Analog Devices Inc./Maxim Integrated MAX156BCNG+

Overview

The MAX156BCNG+ from Maxim Integrated is a high-speed, 4-channel, 8-bit analog-to-digital converter with simultaneous track-and-hold (T/H) inputs, 3.6µs per-channel conversion time, internal 2.5V reference, and support for unipolar/bipolar and single-ended/differential input configurations-designed for phase-sensitive data acquisition in vibration analysis and DSP front-ends.

For engineers reviewing the MAX156BCNG+ datasheet, MAX156BCNG+ pinout, MAX156BCNG+ application, or MAX156BCNG+ equivalent, this page delivers verified technical context, real-world interface timing constraints, channel-matching accuracy (±½ LSB), dynamic performance (48dB SINAD), and supply-flexible operation (single +5V or dual ±5V).

Technical Context

The MAX156BCNG+ implements a successive-approximation ADC core with eight independent T/H amplifiers-four active and four unused (N.C.)-all sampling simultaneously on WR's falling edge. Its configuration register (accessed via bidirectional D0–D7 pins) controls channel selection, input mode (DIFF/BIP), power-down (PD), and read/write sequencing.

It operates in two distinct interface modes: I/O mode (MODE = open circuit) for full programmability of mixed-input conversions, and hard-wired mode (MODE tied low/high with VSS) for fixed 4-channel differential or 8-channel single-ended operation-eliminating software overhead while retaining simultaneous sampling integrity.

Key Specifications

Pinout & Package

MAX156BCNG+ is housed in a 24-pin narrow plastic DIP (PDIP) package with 0.3-inch body width and through-hole mounting. Pin 1 is marked with a notch or dot; pin numbering follows standard counter-clockwise convention from top view.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-channel, 8-bit ADC applications.

Compared with ADS7822U and MAX1166BCAP+, the MAX156BCNG+ uniquely delivers parallel 8-bit output, simultaneous 4-channel sampling with sub-ns matching, and self-contained reference-all in a through-hole PDIP package ideal for prototyping and industrial control modules where layout simplicity and timing determinism are prioritized over density or resolution.

Availability

MAX156BCNG+ is available at Aetrix Electronics and suitable for phase-sensitive data acquisition, vibration monitoring, DSP analog interfacing, and AC power metering requiring stable component supply and long-lifecycle industrial availability.

Supply support for MAX156BCNG+ 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 and mixed-signal ICs for industrial, medical, and communications systems-emphasizing integration, reliability, and application-specific optimization.

The MAX155/MAX156 product line was engineered to solve timing-critical multichannel sampling challenges in real-time signal conditioning-prioritizing simultaneous T/H, flexible input configuration, and embedded reference stability over raw speed or resolution.

FAQ

What is the maximum clock frequency supported by the MAX156BCNG+?

The MAX156BCNG+ accepts an external clock input from 0.5 MHz to 5.0 MHz. At 5 MHz, the device achieves its specified 3.6 µs per-channel conversion time. Operating below 0.5 MHz extends conversion time linearly and may impact throughput in multichannel sequences-but does not affect accuracy or functionality. The MAX156BCNG+ datasheet specifies timing parameters only for fCLK within this validated range.

Does the MAX156BCNG+ require external decoupling capacitors, and if so, what values?

Yes, the MAX156BCNG+ requires specific decoupling: a 4.7 µF electrolytic capacitor plus a 0.1 µF ceramic capacitor must be placed between REFOUT and AGND to stabilize the internal 2.5V reference. Additionally, VDD to AGND requires a 47 µF electrolytic and 0.1 µF ceramic pair. If VSS is used at –5V, it must also be bypassed to AGND with 4.7 µF + 0.1 µF. These values are mandatory for meeting specified accuracy and dynamic performance.

Can the MAX156BCNG+ perform differential conversions on all four channels simultaneously?

Yes-the MAX156BCNG+ supports true simultaneous differential sampling across all four channels (e.g., AIN0–AIN1, AIN2–AIN3) using hard-wired mode (MODE = high, VSS = AGND or –5V) or I/O mode with appropriate DIFF bit settings. All T/H amplifiers sample at the exact same instant on WR's falling edge, ensuring matched aperture delay (<4 ns) and preserved phase relationships essential for coherent differential measurements.

How does the power-down mode affect configuration register contents in the MAX156BCNG+?

In power-down mode (PD = 1), the MAX156BCNG+ retains all configuration register contents-including channel selections, DIFF/BIP settings, and address pointers-while reducing supply current to ≤100 µA. This allows immediate resumption of prior acquisition sequences upon exit (PD = 0). However, no conversions can be initiated and no RAM data can be read until power-down is cleared, and the internal reference requires up to 5 ms to stabilize if re-enabling after internal reference use.

Is the MAX156BCNG+ pin-compatible with the MAX155 series?

No-the MAX156BCNG+ uses a 24-pin narrow PDIP package, while the MAX155 is offered in 28-pin PDIP and wide SO packages. Pin functions differ significantly: MAX156BCNG+ lacks AIN4–AIN7 and D2/A2 (pin 18), and repurposes pins 25–28 as N.C. instead of analog inputs. Direct PCB replacement is not possible; redesign is required to accommodate the reduced pin count and altered signal mapping.