Diodes Incorporated PT8A3240PE

Overview

PT8A3240PE from Pericom Semiconductor is a mixed-signal CMOS LSI heating controller IC for automatic temperature regulation in 120V/240V AC appliances. It integrates dual-voltage detection, 2-bit ADC-based NTC sensing, SCR gate drive, auto-off timer (1h @60Hz), and dual-mode LED indication. Designed for hair curlers, it directly drives an external SCR and implements NTC open-circuit protection.

For engineers reviewing the PT8A3240PE datasheet, PT8A3240PE pinout, PT8A3240PE application, or PT8A3240PE equivalent, key selection factors include its 8-pin DIP-8 package, VDD range of 3.5–5.5V, GATE output capable of 2.5mA sink current, NTC1/NTC2 interface for open-wire detection, and built-in 1-hour auto-shutdown timer synchronized to line frequency.

Technical Context

The PT8A3240PE operates as a self-contained thermal control ASIC with internal clock synchronization to AC line frequency (50/60Hz) via CLK pin. Its 2-bit ADC digitizes NTC voltage at NTC1 and validates NTC integrity using NTC2 as an open-detection output.

Control logic implements three states-Reset, Heating-On, and Heating-Off-with state transitions triggered by ON/OFF button inputs and timer expiration. GATE output is active-high and duty-modulated based on NTC voltage thresholds (VNTC0–VNTC2), enabling proportional SCR triggering without external PWM circuitry.

Key Specifications

Pinout & Package

PT8A3240PE is housed in a lead-free 8-pin DIP package per JEDEC MS-001D/BA, with 2.54mm pitch, 9.2mm max body length, and 6.4mm max body width. Pin 1 is marked by notch or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar heating controller applications.

Compared with PT8A3241PE and PT8A3244PE, the PT8A3240PE provides distinct flashing LED behavior for heating-on state and supports two independent mechanical buttons-making it optimal for premium handheld tools where clear, differentiated user feedback and tactile control are prioritized.

Availability

PT8A3240PE is available at Aetrix Electronics and suitable for hair curlers, flat irons, travel dryers, and electric blankets requiring stable component supply, dual-voltage AC compatibility, and integrated thermal safety features.

Supply support for PT8A3240PE 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) specialized in high-performance interface, timing, and power management ICs for consumer and industrial applications before acquisition in 2016.

The PT8A324x series belongs to Pericom's dedicated heating controller product line, engineered specifically for AC-powered thermal appliances requiring robust NTC-based closed-loop temperature control and intrinsic safety features.

FAQ

What is the function of the NTC2 pin on PT8A3240PE?

NTC2 is a digital output pin that goes low when the NTC sensor is open-circuited. This condition immediately disables the GATE output and causes LED2 to flash at 1/8 the CLK frequency-providing visible fault indication and preventing unsafe heater operation without external supervision.

Can PT8A3240PE drive a TRIAC directly?

No-PT8A3240PE's GATE output is designed for direct SCR triggering only. Its 2.5mA sink current and logic-level voltage swing are insufficient for most TRIAC gates, which typically require higher peak current (≥50mA) and often need zero-crossing isolation. An external driver stage (e.g., MOC3021 + BT136) is required for TRIAC interfacing.

How does PT8A3240PE handle different AC line frequencies?

The device uses the CLK pin to lock its internal timer and modulation logic to the incoming AC line frequency. At 60Hz, the auto-off timer expires after ~1 hour; at 50Hz, it extends to ~1.2 hours-ensuring consistent thermal safety compliance across global markets without configuration.

Is external decoupling capacitor required on VDD?

Yes-a 100nF ceramic capacitor placed as close as possible to the VDD and GND pins is mandatory. This suppresses switching noise from the GATE output and ensures stable ADC reference during NTC sampling, especially critical under fast thermal transients in handheld appliances.