MAX1239LEEE+ - 12-Bit 12-Ch 2-Wire SAR ADC | Maxim Integrated
MPN： MAX1239LEEE+ ✓ 啟用中MAX1239LEEE+ 概覽
An SAR ADC is a successive-approximation-register analog-to-digital converter that uses an internal binary-search algorithm against a precision reference voltage to convert an analog sample to a 12-bit digital word in a fixed number of clock cycles. SAR ADCs sit inside the broader hierarchy of analog-to-digital converters (which also includes delta-sigma, pipeline, flash, and dual-slope types). They are favored when the application needs deterministic latency, low power, and no architectural input-charge kickback, making them dominant in multiplexed multi-channel data-acquisition systems, sensor-interface modules, and battery-powered instrumentation.
Key features include 12 input channels configurable as 6 single-ended or 6 differential pairs, software-configurable unipolar/bipolar operation, an automatic channel-scan mode with internal sequencer, an internal 4.096V reference (or external reference option), software shutdown to 1 microamp typical, an I2C-compatible serial interface supporting standard (100 kHz), fast (400 kHz), and high-speed (3.4 MHz) modes, and an operating temperature range of -40 degrees Celsius to +85 degrees Celsius. The integrated sequencer and channel-scan registers let a host microcontroller configure a one-shot or continuous scan that walks the channels and stores results in internal data registers without per-sample CPU intervention.
The MAX1239LEEE+ is typically deployed in industrial process control loops, 4-20 mA sensor digitizers, handheld multimeters and test instruments, portable medical monitoring equipment, programmable logic controller (PLC) analog input modules, HVAC environmental sensor concentrators, and consumer battery chargers that need to monitor multiple cell voltages. In each case its combination of 12 channels, internal reference, and low operating current allows a single chip to replace a discrete ADC plus an external reference plus multiple analog multiplexers. For designs that need 14-bit or 16-bit noise-free resolution at the same channel density, the MAX130x family or the LTC2360 series would be the next step up.
When designing with this ADC, place 0.1 microfarat ceramic bypass capacitors as close as possible to both AVDD and DVDD pins and keep the analog ground return path short and direct to the system analog ground plane to limit digital coupling. Software configuration must set the reference mode (internal vs external) and the clock-divider bits before initiating a conversion through the I2C setup register. This page synthesizes drop-in cross-reference data, distributor stock, design notes, and pin-compatible alternatives not found on a typical manufacturer product page.
直接替換替代品，適用於 MAX1239LEEE+ — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MAX1239LEEE+ （相同外形與佔位） — 差異在於 Package, Resolution, Number of Input Channels, Internal Reference, Operating Temperature.
MAX1239KEEE+
✅ 直接替換📋 參考替代品（不在目錄中）
MAX1239LEEE+T
✅ 直接替換聯絡詢價
查看資料表 →MAX1239KEEE+T
✅ 直接替換📋 參考替代品（不在目錄中）
MAX1039AEEE+TGC1
✅ 直接替換聯絡詢價
查看資料表 →MAX1239LEEE+ 最大額定值與電氣特性
| 解析度 | 12 bits |
| Number of Input Channels | 12 single-ended / 6 differential |
| ADC Architecture | Successive Approximation (SAR) |
| Sampling Rate (max) | 94.4 ksps |
| Supply Voltage Range | 2.7 V to 3.6 V (and 4.5 V to 5.5 V tolerant) |
| Supply Current (typ) | 670 uA at max sample rate |
| Shutdown Current (typ) | 1 uA |
| Internal Reference Voltage | 4.096 V |
| External Reference Option | Yes |
| Digital Interface | I2C-compatible 2-wire serial (Standard / Fast / High-Speed) |
| Input Configuration | Single-ended or differential, software selectable |
| Channel Scan Mode | Internal sequencer, automatic |
| 工作溫度範圍 | -40 C to +85 C |
| 封裝 | 16-pin QSOP |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant (lead-free + suffix) |
MAX1239LEEE+ 腳位配置
| 腳位 1 | DVDD — Digital supply voltage (2.7 V to 3.6 V) |
| 腳位 2 | AIN0 — Analog input channel 0 |
| 腳位 3 | AIN1 — Analog input channel 1 |
| 腳位 4 | AIN2 — Analog input channel 2 |
| 腳位 5 | AIN3 — Analog input channel 3 |
| 腳位 6 | AIN4 — Analog input channel 4 |
| 腳位 7 | AIN5 — Analog input channel 5 |
| 腳位 8 | GND — Ground |
| 腳位 9 | AIN6 — Analog input channel 6 |
| 腳位 10 | AIN7 — Analog input channel 7 |
| 腳位 11 | SDA — I2C serial data (open-drain, requires pull-up) |
| 腳位 12 | SCL — I2C serial clock |
| 腳位 13 | AIN8 — Analog input channel 8 |
| 腳位 14 | AIN9 — Analog input channel 9 |
| 腳位 15 | AIN10 — Analog input channel 10 |
| 腳位 16 | AVDD — Analog supply voltage (2.7 V to 3.6 V) |
典型應用
MAX1239LEEE+ 適用於 6 應用s: Industrial Process Control & PLC Analog Input Modules, Handheld Multimeters and Test Instrumentation, Portable Medical Patient Monitoring, HVAC Environmental Sensor Concentrators, Battery Cell Monitors for Multi-Cell Packs, Consumer Smart Home Sensor Hubs.
