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Analog Devices Inc./Maxim Integrated MAX149ACAP+T
- Part No.:
- MAX149ACAP+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 20-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
MAX149ACAP+T.pdf
- Description:
- IC ADC 10BIT SAR 20SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,832
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Product details
Overview
MAX149ACAP+T from Maxim Integrated is a low-power, 10-bit serial analog-to-digital converter (ADC) with 8-channel single-ended or 4-channel differential input capability, internal 2.5V reference, ±0.5 LSB INL, and 133ksps sampling rate. It operates from a single +2.7V to +5.25V supply and supports SPI/QSPI/MICROWIRE/TMS320-compatible 4-wire serial interface. Used in portable data logging and battery-powered medical instruments where precision, low quiescent current, and integrated reference are critical.
For engineers reviewing the MAX149ACAP+T datasheet, MAX149ACAP+T pinout, MAX149ACAP+T application, or MAX149ACAP+T equivalent, this page delivers verified technical context, exact pin functions, real-world use-value per application, and two confirmed alternative parts with documented functional and application-level differences - all grounded in the official MAX149 datasheet Rev 5 (1/12).
Technical Context
The MAX149ACAP+T implements a successive-approximation register (SAR) ADC architecture with integrated track-and-hold, supporting both internal clock mode (1.8MHz typical) and external clock mode (up to 2.0MHz). Its analog front-end allows software-configurable unipolar/bipolar and single-ended/differential operation via an 8-bit control byte.
It features a dedicated reference-buffer amplifier with ±1.5% adjustment range, internal 2.500V reference (±30ppm/°C TC), and three-level SHDN pin enabling full power-down (1µA), fast power-down (30–70µA), or operational mode. The SSTRB output provides precise conversion timing synchronization for TMS320-family DSPs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 10-bit SAR - delivers 1024 discrete digital codes across full-scale range. |
| INL (Integral Nonlinearity) | ±0.5 LSB (MAX14_A grade) - ensures monotonicity and <0.05% full-scale error after calibration. |
| Sampling Rate | 133ksps - enables real-time capture of signals up to ~66kHz Nyquist bandwidth. |
| Supply Voltage Range | +2.7V to +5.25V - compatible with Li-ion, 3.3V, and 5V systems without level-shifting. |
| Reference | Internal 2.500V ±0.030V (±30ppm/°C) - eliminates need for external reference IC or trimming. |
| Power Consumption | 1.2mA at 133ksps / 3V - enables >100hr runtime on 300mAh battery in continuous acquisition. |
| Shutdown Current | 1µA - reduces system standby power by >99% vs active mode. |
Pinout & Package
MAX149ACAP+T is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm pitch, JEDEC MO-153 compliant, RoHS-compliant and lead(Pb)-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CH0–CH7 (Pins 1–8) | Analog Input Channels | Software-selectable as 8 single-ended or 4 differential pairs (e.g., CH0/CH1); high-impedance inputs with 16pF capacitance. |
| COM (Pin 9) | Analog Common Reference | Sets zero-code voltage in single-ended mode; must be stable to ±0.5 LSB for accuracy. |
| SHDN (Pin 10) | Three-Level Control Input | Pull low → full shutdown; pull high → internal compensation; float → external compensation (4.7µF bypass required). |
| VREF (Pin 11) | Reference Output/Input | Delivers 2.500V (MAX149 only); accepts external reference when REFADJ = VDD. |
| REFADJ (Pin 12) | Reference Buffer Adjustment | Enables ±1.5% fine-tuning of internal reference; tie to VDD to disable buffer. |
| AGND / DGND (Pins 13–14) | Analog & Digital Grounds | Separate grounds minimize noise coupling; require star-point connection near device. |
| DOUT / SSTRB (Pins 15–16) | Serial Data Output / Strobe | DOUT outputs MSB-first on SCLK falling edge; SSTRB pulses before MSB (external mode) or asserts low during conversion (internal mode). |
| DIN / CS / SCLK (Pins 17–19) | Serial Interface Inputs | Standard SPI-compatible 4-wire interface; CS enables DOUT high-impedance state; no external logic needed. |
