Analog Devices Inc./Maxim Integrated MAX6366HKA29+

Overview

MAX6366HKA29+ from Maxim Integrated is a low-power microprocessor supervisory circuit with integrated watchdog timer, battery-backup switchover, and chip-enable gating. It monitors VCC (1.2V–5.5V), asserts active-high open-drain RESET on power-up/down/brownout or watchdog timeout, provides 2.93V ±70mV factory-set reset threshold, and supports 150ms minimum reset timeout. It is used in portable industrial controllers requiring reliable power monitoring and nonvolatile memory protection during supply failure.

For engineers reviewing the MAX6366HKA29+ datasheet, MAX6366HKA29+ pinout, MAX6366HKA29+ application, or MAX6366HKA29+ equivalent, key selection criteria include its 1.6s watchdog timeout, 10µA quiescent current, 2.93V reset threshold accuracy, open-drain active-high RESET output, and SOT23-8 package compatibility with space-constrained µP systems.

Technical Context

The MAX6366HKA29+ implements a precision voltage monitor with internal 2.93V reference and comparator, coupled to a monostable watchdog timer with 1.6s nominal timeout. Its VCC-to-BATT switchover logic uses 40mV hysteresis and requires both VCC < VTH and VCC < VBATT − 20mV to engage backup mode.

RESET is an open-drain active-high output asserted continuously during brownout or pulsed on watchdog timeout; CE IN/CE OUT forms a transmission gate with 1.5ns propagation delay and 20–100Ω on-resistance, disabled during reset to prevent SRAM corruption.

Key Specifications

Pinout & Package

MAX6366HKA29+ is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), surface-mount compatible with standard reflow profiles and IPC-7351B footprint MS-012AA.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6366PKA29+, the MAX6366HKA29+ provides active-high RESET compatibility with modern low-voltage µPs, while TPS3808G33DBVR offers lower quiescent current but omits critical battery-backup and watchdog functionality required for robust embedded data retention.

Availability

MAX6366HKA29+ is available at Aetrix Electronics and suitable for industrial control systems, portable medical devices, and smart metering applications requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6366HKA29+ 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 communications markets.

The MAX6365–MAX6368 family was designed specifically for µP-based systems needing integrated power monitoring, battery backup, and memory write protection in minimal board area - targeting portable, battery-powered, and mission-critical embedded applications.

FAQ

What is the exact reset threshold voltage of MAX6366HKA29+ and how is it specified?

The MAX6366HKA29+ has a factory-trimmed reset threshold of 2.93V, with guaranteed minimum of 2.85V and maximum of 3.00V over the full -40°C to +85°C operating temperature range. This value is defined in the Electrical Characteristics table under "Reset Threshold (VTH)" and corresponds to the "KA29" suffix in the ordering code. The threshold is internally generated and does not require external components.

Does MAX6366HKA29+ support battery-backup operation when VCC is absent at startup?

No. The MAX6366HKA29+ requires VCC to be present and above the reset threshold at initial power-up to initialize internal circuitry. It cannot start from BATT alone. Once powered, if VCC falls below 2.93V and VBATT exceeds VCC by at least 20mV, the device automatically switches OUT to BATT to maintain SRAM power and data retention.

How does the watchdog function of MAX6366HKA29+ interact with the reset output?

The MAX6366HKA29+ watchdog triggers a pulsed active-high RESET output upon timeout (1.6s nominal). Each pulse lasts for the full reset timeout period (150–280ms). The watchdog timer clears on any rising or falling edge at WDI, and also resets whenever RESET is asserted - ensuring no spurious timeouts during valid reset sequences.

What is the purpose of the CE IN and CE OUT pins on MAX6366HKA29+?

CE IN and CE OUT implement hardware-enforced chip-enable gating. During normal operation, CE IN passes directly to CE OUT with 1.5ns delay. When RESET asserts, the path is disabled: if CE IN is low, CE OUT remains low for 12µs to complete ongoing memory access; if CE IN is high, CE OUT stays high. This prevents erroneous writes to SRAM during power faults.

Can MAX6366HKA29+ operate with a 1.2V supply, and what functions remain active?

Yes. The MAX6366HKA29+ operates down to 1.2V on both VCC and VBATT. At 1.2V, the reset monitor remains functional (asserting RESET when VCC < 2.93V), the watchdog timer continues timing, and the VCC-to-BATT switchover logic engages. However, OUT sourcing capability is reduced, and CE OUT drive strength decreases proportionally with supply voltage.