Diodes Incorporated PT8A3240AWE

Overview

PT8A3240AWE 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 operation, NTC-based closed-loop thermal control, NTC open-circuit protection, 1-hour auto-off timer (50/60 Hz), and direct SCR gate drive. Designed for hair curlers, it delivers precise thermal management with flash-mode LED indication on pin 5.

For engineers reviewing the PT8A3240AWE datasheet, PT8A3240AWE pinout, PT8A3240AWE application, or PT8A3240AWE equivalent, key selection criteria include NTC input voltage thresholds (VNTC0 = 0.385×VDD), GATE output current (2.5 mA sink), SOIC-8 package compatibility, 50–60 Hz clock synchronization, and dual-key control logic for heating-on/off sequencing.

Technical Context

This IC implements a 2-bit ADC-based thermal feedback loop that maps NTC voltage (0.37–0.41×VDD) to SCR trigger duty cycle-12.5% at 110V, 25% at 220V-enabling voltage-adaptive power delivery. Internal state machine enforces strict sequencing: reset → heating-on → timeout → heating-off, with NTC open detection forcing GATE disable and LED2 flash at 1/8 CLK.

CLK input synchronizes timing to AC line frequency (50/60 Hz), enabling accurate 1.2-hour (50 Hz) or 1-hour (60 Hz) auto-shutdown. Pin 5 serves dual role: ON button input (for PT8A3240) and LED1 driver output; pin 7 provides LED2 output or OFF button input, with inverse polarity relative to pin 5.

Key Specifications

Pinout & Package

PT8A3240AWE uses a lead-free, green-compliant SOIC-8 package per JEDEC MS-012E/AA (body width 3.8–4.0 mm, length 4.7–5.1 mm, pitch 1.27 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3241AWE and PT8A3242AWE, PT8A3240AWE uniquely combines flash-mode LED signaling with built-in 1-hour auto-off-making it optimal for consumer-grade portable appliances requiring both intuitive feedback and regulatory compliance.

Availability

PT8A3240AWE is available at Aetrix Electronics and suitable for hair curlers, flat irons, electric blankets, and hot plates requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for PT8A3240AWE 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 Corporation is a fabless provider of high-performance interface, timing, and power management ICs, acquired by Diodes Incorporated in 2016.

The PT8A32xx series belongs to Pericom's dedicated heating controller product line, engineered specifically for cost-sensitive, AC-powered thermal appliances with integrated safety and user-interface features.

FAQ

What is the function of the NTC2 pin?

NTC2 is an open-drain output that pulls low when the NTC sensor is disconnected. This fault signal immediately disables the GATE output and causes LED2 to flash at 1/8 CLK frequency, providing visible and electrical fail-safe response without software intervention.

How does PT8A3240AWE adapt to 110V vs. 220V line voltages?

The IC analyzes CLK input amplitude to distinguish 110V and 220V operation. At 220V, it applies 25% SCR duty cycle; at 110V, it increases to 100%, maintaining consistent thermal output while preventing SCR overdrive or insufficient heating.

Can PT8A3240AWE drive an SCR directly without external components?

Yes-its GATE pin delivers 2.5 mA sink current at 4.5 V, sufficient to trigger common 1–2 A SCRs like the MOC3021/MOC3041 optocouplers or discrete BT136/BT139 devices in low-to-mid power heating applications.

What is the significance of the VNTC0/VNTC1/VNTC2 thresholds?

These three voltage thresholds define NTC resistance bands mapped to SCR firing duty: below VNTC0 (cold), 12.5–25% firing; between VNTC0–VNTC1 (warm), 12.5% firing; above VNTC2 (hot), full conduction. This enables coarse but robust proportional thermal control without microcontroller firmware.