My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX145BCUA+
- Part No.:
- MAX145BCUA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX145BCUA+.pdf
- Description:
- IC ADC 12BIT 108KSPS 8-UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:3,505
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX145BCUA+ from Maxim Integrated is a 12-bit, pseudo-differential-input successive-approximation ADC with 108ksps sampling rate, single +2.7V to +5.25V supply operation, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface. It features internal track-and-hold, automatic power-down (0.2µA), 2.5µs wake-up, and operates in an 8-pin µMAX package. It is used in isolated data acquisition systems requiring low-power, high-precision analog digitization.
For engineers reviewing the MAX145BCUA+ datasheet, MAX145BCUA+ pinout, MAX145BCUA+ application, or MAX145BCUA+ equivalent, this page delivers verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternative parts with documented differences, and supply-chain support details specific to OEM and industrial embedded use cases.
Technical Context
The MAX145BCUA+ implements a SAR architecture with integrated track-and-hold, where sampling occurs on CH+ relative to a stable CH− reference node. Its pseudo-differential input requires CH− to remain within ±0.5LSB of GND during conversion-achieved via 0.1µF bypassing-enabling rejection of common-mode noise while retaining single-ended signal routing simplicity.
It supports two clock modes: external (100kHz–2.17MHz SCLK) for deterministic timing and maximum throughput, and internal (laser-trimmed ~2MHz oscillator) for flexible host-controlled readout at any SCLK ≤5MHz. Conversion time is fixed at 7.4µs (16 clocks), and data output follows MSB-first 16-bit format with channel ID and EOC bit.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 12-bit - delivers 1 LSB = VREF/4096 quantization step; enables 0.024% full-scale precision with 2.5V reference. |
| Sampling Rate | 108ksps - supports Nyquist-limited bandwidth up to 54kHz; sufficient for vibration monitoring and sensor signal capture. |
| INL (Max) | ±1 LSB - ensures monotonicity and <0.025% end-point linearity error across full temperature range (0°C to +70°C). |
| Power (108ksps) | 0.9mA at +3V - equates to 2.7mW, enabling >100hr battery life in 100µA-average-power portable loggers. |
| Power-Down Current | 0.2µA - reduces quiescent draw by 4500× vs active mode; critical for wake-on-event architectures. |
| Full-Power BW | 1MHz - allows accurate digitization of fast transients (e.g., motor current spikes) without aliasing if anti-alias filtered. |
| SPI Compatibility | CPOL=0, CPHA=0 - directly interfaces with standard microcontroller SPI peripherals without glue logic or level shifters. |
Pinout & Package
MAX145BCUA+ is housed in an 8-pin µMAX package (U8-1 code), 3mm × 3mm body, 0.5mm lead pitch, exposed pad for thermal enhancement. Pinout is identical to MAX144 series but configured for pseudo-differential input operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD (Pin 1) | Positive supply input | Accepts +2.7V to +5.25V; powers analog core, digital logic, and internal reference buffer; requires local 0.1µF decoupling. |
| CH0 (CH+) (Pin 2) | Pseudo-differential positive input | Analog signal input node sampled during conversion; referenced to CH−; must drive ≤1kΩ source impedance for full AC performance. |
| CH1 (CH−) (Pin 3) | Pseudo-differential negative reference | Stable return path for CH+; must be held within ±0.5LSB of GND using 0.1µF capacitor to GND to prevent conversion error. |
| GND (Pin 4) | Analog and digital ground | Single ground plane required; separates noise-sensitive analog section from digital switching; connects to system AGND. |
| REF (Pin 5) | External reference voltage input | Sets full-scale range (0 to VREF); requires ≥18kΩ DC input resistance and ≤10Ω source impedance; bypassed with 0.1µF ceramic. |
| CS/SHDN (Pin 6) | Active-low chip select / active-high shutdown | Pulling high disables DOUT (high-Z) and cuts supply current to 0.2µA; falling edge initiates conversion and wake-up (2.5µs). |
| DOUT (Pin 7) | Serial data output | 3-wire interface output; MSB-first 16-bit frame (3 leading 1s + CHID + 12 data bits); transitions on SCLK falling edge. |
| SCLK (Pin 8) | Serial clock input | Controls data timing and selects clock mode: high at CS/SHDN fall → internal clock; low → external clock (100kHz–2.17MHz). |
Key Features
| Feature | Design Value |
|---|---|
