Diodes Incorporated PT7M1818-20TEX

Overview

PT7M1818-20TEX from Pericom Semiconductor is a highly accurate supervisory circuit designed to monitor V_CC supply voltage and assert an active-low reset signal during power-up, brownout, or undervoltage conditions. It features a 2.5V detection threshold (±1.5% at 25°C), 200ms reset timeout period, open-drain bidirectional RST pin with internal 5kΩ pull-up, and operates across 1.0V–5.5V supply and –40°C to +85°C ambient range - used in microprocessor-based embedded control systems requiring reliable power sequencing.

For engineers reviewing the PT7M1818-20TEX datasheet, PT7M1818-20TEX pinout, PT7M1818-20TEX application, or PT7M1818-20TEX equivalent, this device delivers precise undervoltage monitoring with integrated pushbutton support, low quiescent current (10µA at 3.6V), and SOT23-3 package compatibility for space-constrained MCU reset management.

Technical Context

The PT7M1818-20TEX implements a precision bandgap-based voltage reference with hysteresis (50mV typical) to prevent reset chatter near the 2.5V threshold. Its bidirectional RST pin supports both automatic reset assertion and manual reset initiation via external pushbutton, with internal debouncing and 200ms hold time after release.

It operates without external components: internal 5kΩ pull-up eliminates need for discrete resistor; timing is fully internal with no capacitor required; and reset assertion is guaranteed down to V_CC = 1.0V, ensuring robust behavior during deep brownout.

Key Specifications

Pinout & Package

SOT23-3 plastic surface-mount package (Package Code: TA3), lead-free and RoHS-compliant, with 1.05–1.25mm body height and 2.82–3.02mm length.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G12DBVR, the PT7M1818-20TEX uniquely combines ±1.5% accuracy, integrated 5kΩ pull-up, and true bidirectional RST in SOT23-3 - enabling pushbutton support without extra components while maintaining industrial temperature range and ultra-low ICC.

Availability

PT7M1818-20TEX is available at Aetrix Electronics and suitable for industrial PLC controllers, smart metering systems, medical handheld diagnostics, and automotive body control modules requiring stable component supply with long-term lifecycle assurance.

Supply support for PT7M1818-20TEX 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

Pericom Semiconductor (now part of Diodes Incorporated) is a fabless provider of high-performance interface, timing, and power management solutions for communications, computing, and consumer electronics.

The PT7M1818 series belongs to Pericom's supervisory IC product line, engineered specifically for cost-sensitive, space-constrained microprocessor reset management in industrial and embedded applications where reliability and minimal external components are essential.

FAQ

What is the function of the RST pin on PT7M1818-20TEX?

The RST pin is a bidirectional open-drain I/O that asserts active-low reset when V_CC falls below 2.5V and holds for 200ms after recovery. It also accepts external low pulses (≥0.8V threshold) to initiate manual reset, with internal debouncing and 200ms hold time after release - eliminating need for external RC networks or logic gates.

Does PT7M1818-20TEX require an external pull-up resistor?

No. The device integrates a 5kΩ internal pull-up resistor on the RST pin, confirmed in the Electrical Characteristics table (R_p = 3.75–6.25kΩ). This enables direct connection to standard µP reset inputs without discrete components, reducing BOM count and layout complexity.

Can PT7M1818-20TEX operate with a 1.8V supply?

Yes. Its specified supply range is 1.0V to 5.5V, and all electrical characteristics - including 2.5V threshold accuracy and 200ms timeout - are guaranteed across this range. At 1.8V, ICC remains ≤12µA and VOL stays ≤0.3V with 4mA sink, supporting low-voltage microcontrollers.

How does PT7M1818-20TEX handle brownout recovery?

When V_CC rises above the 2.5V threshold, the internal timer initiates a fixed 200ms reset timeout before releasing RST. If a second brownout occurs mid-timer, the timeout resets and extends - ensuring ≥200ms of reset assertion after final recovery, as verified in the AC Electrical Characteristics table (t_RS = 140–280ms).