Analog Devices Inc./Maxim Integrated MAX6865UK33D6S+T

Overview

The MAX6865UK33D6S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 3.3V reset threshold (±2.5%), and a 1200ms minimum reset timeout period. It integrates manual reset input (MR), watchdog timer with 209s typical timeout, and active-high push-pull RESET output - designed for reliable power-on reset and brownout protection in battery-critical systems like glucose monitors and portable medical devices.

For engineers reviewing the MAX6865UK33D6S+T datasheet, MAX6865UK33D6S+T pinout, MAX6865UK33D6S+T application, or MAX6865UK33D6S+T equivalent, key selection considerations include its guaranteed reset validity down to VCC = +1.1V, immunity to short VCC transients (<40µs at 100mV overdrive), watchdog input edge sensitivity (150ns pulse width), and lead-free SOT23-5 packaging compliant with RoHS requirements.

Technical Context

The MAX6865UK33D6S+T implements a dual-monitoring architecture: a precision voltage detector triggers reset when VCC falls below 3.3V (±2.5%), while a dedicated watchdog timer monitors WDI activity and expires after 209s (typ) if no edge transition occurs. Reset assertion persists for 1200ms (min) post-recovery, ensuring µP initialization completes before release.

Its MR input features internal 10kΩ pullup and 250ns MR-to-reset delay, supporting momentary switch interfaces without external debounce. The active-high push-pull RESET output delivers VOH ≥ 0.8×VCC at ISOURCE = 500µA and VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.38V), enabling direct interfacing with 1.8V–5.5V logic domains.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, RoHS-compliant, footprint compatible with industry-standard 5-pin SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6865UK33D6S+T, the L-suffix variant offers identical functionality with longer watchdog timeout, while TPS3838K33DBVR provides simpler reset-only supervision at significantly higher quiescent current - making MAX6865UK33D6S+T optimal for battery-constrained, watchdog-dependent designs.

Availability

MAX6865UK33D6S+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered IoT sensors, wearable health trackers, and low-power industrial telemetry requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK33D6S+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 interface applications in demanding industrial, medical, and automotive environments.

The MAX6854–MAX6869 family delivers nanopower supervisory functions - specifically engineered for ultra-long-life battery operation in portable medical and wearables, with integrated watchdog, manual reset, and factory-trimmed thresholds.

FAQ

What is the exact reset threshold voltage of the MAX6865UK33D6S+T?

The MAX6865UK33D6S+T has a factory-trimmed reset threshold of 3.3V with ±2.5% tolerance over -40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) where suffix "33" corresponds to 3.218V (min), 3.300V (typ), and 3.383V (max). The device requires no external components to achieve this accuracy.

Does the MAX6865UK33D6S+T include a watchdog timer, and what is its timeout?

Yes, the MAX6865UK33D6S+T includes a watchdog timer with a typical timeout of 209s (L suffix), as specified in Table 3 (Watchdog Timeout). The "S" in the part number denotes the 3.3s option, but per the Ordering Information section, MAX6865UK33D6S+T uses the "S" suffix for watchdog - however, cross-referencing the Selector Guide and Pin Description confirms MAX6865 is a watchdog-enabled variant, and the "S" in this specific ordering code maps to the 3.3s timeout (1.5s min, 3.3s typ, 7.75s max).

What is the reset output type and drive capability of the MAX6865UK33D6S+T?

The MAX6865UK33D6S+T features an active-high push-pull RESET output. It sources ≥0.8×VCC at 500µA (VOH) and sinks ≤0.3V at 1.2mA (VOL) when VCC ≥ 2.38V. This allows direct connection to µP reset inputs without external pull-up resistors and supports interoperability across 1.8V–5.5V logic families.

How does the manual reset (MR) input behave on the MAX6865UK33D6S+T?

The MR input on MAX6865UK33D6S+T is active-low with internal 10kΩ pullup to VCC. Driving MR low initiates reset assertion for the full 1200ms timeout period, even if MR returns high earlier. It rejects glitches <200ns and exhibits 250ns propagation delay from MR low to RESET high, enabling reliable switch-based reset without external filtering.

Is the MAX6865UK33D6S+T compatible with lead-free reflow processes?

Yes, the "+T" suffix in MAX6865UK33D6S+T explicitly indicates lead-free, RoHS-compliant packaging. The device is qualified for standard Pb-free reflow profiles (JEDEC J-STD-020), with maximum lead temperature rated at +300°C for 10 seconds, matching industry-standard SOT23-5 assembly requirements.