Diodes Incorporated PT8A3280CPEX

Overview

PT8A3280CPEX from Pericom Semiconductor is a mixed-signal CMOS heating controller IC designed for dual-voltage (120V/240V) AC-powered thermal appliances. It implements proportional temperature control using an external NTC sensor, provides NTC open-circuit protection, delivers 15mA SCR gate trigger pulses (160–240µs width), and integrates internal 5V Zener regulation. It is used in hair curlers and straighteners requiring automatic power adaptation and timed heating cycles.

For engineers reviewing the PT8A3280CPEX datasheet, PT8A3280CPEX pinout, PT8A3280CPEX application, or PT8A3280CPEX equivalent, key selection criteria include its 8-pin DIP package, 50/60Hz CLK-synchronized timing, NTC-based closed-loop temperature regulation, SCR-trigger output capability, and integrated POR and Zener voltage reference.

Technical Context

The PT8A3280CPEX uses a 5-bit ADC to digitize NTC voltage for real-time temperature feedback, enabling proportional control of SCR firing angle based on input amplitude and clock phase. Its internal timer counts 216,000 CLK cycles (≈1.2 hr at 50Hz, ≈1 hr at 60Hz) before auto-shutdown.

NTC open detection is implemented via dual-pin interface (NTC1 input, NTC2 output), where NTC2 transitions low during open-circuit fault. The GATE output drives high-current SCRs with pulse widths tightly specified at 160–240µs, while LED1/LED2 support multi-mode visual status indication synchronized to CLK (e.g., Flash1 = 1/32 CLK, Flash2 = 1/8 CLK).

Key Specifications

Pinout & Package

PT8A3280CPEX is housed in an 8-pin lead-free PDIP (Plastic Dual In-line Package) per JEDEC MS-001D/BA, with body dimensions 9.0–9.4mm × 6.2–6.6mm and 2.54mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3280CPEX, PT8A3284CWE offers SMT compatibility and TRIAC drive for noise-sensitive systems, while PT8A3282CPEX reduces visual feedback complexity at the cost of dynamic status indication - both retain identical thermal control architecture and safety timers.

Availability

PT8A3280CPEX is available at Aetrix Electronics and suitable for hair styling tools, electric blankets, beauty steamers, and portable thermal appliances requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for PT8A3280CPEX 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, computing, and communications markets.

The PT8A328x series was developed specifically for cost-sensitive, safety-critical thermal control in AC-powered personal care appliances - emphasizing integration, fault resilience, and dual-voltage adaptability.

FAQ

What is the maximum SCR gate current drive capability of PT8A3280CPEX?

The GATE pin delivers 5.0mA sink current at 0.5V and −15mA source current at 2.5V under VDD = 4.5V. This supports direct drive of common 1–5A SCRs without external amplification, provided gate trigger energy requirements fall within the 160–240µs pulse window.

How does the NTC open-circuit protection work without external components?

PT8A3280CPEX uses internal comparators and state logic to monitor NTC1 voltage level and transition timing. When NTC opens, NTC1 drops below threshold and NTC2 asserts low within one CLK cycle. No external resistors or op-amps are needed - the function is fully self-contained.

Can PT8A3280CPEX operate with a 400Hz aircraft power supply?

No - the device is designed exclusively for 50Hz or 60Hz AC line synchronization. CLK input must match nominal utility frequency; applying 400Hz will cause incorrect timer counting, inaccurate proportional control, and potential failure to enter heating-on state due to out-of-spec clock detection logic.

Is the internal Zener diode rated for continuous current draw?

Yes - the Zener operates continuously across the full 500µA to 10mA range, with specified 4.5–5.5V output. It is intended to power internal analog blocks and may supply up to 5mA to external circuitry (e.g., NTC bias network), provided total IDD remains ≤500µA under all operating conditions.