Analog Devices Inc./Maxim Integrated MAX6337US22D3

Overview

MAX6337US22D3 from Maxim Integrated is an ultra-low-voltage, open-drain microprocessor supervisory circuit designed for 1.8V–3.3V digital systems. It monitors VCC and asserts an active-low RESET signal when supply voltage falls below 2.20V (±3% over temperature) or when manual reset is triggered, with a guaranteed minimum 100ms timeout period and valid operation down to VCC = 1.0V. Used in portable equipment and automotive controllers for reliable power-on/brownout reset generation.

For engineers reviewing the MAX6337US22D3 datasheet, MAX6337US22D3 pinout, MAX6337US22D3 application, or MAX6337US22D3 equivalent, key selection criteria include its 2.2V factory-trimmed reset threshold, 100ms minimum reset timeout, open-drain output architecture, -40°C to +125°C operating range, and SOT143 package compatibility with MAX811/MAX6314 families.

Technical Context

The MAX6337US22D3 implements a precision bandgap-based reset comparator with factory-trimmed 2.20V threshold (±1.8% at +25°C, ±3% over full temperature range), immune to fast VCC transients up to 24µs at 10mV overdrive. Its internal debounced manual-reset input (MR) features a 20kΩ pull-up resistor and requires only a momentary switch to GND.

This device uses an open-drain RESET output requiring an external pull-up resistor, enabling direct interface with bidirectional µP reset pins (e.g., Motorola 68HC11) and wired-OR configurations. It guarantees correct RESET state down to VCC = 1.0V - unlike push/pull variants (MAX6335/36) rated to 0.7V - and draws only 3.3µA typical supply current at 2.5V.

Key Specifications

Pinout & Package

MAX6337US22D3 is housed in a 4-pin SOT143 surface-mount package (3.0mm × 1.6mm × 0.9mm), optimized for space-constrained PCB layouts. The package is lead-free compatible (suffix +T) and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6336US22D3-T and MAX811TEUS22D3-T, the MAX6337US22D3 uniquely combines open-drain flexibility, 1.0V minimum VCC operation, and 3.3µA supply current - making it optimal for battery-powered and automotive applications demanding both interface compatibility and energy efficiency.

Availability

MAX6337US22D3 is available at Aetrix Electronics and suitable for portable instrumentation, automotive body control modules, and industrial sensor nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6337US22D3 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 analog and mixed-signal ICs for power, sensing, and interface applications.

The MAX633x family delivers ultra-low-voltage, low-power reset supervision for microprocessor-based systems - targeting portable, automotive, and industrial applications where reliability, small size, and minimal power consumption are critical.

FAQ

What is the factory-trimmed reset threshold voltage for MAX6337US22D3?

The MAX6337US22D3 has a factory-trimmed reset threshold of 2.20V, with ±1.8% accuracy at +25°C and ±3% over the full -40°C to +125°C operating range. This value is laser-trimmed during production and specified in Table 1 of the datasheet - it applies exclusively to the "US22" suffix variant and ensures precise brownout detection for 2.5V and 1.8V power rails without external calibration.

Does MAX6337US22D3 require an external pull-up resistor on the RESET pin?

Yes, MAX6337US22D3 requires an external pull-up resistor on the RESET pin because it features an open-drain output structure. The datasheet recommends standard values between 10kΩ and 100kΩ depending on bus capacitance and rise-time requirements. Without this resistor, the RESET signal cannot achieve a defined logic-high state, compromising system reset functionality.

What is the minimum supply voltage at which MAX6337US22D3 guarantees correct RESET assertion?

MAX6337US22D3 guarantees correct RESET assertion and deassertion down to VCC = 1.0V - a key differentiator from the MAX6335/MAX6336 variants, which are rated to 0.7V. This specification ensures reliable operation during deep brownout conditions in 1.8V systems, though the device ceases to function entirely below 1.0V.

Can MAX6337US22D3 interface directly with a Motorola 68HC11 microcontroller?

Yes, MAX6337US22D3 is explicitly designed for direct interface with Motorola 68HC11 and other µPs featuring bidirectional reset pins. Its open-drain RESET output allows seamless connection using a single external pull-up resistor, enabling either the supervisor or the µP to assert reset - a capability confirmed in the Applications Information section and Figure 1 of the MAX6337US22D3 datasheet.

What is the maximum transient duration that MAX6337US22D3 can ignore on the VCC line?

MAX6337US22D3 can ignore negative-going VCC transients up to 24µs in duration when the overdrive is 10mV - per the "Maximum Transient Duration vs. Reset Comparator Overdrive" graph in the Typical Operating Characteristics. This immunity prevents false resets caused by common power-supply noise, especially important in automotive and industrial environments with switching loads.