| Pseudo-differential input architecture | Enables common-mode noise rejection in noisy industrial environments while avoiding dual-channel ADC complexity and cost. |
| Automatic power-down with 2.5µs wake-up | Supports burst-sampling strategies in energy-constrained nodes-e.g., wireless sensor networks-without sacrificing latency. |
| Internal track-and-hold with 7.4µs conversion | Eliminates need for external sample-hold circuitry; acquisition time (tACQ = 2.5µs typical) is fully specified and repeatable. |
| SPI/QSPI/MICROWIRE compatibility | Integrates seamlessly into existing microcontroller firmware stacks using standard peripheral drivers-no custom protocol development. |
| 8-pin µMAX package (3mm × 3mm) | Reduces PCB area by >60% vs. SOIC-8; compatible with automated optical inspection and high-density layout requirements. |
Applications
| Battery-Powered Data Loggers | Isolated Industrial Sensors |
|---|---|
|
Use Scenario: Continuous voltage/current measurement in remote environmental monitors powered by coin-cell or Li-SOCl₂ batteries. IC Role / Device Role / Timing Role: Primary analog front-end ADC; performs triggered or periodic conversions with minimal host intervention. Use Value: 0.2µA shutdown current extends multi-year deployment life; 108ksps rate captures transient events like lightning-induced surges. |
Use Scenario: Digitizing 4–20mA loop signals in hazardous-area transmitters with galvanic isolation. IC Role / Device Role / Timing Role: Isolated-side ADC; receives conditioned analog inputs post-isolation barrier and outputs serial data to isolated UART. Use Value: Pseudo-differential input rejects common-mode noise induced across isolation gaps; 12-bit resolution meets SIL-2 diagnostic accuracy requirements. |
| Portable Medical Instrumentation | Process-Control Loop Monitoring |
|
Use Scenario: Analog signal acquisition in handheld ECG or pulse oximeter units with strict size and power constraints. IC Role / Device Role / Timing Role: Signal-chain digitizer; interfaces directly to op-amp buffers driving CH+/CH− inputs. Use Value: Internal T/H eliminates external hold capacitor; ±1 LSB INL ensures clinical-grade amplitude fidelity across 0°C to +70°C operating range. |
Use Scenario: Real-time monitoring of temperature, pressure, and flow sensors in PLC I/O modules. IC Role / Device Role / Timing Role: Multi-channel scan ADC; multiplexes between sensor inputs under microcontroller control via CS/SHDN toggling. Use Value: SPI compatibility allows daisy-chaining multiple MAX145BCUA+ devices on shared bus; 1MHz full-power BW supports fast-response thermocouple cold-junction compensation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 12-bit serial ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADS7816U | 8-pin SOIC only; no µMAX option; 100ksps max; 2.5V–5.5V supply; requires external reference. | Lacks pseudo-differential input-uses true single-ended channels; lower sampling rate limits high-speed transient capture. | Choose when board space is unconstrained and differential noise rejection is not required; verify REF stability margin. |
| AD7495ARMZ | 12-bit, 1MSPS SAR; 10-pin MSOP; 2.7V–5.25V; internal reference option; SPI-only (no QSPI/MICROWIRE). | Higher speed but higher power (1.5mA @ 1MSPS); no automatic shutdown; larger package increases layout footprint. | Prefer for high-throughput systems where 0.2µA shutdown is unnecessary and internal reference simplifies BOM. |
Compared with ADS7816U and AD7495ARMZ, MAX145BCUA+ uniquely balances ultra-low shutdown current, µMAX footprint, pseudo-differential flexibility, and multi-standard serial compatibility-making it optimal for space- and energy-constrained industrial and portable designs where noise immunity and long service life are prioritized over raw speed.
Availability
MAX145BCUA+ is available at Aetrix Electronics and suitable for battery-powered data loggers, isolated industrial sensors, and portable medical instrumentation requiring stable component supply across extended production lifecycles.
Supply support for MAX145BCUA+ 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) designs precision analog, mixed-signal, and power-management ICs for industrial, automotive, and communications applications.
The MAX144/MAX145 product line targets low-power, space-constrained data acquisition systems-delivering 12-bit accuracy with integrated T/H and serial interface in sub-3mm packages for portable and distributed sensing.
FAQ
What is the guaranteed INL specification for MAX145BCUA+ over its operating temperature range?
