Diodes Incorporated PT8A3302AWEX

Overview

PT8A3302AWEX from Pericom Semiconductor is a ceramic heater controller IC with integrated SCR gate driver, temperature sensing interface (PTC input), internal 5V zener regulator, and auto power-off timer. It operates from 4.0–5.0 V supply, delivers 15 mA high-current gate pulse (200 µs width), supports dual AC line frequencies (50/60 Hz), and enables direct heater control without external thermistors. Used in ceramic heating systems requiring rapid thermal response and fail-safe shutdown.

For engineers reviewing the PT8A3302AWEX datasheet, PT8A3302AWEX pinout, PT8A3302AWEX application, or PT8A3302AWEX equivalent, key selection criteria include its PTC-based self-sensing temperature control, 1.2-hour auto-off at 50 Hz, SOIC-8 lead-free/Green package, and compatibility with 120/240 VAC ceramic heaters using external SCR switching.

Technical Context

The PT8A3302AWEX implements a dedicated analog control loop for ceramic heaters: it samples PTC resistance via VB–REF differential sensing, compares against programmable thresholds (VT and VTH) to modulate SCR duty cycle, and synchronizes timing to AC line frequency via CLK input. Its internal comparator features ±3 mV offset and drives GATE high for 120–300 µs to trigger SCRs reliably under high-temperature leakage conditions.

Unlike general-purpose controllers, it integrates a POR circuit (2.0–3.0 V trip), LED driver with flash/constant modes (configured by part variant), and a fixed-count timer (216,000 clocks) that disables GATE after 1 hour @ 60 Hz or 1.2 hours @ 50 Hz - no external MCU or timing components required.

Key Specifications

Pinout & Package

PT8A3302AWEX is housed in an 8-pin SOIC package per JEDEC MS-012E/AA, with 1.27 mm lead pitch, 4.7–5.1 mm body width, and 3.8–4.0 mm body length. Thermal performance supports 500 mW max power dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ceramic heater control applications.

Compared with PT8A3302APE and PT8A3301BWE, the PT8A3302AWEX uniquely combines SOIC-8 surface-mount packaging, flash-mode LED indication, and high-VTH thermal response - making it optimal for compact, visually guided consumer heating devices targeting 50 Hz markets.

Availability

PT8A3302AWEX is available at Aetrix Electronics and suitable for ceramic hair styling tools, industrial heating panels, consumer coffee makers, and commercial food warmers requiring stable component supply and RoHS-compliant packaging.

Supply support for PT8A3302AWEX 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 analog and mixed-signal ICs for timing, interface, and power management before acquisition in 2017.

The PT8A330x series belongs to Pericom's ceramic heating controller product line, designed specifically for cost-sensitive, safety-critical AC-powered ceramic heater systems requiring zero-microcontroller thermal management.

FAQ

What is the purpose of the VB pin?

The VB pin provides a stable bias voltage for the PTC thermistor bridge. It sources current into the PTC–REF network and is internally short-current protected. Its voltage level defines the differential sensing range used by the internal comparator to detect temperature changes - enabling direct PTC resistance measurement without external op-amps or references.

Does PT8A3302AWEX require an external crystal or oscillator?

No. The PT8A3302AWEX derives all timing from the AC line frequency via the CLK pin, which accepts 50 Hz or 60 Hz zero-crossing signals. This eliminates the need for crystals, oscillators, or PLLs - reducing BOM cost and board space while ensuring synchronization with mains power for precise phase-controlled SCR triggering.

How does the auto power-off timer work?

The internal timer counts 216,000 CLK cycles. At 50 Hz, this equals 1.2 hours (216,000 ÷ 50 ÷ 3600); at 60 Hz, it equals 1 hour. Upon timeout, the GATE output is forced low, disabling the SCR and halting heater operation until power-cycle reset. No external components or firmware are needed - the function is hardwired in silicon.

Can PT8A3302AWEX drive SCRs directly without external components?

Yes - the GATE pin delivers up to 15 mA peak current in 200 µs pulses, sufficient to trigger common 20 A SCRs. A series current-limiting resistor (e.g., 100 Ω) is required between GATE and SCR gate per application circuit guidelines, but no transistor buffer, optocoupler, or gate driver IC is necessary.