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Analog Devices Inc./Maxim Integrated MAX149BCPP+
- Part No.:
- MAX149BCPP+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX149BCPP+.pdf
- Description:
- IC ADC 10BIT SAR 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,535
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Product details
Overview
MAX149BCPP+ from Maxim Integrated is a 10-bit, 8-channel serial analog-to-digital converter (ADC) with integrated track/hold, software-configurable unipolar/bipolar and single-ended/differential inputs, internal 2.5V reference, and SPI/QSPI/MICROWIRE-compatible 4-wire interface. It operates from +2.7V to +5.25V, achieves 133ksps sampling rate, and draws only 1.2mA at 3V - enabling high-precision data acquisition in battery-powered medical instruments and portable data loggers.
For engineers reviewing the MAX149BCPP+ datasheet, MAX149BCPP+ pinout, MAX149BCPP+ application, or MAX149BCPP+ 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 Maxim's official MAX149 datasheet Rev 5 (1/12).
Technical Context
The MAX149BCPP+ employs a successive-approximation register (SAR) architecture with an internal track/hold circuit that acquires input signals in ≤1.5μs and supports both internal clock (1.8MHz typical) and external clock (up to 2.0MHz) conversion modes. Its analog front-end allows flexible channel configuration: 8 single-ended or 4 pseudo-differential input pairs (CH0/CH1 through CH6/CH7), with COM referenced zero-code voltage.
Digital interfacing is handled via a 4-wire serial interface (CS, SCLK, DIN, DOUT) compatible with SPI (CPOL=0, CPHA=0), QSPI, and MICROWIRE protocols; SSTRB provides precise timing strobe for TMS320-family DSPs. The device integrates a reference-buffer amplifier with ±1.5% adjustment range and supports automatic power-down after conversion - reducing supply current to 1μA in full shutdown mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 10-bit SAR ADC - delivers 1024 discrete output codes for precision measurement of analog sensor or signal sources. |
| Sampling Rate | 133ksps maximum - enables accurate digitization of signals up to ~66kHz (Nyquist-limited) without aliasing when paired with anti-alias filtering. |
| INL (Integral Nonlinearity) | ±1 LSB (MAX149B grade) - ensures monotonicity and <0.1% full-scale error after calibration, critical for closed-loop control accuracy. |
| Supply Voltage Range | +2.7V to +5.25V - supports direct operation from Li-ion batteries (3.0–4.2V) or 3.3V/5V system rails without LDO overhead. |
| Reference | Internal 2.500V ±0.030V (±30ppm/°C TC) - eliminates need for external reference IC, simplifying BOM and layout for portable instrumentation. |
| Power Consumption | 1.2mA @133ksps / 54µA @1ksps / 1µA shutdown - extends battery life in intermittent-sampling applications like pen digitizers or remote sensors. |
| Interface Compatibility | SPI/QSPI/MICROWIRE/TMS320 - interoperates directly with common microcontrollers (e.g., STM32, MSP430) and TI C2000 DSPs without level shifters or glue logic. |
Pinout & Package
MAX149BCPP+ is housed in a 20-pin plastic dual in-line package (PDIP) with 0.300-inch body width and through-hole mounting. Pin assignments are validated per Maxim's official pin description table (Rev 5, p.7) and match the MAX149B-grade specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CH0–CH7 (Pins 1–8) | Analog input channels | Software-selectable as 8 single-ended or 4 differential pairs; each supports ±VREF/2 bipolar or 0–VREF unipolar ranges. |
| COM (Pin 9) | Analog ground reference | Sets zero-code voltage in single-ended mode; must remain stable to ±0.5 LSB to avoid INL degradation. |
| SHDN (Pin 10) | Three-level shutdown control | Pull low → full shutdown (1µA); leave floating → external compensation mode; pull high → internal compensation mode. |
| VREF (Pin 11) | Reference buffer output / ADC reference input | Delivers 2.500V ±0.030V (MAX149 only); bypassed with 4.7µF capacitor for stability in internal reference mode. |
| REFADJ (Pin 12) | Reference buffer gain adjust | Enables ±1.5% VREF tuning; tie to VDD to disable internal buffer when using external reference (MAX148 only). |
| AGND / DGND (Pins 13–14) | Analog and digital ground returns | Must be separated on PCB and joined at single point near VDD decoupling to minimize noise coupling into ADC core. |
