MAX1091BCEI+T - 250ksps 10-Bit 8-Ch ADC | Maxim Integrated | QSOP-28
MPN: MAX1091BCEI+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $13.05 | $13.05 |
| 10 | $11.75 | $117.50 |
| 100 | $10.45 | $1,045.00 |
| 500 | $9.18 | $4,590.00 |
| 1,000 | $8.1 | $8,100.00 |
MAX1091BCEI+T Overview
An ADC (analog-to-digital converter) is a data-acquisition integrated circuit that samples continuous analog voltage signals and encodes them into discrete digital codes for use by microcontrollers, DSPs, or processors. Successive-approximation register (SAR) ADCs like the MAX1091BCEI+T sit in the broader data-converter taxonomy between lower-speed delta-sigma and higher-speed flash architectures, offering a balanced trade-off of speed, accuracy, and power consumption. They are widely used in industrial control, instrumentation, motor control, and portable battery-powered monitoring systems where mid-range sampling rates (10 ksps to 1 Msps) are sufficient.
Key features of the MAX1091BCEI+T include 250 ksps sampling rate across 8 single-ended or 4 differential input channels, an internal +2.5 V reference (eliminating the need for an external reference chip), automatic power-down between conversions with 2 microseconds wake-up time, an on-chip clock, and a byte-wide parallel digital interface. The architecture integrates a track-and-hold amplifier ahead of the SAR core so the input remains stable during the conversion cycle, allowing accurate acquisition of multiplexed channels at full speed.
From an electrical perspective, the device operates from a single +3 V supply, draws only a few milliamps during active conversion, and reduces to microamp-level current in power-down mode. This makes it well suited to battery-powered or power-budgeted embedded designs. The internal +2.5 V reference typically offers ±25 ppm/°C temperature drift or better, removing the BOM cost of an external shunt reference and the associated board area in space-constrained layouts.
Typical applications include multi-channel data-acquisition front ends in industrial PLCs, process-control sensor read panels, handheld digital multimeters, motor-current monitoring in variable-frequency drives, and portable medical monitoring instrumentation. The combination of selectable 4-/8-channel input MUX, internal reference, and parallel interface reduces external component count, accelerating design-in versus discrete ADC + op-amp + reference chains.
When designing with this part, ensure the digital interface signals are routed away from analog inputs to minimize digital-to-analog crosstalk. Decouple AVDN and DVDD separately with 0.1 µF ceramic caps close to the pins. The reference decoupling capacitor value is given in the Maxim datasheet and must not be omitted, since it sets reference settling bandwidth.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the Maxim datasheet alone, giving an engineer a single reference for selection, sourcing, and PCB integration of the MAX1091BCEI+T.
Drop-in alternatives for MAX1091BCEI+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 MAX1091BCEI+T (same form factor and footprint) — differing in Number of Input Channels, Architecture, Input Type, On-Chip Clock, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1091BCEI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1091AEEI+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1091BEEI+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX1091ACEI+T
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.1 / Unit
View Datasheet →MAX1093AEEG+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX1091BCEI+T Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices / Maxim Integrated |
| Part Number | MAX1091BCEI+T |
| Resolution | 10 bit |
| Sampling Rate | 250 ksps |
| Number of Input Channels | 4 differential / 8 single-ended (configurable) |
| Input Configuration | MUX-S/H-ADC (1:1 S/H:ADC) |
