Diodes Incorporated PT8A3244PEX

Overview

PT8A3244PEX from Pericom Semiconductor is a mixed-signal CMOS heating controller IC for single-key hair curlers and similar thermal appliances, featuring dual-voltage (120V/240V) operation, auto temperature control via external NTC, NTC open-circuit protection, flash-mode LED indication, and direct SCR gate drive. It integrates a 2-bit ADC, internal 1-hour auto-off timer (50/60 Hz clock synchronized), and operates from 3.5–5.5 V.

For engineers reviewing the PT8A3244PEX datasheet, PT8A3244PEX pinout, PT8A3244PEX application, or PT8A3244PEX equivalent, key selection criteria include NTC-based thermal feedback compatibility, single-button on/off logic with LED feedback, SCR-trigger timing precision at line frequency, and DIP-8 package suitability for cost-sensitive thermal control PCBs.

Technical Context

The PT8A3244PEX implements a dedicated thermal control state machine with three operational states: Reset, Heating-On, and Heating-Off. Its 2-bit ADC digitizes NTC voltage (VNTC0–VNTC2 thresholds defined at 0.37–0.41×VDD) to modulate SCR gate duty cycle and LED flash pattern in real time.

It synchronizes all timing-including the 216,000-clock auto-off timer-to the AC line frequency (50/60 Hz) via the CLK input, enabling precise 1.2-hour (50 Hz) or 1-hour (60 Hz) heating duration without external crystal or RC timing components.

Key Specifications

Pinout & Package

PT8A3244PEX is supplied in a lead-free 8-pin plastic DIP (JEDEC MS-001D/BA compliant), with 2.54 mm pitch, body width 6.2–6.6 mm, and total length 9.0–9.4 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3245WE and PT8A3240PEX, the PT8A3244PEX uniquely balances single-button simplicity, flash-based user feedback, and DIP-8 manufacturability-making it optimal for high-volume, cost-sensitive hair styling tools where layout space and button count are tightly constrained.

Availability

PT8A3244PEX is available at Aetrix Electronics and suitable for hair curlers, flat irons, travel dryers, and electric blanket safety modules requiring stable component supply, RoHS-compliant packaging, and long-term industrial availability.

Supply support for PT8A3244PEX 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 its 2016 acquisition.

The PT8A324x series belongs to Pericom's dedicated thermal control product line, engineered specifically for cost-sensitive, safety-critical AC-powered heating appliances with minimal external component count.

FAQ

What is the function of Pin 2 (NTC2) on the PT8A3244PEX?

Pin 2 is an open-drain output that pulls low when the NTC sensor is disconnected or open-circuited. This signal disables the GATE output immediately and causes LED2 (Pin 7) to flash at 1/8 CLK frequency, providing fail-safe thermal shutdown and visual fault indication without external circuitry.

Can the PT8A3244PEX operate from a DC supply only, without AC line synchronization?

No. The PT8A3244PEX requires a 50/60 Hz square-wave or zero-crossing signal on the CLK pin to synchronize its internal timer, LED flash rate, and SCR firing phase. It cannot function with a static DC clock or crystal oscillator-it is designed exclusively for AC-mains-referenced thermal control.

How does the PT8A3244PEX adjust heating power between 120 V and 240 V line voltages?

The device does not actively adjust power; instead, it uses the same SCR triggering logic and timing across both voltages. Power level is determined externally by the SCR's current rating and heatsink design. The IC ensures safe operation in either configuration by maintaining consistent thermal feedback and auto-off timing referenced to line frequency-not RMS voltage.

Is the GATE output capable of driving a triac directly, or is a buffer required?

The GATE output can directly drive low-gate-charge triacs (e.g., Z0103MN, BT131) and SCRs (e.g., BT136, MAC97A6) with IGTM ≤ 5 mA. For higher IGTM devices or noisy environments, a small-signal transistor buffer (e.g., BC847) is recommended to ensure reliable turn-on and noise immunity.