Diodes Incorporated PT7M1818-5TEX

Overview

PT7M1818-5TEX from Pericom Semiconductor is a highly accurate supervisory circuit designed to monitor V_CC supply voltage in microprocessor and digital systems. It asserts an active-low reset signal when V_CC drops below 3.0 V (±1.5% at 25°C), maintains reset for 200 ms after recovery, and operates across 1.0–5.5 V supply range and –40°C to +85°C ambient temperature - used in embedded controllers requiring reliable power-on reset and brownout protection.

For engineers reviewing the PT7M1818-5TEX datasheet, PT7M1818-5TEX pinout, PT7M1818-5TEX application, or PT7M1818-5TEX equivalent, key selection criteria include its bidirectional RST pin for pushbutton integration, internal 5 kΩ pull-up resistor, ±2.5% voltage threshold temperature coefficient, open-drain output with guaranteed 0.4 V low-level drive at 8 mA, and SOT23-3 package compatibility with space-constrained PCB layouts.

Technical Context

The PT7M1818-5TEX implements a precision voltage monitor with hysteresis (50 mV typical) to prevent oscillation during threshold crossing. Its reset timeout is fixed at 200 ms (140–280 ms over temperature), independent of external components.

It features true bidirectional RST functionality: actively drives low during internal reset or external brownout, and detects external low-going edges on RST (e.g., from a manual reset button) with 1–2 µs pulse sensitivity and automatic 200 ms debounce hold time after release.

Key Specifications

Pinout & Package

PT7M1818-5TEX is housed in a lead-free, RoHS-compliant SOT23-3 plastic package (Package Code: TA3), with 1.05–1.25 mm body height and 2.82–3.02 mm length.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G30DBVR and MAX809SEUR+T, PT7M1818-5TEX uniquely integrates bidirectional RST with internal pull-up and tighter threshold tolerance, reducing component count and enabling unified reset management in resource-constrained embedded systems.

Availability

PT7M1818-5TEX is available at Aetrix Electronics and suitable for industrial PLC controllers, smart meter MCU subsystems, automotive body control modules, and IoT edge sensor nodes requiring stable component supply and long-term lifecycle support.

Supply support for PT7M1818-5TEX 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 ICs for communications, computing, and consumer electronics.

PT7M1818-5TEX belongs to Pericom's supervisory circuit product line, engineered specifically for robust, low-component-count power monitoring in microprocessor-based systems operating across wide temperature and voltage ranges.

FAQ

What is the exact reset threshold voltage for PT7M1818-5TEX?

The PT7M1818-5TEX has a nominal reset threshold voltage (V_TH−) of 3.0 V, with ±1.5% accuracy at 25°C and ±2.5% variation over the full –40°C to +85°C operating temperature range. This value is factory-trimmed and specified in the DC Electrical Characteristics table of the official datasheet (Rev. PT0190-7).

Does PT7M1818-5TEX require an external pull-up resistor?

No. PT7M1818-5TEX includes an internal 5 kΩ pull-up resistor on the RST pin, confirmed in the DC Electrical Characteristics table (R_p = 3.75–6.25 kΩ). This eliminates the need for an external resistor in standard open-drain µP reset interface configurations.

Can PT7M1818-5TEX be used with a 1.8 V supply?

Yes. The device operates across 1.0 V to 5.5 V supply range, and its 3.0 V reset threshold remains valid even at 1.8 V V_CC, provided the monitored rail itself is ≥3.0 V. It does not monitor sub-3.0 V rails - for 1.8 V systems, a different variant (e.g., PT7M1818-20 for 2.5 V) would be required.

How does the bidirectional RST pin function during manual reset?

When not in internal reset, PT7M1818-5TEX monitors RST for a falling edge. Upon detecting a low pulse ≥1 µs, it debounces and pulls RST low for 200 ms. If RST remains low after timeout, it waits for a rising edge and reasserts 200 ms low upon release - enabling clean, glitch-free manual reset without external circuitry.