Analog Devices Inc./Maxim Integrated MAX6956ATL/V+T

Overview

The MAX6956ATL/V+T from Maxim Integrated is a 28-port, I²C-compatible LED display driver and GPIO expander operating from 2.5V to 5.5V over –40°C to +125°C. It supports per-port configuration as constant-current LED sink (1.5–24mA, 16-step), push-pull output (10mA sink/4.5mA source), or Schmitt input with optional pullup. Seven ports feature transition-detection interrupt logic. It targets automotive-grade panel meters and industrial controllers requiring robust, mixed-signal I/O expansion.

For engineers reviewing the MAX6956ATL/V+T datasheet, MAX6956ATL/V+T pinout, MAX6956ATL/V+T application, or MAX6956ATL/V+T equivalent, key selection criteria include its 40-pin thin QFN-EP package with exposed pad, automotive qualification (/V), RoHS-compliant lead-free finish (+), tape-and-reel packaging (T), and support for up to 28 individually configurable I/Os with integrated LED current control and interrupt-capable GPIO.

Technical Context

The MAX6956ATL/V+T implements a dual-role architecture: each of its 28 ports (P4–P31) is software-configurable via I²C register writes as either a constant-current LED sink (with 16-step digital current control set by external ISET resistor) or a bidirectional GPIO with Schmitt-trigger inputs and programmable internal pullups. Its I²C interface operates at up to 400kbps and supports 16 slave addresses using only two address pins (AD0/AD1).

Transition detection is hardware-accelerated on ports P24–P30, generating an interrupt on P31 when masked logic-level changes occur. Shutdown mode reduces supply current to ≤11µA while preserving register contents and allowing full reconfiguration - critical for low-power automotive and industrial monitoring systems.

Key Specifications

Pinout & Package

The MAX6956ATL/V+T is housed in a 40-pin thin QFN package with exposed thermal pad (EP), optimized for high-density PCB layouts and thermal dissipation in automotive modules. Pin numbering follows standard top-view orientation with pin 1 marked by dot or notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED driver and I/O expander applications.

Compared with MAX6956ATL/V+T, MAX6957ATL/V+T offers identical mixed-signal capability but trades I²C flexibility for SPI determinism, while MAX7300ATL+T sacrifices LED control and interrupts to reduce unit cost - making MAX6956ATL/V+T optimal for integrated display+control applications demanding automotive reliability.

Availability

The MAX6956ATL/V+T is available at Aetrix Electronics and suitable for automotive instrument clusters, industrial panel meters, and white goods control panels requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6956ATL/V+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) designs precision analog and mixed-signal ICs for automotive, industrial, and communications markets, emphasizing high reliability and integration.

The MAX6956 product line delivers compact, automotive-qualified LED display drivers with integrated GPIO expansion - targeting space-constrained, thermally demanding applications where display control and system monitoring must coexist on a single chip.

FAQ

What is the package type and thermal design requirement for the MAX6956ATL/V+T?

The MAX6956ATL/V+T uses a 40-pin thin QFN package with exposed thermal pad (EP). For optimal thermal performance, the EP must be soldered to a PCB ground plane with adequate copper area. The device supports continuous power dissipation up to 2105mW at +70°C ambient, derating at 26.3mW/°C above that temperature. This thermal design enables reliable operation in sealed automotive enclosures and industrial housings without forced air cooling.

How does the MAX6956ATL/V+T handle LED current calibration across voltage and temperature variations?

The MAX6956ATL/V+T sets LED current via an external ISET resistor connected between ISET pin and GND. Its internal current mirror architecture ensures stable per-port sink current across V+ (2.5V–5.5V) and temperature (–40°C to +125°C), with typical variation <±10% over full range. Graphs in the datasheet (e.g., MAX6956 toc04, toc05) confirm <5% deviation from nominal at 25°C, supporting consistent brightness without closed-loop feedback.

Can the MAX6956ATL/V+T drive common-anode (CA) LED digits and discrete LEDs simultaneously?

Yes, the MAX6956ATL/V+T is explicitly designed to drive both common-anode numeric/alphanumeric digits and discrete LEDs. Each configured LED port acts as a constant-current sink, so it connects to the cathode of CA segments or discrete LEDs - with the anode tied to V+. This architecture allows mixed usage on the same device, such as driving a 7-segment digit alongside status indicator LEDs, all with independent 16-step brightness control.

What is the function of the P31 pin on the MAX6956ATL/V+T, and how is it configured?

P31 serves as the active-low, open-drain interrupt output on the MAX6956ATL/V+T. It asserts when a logic-level transition occurs on any of the seven maskable ports (P24–P30), as defined in the Transition Detect Mask register (0x06). No external pullup is required if used with a microcontroller's internal pullup; otherwise, a 4.7kΩ resistor to V+ is recommended. The interrupt remains asserted until the status bit is cleared via I²C read or mask update.

Is the MAX6956ATL/V+T pin-compatible with other variants in the MAX6956 family?

No, the MAX6956ATL/V+T is not pin-compatible with other MAX6956 variants. It uses a 40-pin thin QFN package, whereas MAX6956AAX+ uses a 36-pin SSOP and MAX6956AAI+/ANI+ use 28-pin packages. Port mapping also differs: MAX6956ATL/V+T exposes all 28 ports (P4–P31), while 28-pin versions only provide P12–P31. Direct replacement requires PCB redesign and layout revision.