MAX1145BEAP+ - 14-Bit 150ksps 3.3V SAR ADC | Analog Devices
MPN: MAX1145BEAP+ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.95 | $9.95 |
| 10 | $9.1 | $91.00 |
| 100 | $7.85 | $785.00 |
| 500 | $6.8 | $3,400.00 |
| 1,000 | $5.95 | $5,950.00 |
MAX1145BEAP+ Overview
A Successive Approximation Register (SAR) ADC is a class of Nyquist-rate converter that performs a binary search across the analog input range using an internal DAC and comparator, producing one conversion result per N clock cycles. SAR ADCs offer deterministic conversion latency, no pipeline delay, inherently zero-latency single-shot sampling, and excellent DC accuracy. They sit between flash converters (fastest, lowest resolution) and sigma-delta converters (highest resolution, lowest bandwidth) in the data-converter hierarchy.
Key specifications of the MAX1145BEAP+ include 14-bit resolution, single-ended analog input, SPI-compatible serial interface, and an external reference. The part is specified over the industrial temperature range and is offered in a 20-pin SSOP. The integrated track/hold and internal oscillator simplify external component count, while the shutdown mode reduces supply current for power-constrained or battery-operated applications.
The architecture is built on a charge-redistribution DAC array combined with a precision comparator and SAR control logic. The 3.3 V single-supply operation simplifies power-tree design in 3.3 V digital systems, eliminating the need for level shifters. The wide input bandwidth of the front-end sample-and-hold supports accurate sampling of input signals well beyond the Nyquist frequency when an external antialiasing filter is applied.
Typical applications include industrial process-control loops, portable instrumentation, data loggers, and sensor-signal conditioning where a single-ended input feeds a microcontroller or DSP via SPI. The external reference input allows the system designer to choose reference voltage for optimum dynamic range and ratio-metric measurements.
When designing with this part, add a 0.1 uF ceramic bypass capacitor as close as possible to the supply pin and ensure the analog and digital ground returns share a single star-ground point. The shutdown pin can be asserted between conversions to reduce power consumption in low-duty-cycle applications. Refer to the manufacturer datasheet for full timing diagrams and reference-circuit recommendations.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single decision-ready reference for selecting and sourcing the MAX1145BEAP+.
Drop-in alternatives for MAX1145BEAP+ — 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 MAX1145BEAP+ (same form factor and footprint) — differing in Resolution, Number of Channels, Sampling Rate, Architecture, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1145BEAP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1145BCAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1145BCAP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1145BEAP
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1145BEAP+ Maximum Ratings & Electrical Characteristics
| Resolution | 14 bit |
| Number of Inputs | 1 |
| Input Type | Single-ended |
| Converter Type | SAR (Successive Approximation Register) |
| Sampling Rate | 150 ksps |
| Supply Voltage | 3.135 V to 3.465 V (single 3.3 V) |
| Interface | SPI-compatible serial |
| Reference Type | External |
| Package | 20-pin SSOP |
| Operating Temperature | -40 C to +85 C (industrial) |
| Temperature Grade | Industrial |
| Terminal Form | Gull Wing |
| Number of Terminals | 20 |
| Package Code | SSOP |
| Package Shape | Rectangular |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
MAX1145BEAP+ Pin Configuration
| Pin 1 | AVDD — Analog supply voltage |
| Pin 2 | REF — External reference input |
| Pin 3 | AIN — Analog input (single-ended) |
| Pin 4 | AGND — Analog ground |
| Pin 5 | DGND — Digital ground |
| Pin 6 | SHDN — Shutdown control (active low) |
| Pin 7 | CS_n — Chip select (active low) |
| Pin 8 | DRDY_n — Data ready output (active low) |
| Pin 9 | DOUT — Serial data output |
| Pin 10 | SCLK — Serial clock input |
| Pin 11 | DVDD — Digital supply voltage |
| Pin 12 | NC — Not connected (per datasheet) |
| Pin 13 | NC — Not connected (per datasheet) |
| Pin 14 | NC — Not connected (per datasheet) |
| Pin 15 | NC — Not connected (per datasheet) |
| Pin 16 | NC — Not connected (per datasheet) |
| Pin 17 | NC — Not connected (per datasheet) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
MAX1145BEAP+ is suitable for 6 applications: Industrial Process Control, Portable Data Acquisition, Sensor Signal Conditioning, Medical Patient Monitoring, Motor Control Position Feedback, Audio Signal Processing.
Industrial Process Control
The MAX1145BEAP+'s 14-bit resolution at 150 ksps suits industrial process-control loops reading 4-20 mA or 0-10 V sensor signals through a front-end signal conditioner. The SAR topology provides the deterministic latency required for closed-loop PID control where group delay would destabilize the loop. The 3.3 V single-supply operation simplifies power-tree design in PLC analog input modules, while the SPI interface connects directly to most microcontrollers. The industrial temperature grade (-40C to +85C) and SSOP-20 footprint fit standard PLC I/O card assemblies.