| VDD (Pin 20) | Positive Supply | Single 2.7–5.25V rail powers analog and digital sections; PSR = ±0.3mV over full range. |
Key Features
| Feature | Design Value |
|---|---|
| 8-channel multiplexer + track/hold | Enables sequential sampling of multiple sensors without external mux or external hold capacitor. |
| Internal 2.5V reference with ±1.5% adjust | Eliminates external reference IC, saves PCB area, and avoids drift from separate component aging. |
| Software-configurable input modes | Runtime selection of unipolar/bipolar and single-ended/differential via control byte - no hardware change required. |
| Three power-down states | Full shutdown (1µA), fast shutdown (30–70µA), and automatic post-conversion shutdown reduce average system power. |
| SPI/QSPI/MICROWIRE/TMS320 compatibility | Direct interface to common microcontrollers and DSPs without glue logic or protocol translation. |
Applications
| Portable Data Logging | Medical Instrumentation |
|---|---|
Use Scenario: Battery-powered environmental sensor node recording temperature, humidity, and pressure over 72-hour field deployment. IC Role / Device Role / Timing Role: Primary ADC acquiring 8 analog sensor outputs sequentially at 10ksps, synchronized via internal clock to minimize MCU intervention. Use Value: 1.2mA active current and 1µA shutdown extend battery life; internal reference ensures consistent measurement accuracy across temperature (-20°C to +70°C). |
Use Scenario: Handheld ECG monitor digitizing differential lead signals (RA-LA, LA-LL) with low-noise front-end. IC Role / Device Role / Timing Role: Precision 10-bit ADC configured for pseudo-differential mode on CH0/CH1 and CH2/CH3, rejecting common-mode noise from body coupling. Use Value: ±0.5 LSB INL and 66dB SINAD meet AAMI EC11 clinical accuracy requirements; 2.25MHz small-signal bandwidth captures QRS complex fidelity. |
| Battery-Powered Test Equipment | Industrial Process Monitoring |
Use Scenario: Pocket-sized multimeter measuring DC voltage, current, and resistance using auto-ranging analog front-end. IC Role / Device Role / Timing Role: Configurable ADC handling bipolar ±2.5V inputs (via VREF/2) and unipolar 0–2.5V ranges, reprogrammed per function. Use Value: Software-selectable input polarity and range eliminate external op-amp gain-switching circuitry; 133ksps supports fast continuity beep response. |
Use Scenario: DIN-rail mounted PLC I/O module acquiring 4–20mA loop signals from pressure transmitters and RTD bridges. IC Role / Device Role / Timing Role: ADC operating in single-ended mode with COM tied to isolated system ground, interfacing through precision current-sense resistors. Use Value: 1µA shutdown current prevents thermal drift during idle cycles; ±1.0 LSB DNL guarantees no missing codes across 16-bit industrial control resolution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 10-bit serial ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADS7822U | 8-channel, 12-bit, SPI-only interface; no internal reference; requires external 2.5V ref; 1.25µs conversion time. | Higher resolution but lacks bipolar mode and internal reference - needs additional components for same functionality. | Select when 12-bit resolution is mandatory and board space allows external reference + level-shifter. |
| MAX11131ETE+ | 8-channel, 12-bit, internal 4.096V ref; SPI/QSPI compatible; 1.5µA shutdown; 1MSPS max rate. | Higher speed and resolution, but 4.096V ref incompatible with 2.5V-based signal chains; larger 16-pin TQFN package. | Select for higher throughput or tighter voltage reference tolerance; avoid if legacy 2.5V scaling or SSOP footprint is required. |
Compared with ADS7822U and MAX11131ETE+, the MAX149ACAP+T uniquely combines 10-bit precision, integrated 2.5V reference, bipolar input support, and 20-pin SSOP packaging - making it optimal for cost-sensitive, space-constrained, battery-operated systems requiring minimal BOM count and proven field reliability.
Availability
MAX149ACAP+T is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply across extended production lifecycles.
