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Analog Devices Inc./Maxim Integrated MAX1291AEEI+
- Part No.:
- MAX1291AEEI+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Analog to Digital Converters (ADC)
- Package:
- -
- Datasheet:
-
MAX1291AEEI+.pdf
- Description:
- IC ADC 12BIT 250KSPS 28-QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,448
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Product details
Overview
MAX1291AEEI+ from Maxim Integrated is a 12-bit, 250ksps successive-approximation ADC with integrated +2.5V reference, 8-channel single-ended / 4-channel pseudo-differential analog input multiplexer, and byte-wide parallel (8+4) interface. It operates from a single +3V analog supply and supports digital logic levels from +1.8V to +3.6V via VLOGIC. Designed for low-power data acquisition in portable medical and industrial monitoring systems.
For engineers reviewing the MAX1291AEEI+ datasheet, MAX1291AEEI+ pinout, MAX1291AEEI+ application, or MAX1291AEEI+ equivalent, key selection considerations include its -40°C to +85°C extended temperature rating, ±0.5 LSB INL, internal track/hold with 3MHz full-power bandwidth, and software-configurable unipolar/bipolar input modes.
Technical Context
The MAX1291AEEI+ implements a charge-redistribution SAR architecture with an on-chip track/hold stage and internal 3MHz full-power bandwidth amplifier. Its control byte (D7–D0) configures acquisition mode (internal/external), clock source (internal/external), input polarity (unipolar/bipolar), and input topology (single-ended/pseudo-differential).
It supports two power-down modes: standby (10µA) and full shutdown (2µA), triggered by software bits PD0/PD1. The HBEN pin enables high-byte (D8–D11) or low-byte (D0–D7) multiplexing on the shared data bus, reducing I/O count in microprocessor interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 12-bit - delivers 1 LSB = VREF/4096 quantization step for precise sensor digitization |
| Sampling Rate | 250ksps - supports real-time capture of signals up to 125kHz Nyquist frequency |
| INL | ±0.5 LSB - ensures monotonicity and <0.012% full-scale linearity error across temperature |
| Reference | +2.5V internal - eliminates external reference component and layout complexity |
| Supply Current | 1.9mA at 250ksps - enables battery operation with <5.7mW total power at VDD = VLOGIC = +3V |
| Input Channels | 8 single-ended or 4 pseudo-differential - provides flexible signal routing without external MUX |
| Operating Temp | -40°C to +85°C - qualified for industrial and medical environments per AEEI grade |
Pinout & Package
MAX1291AEEI+ is housed in a 28-pin QSOP package (5.3mm × 10.2mm, 0.65mm pitch), optimized for space-constrained PCB layouts while maintaining thermal performance and manufacturability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| HBEN | High-Byte Enable | Selects D8–D11 (HBEN=1) or D0–D7 (HBEN=0) on shared data bus - reduces MCU data bus width requirement |
| D0/D8–D7/D11 | Three-State Data Bus | Byte-multiplexed 12-bit output - avoids need for 12-bit wide parallel interface on host controller |
| INT | Interrupt Output | Active-low conversion-complete flag - enables interrupt-driven sampling without polling overhead |
| WR, RD, CS | Control Interface | Standard 8080-style parallel timing - direct connection to legacy µP I/O ports without glue logic |
| CH0–CH7 | Analog Input Channels | Software-selectable 8-channel MUX - supports multi-sensor monitoring with single ADC |
| VLOGIC | Digital Supply Rail | Independent +1.8V to +3.6V logic supply - enables interfacing with low-voltage MCUs while analog section runs at +3V |
| REF, REFADJ | Reference Control | Internal +2.5V bandgap buffer with adjustable output - allows fine-tuning or disabling for external reference use |
| COM | Analog Common Reference | Zero-code reference point for single-ended mode - must be stable to ±0.5 LSB during conversion |
Key Features
| Feature | Design Value |
|---|---|
| Software-configurable input topology | Single-ended (8 ch) or pseudo-differential (4 ch) mode selected via control byte - eliminates external switch ICs |
