Analog Devices Inc./Maxim Integrated MAX146BCAP+T

Overview

The MAX146BCAP+T 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 achieves ±0.5 LSB INL and 73dB SINAD - enabling high-accuracy data acquisition in portable medical instruments and battery-powered sensor systems.

For engineers reviewing the MAX146BCAP+T datasheet, MAX146BCAP+T pinout, MAX146BCAP+T application, or MAX146BCAP+T equivalent, key selection criteria include its SSOP-20 package, internal reference accuracy (±0.5% initial, ±30ppm/°C drift), 1.5µs acquisition time, shutdown current <1µA, and compatibility with TMS320-family DSPs via SSTRB strobe output.

Technical Context

The MAX146BCAP+T uses successive-approximation architecture with a capacitive DAC and integrated track/hold circuitry. Its analog input sampling supports pseudo-differential operation across four differential pairs (CH0/CH1 through CH6/CH7) or eight single-ended channels referenced to COM, with software-selectable gain and polarity via an 8-bit control byte.

Conversion timing is governed by either internal clock (programmable via PD1/PD0 bits) or external SCLK (2MHz max), requiring 15 clock cycles per conversion. The device features three-level SHDN control for full power-down, fast power-down, or reference buffer compensation mode selection - enabling dynamic power management without external logic.

Key Specifications

Pinout & Package

MAX146BCAP+T is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, optimized for compact PCB layouts in space-constrained portable instrumentation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit serial ADC applications.

Compared with ADS7822U and MAX11131AUT+T, the MAX146BCAP+T offers optimal balance of integrated reference, low quiescent current, and proven 133ksps performance in industrial-temperature SSOP packaging - making it ideal for cost-sensitive, battery-operated, and space-constrained measurement systems.

Availability

MAX146BCAP+T is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MAX146BCAP+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 MAX146BCAP+T belongs to Maxim's precision data-acquisition product line, designed specifically for low-power, high-accuracy 12-bit ADC applications in portable and embedded systems where integration, supply flexibility, and small footprint are critical.

FAQ

What is the operating temperature range for the MAX146BCAP+T?

The MAX146BCAP+T is specified for 0°C to +70°C ambient operation, matching the 'C' grade designation in Maxim's ordering nomenclature. This range covers commercial and industrial environments where ambient conditions remain within standard office or controlled factory settings. The device maintains ±0.5 LSB INL and 73dB SINAD across this full range, with VREF drift limited to ±30ppm/°C. For extended temperature applications, the MAX146ACPP (0°C to +70°C DIP) or MAX146ECPD (−40°C to +85°C SSOP) variants are available.

Does the MAX146BCAP+T require external components for stable reference operation?

Yes - the MAX146BCAP+T requires a 4.7µF tantalum or aluminum electrolytic capacitor at the VREF pin when using internal compensation mode, as specified in the Typical Operating Circuit and Electrical Characteristics tables. This capacitor stabilizes the internal 2.5V reference buffer and prevents oscillation during conversion. A 0.047µF capacitor is also recommended at REFADJ for noise filtering. Omitting the VREF capacitor results in degraded INL and increased reference noise, directly impacting measurement accuracy.

How does the SHDN pin function in the MAX146BCAP+T?

The SHDN pin on the MAX146BCAP+T provides three distinct operational states: pulling SHDN low enables full power-down (1µA supply current); pulling SHDN high configures the reference buffer for internal compensation mode; letting SHDN float selects external compensation mode. This single-pin, three-state control eliminates the need for additional GPIO lines or configuration registers, simplifying power management in resource-constrained microcontroller systems while preserving reference accuracy across modes.

Can the MAX146BCAP+T interface directly with a TMS320C2xx-series DSP?

Yes - the MAX146BCAP+T's SSTRB (serial strobe) output is explicitly designed for direct connection to TMS320-family digital signal processors. In external clock mode, SSTRB pulses high for one SCLK period before the MSB of the 12-bit conversion result is clocked out on DOUT, providing precise hardware synchronization for DMA-triggered data capture. No level-shifting or timing adaptation is required, as both devices operate at compatible voltage levels and timing margins per the MAX146BCAP+T's timing specifications.

What is the maximum source impedance supported by the MAX146BCAP+T's analog inputs?

The MAX146BCAP+T supports analog source impedances up to 1kΩ without degrading AC performance, based on its 1.5µs minimum acquisition time (tACQ) and internal 9kΩ input resistance. For higher source impedances, a 0.01µF capacitor must be placed at each analog input to maintain accuracy - though this forms an RC filter that limits signal bandwidth. Exceeding 1kΩ without external capacitance increases tACQ proportionally and risks missing codes due to incomplete settling before conversion begins.