My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX146ACAP
- Part No.:
- MAX146ACAP
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 20-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
MAX146ACAP.pdf
- Description:
- IC ADC 12BIT SAR 20SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,455
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX146ACAP from Maxim Integrated is a 12-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 serial interface. It operates from a single +2.7V to +3.6V supply, consumes 1.2mA at 133ksps, and supports portable data logging and battery-powered medical instrumentation.
For engineers reviewing the MAX146ACAP datasheet, MAX146ACAP pinout, MAX146ACAP application, or MAX146ACAP equivalent, key selection considerations include its 20-pin SSOP package, ±0.5 LSB INL, 1.5µs acquisition time, internal reference accuracy (±0.2% initial, ±30ppm/°C drift), and shutdown current of 1µA - critical for low-power embedded sensing systems.
Technical Context
The MAX146ACAP uses successive-approximation (SAR) architecture with an integrated track/hold circuit that acquires input signals in 1.5µs and completes conversion in 6µs (133ksps) using either internal or external clocking. Its pseudo-differential sampling architecture supports eight single-ended or four differential input pairs (CH0/CH1 through CH6/CH7), with COM pin serving as zero-reference in single-ended mode.
Analog input range is software-selectable: 0V to VREF (unipolar) or ±VREF/2 (bipolar); VREF is internally generated at 2.500V ±0.2% (TYP) with ±1.5% adjustment via REFADJ. The device features three-level SHDN control (low = full shutdown, high = internal compensation, float = external compensation) and automatic power-down after conversion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 12-bit SAR ADC - delivers 1 LSB = 0.244mV (for 2.5V reference), enabling precise measurement of sub-millivolt sensor signals. |
| INL / DNL | ±0.5 LSB INL, ±0.8 LSB DNL - ensures monotonicity and <0.012% full-scale linearity error for calibration-critical applications like medical instrumentation. |
| Conversion Rate | 133ksps max (external 2MHz clock) - supports real-time sampling of audio-band and vibration signals without undersampling artifacts. |
| Supply Current | 1.2mA active (3V, 133ksps), 54µA at 1ksps, 1µA in power-down - enables >1-year battery life in 1ksps data loggers using coin cells. |
| Reference | Internal 2.500V ±0.2% (0°C to +70°C), ±30ppm/°C TC - eliminates need for external precision reference, reducing BOM count and layout area. |
| Input Configuration | 8-channel single-ended or 4-channel differential (software-selectable) - allows flexible sensor interfacing (e.g., thermocouples, bridge sensors, single-ended voltage outputs). |
| Serial Interface | SPI/QSPI/MICROWIRE/TMS320-compatible 4-wire interface - integrates directly with ARM Cortex-M, MSP430, and C2000 microcontrollers without level-shifting or glue logic. |
Pinout & Package
MAX146ACAP is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm pitch, 7.2mm × 5.3mm body size, and exposed pad for thermal enhancement. Pinout conforms to standard Maxim 20-pin ADC layout with dedicated analog/digital ground separation and reference buffer control.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CH0–CH7 (Pins 1–8) | Analog input channels | Eight multiplexed inputs supporting single-ended (vs. COM) or differential (CHx/CHy) sampling; input protection clamps to VDD/AGND (±0.3V). |
| COM (Pin 9) | Analog common reference | Zero-code reference in single-ended mode; must be stable to ±0.5 LSB (±0.3mV) - requires local 0.1µF bypass to AGND. |
| SHDN (Pin 10) | Three-level shutdown control | Pull low → full shutdown (1µA); pull high → internal compensation mode; float → external compensation mode (REFADJ active). |
| VREF (Pin 11) | Reference output/input | 2.500V nominal output (MAX146 only); accepts external reference when REFADJ = VDD; requires 4.7µF capacitor for internal compensation. |
| REFADJ (Pin 12) | Reference buffer adjustment | ±1.5% fine-tuning of VREF; tie to VDD to disable internal buffer for external reference use; requires 0.047µF bypass. |
| DOUT (Pin 15) | Serial data output | MSB-first, SCLK-falling-edge aligned; high-impedance when CS = high - enables bus sharing with other SPI peripherals. |
| SSTRB (Pin 16) | Serial strobe output | Signals conversion start/end: pulses high before MSB in external clock mode; goes low at conversion start, high at completion in internal clock mode. |
