Infineon Technologies MB3771PF-GT-BND-K5ERE1

Overview

MB3771PF-GT-BND-K5ERE1 from Cypress Semiconductor is a dual-threshold power supply monitor IC designed to protect microprocessor systems by generating a reset signal when +5 V or an arbitrary supply (≥1.23 V) deviates beyond ±2.5% (VSA = 4.20 V) or ±1.5% (VSB = 1.23 V). It features hysteresis, low-power operation (0.35 mA typ), open-collector RESET output, and supports delayed-trigger detection via external capacitor on CT pin. Used in memory boards and large-scale computer systems.

For engineers reviewing the MB3771PF-GT-BND-K5ERE1 datasheet, MB3771PF-GT-BND-K5ERE1 pinout, MB3771PF-GT-BND-K5ERE1 application, or MB3771PF-GT-BND-K5ERE1 equivalent, key selection criteria include precision dual-voltage monitoring capability, built-in hysteresis per comparator, CT-based reset timing control, and compatibility with both 5 V and arbitrary positive supply rails above 1.23 V.

Technical Context

The MB3771 integrates three comparators: Comp.A monitors VSA (4.20 V ±2.5%) with hysteresis for main 5 V rail supervision; Comp.B monitors VSB (1.23 V ±1.5%) with hysteresis and serves as user-configurable threshold input or forced-reset input; Comp.C is a non-hysteretic open-collector comparator referenced to 1.245 V for overvoltage detection or reference generation.

It operates across 3.5–18 V supply range, delivers RESET low at VCC ≥ 0.8 V, sustains reset hold time (tPO = 0.5–1.5 ms) controlled by CT capacitor, and detects transients as short as 5 µs (tPI) while supporting delayed triggering via RC filtering on VSA/VSB pins.

Key Specifications

Pinout & Package

SOP-8 package (SOE008), surface-mount, 150 mil body width, 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power supply monitor applications.

Compared with MAX692CPA+ and TL7705ACPSR, the MB3771PF-GT-BND-K5ERE1 provides unique dual-threshold supervision with independent hysteresis, CT-based timing control, and integrated forced-reset capability-enabling compact, flexible, and deterministic power sequencing in multi-rail embedded systems.

Availability

MB3771PF-GT-BND-K5ERE1 is available at Aetrix Electronics and suitable for industrial PLC control systems, legacy computer memory boards, and telecom line cards requiring stable component supply and long-term lifecycle support.

Supply support for MB3771PF-GT-BND-K5ERE1 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

Cypress Semiconductor (now part of Infineon Technologies) is a fabless semiconductor company specializing in high-performance mixed-signal and programmable solutions for embedded systems.

The MB3771 belongs to Cypress's legacy power supervision IC family, engineered specifically for reliable, low-component-count reset generation in mission-critical computing and industrial control platforms.

FAQ

What is the minimum VCC required to assert RESET?

The MB3771 asserts RESET low when VCC rises above approximately 0.8 V, ensuring early fault detection during power-up. This threshold is guaranteed across −40°C to +85°C ambient temperature and remains stable up to 18 V supply. The device maintains RESET assertion until VCC exceeds the hysteresis-adjusted trip point (e.g., 4.30 V for VSA), then releases after CT capacitor charges to tPO duration.

Can VSB be used as a forced-reset input?

Yes - VSB functions as a TTL-compatible forced-reset input when driven low (≤0.8 V), overriding all internal voltage monitoring and asserting RESET immediately. This behavior is documented in Application Circuit 8.6 and supported by the 20 nA max input leakage current specification, enabling direct connection to microcontroller GPIO or watchdog outputs without level-shifting.

How is reset timing controlled without external timing ICs?

Reset timing is controlled solely by the external capacitor connected to the CT pin: tPO ≈ CT × 10⁵ (e.g., 0.01 µF yields ~1.0 ms). The internal CT charge current is 9–16 µA, making timing predictable and temperature-stable. No resistors or additional ICs are needed - this single-capacitor method replaces traditional RC timers and reduces board area and component count.

Does the MB3771 support negative supply monitoring?

No - the MB3771 is designed exclusively for positive supply monitoring (VCC ≥ 3.5 V, VSA/VSB ≥ 0 V). While Application Circuit 8.9 describes dual (positive/negative) monitoring, it achieves negative rail supervision indirectly using external resistive translation to shift the negative voltage into the 0–5 V input range of VSB. The IC itself has no native negative-input capability or internal level-shifting circuitry.