| DOUT / SSTRB (Pins 15–16) | Serial data output / conversion strobe | DOUT clocks MSB-first on SCLK falling edge; SSTRB pulses high before MSB in external clock mode or asserts low during conversion in internal clock mode. |
| DIN / CS / SCLK / VDD (Pins 17–20) | Serial command input / chip select / clock / supply | Standard SPI control signals; CS must be held low during full 15-clock conversion cycle; VDD requires 0.1µF + 4.7µF local decoupling. |
Key Features
| Feature | Design Value |
|---|---|
| 8-channel multiplexer with software-configurable input mode | Reduces external analog switching components and enables dynamic reconfiguration of sensor inputs in firmware without hardware change. |
| Internal 2.5V reference with ±1.5% adjustability | Eliminates external reference IC and trim pot, cutting BOM cost and board area while maintaining ±0.1% full-scale accuracy over temperature. |
| 1.5μs track/hold acquisition time | Supports accurate sampling of fast transients up to 2.25MHz small-signal bandwidth, enabling undersampling of RF or vibration signals. |
| Auto power-down after conversion | Reduces average supply current by >99% between samples - essential for multi-day battery operation in wireless sensor nodes. |
| SPI/QSPI/MICROWIRE/TMS320 compatibility | Interoperates with industry-standard controllers without custom driver development or protocol translation logic. |
Applications
| Portable Data Logging | Medical Instrumentation |
|---|---|
Use Scenario: Battery-powered environmental sensor node logging temperature, humidity, and pressure every 10 seconds. IC Role / Device Role / Timing Role: 10-bit ADC digitizing conditioned analog outputs from multiple sensors via software-reconfigurable MUX and internal reference. Use Value: 54µA active current at 1ksps and 1µA shutdown extend CR2032 battery life beyond 2 years; internal reference ensures consistent calibration across units. |
Use Scenario: Handheld ECG monitor acquiring lead-II differential signals with low-noise front-end. IC Role / Device Role / Timing Role: Pseudo-differential ADC sampling CH0/CH1 pair at 133ksps with internal 2.5V reference and 1.5μs acquisition for artifact-free waveform capture. Use Value: ±1 LSB INL and 66dB SINAD meet AAMI EC11 clinical accuracy requirements; PDIP package simplifies prototyping and regulatory test fixture design. |
| Battery-Powered Instruments | Process Control Sensors |
Use Scenario: Portable multimeter measuring DC voltage, current, and resistance with autoranging analog front-end. IC Role / Device Role / Timing Role: Configurable unipolar/bipolar 10-bit ADC accepting ±2.5V differential inputs from precision op-amp stages. Use Value: Software-selectable input polarity and range eliminate need for external relays or gain-switching amplifiers, reducing size and power. |
Use Scenario: Industrial temperature transmitter converting RTD or thermocouple output to digital for 4–20mA loop or Modbus RTU. IC Role / Device Role / Timing Role: High-accuracy ADC with COM-referenced single-ended inputs digitizing conditioned bridge outputs in noisy factory environments. Use Value: 70dB SFDR and -75dB channel crosstalk suppress interference from adjacent 50/60Hz AC lines and motor drives. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 10-bit, serial, low-power ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX148BCPP+ | No internal reference; requires external 2.5V source at VREF pin; same INL (±1 LSB), package, and interface. | Suitable where system already provides precision reference or needs adjustable reference voltage beyond ±1.5%. | Select MAX148BCPP+ when reference sharing across multiple ICs reduces cost or when tighter VREF TC (<±10ppm/°C) is required via external IC. |
| ADS7822U | 12-bit resolution, 200ksps, SPI-only interface, no internal reference, 6-pin SOT-23 package. | Better resolution but lacks MUX, bipolar mode, and internal reference - requires external op-amps and reference for multi-channel bipolar sensing. | Choose ADS7822U only for single-channel, high-resolution, space-constrained applications where 12-bit precision outweighs missing features. |
Compared with MAX148BCPP+, the MAX149BCPP+ saves board space and BOM cost by integrating the reference, while ADS7822U trades channel count and flexibility for higher resolution in ultra-compact form - making MAX149BCPP+ optimal for multi-sensor, battery-operated systems needing calibrated accuracy without external support components.
