Analog Devices Inc./Maxim Integrated MAX6847KARD3-T

Overview

MAX6847KARD3-T from Maxim Integrated is a single-output, ultra-low-power battery monitor with integrated microprocessor supervisor and push-pull active-low RESET output. It features user-adjustable low-battery thresholds (615mV typical), 150ms LBO timeout, factory-set 3.075V VCC reset threshold, and operates from -40°C to +85°C in an 8-pin SOT23 package. It is designed for Li+ or multicell alkaline/NiMH battery monitoring in portable medical devices and digital cameras.

For engineers reviewing the MAX6847KARD3-T datasheet, MAX6847KARD3-T pinout, MAX6847KARD3-T application, or MAX6847KARD3-T equivalent, key selection considerations include its push-pull RESET output (vs. open-drain alternatives), single LBO architecture, 2.5µA typical supply current, and compatibility with resistor-programmable battery voltage thresholds for precise state-of-charge signaling.

Technical Context

The MAX6847KARD3-T integrates a precision 615mV internal reference, dual comparators for high/low threshold detection on LTHIN/HTHIN inputs, and independent timing circuitry for both LBO (150ms min) and RESET (150ms min) assertion/deassertion. Its push-pull RESET output is referenced to VCC and guarantees correct logic state for VCC ≥ 1.0V.

It implements manual reset via MR pin with internal 1.5kΩ pullup, 150ms debounce, and 1µs minimum pulse width. Battery monitoring uses external resistor dividers on LTHIN/HTHIN to set trip points, with hysteresis inherent in the comparator design-no external components required for noise immunity.

Key Specifications

Pinout & Package

Package: 8-pin SOT23 (SOT23-8), 3.00mm × 2.60mm footprint, lead-free compatible (suffix +T), fully specified over -40°C to +85°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery monitor and µP supervisor applications.

Compared with MAX6846KARD3-T, the MAX6847KARD3-T saves one BOM component via push-pull RESET but trades off minor flexibility in shared-bus designs; versus TPS3808G33DBVR, it adds essential battery-state awareness at the cost of ~7× higher supply current, making it indispensable for true battery-aware power management.

Availability

MAX6847KARD3-T is available at Aetrix Electronics and suitable for portable medical devices, digital cameras, and electronic toys requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for MAX6847KARD3-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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and consumer applications.

The MAX6846–MAX6849 product line was designed specifically for ultra-low-power battery monitoring and microprocessor supervision in space-constrained portable electronics, emphasizing precision threshold control, hysteresis stability, and minimal quiescent current.

FAQ

What is the function of the HTHIN and LTHIN pins on the MAX6847KARD3-T?

The HTHIN and LTHIN pins on the MAX6847KARD3-T serve as high-threshold and low-threshold monitor inputs, respectively. They accept voltage divider outputs from the battery to set the 615mV reference-based trip points: LTHIN falling below 615mV asserts LBO, and HTHIN rising above 615mV deasserts LBO after 150ms. This dual-input architecture enables precise hysteresis control without external components, ensuring stable battery state detection in the MAX6847KARD3-T.

Does the MAX6847KARD3-T require external components to operate?

Yes, the MAX6847KARD3-T requires external resistor dividers on LTHIN and HTHIN to scale battery voltage to the internal 615mV reference. No external capacitors or pullups are needed for basic operation: the MR pin has an internal 1.5kΩ pullup to VCC, and the push-pull RESET output eliminates the need for an external pullup resistor. All timing functions-including 150ms LBO and RESET timeouts-are fully internal to the MAX6847KARD3-T.

What is the significance of the 'D3' suffix in MAX6847KARD3-T?

The 'D3' suffix in MAX6847KARD3-T indicates a 150ms minimum reset timeout period for both VCC-supervised and manual reset (MR) events. This is defined in Table 2 of the datasheet and distinguishes it from the 'D7' variant, which offers a 1200ms timeout. The 'R' denotes a factory-set 3.075V VCC reset threshold (per Table 1), and '-T' specifies tape-and-reel packaging with lead-free finish. All these identifiers are encoded in the MAX6847KARD3-T ordering code.

Can the MAX6847KARD3-T monitor batteries with voltages above 5.5V?

No, the MAX6847KARD3-T cannot directly monitor batteries above 5.5V. Its VDD and VCC absolute maximum ratings are +6V, but recommended operating range is 1.6V to 5.5V for VDD and 1.2V to 5.5V for VCC. To monitor higher-voltage batteries (e.g., 2-cell Li+ at 8.4V), an external resistor divider must scale the battery voltage down to ≤5.5V before connecting to VDD or VCC, and the LTHIN/HTHIN inputs must be scaled to ≤615mV using appropriate divider ratios. The MAX6847KARD3-T itself does not support direct >5.5V battery sensing.

How does the MAX6847KARD3-T handle manual reset debouncing?

The MAX6847KARD3-T implements hardware-based MR input debouncing with a fixed 150ms rising-edge debounce period (tDEB). During this window, the device ignores any subsequent MR low-to-high transitions, preventing false resets caused by mechanical switch bounce. The MR pin has an internal 1.5kΩ pullup to VCC, accepts CMOS logic levels, and supports direct connection to a momentary pushbutton switch to GND. This integrated debouncing eliminates the need for external RC filters or firmware polling in the MAX6847KARD3-T design.