MAX1090BEEI - 400ksps 8/4-Ch 10-Bit SAR ADC | Maxim Integrated
MPN: MAX1090BEEI ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.95 | $9.95 |
| 10 | $8.75 | $87.50 |
| 100 | $7.42 | $742.00 |
| 500 | $6.18 | $3,090.00 |
| 1,000 | $5.4 | $5,400.00 |
MAX1090BEEI Overview
An ADC (Analog-to-Digital Converter) is a mixed-signal integrated circuit that converts continuous analog voltages into discrete digital codes. SAR (Successive Approximation Register) ADCs use a binary-search algorithm with an internal DAC and comparator, offering an excellent trade-off between speed, accuracy, and power consumption for multi-channel data-acquisition systems. Within the broader taxonomy, the MAX1090BEEI belongs to successive-approximation ADCs -> data converters -> mixed-signal ICs -> signal chain -> semiconductor ICs.
Key features include 400 ksps maximum sampling rate, 10-bit resolution, 8 single-ended or 4 differential input channels, an integrated +2.5V reference (4.0 V/V input range when using internal reference with 5 V supply), automatic hardware power-down between conversions, parallel-architecture start/stop control, and a high-speed byte-wide parallel output bus. The MAX1090 is the 8-channel variant in the 28-pin QSOP; the MAX1092 is the 4-channel variant in the 24-pin QSOP.
The SAR core uses a charge-redistribution DAC with a precision comparator, and the integrated +2.5V reference eliminates the need for an external reference IC. The on-chip T/H (track-and-hold) supports input bandwidths suitable for multiplexed multi-channel acquisition, while the parallel interface simplifies connection to microcontrollers, DSPs, and FPGAs without requiring a serial-clock generator.
Typical applications include industrial process-control and data-acquisition systems, portable instrumentation and battery-powered data loggers, medical instruments and patient monitors, multichannel sensor interfaces (temperature, pressure, strain), and automotive telemetry subsystems. The wide analog input range and parallel output are well matched to legacy 8-bit/16-bit MCU buses.
When designing with this device, note that the MAX1090BEEI has been obsoleted (no longer manufactured); stock exists at authorized distributors but is finite. Designers should validate lifecycle status before committing to new designs. Refer to the manufacturer datasheet for full pinout, timing diagrams, and reference decoupling recommendations.
Drop-in alternatives for MAX1090BEEI — 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 MAX1090BEEI (same form factor and footprint) — differing in Architecture, Input Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1090AEEI
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1090AEEI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1090BEEI+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1090BCEI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1090BCEI+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1090ACEI+
✅ Drop-In📋 Reference alternative (not in catalog)
ADS901E/1K
✅ Drop-In✓ In Stock
$2.59 / Unit
View Datasheet →MAX1090BEEI Maximum Ratings & Electrical Characteristics
| Resolution | 10 bits |
| Number of Channels | 8 single-ended / 4 differential (MAX1090); 4 single-ended / 2 differential (MAX1092) |
| Sampling Rate | 400 ksps |
| Architecture | SAR (Successive Approximation Register) |
| Supply Voltage | +5 V (analog), +5 V (digital, independent) |
| Analog Input Range | 0 to +5 V (unipolar) or ±5 V (bipolar) with external reference |
| Internal Reference | +2.5 V (on-chip) |
| Digital Interface | Byte-wide parallel (8-bit) |
| Number of ADC Converters | 1 |
| Input Type | Single-ended / Differential (software-selectable per channel pair) |
| Power-Down Mode | Automatic hardware power-down between conversions |
| Wake-Up Time | 2 µs (typical) |
| Package | 28-pin QSOP (EE) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40°C to +85°C (industrial) |
| Conversion Channels | 1 SAR core with 8:1 input MUX |
MAX1090BEEI Pin Configuration
| Pin 1 | AIN0 — Analog input channel 0 |
| Pin 2 | AIN1 — Analog input channel 1 |
| Pin 3 | AIN2 — Analog input channel 2 |
| Pin 4 | AIN3 — Analog input channel 3 |
| Pin 5 | AIN4 — Analog input channel 4 |
| Pin 6 | AIN5 — Analog input channel 5 |
| Pin 7 | AIN6 — Analog input channel 6 |
| Pin 8 | AIN7 — Analog input channel 7 |
| Pin 9 | AGND — Analog ground |
| Pin 10 | REF — Reference input/output (+2.5V internal) |
| Pin 11 | VDD — Analog supply (+5V) |
| Pin 12 | DGND — Digital ground |
| Pin 13 | CS — Chip Select (active low) |
| Pin 14 | WR — Write / Convert Start (active low) |
| Pin 15 | RD — Read (active low) |
| Pin 16 | INT — Interrupt / End-of-Conversion (active low) |
| Pin 17 | D0 — Data bit 0 (LSB) |
| Pin 18 | D1 — Data bit 1 |
| Pin 19 | D2 — Data bit 2 |
| Pin 20 | D3 — Data bit 3 |
| Pin 21 | D4 — Data bit 4 |
| Pin 22 | D5 — Data bit 5 |
| Pin 23 | D6 — Data bit 6 |
| Pin 24 | D7 — Data bit 7 (MSB) |
| Pin 25 | PD — Power-Down (active high) |
| Pin 26 | MODE — Mode Select (unipolar/bipolar) |
| Pin 27 | CLK — External Clock (or internal when grounded) |
| Pin 28 | DVDD — Digital supply (+5V) |
Typical Applications
MAX1090BEEI is suitable for 6 applications: Industrial Process Control & Data Acquisition, Portable Instrumentation & Data Loggers, Medical Instruments & Patient Monitoring, Multi-Channel Sensor Interfaces, Test & Measurement Instrumentation, Automotive Telemetry & Sensor Reading.
