Analog Devices Inc./Maxim Integrated MAX6836FXSD3

Overview

MAX6836FXSD3 from Maxim Integrated is a push-pull active-high microprocessor supervisory circuit designed to monitor +1.2V to +1.8V supply rails in low-voltage digital systems. It asserts RESET when VCC falls below 1.050V (±2.5% over temperature) or MR is pulled low, with a fixed 210ms timeout after recovery. Its 7.5µA typical supply current and SC70-4 package support portable and battery-powered applications requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6836FXSD3 datasheet, MAX6836FXSD3 pinout, MAX6836FXSD3 application, or MAX6836FXSD3 equivalent, key selection criteria include its factory-set 1.050V reset threshold, 210ms active-high reset timeout, debounced manual reset input, guaranteed RESET validity down to VCC = 0.75V, and compatibility with ultra-low-voltage µP systems operating at 1.2V–1.8V.

Technical Context

The MAX6836FXSD3 implements a precision voltage comparator with ±2.5% threshold accuracy over –40°C to +85°C, referenced to an internal 444mV bandgap. Its reset logic includes a fixed 210ms timeout (D3 suffix), debounced MR input with 20kΩ internal pullup, and push-pull active-high RESET output capable of sourcing 50µA at 0.8×VCC down to VCC = 0.75V.

It operates across VCC = 0.75V to 3.6V, with guaranteed reset assertion during VCC fall below 1.050V and immunity to transients <100ns. The device uses BiCMOS process technology (681 transistors) and requires no external components for basic supervision functionality.

Key Specifications

Pinout & Package

MAX6836FXSD3 is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.5mm pitch), optimized for space-constrained portable designs. Pin 1 is GND, Pin 2 is RESET (push-pull active-high), Pin 3 is MR (debounced manual reset), and Pin 4 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6836FXSD3, the HXSD3 and VXSD3 variants share identical timing, packaging, and manual reset architecture but differ solely in factory-trimmed reset thresholds-enabling precise matching to specific supply rail voltages without redesigning the supervision circuit.

Availability

MAX6836FXSD3 is available at Aetrix Electronics and suitable for portable medical sensors, wearable health monitors, industrial IoT edge nodes, low-power microcontroller modules, and battery-backed memory systems requiring stable component supply and long-term lifecycle support.

Supply support for MAX6836FXSD3 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, mixed-signal, and power management ICs for demanding industrial, automotive, and computing applications.

The MAX6832–MAX6840 family delivers ultra-low-voltage supervision for sub-1.8V digital systems, targeting portable, battery-powered, and energy-efficient embedded platforms where space, power, and reliability are critical.

FAQ

What is the exact reset threshold voltage of the MAX6836FXSD3 and how accurate is it over temperature?

The MAX6836FXSD3 has a factory-set reset threshold of 1.050V with ±2.5% accuracy over the full operating temperature range of –40°C to +85°C. This specification is guaranteed by design and verified across production lots. The threshold remains stable due to internal bandgap referencing and hysteresis of 0.75% of VTH, ensuring noise immunity during marginal supply conditions. This accuracy enables reliable operation in 1.2V core domains without external calibration.

Does the MAX6836FXSD3 require external components to function as a reset supervisor?

No, the MAX6836FXSD3 requires no external components for basic supervision functionality. Its 1.050V threshold is factory-trimmed, the 210ms timeout is internally generated, and the MR input includes a 20kΩ internal pullup resistor. Only decoupling capacitance (e.g., 0.1µF near VCC) is recommended for transient immunity. Unlike open-drain supervisors, the push-pull active-high RESET output eliminates the need for an external pullup resistor.

How does the MAX6836FXSD3 behave when VCC drops below 0.75V?

The MAX6836FXSD3 guarantees valid RESET output down to VCC = 0.75V for active-high operation. Below this voltage, the push-pull driver may not maintain full VOH compliance, though RESET remains asserted as long as VCC stays above the 1.050V threshold hysteresis band. For applications requiring RESET validity down to 0V, a 100kΩ pullup resistor to VCC is recommended per Maxim's application guidance to ensure defined logic level during deep brownout.

Is the MAX6836FXSD3 pin-compatible with other devices in the MAX6832–MAX6840 family?

Yes, the MAX6836FXSD3 shares identical SC70-4 pinout and terminal functions with all MAX6835/MAX6836/MAX6837 variants. Pin 1 = GND, Pin 2 = RESET, Pin 3 = MR, Pin 4 = VCC. This allows drop-in replacement across threshold (F/H/V/I/G/W) and timeout (D0–D4) variants without PCB modification, enabling design flexibility and inventory rationalization across multiple voltage and timing requirements.

What is the purpose of the debounced MR input on the MAX6836FXSD3?

The debounced MR input on the MAX6836FXSD3 rejects noise spikes shorter than 100ns and accepts minimum pulse widths of 2µs, allowing direct connection of mechanical pushbuttons without external RC filters. Internally, it includes a 20kΩ pullup to VCC, so the pin can be left floating if unused. This feature simplifies system-level reset implementation in handheld and field-deployable equipment where EMI and switch bounce are common concerns.