Availability
MAX149BCPP+ is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered instruments requiring stable component supply, long-term lifecycle support, and RoHS-compliant through-hole packaging.
Supply support for MAX149BCPP+ 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 MAX148/MAX149 product line was designed for low-power, multi-channel data acquisition in portable and embedded systems - emphasizing integration of MUX, track/hold, reference, and digital interface in a single 20-pin package.
FAQ
What is the internal reference voltage tolerance and temperature coefficient of the MAX149BCPP+?
The MAX149BCPP+ provides a nominal 2.500V internal reference with ±0.030V (±1.2%) initial tolerance at +25°C and a temperature coefficient of ±30ppm/°C over the 0°C to +70°C operating range. This is specified in the Electrical Characteristics table (p.3) of the MAX149 datasheet Rev 5 and applies directly to the MAX149BCPP+ grade. The reference remains stable under load currents up to 0.2mA and is bypassed with a 4.7µF capacitor for optimal performance.
Does the MAX149BCPP+ support differential input mode, and how is it configured?
Yes, the MAX149BCPP+ supports pseudo-differential input mode using four channel pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7. Configuration is done via the 3-bit SEL field (bits 6–4) and SGL/DIF bit (bit 2) in the 8-bit control byte. When SGL/DIF = 0, the selected pair is applied to IN+ and IN− of the internal comparator. The MAX149BCPP+ does not perform true differential sampling but measures |IN+ − IN−| with IN− held stable to ±0.5 LSB relative to AGND.
What is the minimum acquisition time required for accurate conversions on the MAX149BCPP+?
The MAX149BCPP+ specifies a maximum acquisition time (tACQ) of 1.5μs, which is also the minimum time required for full settling of the internal track/hold capacitor. This value assumes source impedance ≤4kΩ; higher impedances increase tACQ per the formula tACQ = 7 × (RS + 9kΩ) × 16pF. For reliable 10-bit accuracy, the analog input must remain stable within this window - verified in the Timing Characteristics table (p.5) and Detailed Description section (p.8) of the MAX149 datasheet.
How does the SHDN pin function on the MAX149BCPP+, and what are its three states?
The SHDN pin on the MAX149BCPP+ operates in three distinct states: pulled low → full power-down (1µA supply current); left unconnected → reference-buffer amplifier in external compensation mode (requires 4.7µF at VREF); pulled high → internal compensation mode (enables 0µF bypass). These behaviors are explicitly defined in the Pin Description table (p.7) and confirmed across the General Description and Detailed Description sections of the MAX149 datasheet Rev 5.
Can the MAX149BCPP+ interface directly with a TMS320C28x DSP, and what signal is used for synchronization?
Yes, the MAX149BCPP+ interfaces directly with TMS320C28x DSPs using its SSTRB (serial-strobe) output. In internal clock mode, SSTRB goes low at conversion start and high upon completion - providing a clean hardware trigger for DMA or interrupt-driven data capture. In external clock mode, SSTRB pulses high for one SCLK period before the MSB appears on DOUT. This timing is fully compatible with the TMS320 serial port and requires no additional logic, as stated in the General Description and Figure 10 of the MAX149 datasheet.
MAX149BCPP+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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-PDIP
- Mounting Type:
- Through Hole
- Grade:
- -
- Qualification:
- -
MAX149BCPP+ FAQ
1.How can I place an order for MAX149BCPP+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX149BCPP+ 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 MAX149BCPP+ reliable?
The price and inventory of MAX149BCPP+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX149BCPP+ is usually 5 days.
3.What payment methods are accepted for MAX149BCPP+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX149BCPP+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX149BCPP+?
MAX149BCPP+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX149BCPP+ 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 MAX149BCPP+?
For technical support, including MAX149BCPP+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX149BCPP+ requirements.
6.How does Aetrix verify that MAX149BCPP+ is sourced from the original manufacturer or authorized distributors?
All MAX149BCPP+ 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 MAX149BCPP+ meets industry standards.
7.What is the process for return or replacement of MAX149BCPP+?
All MAX149BCPP+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX149BCPP+, 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 MAX149BCPP+ part is unused and in its original packaging.
Return procedure for MAX149BCPP+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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