Industrial Process Control & Data Acquisition
The MAX1090BEEI's 8 single-ended or 4 differential input channels at 400 ksps make it well-suited for multi-sensor industrial process control panels and SCADA data-acquisition cards. With its integrated +2.5V reference, successive-approximation architecture, and +5V analog supply, the device handles thermocouple, RTD-bridge, 4-20 mA loop, and pressure transducer inputs with 10-bit precision and low noise. Placed between sensor signal-conditioning amplifiers and the host MCU/DSP, the MAX1090BEEI provides parallel-byte outputs that map directly to legacy 8-bit and 16-bit microcontrollers without requiring serial-clock generation. For factory-floor designs, its automatic hardware power-down between conversions reduces system thermal load - a key advantage for high-density DIN-rail and rack-mountable control systems.
Recommended
Portable Instrumentation & Data Loggers
With automatic hardware power-down and a 2 µs wake-up time, the MAX1090BEEI is engineered for battery-powered data loggers, portable multimeters, and field-rugged instrumentation where average supply current matters. The integrated +2.5V reference eliminates the external reference IC's quiescent draw, and the byte-wide parallel interface allows low-power MCUs to read conversions without active serial clocks. At a 400 ksps peak, the device is suitable for capturing transient events in handheld vibration, acoustic, or environmental monitors. Designers using the MAX1090BEEI in portable applications should note that the part is Obsolete; design teams planning new portable instruments should evaluate modern low-power 10-bit SAR ADCs (e.g., ADS7825 or AD7980 family) that draw microamps in standby.
Recommended
Medical Instruments & Patient Monitoring
The MAX1090BEEI's 8 single-ended channels are useful for medical front-end signal acquisition from ECG electrodes, pulse-oximetry photodiodes, temperature probes, and respiration sensors in patient monitoring equipment. Its 400 ksps sampling rate supports ECG front-ends up to 200 ksps per channel pair with simultaneous sampling techniques, while the integrated +2.5V reference and +5V analog supply simplify the medical IEC 60601-1 isolated power tree. The parallel interface enables direct DMA to medical microcontrollers and DSPs without serial-clock overhead. Engineers should verify that any medical design using the MAX1090BEEI accounts for the part's Obsolete status and plans end-of-life procurement or a planned redesign on a current-generation Maxim/Analog Devices 10-bit SAR ADC before regulatory submission.
Recommended
Multi-Channel Sensor Interfaces
With 8 single-ended / 4 differential inputs and software-selectable channel pairing, the MAX1090BEEI interfaces directly to multiplexed arrays of temperature sensors (thermistors, RTDs), strain gauges, pressure transducers, and flow sensors in industrial and HVAC control boards. The 400 ksps throughput supports polling rates of 50 ksps per channel across all 8 channels, which is adequate for slow-moving process variables (ms) up to mid-speed motion control feedback. The integrated +2.5V reference provides a stable ADC full-scale, while the differential input mode rejects common-mode noise from long sensor cables - critical for factory-floor installations. Note that the part is Obsolete; new sensor-interface designs should evaluate MAX1067/MAX1069, MAX1071, or TI ADS7825 family.
