Analog Devices Inc./Maxim Integrated MAX13036ATI+

Overview

MAX13036ATI+ from Maxim Integrated is an 8-channel mechanical switch contact monitor and level shifter IC with integrated SPI interface, programmable hysteresis (via external resistor), adjustable wetting current (7.5–40 mA), and dual direct-level-shifted outputs (DO0/DO1). It operates from +6V to +26V battery supply (BAT) and +2.7V to +5.5V logic supply (VL), delivering ultra-low 17 µA typical supply current in scan mode. It is used in automotive control ECUs for reliable remote switch monitoring under harsh conditions.

For engineers reviewing the MAX13036ATI+ datasheet, MAX13036ATI+ pinout, MAX13036ATI+ application, or MAX13036ATI+ equivalent, key selection considerations include its 28-pin TQFN package, -40°C to +125°C operating range, ±8 kV HBM ESD protection on all IN0–IN7 inputs, interrupt-driven state change detection, and support for both ground- and battery-connected switch configurations.

Technical Context

The MAX13036ATI+ implements a configurable 8-input switch monitoring architecture with shared debounce timing (3.18–188 ms via external capacitor), resistor-adjustable input hysteresis (0.133×VBATREF to 0.48×VBATREF), and programmable wetting current (22–51 mA depending on RWET and VBAT). Its SPI slave interface supports up to 5 MHz clock rate with precise timing margins (tSI(SU) = 30 ns, tVALID = 70 ns).

It features three operational modes: normal (full sensing), scan (periodic polling at 2–14 ms intervals), and shutdown (2–4 µA total supply current). Input thresholds are centered at 50% of BATREF voltage, and thermal protection activates at +170°C (typ) with +15°C hysteresis, disabling wetting current but preserving monitoring functionality.

Key Specifications

Pinout & Package

The MAX13036ATI+ is housed in a 5 mm × 5 mm, 28-pin TQFN-EP package with exposed pad (EP) requiring connection to GND for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar contact monitoring and level shifting applications.

Compared with MAX13035ATI+, the MAX13036ATI+ adds full 8-channel capability without trade-offs in power, protection, or configurability; compared with MAX13037ATI+, it omits watchdog and diagnostic extensions-making it optimal for cost-sensitive, non-safety ECU designs requiring maximum channel count and minimal BOM overhead.

Availability

MAX13036ATI+ is available at Aetrix Electronics and suitable for automotive control ECUs, industrial HMI panels, off-highway equipment consoles, and commercial vehicle telematics units requiring stable component supply across extended temperature and voltage ranges.

Supply support for MAX13036ATI+ 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 automotive, industrial, and communications markets.

The MAX13036ATI+ belongs to Maxim's contact monitoring and level-shifting product line, designed specifically for robust, low-power remote switch interfacing in harsh environments where reliability, ESD immunity, and flexible power domain translation are essential.

FAQ

What is the function of the BATREF pin on the MAX13036ATI+?

The BATREF pin sets the reference voltage for all eight switch input thresholds, which are fixed at 50% of the voltage applied to BATREF. It is typically connected to the system battery voltage before any reverse-battery protection diode. The MAX13036ATI+ uses this reference to maintain consistent switching points across varying battery voltages (6V–26V), ensuring reliable operation even during cranking or load-dump events.

Can the MAX13036ATI+ monitor battery-connected switches, and how is that configured?

Yes, the MAX13036ATI+ supports battery-connected switches on IN4–IN7 via programmable configuration. Using the M0 and M1 bits in the command register, these four inputs are grouped into two pairs (IN4/IN5 and IN6/IN7), each independently set for either ground- or battery-connected operation. IN0–IN3 are fixed for ground-connected switches. This flexibility allows a single MAX13036ATI+ to interface with mixed-switch topologies in complex control panels.

How does the wetting current feature work on the MAX13036ATI+ and what resistor values are recommended?

The MAX13036ATI+ applies a controlled wetting current (7.5–40 mA) to closed mechanical switches via the WET pin, using an external resistor (30 kΩ–330 kΩ) to ground. A 61 kΩ resistor yields ~22 mA (typ), while 30 kΩ gives ~40 mA. Wetting pulses activate after debounce completion and last 10–35 ms (configurable via WTOFF bit). This current cleans oxide layers from contacts, improving long-term reliability in humid or corrosive environments.

What are the key timing requirements for the SPI interface of the MAX13036ATI+?

The MAX13036ATI+ supports SPI clock frequencies up to 5 MHz. Critical timing parameters include: tSI(SU) = 30 ns (SDI setup before CLK fall), tSI(HOLD) = 20 ns (SDI hold after CLK fall), tVALID = 70 ns (data valid after CLK rise), and tSO(EN)/tSO(DIS) = 55 ns (SDO enable/disable delay from CS edge). These specs ensure robust communication with standard microcontrollers-even at temperature extremes-without requiring special timing margins or glue logic.

Does the MAX13036ATI+ provide thermal protection, and how is it signaled?

Yes, the MAX13036ATI+ includes thermal protection that triggers at +170°C (typ), disabling wetting current while maintaining switch monitoring. It signals overtemperature via two redundant paths: the open-drain OT pin (active-low) and the OT bit (bit 7) in the SPI-read status register. Both clear automatically when internal temperature falls below +155°C (typ hysteresis). This dual reporting enables fail-safe monitoring even if one path is compromised in the system design.