B-grade drop-in compatibility （对比 MAX1243BEPA (B-grade))
- 3 mA operating current at 73 ksps is industry-typical （对比 MAX1241AEPA)
设计说明
Each conversion draws up to 3 mA from VDD, so the host should not rely on a low-power LDO for VDD if many MAX1243AEPA parts are paralleled. Tie CS high between conversions and the part enters 2 uA shutdown - using a dedicated MCU GPIO for CS allows the firmware to duty-cycle the ADC and average <20 uA at a 1 Hz sample rate. Add a 0.1 uF ceramic bypass within 2-3 mm of VDD (pin 1) to suppress conversion-time current spikes that could otherwise couple into the analog input.
Route REF and AIN traces as short as possible, surrounded by a ground pour on the same layer to reduce digital switching noise coupling. Place the reference decoupling capacitor (typically 4.7 uF to 10 uF ceramic) close to the REF pin with its ground terminus going to the same ground island as pin 4 GND. The PDIP-8 through-hole pads are forgiving of hand-routing but keep CS, SCLK and DOUT traces short and away from the analog input trace to avoid digital-clock feedthrough that may show up as a 1-2 LSB noise floor at high input impedances.
Drive the analog input with an op-amp buffer whose output impedance is below 1 kohm at the worst-case source-impedance point; the MAX1243AEPA's track-and-hold has a 1.5 us acquisition window which demands sub-1 kohm source impedance for 10-bit settling accuracy at the maximum 73 ksps rate. Above ~5 kohm source impedance, consider adding a wider track-time precharge or reducing the sample rate. Add a 100 pF to 10 nF RC filter between the input op-amp and the ADC if the source has broadband noise above 100 kHz.
Do not exceed VDD on the AIN or REF pins - both inputs are limited to VDD+0.3V. The CS pin must return high (de-asserted) to enter shutdown; floating CS can leave the part in an undefined state. When reading DOUT, observe the SCLK falling-edge timing noted in the datasheet - reading on the rising edge will see one bit of timing-uncertainty owing to internal propagation delay. Finally, the part requires a hardware reset pattern on first power-up if VDD ramps slowly; in such cases the firmware should issue a dummy SCLK burst to clock out any garbage from the shift register before initiating the first valid conversion.
合规信息
RoHS status of the non-plus MAX1243AEPA package not confirmed in the verified web data - use MAX1243ACPA+ (RoHS-compliant) variant if regulatory compliance is required. Not AEC-Q100 qualified - select SO-8 AEC-Q100 variant for automotive.
