Diodes Incorporated PT8A3275PE

Overview

PT8A3275PE from Pericom Semiconductor is a mixed-signal CMOS heating controller IC for 120V/240V AC-powered thermal appliances. It implements proportional temperature control using an external NTC sensor, features integrated Zener regulation (5.0 V), 1.2-hour auto-off timer at 50 Hz, and SCR gate pulse output (160–240 µs width). Used in hair straighteners and curling irons for safe, voltage-adaptive heating.

For engineers reviewing the PT8A3275PE datasheet, PT8A3275PE pinout, PT8A3275PE application, or PT8A3275PE equivalent, key selection criteria include its single-button ON/OFF logic, constant-mode LED indicator, 8-pin DIP-8 package, NTC open-detection capability, and 5.0 V internal Zener clamp - all critical for thermally protected consumer heating designs.

Technical Context

The PT8A3275PE integrates a 5-bit ADC for NTC-based closed-loop temperature sensing and a state machine that transitions between reset, heating-on, and heating-off states. Its CLK input synchronizes to line frequency (50/60 Hz), enabling precise timing of the 216,000-cycle auto-shutoff timer.

It delivers proportional gate drive to external SCRs based on NTC voltage and line-voltage level detection (120V vs. 240V), with dedicated NTC1/NTC2 pins for open-circuit fault detection and LED2 output for status indication in constant-on mode.

Key Specifications

Pinout & Package

PT8A3275PE is housed in an 8-pin lead-free DIP package per JEDEC MS-001D/BA, with 2.54 mm pitch and 9.0–9.4 mm body width.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3274PE and PT8A3271WE, PT8A3275PE uniquely combines DIP-8 packaging, single-button toggle logic, and non-flashing LED2 - optimizing for cost-sensitive, mechanically simple, and globally voltage-compatible thermal appliances.

Availability

PT8A3275PE is available at Aetrix Electronics and suitable for hair straighteners, curling irons, and electric blanket controllers requiring stable component supply, long-lifecycle availability, and RoHS-compliant lead-free packaging.

Supply support for PT8A3275PE 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) designed high-performance interface, timing, and power management ICs for consumer, computing, and communications markets.

The PT8A327x series targets thermally regulated small appliances, delivering integrated analog sensing, digital control, and robust AC-line interfacing in minimal footprint packages.

FAQ

What is the function of the NTC2 pin on PT8A3275PE?

NTC2 is an open-drain output that pulls low when the NTC sensor is detected as open-circuited. This provides immediate hardware-level fault signaling to disable heating and alert the system - no firmware or external comparator is needed. The pin remains high-impedance during normal operation.

Does PT8A3275PE require an external crystal or oscillator?

No. PT8A3275PE uses the AC mains frequency as its timing reference via the CLK pin, eliminating need for crystals, oscillators, or RC networks. It accepts 50 Hz or 60 Hz line-synchronous input directly, enabling precise auto-off timing and zero-crossing synchronized SCR triggering.

Can PT8A3275PE drive a TRIAC directly, or is an SCR mandatory?

PT8A3275PE's GATE output is optimized for SCR triggering (160–240 µs pulse), but it can drive sensitive-gate TRIACs with appropriate current-limiting and snubber design. For standard TRIACs requiring longer gate pulses or higher peak current, an external buffer transistor is recommended per application circuit guidelines.

How does PT8A3275PE distinguish between 120V and 240V line operation?

It analyzes the amplitude of the CLK input waveform relative to internal thresholds (VTCLK Level 2). High-amplitude CLK indicates 240V operation and scales proportional control accordingly; low amplitude triggers 120V mode - ensuring consistent heating performance and preventing thermal stress across global voltage standards.