Analog Devices Inc./Maxim Integrated MAX122BCAG+

Overview

The MAX122BCAG+ from Maxim Integrated is a 12-bit, 333ksps BiCMOS sampling analog-to-digital converter with integrated track/hold and -5V buried-zener reference, designed for high-speed bipolar data acquisition in systems requiring ±5V input range, TTL/CMOS-compatible digital interfacing, and low-noise performance up to 1.5MHz full-power bandwidth.

For engineers reviewing the MAX122BCAG+ datasheet, MAX122BCAG+ pinout, MAX122BCAG+ application, or MAX122BCAG+ equivalent, this page delivers verified electrical specifications, mode-specific timing behavior, real-world dynamic performance (SINAD ≥69dB, THD ≤-75dB), package-confirmed pin functions, and validated alternative options for signal chain design.

Technical Context

The MAX122BCAG+ implements successive approximation architecture with on-chip track/hold, supporting five distinct operational modes (full-control, stand-alone, slow-memory, ROM, and continuous-conversion) via MODE, CONVST, RD, and CS control logic. Its internal -5V reference provides ±25ppm/°C drift and sinks up to 5mA.

It accepts 0.1MHz–5MHz TTL-compatible clock inputs, achieves 2.6µs conversion time (14-clock-cycle fixed or 13/14-cycle variable), and delivers two's-complement 12-bit output with 75ns data-access time, 30ps aperture jitter, and ±5V analog input tolerance to ±15V.

Key Specifications

Pinout & Package

MAX122BCAG+ is housed in a 24-pin SSOP (Shrink Small Outline Package) with 0.635mm pitch, RoHS-compliant lead-free finish, and thermal derating of 8.00mW/°C above +70°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and AD7892BRZ-2, the MAX122BCAG+ uniquely integrates both track/hold and -5V reference in a single SSOP package, reducing component count and layout complexity for ±5V bipolar acquisition-whereas alternatives require external support circuitry or sacrifice integration for speed or interface flexibility.

Availability

MAX122BCAG+ is available at Aetrix Electronics and suitable for digital signal processing, audio and telecom processing, speech recognition systems, and high-speed data acquisition requiring stable component supply, long-term industrial lifecycle support, and RoHS-compliant packaging.

Supply support for MAX122BCAG+ 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, communications, and computing applications.

The MAX120/MAX122 product line was engineered for precision, high-throughput data acquisition in systems demanding integrated signal conditioning-specifically targeting applications where ±5V bipolar input, low-jitter sampling, and minimal external components are critical design constraints.

FAQ

What is the maximum clock frequency supported by the MAX122BCAG+?

The MAX122BCAG+ accepts TTL-compatible clock inputs from 0.1MHz to 5MHz. Operation above 5MHz is not guaranteed and may result in invalid conversions or timing violations. The 5MHz limit ensures reliable 2.6µs conversion time and 333ksps throughput across the full industrial temperature range (-40°C to +85°C). This specification is confirmed in the Electrical Characteristics table under "Clock Frequency" for MAX122.

Does the MAX122BCAG+ require external components for basic operation?

Yes-the MAX122BCAG+ requires external decoupling capacitors: 0.1µF ceramic + 10µF electrolytic on VDD to AGND, and 22µF electrolytic + 0.1µF ceramic on VREF to AGND. These are mandatory for stable reference operation and noise suppression. No external track/hold capacitor or reference IC is needed, as both are integrated. All logic I/O is TTL/CMOS-compatible and requires no level shifters.

How does the MODE pin configure the INT/BUSY output on the MAX122BCAG+?

On the MAX122BCAG+, the MODE pin determines INT/BUSY behavior: when tied to VDD, it functions as an interrupt output (low pulse upon conversion completion); when open or tied to DGND, it functions as a busy flag (low during conversion, high when data is ready). This configuration is hardwired and affects timing relationships in all five operational modes-verified in the Pin Description and Operating Modes sections of the datasheet.

What is the analog input impedance of the MAX122BCAG+ and how does it affect signal source design?

The MAX122BCAG+ presents a 6kΩ resistance in parallel with 10pF capacitance at the AIN pin. This loading requires source impedances ≤1kΩ to maintain full 1.5MHz full-power bandwidth and minimize settling error. High-impedance sensors must use a unity-gain buffer (e.g., rail-to-rail op-amp) before AIN. The 350ns acquisition time assumes proper drive capability-confirmed in the "Analog Input Track/Hold" section and Figure 4 equivalent circuit.

Can the MAX122BCAG+ operate with an external reference voltage?

Yes-the MAX122BCAG+ allows external override of its internal -5V reference if the external source provides -5.05V to -5.10V and can sink ≥5mA. The same VREF bypass capacitors (22µF + 0.1µF) remain mandatory. This mode is used when higher initial accuracy or lower drift than the internal ±25ppm/°C is required. External reference compatibility is explicitly stated in the "Internal Reference" section of the datasheet.