Analog Devices Inc./Maxim Integrated MAX6348XR35

Overview

MAX6348XR35 from Maxim Integrated is an ultra-low-power open-drain microprocessor reset supervisor IC designed to monitor 3.3V power supplies in embedded digital systems. It asserts an active-low reset signal when VCC falls below 3.5V (±1.5% at +25°C), holds reset for ≥100ms after VCC recovers, and draws ≤1µA supply current. It operates over -40°C to +85°C and is used in battery-powered controllers requiring reliable brownout protection.

For engineers reviewing the MAX6348XR35 datasheet, MAX6348XR35 pinout, MAX6348XR35 application, or MAX6348XR35 equivalent, key selection criteria include its factory-trimmed 3.5V reset threshold, SC70-3 open-drain output architecture, guaranteed 1V minimum operating voltage, and immunity to fast VCC transients up to 200µs at 100mV overdrive.

Technical Context

The MAX6348XR35 implements a precision bandgap-based reset comparator with 1.5% initial accuracy and 40ppm/°C temperature coefficient, ensuring stable threshold behavior across industrial temperature range. Its open-drain RESET output requires an external pull-up and supports bidirectional reset interfacing with µPs like the Motorola 68HC11.

It features built-in transient immunity: negative-going VCC glitches shorter than 185µs at 100mV overdrive (VTH – VCC) are rejected, preventing false resets. The device remains functional down to VCC = 1V, enabling operation during deep brownout conditions before full system shutdown.

Key Specifications

Pinout & Package

MAX6348XR35 is housed in a 3-pin SC70 package (2.0mm × 2.1mm × 0.9mm), optimized for space-constrained portable designs. Pin 1 is GND, Pin 2 is open-drain RESET, and Pin 3 is VCC - identical pinout to SOT23-3 but with smaller footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6348XR35, MAX809TR35D3T offers push-pull simplicity but lacks bidirectional interface capability, while TPS3808G33DBVR provides lower threshold precision for 3.3V rails but increases PCB area and quiescent current by 80%.

Availability

MAX6348XR35 is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, automotive body electronics, smart energy meters, and battery-powered instrumentation requiring stable component supply with long-term traceability.

Supply support for MAX6348XR35 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, automotive, and communications markets.

The MAX63xx family was designed specifically for ultra-low-power, precision voltage monitoring in space- and energy-constrained microprocessor systems, emphasizing reliability, minimal external components, and wide temperature operation.

FAQ

What is the exact reset threshold voltage of MAX6348XR35 and how tightly is it specified?

The MAX6348XR35 has a factory-trimmed reset threshold of 3.5V, with initial accuracy of ±1.5% at +25°C and guaranteed performance over -40°C to +85°C. Its temperature coefficient is 40ppm/°C, resulting in total variation of less than ±25mV across the full industrial temperature range. This precision eliminates need for external calibration and ensures robust brownout detection for 3.3V systems.

Does MAX6348XR35 require an external pull-up resistor on its RESET pin?

Yes, MAX6348XR35 features an open-drain RESET output and requires an external pull-up resistor to VCC or another logic rail. Typical values range from 10kΩ to 100kΩ depending on bus capacitance and rise-time requirements. This architecture enables wired-OR configurations and direct interfacing with bidirectional µP reset pins such as those found on Motorola 68HC11 derivatives.

Can MAX6348XR35 operate reliably when VCC drops below 2.0V?

Yes, MAX6348XR35 is fully specified to operate down to VCC = 1.0V, and its reset comparator remains functional and accurate throughout this range. This guarantees that the device continues asserting RESET during deep brownout conditions - critical for preserving SRAM contents and preventing partial execution in low-power microcontrollers before full shutdown.

How does MAX6348XR35 handle fast voltage transients on the VCC line?

MAX6348XR35 incorporates transient-immune design: its reset comparator ignores negative-going VCC glitches shorter than 185µs when the overdrive (VTH – VCC) is 100mV. This rejection window scales inversely with overdrive amplitude - e.g., 200µs at 50mV overdrive - eliminating need for external RC filters while preventing false resets caused by switching noise or ESD coupling.

Is MAX6348XR35 pin-compatible with legacy Maxim reset supervisors like MAX809?

Yes, MAX6348XR35 uses the same SC70-3 footprint and identical pinout (GND–RESET–VCC) as MAX809 series devices. While electrical behavior differs - MAX809 has push-pull output whereas MAX6348XR35 is open-drain - mechanical compatibility allows direct substitution in layouts designed for MAX809/MAX810, provided the external pull-up is present and system logic accommodates active-low open-drain signaling.