| DGND / AGND (Pins 13–14) | Digital/analog ground returns | Separate ground pins minimize digital noise coupling into analog path; require star grounding at single-point AGND/DGND connection. |
| SCLK / DIN / CS (Pins 17–19) | Serial interface control | Standard SPI timing (CPOL=0, CPHA=0); CS active-low enables interface; DIN latched on SCLK rising edge; SCLK duty cycle 40–60%. |
| VDD (Pin 20) | Positive supply | +2.7V to +3.6V single supply; powers analog core, digital interface, and reference buffer; requires 0.1µF + 4.7µF local decoupling. |
Key Features
| Feature | Design Value |
|---|---|
| Internal 2.5V reference with ±1.5% adjustability | Eliminates external reference IC and trim pot, reducing component count by ≥2 and PCB area by >15mm² in portable designs. |
| Software-configurable unipolar/bipolar and single-ended/differential inputs | One firmware build supports multiple sensor types (e.g., RTDs, strain gauges, thermistors) without hardware changes or board variants. |
| 1.5µs track/hold acquisition time | Enables accurate sampling of fast transients (e.g., ECG spikes, motor current surges) with source impedances up to 1kΩ without external buffering. |
| Three-level SHDN with auto-power-down capability | Reduces average current to <54µA at 1ksps, extending AA battery life to >5 years in intermittent-sampling IoT nodes. |
| SPI/QSPI/MICROWIRE/TMS320 compatibility | Direct interface to TI C2000 DSPs and legacy microcontrollers without protocol translation firmware or external logic. |
Applications
| Portable Data Logging | Medical Instrumentation |
|---|---|
Use Scenario: Battery-powered environmental sensor node recording temperature, humidity, and CO₂ every 10 seconds for 2+ years on two AA cells. IC Role / Device Role / Timing Role: Primary ADC digitizing analog outputs from low-power sensors; internal reference ensures consistent scaling across temperature and battery voltage sag. Use Value: 1µA shutdown current and 54µA 1ksps operation enable multi-year deployment without maintenance or battery replacement. | Use Scenario: Handheld ECG monitor acquiring lead-II signals at 1ksps with real-time QRS detection and Bluetooth LE transmission. IC Role / Device Role / Timing Role: Front-end ADC with programmable gain and bipolar input range for ±2.5mV ECG signals referenced to Wilson central terminal. Use Value: ±0.5 LSB INL and 73dB SINAD ensure diagnostic-grade waveform fidelity required for FDA Class II clearance. |
| Battery-Powered Instruments | Process Control Sensors |
Use Scenario: Field-deployable pH/ORP meter using glass electrode and temperature compensation, operating 6 months per charge on Li-ion cell. IC Role / Device Role / Timing Role: Precision ADC measuring high-impedance electrode output (≥100MΩ) with COM-referenced single-ended input and adjustable reference. Use Value: 1.5µs acquisition time and internal 2.5V reference eliminate need for external op-amp buffers and reference ICs, cutting BOM cost by 30%. | Use Scenario: Industrial 4–20mA loop-powered transmitter for pressure sensing in hazardous areas, requiring intrinsic safety compliance. IC Role / Device Role / Timing Role: Isolated ADC digitizing conditioned bridge output; differential input rejects common-mode noise from long sensor cables. Use Value: Channel-to-channel offset matching <±0.25 LSB ensures consistent calibration across multi-channel transmitters without per-channel trimming. |
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 |
|---|---|---|---|
| ADS7822U | 12-bit, 200ksps, SPI-only interface, no internal reference, requires external 2.5V ref; 8-pin SOIC package. | Lacks bipolar input support and software-configurable modes; suited for fixed unipolar sensor interfaces only. | Select when board space is constrained (<5mm²) and system already provides precision reference; avoid if bipolar or differential operation needed. |
| MAX11131AUT+ | 12-bit, 500ksps, internal reference (2.048V), SPI/QSPI compatible, 10-pin µDFN; lower power (350µA @ 500ksps). | Smaller package and higher speed but no SHDN pin - power management requires software-controlled sleep mode. | Prefer for ultra-compact, high-throughput designs where reference voltage tolerance (2.048V vs. 2.500V) and absence of hardware shutdown are acceptable trade-offs. |
Compared with ADS7822U and MAX11131AUT+, the MAX146ACAP uniquely combines internal 2.5V reference, three-level hardware shutdown, and full software configurability (unipolar/bipolar, single/diff) in a production-proven 20-pin SSOP - making it optimal for field-serviceable, multi-sensor industrial instruments.
