Analog Devices Inc./Maxim Integrated MAX6386XS29D1+T

Overview

MAX6386XS29D1+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 2.93V reset threshold (±2.5% over -40°C to +125°C), 140ms minimum VCC reset timeout, and debounced manual reset input (MR) with internal 63kΩ pullup. It monitors single supply voltage in battery-powered embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6386XS29D1+T datasheet, MAX6386XS29D1+T pinout, MAX6386XS29D1+T application, or MAX6386XS29D1+T equivalent, key selection criteria include its 4-pin SC70 package, 3μA supply current at 1.8V, guaranteed reset validity down to VCC = 1V, and compatibility with dual-voltage monitoring systems via external resistor dividers.

Technical Context

The MAX6386XS29D1+T implements a precision bandgap-based reset comparator with ±2.5% threshold accuracy across temperature, paired with a monotonic RC-based timeout timer. Its MR input features built-in glitch rejection (100ns) and 1µs minimum pulse width requirement, eliminating need for external debounce circuitry.

This device operates within 1.0V–5.5V supply range and guarantees correct reset logic state even as VCC decays to 1V; the open-drain RESET output requires an external pullup and sinks up to 3.2mA at VCC ≥ 4.5V with VOL ≤ 0.4V.

Key Specifications

Pinout & Package

MAX6386XS29D1+T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 2.0mm × 2.1mm × 0.95mm, suitable for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR29D3+T and TPS3808G33DBVR, MAX6386XS29D1+T uniquely combines open-drain output, integrated MR with pullup, and ultra-low 3μA supply current in a 4-pin SC70 - making it optimal for space- and power-constrained designs requiring field-serviceable reset.

Availability

MAX6386XS29D1+T is available at Aetrix Electronics and suitable for battery-powered IoT sensors, industrial PLC I/O modules, medical wearables, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for MAX6386XS29D1+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, automotive, communications, and computing applications.

The MAX6381–MAX6390 family delivers single/dual low-voltage, low-power μP reset circuits optimized for reliability-critical embedded systems where supply monitoring, brownout protection, and manual reset capability are essential.

FAQ

What is the exact reset threshold voltage of MAX6386XS29D1+T and how stable is it over temperature?

The MAX6386XS29D1+T has a factory-set nominal reset threshold of 2.93V, with guaranteed accuracy of ±2.5% over the full operating temperature range of -40°C to +125°C. This stability is achieved through laser-trimmed bandgap references and low-tempco design, ensuring consistent trip points in automotive and industrial environments where thermal cycling is common. The MAX6386XS29D1+T maintains this specification without requiring external calibration or compensation.

Does MAX6386XS29D1+T require an external pullup resistor on the RESET pin?

Yes, MAX6386XS29D1+T features an open-drain active-low RESET output, which requires an external pullup resistor to the appropriate logic rail (e.g., 3.3V or 5V). The value is typically 10kΩ–100kΩ depending on bus capacitance and rise-time requirements. Unlike push-pull variants, the MAX6386XS29D1+T cannot drive high actively, so omission of the pullup will result in undefined or floating reset states. This architecture enables wired-OR configurations and voltage-level translation.

Can MAX6386XS29D1+T monitor a second voltage rail like some other members of the MAX6381–MAX6390 family?

No, MAX6386XS29D1+T does not include a RESET IN input and is designed exclusively for single-rail supervision. Devices such as MAX6387, MAX6388, and MAX6389 provide auxiliary RESET IN pins for monitoring a second voltage via external resistor divider. The MAX6386XS29D1+T's pinout and internal architecture omit this feature - its function is strictly VCC monitoring plus manual reset. For dual-rail applications, a separate supervisor or redesign using a RESET IN–capable variant is required.

What is the minimum VCC voltage at which MAX6386XS29D1+T guarantees correct RESET output logic state?

MAX6386XS29D1+T guarantees valid RESET output logic state down to VCC = 1.0V. Below this, the internal comparators and timer may become indeterminate. This specification ensures robust brownout detection even during severe undervoltage events - for example, when a lithium battery discharges below 2.5V. The guarantee applies across the full -40°C to +125°C temperature range and is validated in the device's electrical characteristics table under "RESET Output State Guaranteed Valid Down to VCC = 1V".

Is MAX6386XS29D1+T pin-compatible with legacy Maxim reset ICs like MAX809 or MAX6326?

MAX6386XS29D1+T is not pin-compatible with MAX809 (3-pin SOT-23) or MAX6326 (3-pin SC70), due to its 4-pin SC70 configuration and inclusion of MR. However, it shares functional equivalence and package outline compatibility with other 4-pin SC70 variants in the MAX6384–MAX6390 series. Pin mapping differs fundamentally: MAX6386XS29D1+T uses pins 1(VCC), 2(GND), 3(MR), 4(RESET), whereas MAX809 uses 1(VCC), 2(GND), 3(RES). Direct replacement requires PCB layout revision.