Recommended
Test & Measurement Instrumentation
Test equipment such as bench-top multimeters, oscilloscope front-end digitizer boards, and signal-analyzer sub-systems benefit from the MAX1090BEEI's parallel output and multi-channel MUX. The 400 ksps sampling rate captures repetitive waveforms with sufficient temporal resolution for 50 kHz-class audio and vibration analyses, while the 8-channel input supports multi-probe bench setups without external MUX ICs. The integrated +2.5V reference maintains conversion accuracy over temperature, and the byte-wide parallel interface plugs directly into FPGA-based data-acquisition backplanes. New bench-instrument designs should consider the TI ADS901E (28-pin QSOP, 100 ksps), ADI AD7980 family, or Linear Tech (Analog Devices) LTC2360/2365 12-/14-bit SAR ADCs for improved dynamic range.
Recommended
Automotive Telemetry & Sensor Reading
The MAX1090BEEI's wide analog input range (0 to +5V) and +5V supply tolerance suit automotive body-electronics and telemetry modules reading 0-5V sensor outputs (MAP, MAF, throttle position, oil pressure, battery current shunt amps). With 400 ksps throughput and 8 input channels, the device handles multiple sensor channels with adequate margin for engine-control and dashboard telemetry sampling. Designers should be aware that the MAX1090BEEI is not AEC-Q100 qualified and is Obsolete - new automotive designs should use the AEC-Q100-qualified MAX11131 or TI ADS7038 family. The MAX1090BEEI remains useful for retrofit, hobbyist, and non-safety automotive applications where qualification and long-term support are not critical.
Recommended
Recommended Products Summary
Engineering reference data for MAX1090BEEI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1090AEEI | MAX1090BCEI+ | MAX1090ACEI+ | ADS901E/1K |
|---|---|---|---|---|---|
| Package | 28-QSOP | 28-QSOP (same) | 28-QSOP (same) | 28-QSOP (same) | 28-QSOP (same) |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Texas Instruments |
| Resolution | 10 bits | 10 bits | 10 bits | 10 bits | 10 bits |
| Sampling Rate | 400 ksps | 400 ksps | 400 ksps | 400 ksps | 100 ksps (slower) |
| Channels (single-ended) | 8 | 8 | 8 | 8 | 1 (single channel) |
| Supply Voltage | +5V | +5V | +5V | +5V | +5V |
| Internal Reference | +2.5V (yes) | +2.5V (yes) | +2.5V (yes) | +2.5V (yes) | External required |
| Interface | Byte-wide parallel | Byte-wide parallel | Byte-wide parallel | Byte-wide parallel | Parallel (different pinout detail) |
Key Differentiators
- Integrated +2.5V reference eliminates external reference IC (vs ADS901E/1K (TI))
- Automatic hardware power-down with 2 µs wake-up (vs MAX1071 series / older discrete ADCs)
- 8 single-ended / 4 differential channels in single 28-QSOP (vs ADS901E/1K (single-channel TI ADC))
Design Notes
The MAX1090BEEI requires a clean +5V analog supply on AVDD (pin 11) and a separate +5V digital supply on DVDD (pin 28). Place a 10 µF tantalum and a 0.1 µF ceramic decoupling capacitor as close as possible to each supply pin. Use a ferrite bead or small inductor between AVDD and DVDD to prevent digital switching noise from coupling into the analog section. The analog and digital grounds should be tied together at a single point under the IC to avoid ground loops.
Route analog input traces (AIN0-AIN7) as short as possible and shield them with analog ground on both sides. Keep digital outputs (D0-D7) and control lines (RD, WR, CS, INT) routed on the opposite side of the IC from the analog inputs. Place the reference bypass capacitor (typically 0.1 µF ceramic in parallel with 1 µF) directly on the REF pin (pin 10). The MAX1090 datasheet recommends a star-ground topology where AGND and DGND meet under the IC.
The MAX1090BEEI is Obsolete as of the latest distributor data. Do not design it into new production boards without confirming long-term procurement. If an existing design needs to replace failed units, MAX1090AEEI+ is the recommended drop-in. Note that MODE pin configuration selects unipolar (0 to VREF*2) or bipolar (-VREF to +VREF) input ranges - mis-wiring MODE causes incorrect conversion results. The PD pin must be tied low (or driven low) for normal operation; leaving it floating may cause intermittent operation.
When reading the parallel output bus at full 400 ksps, ensure the host MCU/FPGA data bus has sufficient setup/hold margin to the RD signal (active low). Add 10-20 kΩ pull-up resistors on D0-D7 if the host bus is shared with slow peripherals. For multi-channel scanning, insert 1 µs settling time between channel switches - this is internal to the MAX1090's MUX. Reading the INT pin (active low) instead of polling avoids host-side timing jitter.
Compliance Information
RoHS compliance status not confirmed in verified web data - the '+' suffix variant (MAX1090BEEI+) is typically RoHS compliant per Maxim convention. Part is not AEC-Q100 qualified for automotive. Lifecycle status is Obsolete per DigiKey distributor data.