Availability
MAX146ACAP is available at Aetrix Electronics and suitable for portable data logging, battery-powered medical devices, and industrial process control systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for MAX146ACAP 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 fabless semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.
The MAX146/MAX147 product line was designed specifically for low-power, multi-channel data acquisition in portable and battery-operated systems - emphasizing integrated references, flexible input configurations, and minimal external components.
FAQ
What is the operating temperature range for the MAX146ACAP?
The MAX146ACAP is specified for 0°C to +70°C ambient operation, matching the 'C' grade commercial temperature range. This is confirmed in the Ordering Information table where MAX146ACAP is explicitly listed with "0°C to +70°C" under TEMP RANGE. The device's DC accuracy (e.g., ±0.5 LSB INL) and dynamic performance (e.g., 73dB SINAD) are guaranteed across this full range, making it suitable for indoor industrial and consumer portable equipment.
Does the MAX146ACAP require an external reference, or does it have an internal one?
The MAX146ACAP has an internal 2.500V reference, as stated in the General Description: "The MAX146 has an internal 2.5V reference, while the MAX147 requires an external reference." Electrical Characteristics confirm VREF output is 2.480V to 2.520V (TYP 2.500V) at TA = 0°C to +70°C. No external reference is needed unless tighter initial accuracy or different voltage is required - in which case REFADJ can adjust VREF ±1.5% or the internal buffer can be disabled.
What package type is used for the MAX146ACAP?
The MAX146ACAP uses a 20-pin SSOP (Shrink Small Outline Package), as clearly indicated in the Ordering Information table: "MAX146ACAP" maps to "20 SSOP" under PIN-PACKAGE. This is distinct from the MAX146ACPP (20 Plastic DIP) and confirms the device's surface-mount, space-efficient form factor with 0.65mm lead pitch.
How does the SHDN pin function on the MAX146ACAP?
The SHDN pin on the MAX146ACAP is a three-level control: pulling it low places the device in full shutdown (1µA supply current); pulling it high configures the reference buffer for internal compensation mode; letting it float selects external compensation mode (enabling REFADJ adjustment). This is documented in the Pin Description section (Pin 10) and supported by electrical specs showing SHDN input thresholds (VSL = 0.4V, VSH = VDD – 0.4V, VFLT = VDD/2).
Can the MAX146ACAP perform differential measurements, and how many channels support it?
Yes, the MAX146ACAP supports differential measurements across four channel pairs: CH0/CH1, CH2/CH3, CH4/CH5, and CH6/CH7 - configured via the SGL/DIF bit (bit 2) and SEL[2:0] bits in the 8-bit control byte. Table 3 in the datasheet explicitly defines differential channel selection, and the General Description states "8-channel single-ended or 4-channel differential inputs." This pseudo-differential architecture samples only the positive input but requires stable negative input within ±0.5 LSB.
MAX146ACAP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 20-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Number of Bits:
- 12
- 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 ~ 3.6V
- Voltage - Supply, Digital:
- 2.7V ~ 3.6V
- Features:
- -
- Operating Temperature:
- 0°C ~ 70°C
- Supplier Device Package:
- 20-SSOP
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
MAX146ACAP FAQ
1.How can I place an order for MAX146ACAP through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX146ACAP 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 MAX146ACAP reliable?
The price and inventory of MAX146ACAP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX146ACAP is usually 5 days.
3.What payment methods are accepted for MAX146ACAP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX146ACAP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX146ACAP?
MAX146ACAP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX146ACAP 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 MAX146ACAP?
For technical support, including MAX146ACAP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX146ACAP requirements.
6.How does Aetrix verify that MAX146ACAP is sourced from the original manufacturer or authorized distributors?
All MAX146ACAP 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 MAX146ACAP meets industry standards.
7.What is the process for return or replacement of MAX146ACAP?
All MAX146ACAP units undergo pre-shipment inspection (PSI). If there is an issue with MAX146ACAP, 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 MAX146ACAP part is unused and in its original packaging.
Return procedure for MAX146ACAP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX146ACAP 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…
