Analog Devices Inc./Maxim Integrated MAX6789TB+

Overview

MAX6789TB+ from Maxim Integrated is a quad-level overvoltage detector IC with complementary push-pull outputs, designed for precise battery overvoltage protection in space-constrained portable systems. It monitors four independent input voltages (IN1–IN4), features 1% threshold accuracy over –40°C to +85°C, 31mV fixed hysteresis per channel, and operates from 1.6V to 5.5V supply. It is used in Li+-based power management to prevent cell damage during charging or fault conditions.

For engineers reviewing the MAX6789TB+ datasheet, MAX6789TB+ pinout, MAX6789TB+ application, or MAX6789TB+ equivalent, key selection considerations include its quad OV detection architecture, latch-and-clear functionality, complementary active-low/active-high outputs, low 5.7µA quiescent current, and TQFN-10 package compatibility with high-density PCB layouts.

Technical Context

The MAX6789TB+ implements four independent voltage comparators referenced to an internal 0.6085V bandgap, each with fixed 31mV hysteresis. Thresholds are set externally via resistive dividers on IN1–IN4, enabling flexible overvoltage trip points across diverse battery chemistries and configurations.

Its latch control block asserts OV (active-low) and OV (active-high) outputs when any input exceeds its rising threshold; outputs remain latched until CLEAR is pulsed low or power is cycled. The integrated pullup on CLEAR (25–80kΩ to BATT) enables simple microcontroller-driven reset without external components.

Key Specifications

Pinout & Package

The MAX6789TB+ is housed in a 10-pin TQFN-EP package (3mm × 3mm, 0.5mm pitch) with exposed pad for thermal performance and grounding. Pin 10 is the exposed pad (EP), which must be soldered to the PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar overvoltage detection applications.

Compared with MAX6790TB+, MAX6789TB+ offers direct-drive push-pull outputs eliminating external pull-ups, while TLV809E33DBZR lacks multi-channel capability, latch control, and adjustable thresholds - making MAX6789TB+ uniquely suited for robust, scalable battery overvoltage safety in portable electronics.

Availability

MAX6789TB+ is available at Aetrix Electronics and suitable for smartphone battery protection, medical wearable charger monitoring, and industrial handheld scanner power management requiring stable component supply and long-term lifecycle support.

Supply support for MAX6789TB+ 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 power management, sensing, and interface applications in demanding environments.

The MAX6782–MAX6790 family delivers ultra-low-power, high-accuracy battery monitoring solutions targeting portable, battery-operated devices where size, accuracy, and reliability are critical.

FAQ

What is the function of the CLEAR pin on the MAX6789TB+?

The CLEAR pin on the MAX6789TB+ is an active-low input that resets the latched OV and OV outputs when pulled low. It features an internal 25–80kΩ pullup resistor to BATT, allowing direct connection to a microcontroller GPIO for controlled fault recovery. When CLEAR is held low, overvoltage faults do not latch - enabling continuous monitoring mode. This behavior is confirmed in the MAX6789TB+ datasheet Figure 5 timing diagram and Pin Description section.

Does the MAX6789TB+ support adjustable overvoltage thresholds?

Yes, the MAX6789TB+ supports fully adjustable overvoltage thresholds via external resistive dividers on IN1–IN4. Each input accepts a voltage divider from BATT to GND, setting the trip point relative to the internal 0.6085V reference. The rising threshold is fixed at 0.6085V, and hysteresis is fixed at 31mV - so the falling threshold is always 0.5775V. This configuration is explicitly described in the MAX6789TB+ Detailed Description and Pin Configuration sections.

What package type and dimensions does the MAX6789TB+ use?

The MAX6789TB+ uses a 10-pin TQFN-EP package measuring 3mm × 3mm with 0.5mm pitch and an exposed thermal pad (EP). The top mark is +AQI, and the RoHS-compliant lead-free finish is indicated by the "+" suffix. This package is documented in the Ordering Information table and Pin Configuration section of the MAX6789TB+ datasheet, and its thermal pad must be soldered to the PCB ground plane for optimal performance.

Can the MAX6789TB+ monitor voltages higher than its 5.5V supply rating?

Yes - the MAX6789TB+ can monitor voltages above 5.5V by powering BATT from a regulated supply within 1.6V–5.5V while connecting the high-voltage source to IN1–IN4 through external resistive dividers. The absolute maximum rating for INx pins is +6V, and input leakage is limited to 5nA, minimizing divider error. This method is validated in the "Monitoring a Battery Voltage Higher than the Allowable VBATT" application note section of the MAX6789TB+ datasheet.

How does the MAX6789TB+ differ from the MAX6782–MAX6788 variants?

The MAX6789TB+ differs fundamentally from MAX6782–MAX6788 by implementing quad overvoltage detection (not low-battery monitoring), featuring complementary OV/OV outputs and a CLEAR latch input - whereas MAX6782–MAX6788 provide low-battery outputs (LBO1–LBO4) with hysteresis options. MAX6789TB+ has no reference output (REF), no hysteresis adjustment pins (HADJx), and no LBO functionality - its architecture is dedicated to overvoltage fault detection and latching, as confirmed in the Selector Guide and Detailed Description sections.