Diodes Incorporated PT7M3808G18TAEX

Overview

PT7M3808G18TAEX from Diodes Incorporated is a low-quiescent-current, programmable-delay supervisory IC with fixed 1.8V supply monitoring threshold (VIT = 1.67V typ), open-drain RESET output, manual reset input (MR), and CT-pin-based delay configuration. It operates from 1.7V to 6.5V, draws only 2.8–5.0µA supply current, and supports 20ms fixed or 300ms/programmable delay modes - used for reliable power-on reset in microcontroller-based embedded systems.

For engineers reviewing the PT7M3808G18TAEX datasheet, PT7M3808G18TAEX pinout, PT7M3808G18TAEX application, or PT7M3808G18TAEX equivalent, key selection criteria include its 1.67V VIT accuracy (±3% over temperature), 150ns MR-to-RESET propagation, 20µs SENSE transient immunity, and compatibility with 0.1µF local decoupling on VDD.

Technical Context

This device implements a precision voltage monitor with hysteresis (2.5% VIT) and dual-mode reset timing control: fixed 20ms delay when CT is open, or 300ms delay when CT is tied to VDD via 40–200kΩ. The SENSE input features ultra-low bias current (±25nA at VIT), enabling high-impedance monitoring of regulated rails without loading.

The open-drain RESET output supports rail-flexible pull-up (up to VDD+0.5V), while MR includes an internal 90kΩ pull-up and accepts logic-level inputs. Its operation is fully specified across –40°C to +125°C junction temperature, with ESD ratings of 2kV HBM and 500V CDM.

Key Specifications

Pinout & Package

PT7M3808G18TAEX is packaged in RoHS-compliant, lead-free SOT23-6 (TA) with exposed thermal pad (connected to GND). Pin 1 is marked by a dot; thermal pad must be soldered to PCB ground plane for optimal thermal performance and stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with MAX6326T18D2T and TPS3808G18DBVR, PT7M3808G18TAEX uniquely combines ultra-low IDD (≤5µA), analog CT-pin programmability (enabling sub-ms to second-scale delays), and integrated MR functionality - making it optimal for compact, battery-sensitive, and thermally demanding designs.

Availability

PT7M3808G18TAEX is available at Aetrix Electronics and suitable for microcontroller power sequencing, industrial PLC supervision, medical wearable sensor nodes, and automotive body control modules requiring stable component supply with guaranteed long-term manufacturability.

Supply support for PT7M3808G18TAEX 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.

PT7M3808 belongs to Diodes' precision supervisory IC product line, engineered specifically for low-power, high-accuracy reset generation in space-constrained embedded systems operating across extended temperature ranges.

FAQ

What is the minimum VDD required for PT7M3808G18TAEX to assert RESET reliably?

The device guarantees RESET assertion when VDD drops below 1.0V (VPOR), independent of the 1.67V SENSE threshold. This ensures valid reset generation even during deep brownout conditions where VDD falls below nominal operating range, preventing partial or corrupted MCU initialization.

Can the CT pin be left floating to achieve the 20ms delay mode?

Yes - leaving CT unconnected (open) configures the device for fixed 20ms reset delay. The datasheet explicitly states this condition yields tD = 12–28ms, with 20ms typical. No pull-up or pull-down is required; the internal circuitry detects open-circuit state automatically.

Does PT7M3808G18TAEX support monitoring a 1.8V rail that powers its own VDD?

Yes - the device supports "self-supply" monitoring: VDD and SENSE can be connected to the same 1.8V rail. Its internal bandgap reference and low-input-bias architecture ensure accurate threshold detection without loading or feedback instability, verified across –40°C to +125°C.

How is the thermal pad (exposed paddle) in the SOT23-6 (TA) package intended to be used?

The thermal pad must be soldered to a dedicated PCB copper pour connected to GND. This connection lowers thermal resistance by ~30°C/W, maintains junction temperature within spec under continuous operation, and improves long-term reliability - especially critical in sealed enclosures or high-ambient-temperature deployments.