| Internal track/hold with 3MHz bandwidth | Supports undersampling of transients beyond Nyquist - enables spectral analysis of fast events without anti-alias filter redesign |
| Two-stage power-down | Standby (10µA) and full shutdown (2µA) modes - extends battery life in intermittent-sampling applications |
| Aperture jitter <50ps (external acquisition) | Enables high-SFDR (>80dB) measurements at medium frequencies - critical for energy metering accuracy |
| Unipolar/bipolar input selection | Configured in real time via UNI/BIP bit - accommodates both sensor types (e.g., thermocouples vs. RTDs) on same hardware |
Applications
| Industrial Process Monitoring | Patient Vital Sign Acquisition |
|---|---|
Use Scenario: Continuous logging of pressure, temperature, and flow sensor outputs in PLC-based control cabinets. IC Role / Device Role / Timing Role: Primary ADC digitizing 8 analog sensor channels with synchronized sampling and interrupt-driven data transfer. Use Value: Internal +2.5V reference and ±0.5 LSB INL ensure measurement repeatability across temperature without calibration drift compensation. |
Use Scenario: Portable ECG and SpO₂ monitor acquiring biopotential signals with low noise and high DC accuracy. IC Role / Device Role / Timing Role: Bipolar-mode ADC capturing differential lead signals with COM-referenced zero point and software-triggered conversions. Use Value: 3MHz track/hold bandwidth preserves signal integrity of fast QRS complexes; 2µA shutdown current extends battery runtime between patient checks. |
| Energy Metering Front-End | Automated Test Equipment (ATE) Channel Expansion |
Use Scenario: Multi-phase electricity meter measuring voltage/current waveforms for active/reactive power calculation. IC Role / Device Role / Timing Role: High-SFDR ADC operating in external acquisition mode to minimize aperture jitter during synchronized sampling across phases. Use Value: <50ps aperture jitter and 80dB SFDR enable Class 0.2 metering accuracy per IEC 62053-21 without oversampling or post-processing. |
Use Scenario: Adding 8-channel analog input capability to benchtop ATE systems using existing 8-bit data buses. IC Role / Device Role / Timing Role: Parallel-interface ADC with HBEN-controlled byte multiplexing, enabling 12-bit resolution over legacy 8-bit microcontroller buses. Use Value: Eliminates need for external bus transceivers or FPGA glue logic - reduces BOM cost and board area in modular test instrumentation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 12-bit SAR ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADS7822U | 2.7V–5.25V supply; SPI interface; no internal reference; 200ksps max rate | Requires external reference and level-shifting for +1.8V logic; lower sampling rate limits dynamic signal capture | Preferred when serial interface and smaller footprint (8-pin SOIC) outweigh parallel interface and internal reference benefits |
| AD7892BRZ-1 | +5V-only supply; 14-bit resolution; 250ksps; internal reference; parallel interface | Higher resolution but incompatible with +3V-only systems; larger 28-pin SOIC package increases PCB area | Selected when 14-bit precision is mandatory and system design accommodates +5V supply and larger layout footprint |
Compared with ADS7822U and AD7892BRZ-1, MAX1291AEEI+ uniquely balances extended temperature operation (-40°C to +85°C), integrated +2.5V reference, +1.8V–+3.6V logic compatibility, and 28-pin QSOP compactness - making it optimal for space- and power-constrained industrial and medical DAQ designs.
Availability
MAX1291AEEI+ is available at Aetrix Electronics and suitable for industrial process monitoring, portable medical devices, energy metering, and automated test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX1291AEEI+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.
The MAX1291AEEI+ belongs to Maxim's precision data acquisition product line, engineered for low-power, high-accuracy sensor interfacing in battery-operated and thermally demanding environments.
FAQ
What is the operating temperature range of the MAX1291AEEI+?
