Analog Devices Inc./Maxim Integrated MAX6366PKA29-T

Overview

MAX6366PKA29-T from Maxim Integrated is a low-power microprocessor supervisory circuit with integrated watchdog timer, battery-backup switchover, and chip-enable gating. It monitors VCC supply (1.2V–5.5V), asserts active-low open-drain RESET on power-up/down/brownout or watchdog timeout, provides 2.93V ±70mV factory-set reset threshold, and supports CMOS RAM backup via OUT switching between VCC and BATT. Used in portable POS terminals and industrial controllers requiring reliable power sequencing and fault recovery.

For engineers reviewing the MAX6366PKA29-T datasheet, MAX6366PKA29-T pinout, MAX6366PKA29-T application, or MAX6366PKA29-T equivalent, key selection criteria include its 1.6s watchdog timeout, 150ms minimum reset timeout, 10µA quiescent current, 2.93V reset threshold, and SOT23-8 package compatibility with space-constrained µP systems.

Technical Context

The MAX6366PKA29-T implements a precision voltage monitor with internal 2.93V reference, a monostable watchdog timer triggered by WDI edge transitions, and bidirectional VCC/BATT switchover controlled by 40mV hysteresis. Its CE IN-to-CE OUT transmission gate enables chip-enable signal gating with 1.5ns propagation delay and 20–100Ω on-resistance during normal operation.

RESET assertion logic combines three independent conditions: VCC falling below 2.93V, WDI timeout (>1.00–2.25s), or MR/RESET IN assertion (not applicable to MAX6366). The open-drain RESET output remains asserted for ≥150ms after VCC recovery or watchdog event, ensuring µP initialization completes before release.

Key Specifications

Pinout & Package

MAX6366PKA29-T is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm) with gull-wing leads, RoHS-compliant and tape-and-reel packaged (2500 pcs/reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6366PKA29-T, MAX6366HKA29-T offers identical supervision and timing but eliminates external pull-up dependency, while TPS3808G33DBVR reduces cost and complexity at the expense of integrated fault-recovery capabilities.

Availability

MAX6366PKA29-T is available at Aetrix Electronics and suitable for portable POS terminals, industrial PLC controllers, medical handheld devices, and smart energy meters requiring stable component supply across extended production lifecycles.

Supply support for MAX6366PKA29-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 and mixed-signal ICs for power management, sensing, and connectivity in demanding industrial and automotive applications.

The MAX6365–MAX6368 family delivers integrated µP supervision with battery backup and chip-enable gating, targeting space-constrained embedded systems needing robust power-fault recovery without discrete component overhead.

FAQ

What is the exact reset threshold voltage of MAX6366PKA29-T?

The MAX6366PKA29-T has a factory-trimmed reset threshold of 2.93V with ±70mV tolerance over the full -40°C to +85°C operating range. This value is confirmed in the Reset Threshold Ranges table and Electrical Characteristics section of the official datasheet, where "KA29" suffix denotes the 2.85V–3.00V range centered at 2.93V. The MAX6366PKA29-T uses this precise threshold to reliably detect brownout on 3.3V rails.

Does MAX6366PKA29-T support both VCC and battery backup power sources simultaneously?

Yes, MAX6366PKA29-T supports dual-supply operation: it powers the connected SRAM or real-time clock from VCC during normal operation and automatically switches to the BATT source when VCC falls below the 2.93V threshold and VBATT exceeds VCC by at least 20mV. The internal MOSFET switchover circuit ensures seamless transition with 40mV hysteresis to prevent oscillation, and the MAX6366PKA29-T maintains backup current below 3µA to extend coin-cell life.

How does the watchdog function operate in MAX6366PKA29-T?

The MAX6366PKA29-T watchdog timer triggers a reset pulse if the WDI input remains static (high or low) for longer than 1.00–2.25s (1.6s typical). Each rising or falling edge on WDI resets the timer. When timeout occurs, the open-drain RESET output pulses low for 150–280ms. This behavior is documented in the Electrical Characteristics table and Typical Operating Characteristics graph MAX6365/8-14, confirming the MAX6366PKA29-T's role in detecting firmware hangs without CPU involvement.

What is the purpose of the CE IN and CE OUT pins on MAX6366PKA29-T?

The CE IN and CE OUT pins implement chip-enable signal gating: CE IN connects to the µP's chip-enable output, and CE OUT drives the SRAM's CE input. During normal operation, CE IN passes through with 1.5ns delay and low on-resistance. When RESET asserts, CE OUT is disabled-holding low for 12µs if CE IN was low-to prevent erroneous writes during power faults. This function is explicitly defined in the Pin Description and Detailed Description sections for MAX6366PKA29-T.

Can MAX6366PKA29-T operate with a 1.8V supply voltage?

Yes, MAX6366PKA29-T operates down to 1.2V VCC, fully supporting 1.8V systems. Its reset comparator, watchdog timer, and output drivers remain functional across the entire 1.2V–5.5V range, and RESET/RESET outputs are guaranteed valid down to 1.2V per the Electrical Characteristics table. This enables direct integration with ultra-low-voltage microcontrollers without level-shifting, as confirmed in the Absolute Maximum Ratings and Operating Voltage Range specifications for MAX6366PKA29-T.