MAX1236KEUA+T - 12-Bit 4-Ch SAR ADC | Analog Devices
MPN: MAX1236KEUA+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.62 | $5.62 |
| 10 | $5.21 | $52.10 |
| 100 | $4.71 | $471.00 |
| 500 | $4.05 | $2,025.00 |
| 1,000 | $3.55 | $3,550.00 |
MAX1236KEUA+T Overview
An ADC (Analog-to-Digital Converter) is a semiconductor device that converts continuous analog voltage signals into discrete digital codes for processing by microcontrollers, FPGAs, or DSPs. The SAR (Successive Approximation Register) architecture uses a binary search algorithm against an internal DAC to determine each bit in sequence, providing a deterministic conversion time independent of input signal amplitude. The MAX1236 belongs to the SAR ADC sub-family within the broader category of data converters and is one of the smallest pin-count multi-channel SAR ADCs available for embedded sensing applications.
Key features include 4 single-ended analog input channels (multiplexed to one ADC core), an internal 2.5V reference, internal track/hold amplifier, internal oscillator eliminating the need for an external crystal, and an automatic power-down mode between conversions that reduces supply current to a few microamps. The I2C-compatible serial interface supports standard mode (100 kHz), fast mode (400 kHz), and high-speed mode (1.7 MHz), and the device includes two slave address options for bus sharing.
The MAX1236-MAX1239 family is organized by channel count and input configuration: MAX1236 provides 4 single-ended inputs, MAX1238 provides 12 single-ended inputs, and MAX1237/MAX1239 provide pseudo-differential inputs. The MAX1236KEUA+T variant operates from 2.7V to 3.6V and 4.5V to 5.5V, while the MAX1236LEUA+ operates from 2.7V to 3.6V only, making the K variant more suitable for 5V-tolerant industrial systems.
Typical applications include industrial process control sensor monitoring, portable battery-powered data acquisition, handheld instrumentation, 4-20 mA loop-powered transmitters, HVAC sensor interfaces, and consumer equipment monitoring. The combination of low power consumption and small µMAX-8 footprint makes it well-suited for space-constrained designs.
When designing with this ADC, place the 0.1 µF bypass capacitor as close as possible to the AVDD pin and route analog and digital grounds to a common star point to minimize digital switching noise coupling into the analog inputs. For best linearity performance, average multiple conversions or oversample when input bandwidth permits.
This page synthesizes distributor pricing, drop-in alternatives, and parametric comparisons not consolidated in the manufacturer datasheet alone, providing a single-source reference for design engineers evaluating the MAX1236KEUA+T for low-power multi-channel ADC applications.
Drop-in alternatives for MAX1236KEUA+T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MAX1236KEUA+T (same form factor and footprint) — differing in Package, Architecture, Resolution, Input Type, Internal Reference.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1236LEUA+
✅ Drop-In✓ In Stock
$4.12 / Unit
View Datasheet →MAX1236EUA+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1236EUA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1136EUA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1237EUA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1236KEUA+T Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Number of Channels | 4 single-ended / 2 pseudo-differential |
| Input Type | Single-Ended, Pseudo-Differential |
| Sampling Rate (max) | 94.4 ksps |
| Architecture | SAR (Successive Approximation Register) |
| Supply Voltage Range | 2.7V to 3.6V and 4.5V to 5.5V |
| Supply Current (typical) | 670 µA at max sampling rate |
| Internal Reference | 2.5 V |
| External Reference Support | Yes (1.0V to VDD) |
| Digital Interface | I2C-compatible 2-wire serial (Standard/Fast/High-Speed) |
| I2C Maximum Clock | 1.7 MHz (High-Speed mode) |
| Number of Slave Addresses | 2 selectable |
| Package | 8-pin µMAX (uSOP) |
| Operating Temperature Range | -40°C to +85°C (Industrial) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
MAX1236KEUA+T Pin Configuration
| Pin 1 | SDA — Serial data input/output (I2C data line) |
| Pin 2 | SCL — Serial clock input (I2C clock line) |
| Pin 3 | GND — Ground |
| Pin 4 | AIN0 — Analog input channel 0 |
| Pin 5 | AIN1 — Analog input channel 1 |
| Pin 6 | AIN2/AIN2+ — Analog input channel 2 (single-ended) or positive input (pseudo-differential) |
| Pin 7 | AIN3/AIN1- — Analog input channel 3 (single-ended) or negative input (pseudo-differential) |
| Pin 8 | AVDD — Analog supply voltage (2.7V-3.6V or 4.5V-5.5V) |
Typical Applications
MAX1236KEUA+T is suitable for 6 applications: Industrial Process Control Sensor Monitoring, Portable Battery-Powered Data Acquisition, HVAC Sensor Interface Systems, 4-20 mA Loop-Powered Transmitters, Consumer Equipment Monitoring, Handheld Test Instrumentation.