| Architecture | SAR (Successive Approximation Register) |
| Input Type | Single-Ended, Differential, Pseudo-Differential |
| Supply Voltage | +3 V (single supply) |
| Internal Reference Voltage | +2.5 V |
| Data Interface | Parallel (byte-wide) |
| On-Chip Clock | Yes |
| Automatic Power-Down | Yes (2 microseconds wake-up) |
| Track-and-Hold | Integrated |
| Package | 28-pin SSOP / QSOP |
| Temperature Grade | Commercial |
| Terminal Form | Gull Wing |
| Package Code | SSOP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
MAX1091BCEI+T Pin Configuration
| Pin 1 | AGND — Analog Ground |
| Pin 2 | AVDD — Analog +3V Supply |
| Pin 3 | AIN0 — Analog Input Channel 0 |
| Pin 4 | AIN1 — Analog Input Channel 1 |
| Pin 5 | AIN2 — Analog Input Channel 2 |
| Pin 6 | AIN3 — Analog Input Channel 3 |
| Pin 7 | AIN4 — Analog Input Channel 4 |
| Pin 8 | AIN5 — Analog Input Channel 5 |
| Pin 9 | AIN6 — Analog Input Channel 6 |
| Pin 10 | AIN7 — Analog Input Channel 7 |
| Pin 11 | REF — Internal +2.5V Reference Bypass |
| Pin 12 | AGND — Analog Ground |
| Pin 13 | DGND — Digital Ground |
| Pin 14 | DVDD — Digital +3V Supply |
| Pin 15 | DOUT0 — Parallel Data Output Bit 0 (LSB) |
| Pin 16 | DOUT1 — Parallel Data Output Bit 1 |
| Pin 17 | DOUT2 — Parallel Data Output Bit 2 |
| Pin 18 | DOUT3 — Parallel Data Output Bit 3 |
| Pin 19 | DOUT4 — Parallel Data Output Bit 4 |
| Pin 20 | DOUT5 — Parallel Data Output Bit 5 |
| Pin 21 | DOUT6 — Parallel Data Output Bit 6 |
| Pin 22 | DOUT7 — Parallel Data Output Bit 7 (MSB) |
| Pin 23 | CS — Chip Select |
| Pin 24 | RD — Read Strobe |
| Pin 25 | WR — Write / Conversion Start |
| Pin 26 | INT — Interrupt / Conversion End |
| Pin 27 | HBEN — High-Byte Enable |
| Pin 28 | MODE — Mode Selection (Internal/External Clock, Power-Down) |
Typical Applications
MAX1091BCEI+T is suitable for 7 applications: Industrial Multi-Channel Data Acquisition (DAQ), Handheld Digital Multimeter and Test Instrumentation, Motor Control and Variable-Frequency Drive Current Sensing, Portable Patient Monitoring and Medical Instrumentation, Process Control Sensor Read Panels (PLC Analog Input Modules), Battery-Operated Wireless Sensor Nodes (IoT Edge Devices), Audio and Voice-Band Signal Capture (Auxiliary ADC for DSP).
Industrial Multi-Channel Data Acquisition (DAQ)
The MAX1091BCEI+T is well suited to multi-channel industrial DAQ front ends where it serves as the core ADC for digitizing 4 to 8 sensor signals (temperature, pressure, transducer, or 4-20 mA loop inputs). Its 250 ksps sampling rate exceeds the needs of typical thermocouple and strain-gauge measurements that sample at 1 to 10 ksps per channel, while its 8-channel MUX eliminates external analog switches and reduces PCB area. The integrated +2.5 V reference removes the cost of a discrete reference IC, and automatic power-down between conversions reduces average current draw in duty-cycled remote sensor nodes. Compared to a discrete op-amp + external reference + separate ADC chain, the MAX1091BCEI+T simplifies the BOM while delivering 10-bit sufficient resolution for industrial control loops.
Recommended
Handheld Digital Multimeter and Test Instrumentation
Portable digital multimeters and bench multimeters benefit from the MAX1091BCEI+T's 8-channel input MUX, which lets the meter scan between voltage, current, resistance, frequency, and temperature inputs without external switching. Its low duty-cycle power-down current makes it ideal for battery-powered handheld meters that must run for hundreds of hours on AA cells. The integrated +2.5 V reference is ratiometrically tied to the on-board shunt resistor for current measurements, simplifying calibration. For handheld oscilloscopes and panel meters, the parallel interface drops straight into 8-bit or 16-bit microcontrollers without serial-port glue logic, and 250 ksps catches transient behavior on signal input lines.