Industrial Process Control & PLC Analog Input Modules
The MAX1239LEEE+ integrates 12 single-ended or 6 differential analog inputs into a single 16-QSOP ADC, which lets a single PLC analog input card digitize up to a dozen 4-20 mA sense resistors without an external analog mux. Its 12-bit resolution (1 LSB = 1 mV at the internal 4.096 V reference) provides roughly 0.024% full-scale accuracy, sufficient for most supervisory control loops. Built-in channel sequencing removes per-sample CPU overhead, and software shutdown dropping the IC to 1 uA is excellent for loop-powered 4-20 mA transmitters that must minimize quiescent budget. The internal 4.096 V reference eliminates an external reference IC for a clean industrial BOM.
推薦
Handheld Multimeters and Test Instrumentation
The MAX1239LEEE+ is well-suited for handheld DMMs and bench multimeters thanks to its low 670 uA operating current and 1 uA software-shutdown current, which translate directly to longer battery life. Its 12-bit resolution is sufficient for most 3.5-digit and 4.5-digit handheld meters, and 12 input channels allow simultaneous digitizing of voltage, current, and temperature inputs from sensors in the probe head. The internal 4.096 V reference removes the need for a precision external reference that would otherwise consume additional board space and battery current. The compact 16-QSOP package fits inside slim meter enclosures without sacrificing channel count.
推薦
Portable Medical Patient Monitoring
The MAX1239LEEE+ is well-suited for portable patient monitors because it draws only 670 uA at full sample rate and drops to 1 uA in software shutdown, which directly extends battery life in battery-powered bedside monitors. Its 12-bit resolution and 12 single-ended channels let a single ADC digitize ECG leads, SpO2 photodiode currents, respiration thermistor, NTC skin temperature, and battery telemetry from the same chip, shrinking the analog front-end area. The internal 4.096 V reference reduces calibration burden and BOM count for FDA-quality designs. Operating temperature of -40 to +85 C supports both cold-pack shipping stress and warm skin-contact use cases.
推薦
HVAC Environmental Sensor Concentrators
The MAX1239LEEE+ can digitize temperature, humidity, CO2, particulate-matter (PM2.5), VOC, and pressure sensors in a single HVAC controller board, replacing what would otherwise be multiple single-channel ADCs. Its 94.4 ksps burst sample rate is overkill for slow environmental signals (typically sampled at 1 Hz) but provides plenty of headroom for per-channel digital filtering and oversampling to improve effective resolution. The internal channel-sequencer walks all 12 channels automatically so the host MCU can sleep between scans. Software shutdown drops total ADC drain to under 2 uA, allowing the controller to sleep most of the time on a battery-backed HVAC thermostat.
推薦
Battery Cell Monitors for Multi-Cell Packs
The MAX1239LEEE+ works well as a per-pack cell monitor for multi-cell Li-ion battery packs where each of the 12 channels can be assigned to a cell voltage divider. Its 12-bit resolution (1 mV LSB) is sufficient for basic over-voltage/under-voltage protection on consumer-grade 18650 or 21700 packs. I2C addressing allows up to 4 devices on the same bus for 48S configurations, which is the practical upper limit for small e-bike and power-tool packs. The internal 4.096 V reference keeps part count low, and software shutdown to 1 uA prevents the ADC from draining the cells when the pack is idle in storage.
