Analog Devices Inc./Maxim Integrated MAX6835HXSD3

Overview

MAX6835HXSD3 from Maxim Integrated is a precision ultra-low-voltage microprocessor supervisory circuit in SC70-4 package, featuring 1.313V factory-set reset threshold, 210ms active timeout period (D3 suffix), push-pull active-low RESET output, and debounced manual reset input (MR). It monitors +1.2V to +1.8V supplies in portable systems and ensures reliable power-on reset during brownout conditions.

For engineers reviewing the MAX6835HXSD3 datasheet, MAX6835HXSD3 pinout, MAX6835HXSD3 application, or MAX6835HXSD3 equivalent, this device serves as a low-power (7.5µA typ), ±2.5% threshold-accurate reset supervisor for battery-powered µP systems requiring guaranteed reset assertion down to VCC = 0.55V and immunity to sub-100ns MR glitches.

Technical Context

The MAX6835HXSD3 implements a precision bandgap-based voltage comparator with 444mV internal reference, driving a fixed-timing reset state machine. Its reset assertion logic responds to VCC falling below 1.313V or MR pulled low, holding RESET low for exactly 210ms after recovery - independent of supply ramp rate or temperature.

It integrates an internal 20kΩ MR pullup resistor and supports CMOS-level MR drive; the push-pull RESET output sinks ≥15µA at VCC ≥ 0.55V and maintains valid logic levels across full -40°C to +85°C operation without external components.

Key Specifications

Pinout & Package

MAX6835HXSD3 is housed in a 4-pin SC70 package (1.3mm × 1.1mm, 0.5mm pitch) with exposed pad option not specified. Pin 1 = GND, Pin 2 = RESET (push-pull active-low), Pin 3 = MR (debounced manual reset input), Pin 4 = VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6835HXSD3, MAX6835VXSD3 shifts threshold upward for higher-voltage rails while maintaining identical timing and interface behavior; MAX6835HXSD0 retains the same threshold but sacrifices 210ms reliability hold time for nanosecond-scale detection speed - making it unsuitable as a standalone µP reset solution.

Availability

MAX6835HXSD3 is available at Aetrix Electronics and suitable for portable medical sensors, wearable fitness trackers, and industrial IoT edge nodes requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for MAX6835HXSD3 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, sensing, and interface applications in industrial, automotive, and consumer systems.

The MAX6832–MAX6840 family was engineered specifically for ultra-low-voltage microprocessor supervision in battery-powered equipment, delivering sub-1V reset validity, nanoamp quiescent current, and SC70 packaging for minimal board area.

FAQ

What is the exact reset threshold voltage of the MAX6835HXSD3 and how stable is it over temperature?

The MAX6835HXSD3 has a factory-set reset threshold of 1.313V with ±2.5% accuracy over the full -40°C to +85°C operating range. This specification is guaranteed by design and 100% production tested at +25°C. The threshold remains stable due to an internal bandgap reference and hysteresis of 0.75% of VTH, preventing chatter near trip point.

Does the MAX6835HXSD3 require an external pullup resistor on its RESET pin?

No, the MAX6835HXSD3 features a push-pull active-low RESET output, so no external pullup resistor is needed. The output actively drives LOW during reset and HIGH otherwise, enabling direct connection to standard µP reset inputs without additional components - unlike open-drain variants such as MAX6834/MAX6837.

What is the function of the MR pin on the MAX6835HXSD3 and how should it be used?

The MR pin on the MAX6835HXSD3 is a debounced, active-low manual reset input with an internal 20kΩ pullup to VCC. To initiate a reset, pull MR to GND via a momentary switch; release to allow automatic 210ms timeout. No external debounce circuitry is required, and MR accepts standard CMOS logic levels.

Can the MAX6835HXSD3 operate reliably at VCC = 0.6V?

Yes - the MAX6835HXSD3 guarantees valid reset assertion down to VCC = 0.55V. At 0.6V, the device remains fully functional: RESET output sinks ≥15µA, MR input is responsive, and the 1.313V threshold comparator operates correctly. Below 0.55V, RESET becomes high-impedance, but this is outside specified operation.

How does the 210ms timeout period (D3 suffix) of the MAX6835HXSD3 compare to other options in the family?

The D3 suffix denotes a 210ms reset active timeout period - one of five fixed values (70µs, 1.5ms, 30ms, 210ms, 1.68s). This duration exceeds typical ARM Cortex-M boot times and provides robust margin against slow power-rail rise times, making it the most widely adopted option for general-purpose µP reset in portable systems using the MAX6835HXSD3.