Analog Devices Inc./Maxim Integrated MAX6865UK30D5L+T

Overview

The MAX6865UK30D5L+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, combining voltage monitoring, manual reset input (MR), and watchdog timer (WDI) functions. It asserts an active-high push-pull RESET output when VCC drops below 3.000V (±2.5%), MR is pulled low, or the watchdog times out after 209s (typ). Designed for ultra-low-power systems, it draws only 170nA (typ) at 2.5V and guarantees valid reset operation down to VCC = 1.1V.

For engineers reviewing the MAX6865UK30D5L+T datasheet, MAX6865UK30D5L+T pinout, MAX6865UK30D5L+T application, or MAX6865UK30D5L+T equivalent, key selection criteria include its 3.0V reset threshold, 300ms minimum reset timeout (D5), 209s watchdog period (L suffix), active-high push-pull RESET output, and immunity to short VCC transients - all critical for battery-powered medical and portable electronics.

Technical Context

This device implements a precision bandgap-based voltage monitor with 2.5% threshold tolerance and 0.5% hysteresis, coupled with a digital watchdog timer that clears on any WDI edge and expires if WDI remains static beyond 209s (typ). The internal reset timeout generator provides fixed 300ms (D5) assertion after VCC recovery or MR release.

The MR input features 10kΩ internal pullup, 1µs minimum pulse width, and 200ns glitch rejection; the WDI input accepts CMOS-level signals with 0.3×VCC/0.7×VCC thresholds and supports 150ns minimum pulse width. RESET output delivers VOH ≥ 0.8×VCC (ISOURCE = 500µA) and VOL ≤ 0.3V (ISINK = 1.2mA) under specified conditions.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Compact footprint (2.9mm × 1.6mm × 1.1mm) optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6864UK30D5S+T and TPS3836K33DBVR, the MAX6865UK30D5L+T uniquely combines 3.0V supervision, 300ms reset hold, and 209s watchdog in a single active-high push-pull output - reducing BOM count and layout complexity for long-duration battery-powered medical devices.

Availability

MAX6865UK30D5L+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign loggers, smart hearing aids, and industrial wireless sensors requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK30D5L+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, medical, and communications applications.

The MAX6854–MAX6869 family was designed specifically for ultra-low-power microprocessor supervision in battery-critical portable medical and consumer electronics, integrating voltage monitoring, manual reset, and configurable watchdog functionality into minimal-area SOT23 packages.

FAQ

What is the exact reset threshold voltage of the MAX6865UK30D5L+T?

The MAX6865UK30D5L+T has a factory-trimmed reset threshold of 3.000V with ±2.5% tolerance over -40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "30" corresponds to 3.000V nominal. The device guarantees valid reset assertion down to VCC = 1.1V, making it suitable for deep brownout protection in the MAX6865UK30D5L+T application space.

Does the MAX6865UK30D5L+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK30D5L+T includes a watchdog timer with a typical timeout period of 209 seconds, indicated by the "L" suffix in the part number. The timer clears on any rising or falling edge at the WDI pin and expires only if WDI remains static beyond this period. This long timeout is ideal for firmware tasks such as sensor calibration or BLE connection establishment in the MAX6865UK30D5L+T's target applications.

What type of RESET output does the MAX6865UK30D5L+T provide, and how is it configured?

The MAX6865UK30D5L+T provides an active-high push-pull RESET output, as confirmed by its pin description (Pin 1 = RESET, active-high) and Selector Guide. This eliminates the need for an external pullup resistor and allows direct interfacing with microcontrollers requiring high-active reset inputs. The output delivers VOH ≥ 0.8×VCC at 500µA source current, ensuring robust logic-level compatibility across the MAX6865UK30D5L+T's 1.2V–5.5V operating range.

What is the reset timeout period for the MAX6865UK30D5L+T, and how is it selected?

The MAX6865UK30D5L+T has a fixed minimum reset timeout period of 300ms, denoted by the "D5" suffix per Table 4 (Reset Timeout Periods). This duration is factory-set and non-adjustable - unlike the CT-selectable MAX6861–MAX6863 variants. The 300ms hold time ensures sufficient delay for power supply stabilization and µP internal initialization before releasing reset in the MAX6865UK30D5L+T circuit design.

Is the MAX6865UK30D5L+T compatible with standard SOT23-5 footprints and reflow processes?

Yes, the MAX6865UK30D5L+T uses a standard 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm) with lead-free termination (+T suffix), fully compliant with IPC-7351B footprint standards and JEDEC J-STD-020 reflow profiles. Its pinout matches the MAX6864–MAX6866 series, enabling drop-in replacement in existing layouts - a key advantage for production continuity of the MAX6865UK30D5L+T in high-volume medical and portable designs.