推薦
Consumer Smart Home Sensor Hubs
The MAX1239LEEE+ is a strong choice for smart-home sensor hubs that aggregate multiple analog sensors (light, motion PIR, thermistor NTC, gas sensor, leak sensor) into a single ADC. Its I2C interface integrates easily with common Wi-Fi/BLE SoCs (ESP32, nRF52) because of firmware driver compatibility with any I2C-compatible 2-wire host. The 12-bit resolution (1 mV LSB) is enough for motion PIR digitizing and thermistor linearization over consumer temperature ranges. Software shutdown to 1 uA keeps standby drain below the typical 30 uA budget of coin-cell sensor nodes, extending battery life to multi-year operation.
推薦
推薦產品摘要
工程參考資料，適用於 MAX1239LEEE+ — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MAX1239KEEE+ | MAX1239LEEE+T | MAX1239KEEE+T | MAX1039AEEE+T |
|---|---|---|---|---|---|
| Package | 16-QSOP | 16-QSOP - same | 16-QSOP - same | 16-QSOP - same | 16-QSOP - same |
| Brand | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Number of Input Channels | 12 single-ended / 6 differential | 12 / 6 | 12 / 6 | 12 / 6 | 12 / 6 |
| Operating Temperature Range | -40 C to +85 C | 0 C to +70 C | -40 C to +85 C | 0 C to +70 C | -40 C to +85 C |
| Supply Voltage Range | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 2.7 V to 3.6 V |
| Internal Reference | 4.096 V | 4.096 V | 4.096 V | 4.096 V | 2.048 V |
| Digital Interface | I2C 2-wire (Std/Fast/HS) | I2C 2-wire (Std/Fast/HS) | I2C 2-wire (Std/Fast/HS) | I2C 2-wire (Std/Fast/HS) | SPI/QSPI/MICROWIRE |
| Packaging Code / Reel | Tube (LEEE+) | Tube | Tape & Reel | Tape & Reel | Tape & Reel |
主要差異化特點
- Industrial -40 C to +85 C temperature range (LEEE grade) (對比MAX1239KEEE+)
- Modern internal reference (4.096 V) provides ratiometric full-scale = 1 mV/LSB (對比MAX1039AEEE+T)
- I2C-compatible interface supports Standard, Fast, and High-Speed modes up to 3.4 MHz (對比MAX1039AEEE+T)
設計說明
Place 0.1 uF ceramic bypass capacitors as close as possible to both AVDD (pin 16) and DVDD (pin 1) of the MAX1239LEEE+, using the shortest possible trace length to a low-impedance ground return. If the supply is fed from a switching regulator, add a 10 uF tantalum or polymer bulk capacitor near AVDD to suppress switching noise - the internal 4.096 V reference derives directly from AVDD, so any noise here couples into the conversion result. Keep the DVDD supply clean because the SDA/SCL I2C drivers draw transient current during acknowledge and data-bit transitions, and a noisy DVDD can cause intermittent I2C bus errors at high bus speeds.
Route the analog input traces (AIN0-AIN11) away from the SDA/SCL clock lines and from any high-current switching node (inductor, gate drive, USB differential pair). Use a single continuous analog ground pour under the device and tie it to the system AGND star-point, with a single-via island under the GND pin (pin 8). Differential input pairs (when configured as AIN0/AIN6, AIN1/AIN7, etc.) should be routed as matched-length pairs to preserve common-mode rejection; the MAX1239LEEE+ datasheet recommends matching to within 0.1 inch for optimal 12-bit performance in noisy industrial environments.
Do not apply voltages to AIN0-AIN11 that exceed AVDD by more than 0.3 V or go below GND by more than 0.3 V, even with the device powered down - the input ESD diodes will forward-conduct and may damage the part. Always configure the setup register to select internal or external reference mode BEFORE the first conversion, because switching reference modes mid-stream can produce a transient full-scale error. When using unipolar inputs near 0 V, allow 1 ms of settling time after power-up before issuing the first conversion - the internal reference typically needs 1-2 ms to settle within 1 LSB. If the application is exposed to ESD or fast transients on the analog inputs, add a TVS diode array (such as an SMBJ series) in parallel with each AIN line for industrial IEC 61000-4-2 compliance.
合規資訊
The '+' suffix denotes lead-free RoHS-compliant packaging per Maxim Integrated (now Analog Devices) standard part-numbering conventions. The MAX1239LEEE+ is NOT AEC-Q100 qualified for automotive under-hood use - for automotive-qualified 12-bit SAR ADCs consider dedicated -Q1 parts.