The MAX145BCUA+ has a guaranteed integral nonlinearity (INL) of ±1 LSB over its full operating temperature range of 0°C to +70°C. This value is specified in the Absolute Maximum Ratings table and confirmed in the Electrical Characteristics section under "Relative Accuracy (INL)" for the _B grade. It ensures monotonic behavior and predictable end-point error in closed-loop control and calibration-critical applications using the MAX145BCUA+.
Does MAX145BCUA+ support true differential input, or is it pseudo-differential only?
The MAX145BCUA+ supports pseudo-differential input only-not true differential. Its CH+ and CH− pins accept a single-ended signal on CH+ referenced to a stable CH− node (typically tied to GND via 0.1µF). CH− must remain within ±0.5LSB of GND during conversion; it does not actively sample the voltage difference between CH+ and CH−. This architecture is explicitly defined in the "Analog Inputs" section of the MAX145BCUA+ datasheet.
Can MAX145BCUA+ operate with an internal reference, or does it require an external reference?
The MAX145BCUA+ requires an external reference voltage applied to the REF pin-it does not include an internal reference. The device specifies minimum input resistance (18kΩ), maximum load current (250µA), and recommended 0.1µF bypass capacitance at REF. Reference voltage range is 0V to VDD + 50mV, with optimal performance at 2.5V. No internal reference option exists for the MAX145BCUA+.
What is the minimum acquisition time (tACQ) for MAX145BCUA+, and how is it affected by source impedance?
The MAX145BCUA+ has a typical acquisition time (tACQ) of 2.5µs, with a maximum of 7µs under worst-case conditions. It scales linearly with source impedance per tACQ = 9(RS + 9kΩ) × 16pF. For RS ≤ 1kΩ, tACQ remains near 2.5µs; above 1kΩ, acquisition time increases-e.g., RS = 10kΩ yields ~15µs tACQ. This relationship is derived from the input RC network and is documented in the "Track/Hold" section of the MAX145BCUA+ datasheet.
Is MAX145BCUA+ pin-compatible with MAX144 series devices, and what design changes are needed when substituting?
Yes, MAX145BCUA+ is pin-compatible with MAX144 series devices in the same µMAX package (U8-1), sharing identical pinout and footprint. However, substitution requires functional validation: MAX144 uses two single-ended channels (CH0, CH1), while MAX145 uses one pseudo-differential pair (CH+, CH−). Firmware must be updated to interpret CHID bit and manage CH− biasing; analog input routing must be revised to ensure CH− stability per MAX145BCUA+ specifications.
MAX145BCUA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Number of Bits:
- 12
- Sampling Rate (Per Second):
- 108k
- Number of Inputs:
- 1
- Input Type:
- Pseudo-Differential
- 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
- Voltage - Supply, Analog:
- 2.7V ~ 5.25V
- Voltage - Supply, Digital:
- 2.7V ~ 5.25V
- Features:
- -
- Operating Temperature:
- 0°C ~ 70°C
- Supplier Device Package:
- 8-uMAX/uSOP
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
MAX145BCUA+ FAQ
1.How can I place an order for MAX145BCUA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX145BCUA+ 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 MAX145BCUA+ reliable?
The price and inventory of MAX145BCUA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX145BCUA+ is usually 5 days.
3.What payment methods are accepted for MAX145BCUA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX145BCUA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX145BCUA+?
MAX145BCUA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX145BCUA+ 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 MAX145BCUA+?
For technical support, including MAX145BCUA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX145BCUA+ requirements.
6.How does Aetrix verify that MAX145BCUA+ is sourced from the original manufacturer or authorized distributors?
All MAX145BCUA+ 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 MAX145BCUA+ meets industry standards.
7.What is the process for return or replacement of MAX145BCUA+?
All MAX145BCUA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX145BCUA+, 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 MAX145BCUA+ part is unused and in its original packaging.
Return procedure for MAX145BCUA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX145BCUA+ Tags
-
ADC081C021CIMKX/NOPB
Texas Instruments
-
MCP3021A5T-E/OT
Microchip Technology
-
TLA2024IRUGR
Texas Instruments
-
MCP3221A5T-E/OT
Microchip Technology
-
MCP3221A5T-I/OT
Microchip Technology
-
MCP3221A4T-E/OT
Microchip Technology
-
MCP3221A6T-E/OT
Microchip Technology
-
MCP3221A0T-E/OT
Microchip Technology
-
MCP3221A1T-E/OT
Microchip Technology
-
ADC121S021CIMFX/NOPB
Texas Instruments
-
MCP3001-I/MS
Microchip Technology
-
MCP3001-I/SN
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
