Analog Devices Inc./Maxim Integrated MAX6328XR22+T

Overview

MAX6328XR22+T from Maxim Integrated is an ultra-low-power open-drain microprocessor supervisory circuit that monitors VCC supply voltage and asserts an active-low reset signal when voltage falls below 2.20V, maintaining reset for ≥100ms after recovery. It operates from 1.2V to 5.5V, draws ≤1µA supply current, and is housed in a 3-pin SC70 package - ideal for battery-powered µP systems requiring brownout protection.

For engineers reviewing the MAX6328XR22+T datasheet, MAX6328XR22+T pinout, MAX6328XR22+T application, or MAX6328XR22+T equivalent, key selection criteria include its factory-trimmed 2.20V reset threshold (±2.5% over –40°C to +85°C), open-drain output compatibility with bidirectional µP reset pins, transient immunity up to 200µs at 100mV overdrive, and lead-free SC70-3 packaging.

Technical Context

The MAX6328XR22+T implements a precision bandgap-based reset comparator with 40ppm/°C tempco and 6.3mV hysteresis, ensuring stable threshold behavior across temperature. Its internal timing circuit guarantees a minimum 100ms power-up reset timeout and responds to VCC drops within 20µs.

As an open-drain device, it requires an external pull-up resistor and interfaces directly with µPs like the Motorola 68HC11 having bidirectional reset I/O. It ignores fast negative-going transients on VCC - immune to glitches ≤200µs at 100mV overdrive - and remains functional down to VCC = 1.2V.

Key Specifications

Pinout & Package

The MAX6328XR22+T is supplied in a 3-pin SC70 package (outline X3-2, land pattern 90-0208), with 0.65mm pitch and exposed pad not present. Pin 1 is GND, Pin 2 is open-drain RESET, Pin 3 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TR22+T and TPS3808G12DBVR, the MAX6328XR22+T uniquely combines ultra-low 1µA supply current, factory-trimmed 2.20V threshold, and open-drain output in a 3-pin SC70 - making it optimal for space- and power-constrained designs where reset line sharing or µP bidirectional compatibility is mandatory.

Availability

MAX6328XR22+T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart energy meters, and automotive body control units requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6328XR22+T 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 industrial, computing, and communications applications.

The MAX6326/MAX6327/MAX6328 family delivers ultra-low-power, factory-trimmed µP supervisors targeting battery-operated and space-constrained embedded systems requiring deterministic reset behavior under brownout and transient conditions.

FAQ

What is the exact reset threshold voltage of MAX6328XR22+T and how does it vary with temperature?

The MAX6328XR22+T has a nominal reset threshold of 2.20V at +25°C, with guaranteed tolerance of ±2.5% over the full operating range of –40°C to +85°C. Its temperature coefficient is 40ppm/°C, resulting in a maximum total drift of approximately 14.4mV across the temperature range - well within the 6.3mV hysteresis window to prevent chatter.

Does MAX6328XR22+T require an external pull-up resistor on the RESET pin?

Yes, MAX6328XR22+T features an open-drain RESET output and requires an external pull-up resistor to a valid logic-high voltage (e.g., VCC or IOVDD). Typical values range from 4.7kΩ to 10kΩ. Without this resistor, the RESET signal cannot be pulled high and the supervised µP will remain held in reset indefinitely.

Can MAX6328XR22+T operate reliably at VCC = 1.2V?

Yes, MAX6328XR22+T is fully specified to operate down to VCC = 1.2V over the full temperature range. At this voltage, it maintains correct reset assertion state and delivers RESET output low voltage (VOL) ≤0.4V with 100µA sink current - enabling use in ultra-low-voltage systems such as energy-harvesting nodes and backup power domains.

How does the transient immunity of MAX6328XR22+T compare to standard reset ICs?

MAX6328XR22+T rejects VCC transients up to 200µs in duration when the overdrive (VTH – VCC) is 100mV - significantly exceeding typical 10–50µs immunity of basic reset ICs. This is achieved via internal filtering and comparator design optimized to ignore short glitches, reducing false resets in electrically noisy environments like motor drives or automotive subsystems.

Is MAX6328XR22+T pin-compatible with other members of the MAX632x family?

Yes, MAX6328XR22+T shares identical 3-pin SC70 pinout (GND, RESET, VCC) with all MAX6326/MAX6327/MAX6328 variants in the XR package. However, output type differs: MAX6326/MAX6346 are push-pull, while MAX6328/MAX6348 are open-drain. Swapping requires verifying external pull-up presence and µP reset pin compatibility - MAX6328XR22+T is not a drop-in replacement for push-pull versions.