Recommended
Motor Control and Variable-Frequency Drive Current Sensing
Three-phase variable-frequency drives require simultaneous sampling of two motor currents and the DC bus voltage to perform Clarke/Park transformations and field-oriented control. The MAX1091BCEI+T supports up to 8 channels at 250 ksps, more than sufficient for current-sense amplifier outputs running at typical PWM carrier frequencies below 20 kHz. Its parallel interface gives tight deterministic timing for closed-loop control loops running on a DSP or microcontroller. The internal +2.5 V reference simplifies the analog front end by eliminating a separate reference IC, and auto power-down reduces quiescent current between PWM-edge-triggered samples. Drop-in compatibility with the A-grade version (MAX1091ACEI+T) lets designers step up to higher ±1 LSB INL accuracy for precision servo drives without redesigning the board.
Recommended
Portable Patient Monitoring and Medical Instrumentation
Compact medical devices (pulse oximeters, glucose meters, ECG front ends, body-worn monitors) integrate multiple biometric sensors into a single low-power board. The MAX1091BCEI+T digitizes up to 8 sensor channels (SpO2 photodiode, EKG leads, temperature, motion) with 10-bit resolution sufficient for these applications, while the auto-power-down feature drops its quiescent current to microamp levels between samples. The +3 V single supply pairs cleanly with single-cell Li-ion batteries used in wearable platforms. Its internal +2.5 V reference eases regulatory compliance by reducing the bill of materials that must be quality-controlled. Compared to integrating multiple single-channel ADCs, the MAX1091BCEI+T shrinks PCB area and simplifies firmware-driven channel scanning.
Recommended
Process Control Sensor Read Panels (PLC Analog Input Modules)
Modular PLC analog input cards with 4 to 16 channels per slot benefit from the MAX1091BCEI+T's compact SSOP-28 footprint and 8-channel multiplexer. The byte-wide parallel interface allows the PLC backplane microcontroller to read the conversion result directly without DMA or SPI overhead, enabling deterministic 1 ms refresh rates on 8 channels (125 ksps per channel). The integrated +2.5 V reference removes one component from the design-for-manufacture BOM and trims calibration time in production. Operating from +3 V simplifies the power tree; the entire card can be supplied from the backplane 5 V rail with a linear regulator rather than dual rails. Designers can also use it with diff inputs for ±10 V or 4-20 mA loop conditioning with simple resistive dividers or shunt resistors.
Recommended
Battery-Operated Wireless Sensor Nodes (IoT Edge Devices)
IoT edge nodes distributed across factories, agricultural fields, or building-management systems must run for years on a single battery while sampling sensors on low duty cycles. The MAX1091BCEI+T's automatic power-down between conversions drops average supply current to microamps, ideal for nodes that wake once per second to sample temperature, humidity, vibration, or gas sensors. The internal +2.5 V reference powers the SAR directly with no external reference-current overhead, and the SSOP-28 footprint fits inside the slim form factors typical of wireless sensor modules. The 10-bit resolution is sufficient for environmental monitoring and asset-tracking telemetry where 12+ bits are not required. The parallel interface also lends itself well to low-end MCUs without SPI peripherals, reducing total BOM cost.
Recommended
Audio and Voice-Band Signal Capture (Auxiliary ADC for DSP)
DSP front-end cards that handle audio codec, voice-band processing, or vibration analysis can use the MAX1091BCEI+T as an auxiliary high-speed ADC for control-loop signals alongside the main audio codec. At 250 ksps the device comfortably captures up to 100 kHz signal bandwidth, suitable for ultrasound or vibration input stages. The 8-channel MUX lets designers route multiple microphone, accelerometer, or photo-sensor inputs through a single ADC. Its SAR architecture provides low-latency single-sample conversion (no pipeline delay) which is critical for closed-loop control. The internal +2.5 V reference also calibrates accurately to common microphone bias voltages for direct connection. For higher-resolution audio capture, designers can switch to the MAX1093AEEG+, a 12-bit pin-compatible variant.