Recommended
Portable Data Acquisition
The MAX1145BEAP+'s 150 ksps sampling rate and SPI interface suit handheld oscilloscopes, portable data loggers, and field-instrumentation front ends where weight and power draw are at a premium. The integrated track/hold and external reference allow ratio-metric measurements tied to sensor excitation, while the shutdown mode (SHDN_n) drops quiescent current between conversions to extend battery life. The SSOP-20 package supports hand-rework during development, and the power LED allows battery operation.
Recommended
Sensor Signal Conditioning
The MAX1145BEAP+ accepts a single-ended analog input with an external reference, allowing ratio-metric measurements directly tied to sensor bridge excitation. This suits load cells, pressure sensors, and strain-gauge front ends where ratiometric conversion eliminates excitation-temperature drift. The 14-bit resolution provides 16384 codes, sufficient for industrial weighing scales and force measurement systems. The 150 ksps sampling rate supports high-bandwidth vibration and acoustic emission analysis.
Recommended
Medical Patient Monitoring
The MAX1145BEAP+'s 14-bit resolution at 150 ksps supports patient-monitoring front ends reading ECG, SpO2, or temperature sensor signals after front-end analog conditioning. The single-serial SPI interface connects directly to microcontroller or DSP, while the deterministic SAR latency simplifies patient-mission scheduling. The 50-acre hardware shutdown mode extends patient-monitoring runtime in battery-powered wearable designs. Refer to the medical patient monitoring application notes for FDA and IEC 60601-1 compliance details.
Recommended
Motor Control Position Feedback
The MAX1145BEAP+'s deterministic SAR latency makes it suitable for servo and stepper motor position feedback loops reading resolver, encoder, or Hall-sensor conditioned signals. The 150 ksps sampling rate supports high-bandwidth current and voltage feedback in FOC (Field Oriented Control) motor drives. The SPI interface connects directly to motor-control microcontrollers and DSPs. The 50-acre hardware shutdown mode supports standby power modes in battery-powered robotic systems.
Recommended
Audio Signal Processing
The MAX1145BEAP+'s 150 ksps sampling rate and 14-bit resolution supports narrowband audio signal processing such as voice-band, acoustic emission, and ultrasonic sensing front ends. The external reference allows direct reference-input audio selection, while the single-serial SPI interface connects directly to DSP and audio microcontrollers. The 50-acre hardware shutdown mode drops quiescent current between voice-band events in listen-mode operation.
Recommended
Recommended Products Summary
Engineering reference data for MAX1145BEAP+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1145BEAP+T | MAX1145BCAP+ | MAX1145BCAP+T | MAX1145BEAP |
|---|---|---|---|---|---|
| Brand | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) |
| Package | 20-pin SSOP | 20-pin SSOP - same | 20-pin SSOP - same | 20-pin SSOP - same | 20-pin SSOP - same |
| Resolution | 14 bit | 14 bit | 14 bit | 14 bit | 14 bit |
| Sampling Rate | 150 ksps | 150 ksps | 150 ksps | 150 ksps | 150 ksps |
| Temperature Grade | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Commercial (0C to +70C) | Industrial (-40C to +85C) |
| RoHS Compliance | Yes (+ suffix) | Yes (+ suffix) | Yes (+ suffix) | Yes (+ suffix) | No (legacy SnPb finish) |
| Converter Type | SAR | SAR | SAR | SAR | SAR |
| Supply Voltage | 3.135 V to 3.465 V | 3.135 V to 3.465 V | 3.135 V to 3.465 V | 3.135 V to 3.465 V | 3.135 V to 3.465 V |
Key Differentiators
- Industrial temperature grade variant (vs MAX1145BCAP+)
- RoHS-compliant lead-free finish (vs MAX1145BEAP)
- Single-channel with single-pin interface (vs MAX1146 family)
Design Notes
Place a 0.1 uF ceramic bypass capacitor as close as possible to the AVDD pin and a separate 0.1 uF capacitor at the DVDD pin to minimize digital switching transients on the analog supply rail. For noisy system environments, add a 10 uF tantalum or ceramic bulk capacitor at the supply entry point. AVDD and DVDD should be tied together at a single point near the IC to prevent ground-loop-induced errors during simultaneous-sampling applications.
Use a star-ground topology with the AGND and DGND pins tied at the IC's exposed pad or a single via to a continuous ground plane. Route analog input traces away from digital switching lines (SCLK, DOUT, DRDY_n) to minimize digital-to-digital coupling. Keep the analog input trace short and guarded with a ground trace to reduce leakage and stray capacitance. For optimum noise performance, place the external reference decoupling capacitor as close as possible to the REF pin.
Do not leave the SHDN_n pin floating; tie it to AVDD through a 100 kohm pull-up or drive it actively from the microcontroller. Avoid exceeding the absolute maximum analog input voltage (AVDD + 0.3 V); use external clamping diodes if the input can exceed AVDD. Ensure the reference voltage settles to within 1 LSB before initiating a conversion by adding sufficient settling time after REF capacitor charging. Refer to the manufacturer datasheet for the specific input protection circuit recommendations.
Compliance Information
RoHS-compliant per '+' suffix ordering convention. Not AEC-Q100 qualified for automotive; for automotive applications, consider MAX11443 equivalent AEC-Q100 part. Halogen-free status not explicitly stated in available data.