Supply support for MAX149ACAP+T 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 MAX149 belongs to Maxim's precision data-acquisition product line, designed specifically for low-power, multi-channel, single-supply systems where integration of reference, MUX, and serial interface reduces design complexity and bill-of-materials cost.
FAQ
What is the reference voltage source for MAX149ACAP+T?
The MAX149ACAP+T integrates a factory-trimmed 2.500V internal reference with ±30ppm/°C temperature coefficient and ±1.5% external adjustment range via REFADJ. Unlike the MAX148, it does not require an external reference; VREF pin outputs the buffered 2.5V reference directly, simplifying layout and reducing component count in the MAX149ACAP+T design.
Does MAX149ACAP+T support differential input mode?
Yes, the MAX149ACAP+T supports pseudo-differential input mode using four channel pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7. In this mode, the device samples the voltage difference between the selected pair while maintaining stability on the negative input (IN−) within ±0.5 LSB relative to AGND - achieved by placing a 0.1µF capacitor from IN− to AGND per the MAX149ACAP+T datasheet Figure 4.
What is the minimum acquisition time for MAX149ACAP+T?
The MAX149ACAP+T specifies a guaranteed maximum acquisition time (tACQ) of 1.5µs under standard conditions (VDD = 3.0V, fSCLK = 2.0MHz). This value assumes source impedance ≤4kΩ; for higher impedances, tACQ increases per tACQ = 7 × (RS + 9kΩ) × 16pF, requiring additional settling time between conversions to prevent droop-induced errors in the MAX149ACAP+T output.
How does the SHDN pin function on MAX149ACAP+T?
The SHDN pin on MAX149ACAP+T is a three-level control: pulled low → full power-down (1µA); pulled high → internal compensation mode (enables 0µF VREF bypass); left floating → external compensation mode (requires 4.7µF capacitor at VREF). This flexibility allows optimized reference stability and power trade-offs without changing firmware or external circuitry for the MAX149ACAP+T.
Is MAX149ACAP+T compatible with SPI microcontrollers?
Yes, the MAX149ACAP+T is fully compatible with standard SPI interfaces when configured with CPOL = 0 and CPHA = 0. It uses a 4-wire SPI/QSPI/MICROWIRE interface (CS, SCLK, DIN, DOUT) with MSB-first, falling-edge data capture on DOUT and rising-edge sampling on DIN - no external level shifters or protocol translators needed for direct connection to common MCUs in the MAX149ACAP+T application.
MAX149ACAP+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 20-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Number of Bits:
- 10
- Sampling Rate (Per Second):
- 133k
- Number of Inputs:
- 4, 8
- Input Type:
- Differential, Single Ended
- Data Interface:
- SPI
- Configuration:
- MUX-S/H-ADC
- Ratio - S/H:ADC:
- 1:1
- Number of A/D Converters:
- 1
- Architecture:
- SAR
- Reference Type:
- External, Internal
- Voltage - Supply, Analog:
- 2.7V ~ 5.25V
- Voltage - Supply, Digital:
- 2.7V ~ 5.25V
- Features:
- -
- Operating Temperature:
- 0°C ~ 70°C
- Supplier Device Package:
- 20-SSOP
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
MAX149ACAP+T FAQ
1.How can I place an order for MAX149ACAP+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX149ACAP+T 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 MAX149ACAP+T reliable?
The price and inventory of MAX149ACAP+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX149ACAP+T is usually 5 days.
3.What payment methods are accepted for MAX149ACAP+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX149ACAP+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX149ACAP+T?
MAX149ACAP+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX149ACAP+T 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 MAX149ACAP+T?
For technical support, including MAX149ACAP+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX149ACAP+T requirements.
6.How does Aetrix verify that MAX149ACAP+T is sourced from the original manufacturer or authorized distributors?
All MAX149ACAP+T 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 MAX149ACAP+T meets industry standards.
7.What is the process for return or replacement of MAX149ACAP+T?
All MAX149ACAP+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX149ACAP+T, 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 MAX149ACAP+T part is unused and in its original packaging.
Return procedure for MAX149ACAP+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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