Recommended
Recommended Products Summary
Engineering reference data for MAX1091BCEI+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1091BCEI+ | MAX1091AEEI+ | MAX1091BEEI+ | MAX1091ACEI+T | MAX1093AEEG+ |
|---|---|---|---|---|---|---|
| Package | SSOP-28 (QSOP-28) | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same | SSOP-28 - same |
| Brand | Analog Devices / Maxim Integrated | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 10 bit | 10 bit | 10 bit | 10 bit | 10 bit | 12 bit |
| Sampling Rate | 250 ksps | 250 ksps | 250 ksps | 250 ksps | 250 ksps | 250 ksps |
| Number of Input Channels | 8 single-ended / 4 differential | 8 / 4 | 8 / 4 | 8 / 4 | 8 / 4 | 8 / 4 |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR |
| Internal Reference | +2.5 V | +2.5 V | +2.5 V | +2.5 V | +2.5 V | +2.5 V |
| Data Interface | Parallel (byte-wide) | Parallel | Parallel | Parallel | Parallel | Parallel |
| Temperature Grade | Commercial | Commercial | Industrial | Industrial | Commercial | Industrial |
| Linearity (INL) | ±1.5 LSB (B-grade) | ±1.5 LSB | ±1 LSB | ±1.5 LSB | ±1 LSB | ±1 LSB (12-bit) |
Key Differentiators
- Integrated +2.5 V reference eliminates external reference BOM (vs MAX1090BCEI+)
- SSOP-28 small-outline package with 8 single-ended input channels (vs MAX1060AEEI+)
- Automatic power-down between conversions extends battery life (vs MAX1076CTC+T)
Design Notes
AVDD and DVDD must each be decoupled separately with a 0.1 microfarat ceramic capacitor placed as close as possible to the respective supply pin, plus a bulk 1 to 10 microfarat tantalum or ceramic bypass. Estimated: at 250 ksps and 3 V single supply, the MAX1091BCEI+T draws a few mA in continuous conversion and drops to microamp-level current in power-down. Hold DVDD current away from the AGND return path on the PCB to avoid ground-bounce noise on the analog inputs.
Route analog input traces and digital output traces on opposite sides of the ground plane to minimize digital-to-analog crosstalk. The reference-bypass capacitor on the REF pin must use a low-ESR ceramic with a value given in the Maxim datasheet; omitting it causes reference settling errors that limit INL. Place the bypass cap within 5 mm of the REF pin and use a star-ground topology tying AGND and DGND together at a single point near the IC.
When driving the analog input multiplexer from high-impedance sources, add a wide-bandwidth op-amp buffer immediately before each AIN pin; the MUX-S/H-ADC path samples the input in tens of nanoseconds, so source-impedance above 1 kilohm introduces acquisition-time errors. Estimated: a unity-gain buffer with 10 MHz GBP and adequate slew rate is sufficient for the 250 ksps throughput. For pseudo-differential inputs, short the unused AIN pin to common-mode to avoid noise pickup on the floating input.
Common pitfalls when designing with the MAX1091BCEI+T include: (1) forgetting to configure the MODE pin for internal clock vs external-clock operation, (2) driving AVDD and DVDD from the same net without separate decoupling, and (3) leaving the HBEN pin floating when only 8-bit reads are needed; tie HBEN to VDD or GND per the datasheet to avoid indeterminate bus states. Always consult the Maxim datasheet pinout table because the SSOP-28 pin assignments differ from generic 28-pin SOIC parts.
Compliance Information
RoHS-compliant per Maxim Integrated product page. Not AEC-Q100 qualified - commercial/industrial-grade part. Halogen-free status not explicitly stated in the verified web data.
