Analog Devices Inc./Maxim Integrated MAX14575ALETA+T

Overview

MAX14575ALETA+T from Maxim Integrated is an active-low enable, autoretry-mode programmable current-limit switch with 32mΩ typical R_ON, adjustable 250mA–2.5A current limit, and reverse-current blocking. It operates from +2.3V to +5.5V and delivers robust overcurrent protection for USB ports and portable media player power rails.

For engineers reviewing the MAX14575ALETA+T datasheet, MAX14575ALETA+T pinout, MAX14575ALETA+T application, or MAX14575ALETA+T equivalent, key selection criteria include EN polarity (active-low), autoretry fault response, thermal shutdown at +160°C, and 8-pin TDFN-EP package compatibility with high-density portable designs.

Technical Context

The MAX14575ALETA+T implements a BiCMOS-based current-limit architecture with fixed 10–25ms blanking time and 320–875ms retry interval. Its SETI pin accepts a resistor to program forward current limit across five decades (250mA–2.5A) using a 135kV coefficient and 1.35kΩ constant.

It features open-drain FLAG output asserting on overcurrent (after blanking), reverse current detection (V_OUT–V_IN ≥ 25–145mV), thermal shutdown (+160°C), or grounded SETI. Reverse blocking limits backflow to ≤1µA at shutdown and ≤2µA during fault tripping.

Key Specifications

Pinout & Package

MAX14575ALETA+T uses an 8-pin, 2mm × 2mm TDFN-EP package with exposed pad soldered to GND for thermal performance. Pin 1 is FLAG (open-drain fault indicator), Pin 2 is SETI (current-limit programming input), Pins 3–4 are paralleled OUT terminals, Pins 5–6 are paralleled IN inputs, Pin 7 is active-low EN, and Pin 8 is GND. The exposed pad (EP) must be connected to a large ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-limit switch applications.

Compared with MAX14575AETA+T, MAX14575ALETA+T saves board space by eliminating external inverters; versus TPS2557DRCT, it adds reverse-current blocking and autoretry-critical for USB and hot-swap applications where continuous operation after transient faults is mandatory.

Availability

MAX14575ALETA+T is available at Aetrix Electronics and suitable for USB port protection, portable media player power management, and SDXC card supply protection requiring stable component supply across industrial and consumer production cycles.

Supply support for MAX14575ALETA+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, mixed-signal, and power-management ICs for industrial, automotive, communications, and computing applications.

The MAX14575 family targets high-reliability portable power distribution, delivering programmable current limiting, reverse-current blocking, and thermal protection in ultra-small TDFN packages for space-constrained mobile platforms.

FAQ

What is the EN polarity and logic threshold specification for MAX14575ALETA+T?

MAX14575ALETA+T features active-low enable (EN) with logic-low threshold ≤0.4V and logic-high threshold ≥1.6V. Driving EN below 0.4V turns the switch ON; pulling EN above 1.6V turns it OFF. No internal pullup or pulldown is present, so external biasing is required for defined idle state. This polarity allows direct connection to microcontroller GPIOs configured as open-drain outputs or active-low reset signals without inversion circuitry.

How does the autoretry fault response work in MAX14575ALETA+T?

When an overcurrent condition persists beyond the blanking time (10–25ms), MAX14575ALETA+T asserts FLAG and latches OFF for the retry interval (320–875ms). At the end of retry, it automatically attempts to re-enable. If the fault remains, the cycle repeats; if cleared, the switch stays ON. This reduces average fault power by >95% compared to continuous limiting, extending thermal margin and preventing system lockup during transient shorts.

What resistor value is needed to set a 1.5A current limit on MAX14575ALETA+T?

To achieve a 1.5A current limit on MAX14575ALETA+T, connect an 85kΩ resistor between SETI and GND. This value is confirmed in Table 2 of the datasheet, which lists R_SETI = 85kΩ yielding 1.55A (within ±10% tolerance). Values below 40kΩ are prohibited, and capacitors larger than 20pF on SETI must be avoided to prevent instability. The relationship follows I_LIM(A) = (135kV − R_SETI(kΩ)) / 1.35kΩ.

Does MAX14575ALETA+T provide reverse-current protection, and how does it behave?

Yes, MAX14575ALETA+T provides reverse-current protection that activates when V_OUT exceeds V_IN by 25–145mV. Upon detection, the switch turns OFF and FLAG asserts immediately-no blanking delay applies. Reverse leakage is limited to ≤2µA during blocking. Recovery occurs automatically when V_OUT–V_IN drops below the threshold. This prevents backfeed into weak or shared power rails during hot-swap or multi-source configurations.

What are the thermal characteristics and shutdown behavior of MAX14575ALETA+T?

MAX14575ALETA+T triggers thermal shutdown at +160°C (typical junction temperature) and remains latched OFF until temperature falls by ~20°C hysteresis. Junction-to-ambient thermal resistance is 83.9°C/W (TDFN package, 4-layer board). During autoretry operation, average power dissipation scales with duty cycle (t_BLANK/(t_BLANK + t_RETRY)), reducing thermal stress. For continuous faults, thermal shutdown prevents permanent damage while enabling safe cooldown and automatic recovery.