Industrial Process Control Sensor Monitoring
The MAX1236KEUA+T is well-suited for industrial process control sensor monitoring due to its 4-channel single-ended input multiplexer and 12-bit resolution (1 mV LSB at 4.096V range). With 670 µA typical supply current and a wide 4.5V-5.5V supply tolerance, it interfaces to 4-20 mA loop-powered sensors, RTDs, and bridge sensors through signal conditioning. The internal 2.5V reference and internal oscillator minimize external component count, and the I2C interface supports multi-drop sensor networks on a single 2-wire bus from a PLC or industrial controller.
Recommended
Portable Battery-Powered Data Acquisition
The MAX1236KEUA+T is an excellent choice for portable battery-powered data acquisition due to its 670 µA active supply current and automatic shutdown between conversions that drops current to a few microamps. With 4 single-ended channels, an internal 2.5V reference, and 8-pin µMAX footprint (3 mm x 3 mm), it fits handheld instruments powered from 2x AA or lithium cells. The wide 2.7V-3.6V operating range directly supports single-cell Li-ion operation. Combined with sleep-mode current below 10 µA, average power consumption stays well under 1 mW in typical duty-cycled sampling.
Recommended
HVAC Sensor Interface Systems
The MAX1236KEUA+T is well-matched for HVAC sensor interface systems where multiple temperature, humidity, and pressure sensors must be monitored from a single microcontroller. With 4 single-ended inputs, an I2C interface supporting multi-device addressing, and a -40°C to +85°C industrial temperature range, it operates reliably in equipment-room thermal environments. The 12-bit resolution provides 0.1°C temperature resolution when used with 10 mV/°C temperature sensors like the LM35, and the 4.5V-5.5V supply operation supports 24V-derived HVAC bus voltages with simple regulation.
Recommended
4-20 mA Loop-Powered Transmitters
The MAX1236KEUA+T suits 4-20 mA loop-powered transmitters because its 670 µA supply current fits within the 3.6 mA minimum loop budget when duty-cycled. With 12-bit resolution, internal 2.5V reference, and I2C interface, it accepts inputs from pressure, flow, or level transducers and reports digitized measurements through the loop-powered microcontroller. The 4.5V-5.5V supply tolerance accommodates the typical 12V-24V loop supply after regulation, and the low shutdown current between conversions extends battery life in wireless HART field instruments.
Recommended
Consumer Equipment Monitoring
The MAX1236KEUA+T fits consumer equipment monitoring applications such as appliance sensors, smart-home devices, and battery chargers that need to monitor voltage, current, and temperature with 12-bit accuracy. Its small 8-pin µMAX package fits compact consumer PCB layouts, and the I2C interface simplifies connection to host microcontrollers. The wide 2.7V-3.6V and 4.5V-5.5V supply range supports both 3.3V and 5V consumer designs, and the low shutdown current is critical for always-on battery-powered devices like smoke detectors and doorbell cameras.
Recommended
Handheld Test Instrumentation
The MAX1236KEUA+T is well-suited for handheld test instruments such as multimeters, oscilloscope probes, and benchtop meters due to its compact 8-pin µMAX footprint, low 670 µA supply current, and 12-bit resolution that meets the precision requirements of entry-level measurement equipment. The 4 single-ended channels enable voltage, current (via shunt), temperature, and reference measurements through one ADC. With high-speed I2C mode up to 1.7 MHz, conversion data streams to the host microcontroller fast enough for real-time display refresh without buffering.
