Analog Devices Inc./Maxim Integrated MAX6835FXSD3

Overview

MAX6835FXSD3 from Maxim Integrated is a micropower voltage supervisor IC designed to monitor +1.05V supply rails in ultra-low-voltage microprocessor and digital systems. It features a factory-set 1.05V reset threshold (±2.5% over temperature), 210ms active timeout period, push-pull active-low RESET output, and debounced manual reset (MR) input. It operates down to VCC = 0.55V and draws only 7.5µA typical supply current, making it suitable for battery-powered portable equipment.

For engineers reviewing the MAX6835FXSD3 datasheet, MAX6835FXSD3 pinout, MAX6835FXSD3 application, or MAX6835FXSD3 equivalent, this device serves as a precision low-voltage reset solution with guaranteed reset validity at VCC ≥ 0.55V, immunity to short VCC transients, and compatibility with SC70-4 footprint constraints in space-constrained embedded designs.

Technical Context

The MAX6835FXSD3 implements a precision bandgap-based voltage comparator with 444mV internal reference, comparing VCC against its factory-trimmed 1.05V threshold. Its reset assertion logic includes fixed 210ms timeout after VCC recovery or MR release, with propagation delay of ≤60µs on VCC fall and ≤500ns on MR deassertion.

It integrates an internal 20kΩ pullup on the MR pin and guarantees push-pull RESET output drive capability: VOL ≤ 0.15V at ISINK = 15µA (VCC ≥ 0.55V), ensuring robust interface with CMOS µP reset inputs. The device is immune to VCC transients <100ns wide when overdrive exceeds 100mV.

Key Specifications

Pinout & Package

MAX6835FXSD3 is housed in a 4-pin SC70-4 package (2.0mm × 2.1mm, 0.5mm pitch), optimized for high-density portable PCBs. Pin 1 is GND, Pin 2 is RESET, Pin 3 is MR, and Pin 4 is VCC - consistent with JEDEC MO-203AA outline and compatible with standard SC70 reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with MAX6835FXSD3, MAX6381XR24-T targets higher supply voltages and lacks MR debounce, while TPS3123E10DBVR trades threshold accuracy and MR functionality for lower ICC - making MAX6835FXSD3 optimal for 1.05V systems requiring robust manual reset and industrial-grade tolerance.

Availability

MAX6835FXSD3 is available at Aetrix Electronics and suitable for portable medical sensors, wearable health monitors, industrial IoT edge nodes, and low-power microcontroller modules requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6835FXSD3 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, communications, and consumer applications.

The MAX6832–MAX6840 family was designed specifically for ultra-low-voltage microprocessor supervision in portable and battery-critical systems, emphasizing minimal ICC, small SC70 packaging, and precise factory-trimmed thresholds from 1.05V to 1.665V.

FAQ

What is the exact reset threshold voltage of the MAX6835FXSD3 and how stable is it over temperature?

The MAX6835FXSD3 has a factory-set reset threshold of 1.05V with ±2.5% accuracy over the full industrial temperature range (-40°C to +85°C). This specification is guaranteed by design and confirmed in the Electrical Characteristics table of the official datasheet. The device uses a precision bandgap reference and laser-trimmed resistors to maintain stability, and normalized threshold drift versus temperature is shown in Figure MAX6832-40 toc04.

Does the MAX6835FXSD3 include a manual reset input, and what are its electrical characteristics?

Yes, the MAX6835FXSD3 includes a debounced manual reset (MR) input on Pin 3. It features an internal 20kΩ pullup resistor to VCC, accepts CMOS-compatible logic levels (VIL ≤ 0.3×VCC, VIH ≥ 0.7×VCC), requires a minimum pulse width of 2µs, and rejects glitches shorter than 100ns. MR assertion forces immediate reset, and reset remains active for the full 210ms timeout after MR is released.

What is the guaranteed minimum VCC level at which the MAX6835FXSD3 maintains a valid RESET output?

The MAX6835FXSD3 guarantees valid active-low RESET output down to VCC = 0.55V. Below this voltage, the output stage becomes high-impedance. At VCC ≥ 0.55V, the push-pull driver ensures VOL ≤ 0.15V when sinking 15µA - sufficient to meet CMOS input low-level requirements for most µPs. This is explicitly specified in the Absolute Maximum Ratings and Electrical Characteristics tables.

How does the 210ms reset timeout period of the MAX6835FXSD3 compare to other options in the MAX6832–MAX6840 family?

The "D3" suffix in MAX6835FXSD3 denotes the 210ms active timeout period, one of five fixed options (D0 = 70µs, D1 = 1.5ms, D2 = 30ms, D3 = 210ms, D4 = 1680ms). This value is laser-trimmed and guaranteed over temperature. It is selected for applications requiring longer stabilization time than basic power-on reset - such as systems with slow-starting DC/DC converters or complex peripheral initialization sequences.

Is the MAX6835FXSD3 pin-compatible with legacy Maxim reset supervisors like the MAX809?

Yes, the MAX6835FXSD3 is explicitly stated in the datasheet to be pin-compatible with the MAX803/MAX809/MAX810, MAX6711–MAX6713, and MAX6381–MAX6390 series - all in SC70-4 package. Pin 1 = GND, Pin 2 = RESET, Pin 3 = MR, Pin 4 = VCC matches these families, enabling drop-in replacement in existing layouts where 1.05V threshold and 210ms timeout meet system requirements.