The MAX1291AEEI+ is rated for operation from -40°C to +85°C, meeting industrial-grade environmental requirements. This extended temperature range is confirmed in the device's ordering information table, where "AEEI" suffix denotes the -40°C to +85°C grade, distinct from the "ACEI" (0°C to +70°C) variant. All electrical specifications in the datasheet are guaranteed across this full range.
Does the MAX1291AEEI+ require an external clock source?
No, the MAX1291AEEI+ includes an internal clock generator and can operate in internal clock mode (configured via control byte bits D7/D6). When used in this mode, the CLK pin must be tied to VDD or GND to prevent floating. An external clock (100kHz–4.8MHz) is optional and only required when lowest aperture jitter (<50ps) is needed, as internal clock mode exhibits up to 200ps jitter.
How does the HBEN pin affect data readout on the MAX1291AEEI+?
The HBEN (High Byte Enable) pin controls multiplexing of the 12-bit conversion result onto the 8-bit data bus: when HBEN = 1, D0–D7 carry D8–D11 (the four MSBs); when HBEN = 0, D0–D7 carry D0–D7 (the eight LSBs). This allows full 12-bit resolution to be read using only an 8-bit microprocessor data bus, eliminating the need for wider I/O or additional latching logic.
Can the MAX1291AEEI+ interface directly with a +1.8V microcontroller?
Yes, the MAX1291AEEI+ supports digital logic levels from +1.8V to +3.6V via its dedicated VLOGIC pin. When VLOGIC is supplied at +1.8V, all digital inputs (CS, WR, RD, HBEN) recognize VIH ≥ 1.5V and VIL ≤ 0.5V, and digital outputs (D0–D7, INT) drive VOH ≥ 1.3V and VOL ≤ 0.4V - ensuring reliable, rail-to-rail-compatible communication with +1.8V-core MCUs without level shifters.
What analog input configurations does the MAX1291AEEI+ support?
The MAX1291AEEI+ supports four software-selectable analog input modes via its control byte: single-ended unipolar (0V to +2.5V), single-ended bipolar (-1.25V to +1.25V), pseudo-differential unipolar, and pseudo-differential bipolar. In single-ended mode, it accepts 8 independent channels (CH0–CH7); in pseudo-differential mode, it measures voltage differences across four channel pairs (CH0/CH1, CH2/CH3, etc.), with COM serving as the common reference.
MAX1291AEEI+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Tube
- Product Status:
- Active
- Number of Bits:
- -
- Sampling Rate (Per Second):
- -
- Number of Inputs:
- -
- Input Type:
- -
- Data Interface:
- -
- Configuration:
- -
- Ratio - S/H:ADC:
- -
- Number of A/D Converters:
- -
- Architecture:
- -
- Reference Type:
- -
- Voltage - Supply, Analog:
- -
- Voltage - Supply, Digital:
- -
- Features:
- -
- Operating Temperature:
- -
- Supplier Device Package:
- -
- Mounting Type:
- -
- Grade:
- -
- Qualification:
- -
MAX1291AEEI+ FAQ
1.How can I place an order for MAX1291AEEI+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX1291AEEI+ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX1291AEEI+ reliable?
The price and inventory of MAX1291AEEI+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX1291AEEI+ is usually 5 days.
3.What payment methods are accepted for MAX1291AEEI+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX1291AEEI+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX1291AEEI+?
MAX1291AEEI+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX1291AEEI+ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX1291AEEI+?
For technical support, including MAX1291AEEI+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX1291AEEI+ requirements.
6.How does Aetrix verify that MAX1291AEEI+ is sourced from the original manufacturer or authorized distributors?
All MAX1291AEEI+ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX1291AEEI+ meets industry standards.
7.What is the process for return or replacement of MAX1291AEEI+?
All MAX1291AEEI+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX1291AEEI+, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX1291AEEI+ part is unused and in its original packaging.
Return procedure for MAX1291AEEI+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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