Recommended
Recommended Products Summary
Engineering reference data for MAX1236KEUA+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1236LEUA+ | MAX1236EUA+T | MAX1136EUA+ | MAX1237EUA+ |
|---|---|---|---|---|---|
| Brand | Analog Devices (formerly Maxim Integrated) | Analog Devices (formerly Maxim Integrated) | Analog Devices (formerly Maxim Integrated) | Analog Devices (formerly Maxim Integrated) | Analog Devices (formerly Maxim Integrated) |
| Package | 8-pin µMAX | 8-pin µMAX - same | 8-pin µMAX - same | 8-pin µMAX - same | 8-pin µMAX - same |
| Resolution | 12 bits | 12 bits | 12 bits | 10 bits (-17%) | 12 bits |
| Number of Channels | 4 single-ended | 4 single-ended | 4 single-ended | 4 single-ended | 2 pseudo-differential |
| Supply Voltage Range | 2.7V-3.6V and 4.5V-5.5V | 2.7V-3.6V only | 2.7V-3.6V and 4.5V-5.5V | 2.7V-3.6V and 4.5V-5.5V | 2.7V-3.6V and 4.5V-5.5V |
| I2C Maximum Clock | 1.7 MHz (High-Speed mode) | 1.7 MHz | 1.7 MHz | 1.7 MHz | 1.7 MHz |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| Input Configuration | Single-Ended | Single-Ended | Single-Ended | Single-Ended | Pseudo-Differential |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C |
Key Differentiators
- Wide 4.5V-5.5V supply tolerance for 5V industrial systems (vs MAX1236LEUA+)
- 12-bit resolution in 8-pin µMAX package (vs MAX1136EUA+)
- Single-ended input configuration with 4 channels (vs MAX1237EUA+)
- Tape-and-reel packaging for high-volume SMT production (vs MAX1236EUA+)
- Internal 2.5V reference eliminates external reference IC (vs Generic discrete ADC designs)
Design Notes
Place the 0.1 µF AVDD bypass capacitor as close as possible to pin 8 of the MAX1236KEUA+T, with the trace to the pin shorter than 2 mm to minimize inductance. Use a star-ground topology connecting the MAX1236 GND pin (pin 3) directly to the analog ground plane at a single point. Route analog input traces (AIN0-AIN3) as short as possible and away from the I2C SDA/SCL lines to avoid digital coupling into the analog inputs.
The MAX1236KEUA+T includes an automatic power-down feature that drops supply current to a few microamps between conversions. Use this aggressively in battery-powered designs by issuing the power-down command in the I2C sequence between samples. For duty-cycled 1 sample per second operation, average current consumption drops below 10 µA, enabling multi-year battery life from a single CR2032 coin cell in low-duty-cycle applications.
For best 12-bit linearity performance, average 16 or more consecutive conversions in firmware when input bandwidth permits. The internal track/hold has a 1.5 MHz small-signal bandwidth, but routing high-impedance analog inputs (>10 kΩ source impedance) requires an external input buffer op-amp to avoid ADC gain error. Add a 100 pF capacitor at the AIN pin to filter RF noise when long input traces are unavoidable.
Do not operate the MAX1236KEUA+T below 2.7V or above 5.5V - even brief over-voltage transients on AVDD can damage the internal reference. Always issue the I2C reset sequence (writing 0x54 to the setup register) after power-up to ensure the device enters a known state. When using high-speed I2C mode (1.7 MHz), verify the host microcontroller supports the high-speed mode start condition or use fast mode (400 kHz) as a safer default.
Keep the analog input traces (AIN0-AIN3) impedance-matched if using differential pairs, and place input protection diodes (BAT54S) near the connector when interfacing with external sensors that may carry ESD or transient over-voltage. The µMAX package thermal pad is internally connected to GND - place a copper pour under the IC connected to the analog ground plane for additional thermal dissipation and low-impedance grounding.
Compliance Information
RoHS compliant per Maxim Integrated / Analog Devices product documentation. Not AEC-Q100 qualified (industrial temperature grade only). Halogen-free status not explicitly stated in available data.
