Diodes Incorporated PT8A3307HPEX

Overview

PT8A3307HPEX from Pericom Semiconductor is a ceramic heating controller IC designed for direct SCR-triggered temperature regulation in alumina heater systems. It integrates PTC-based temperature sensing, 50/60 Hz line-synchronized clock input, internal 5V zener regulator, and auto power-off timer (1.2 hr @ 50 Hz). It operates across -20°C to +85°C with 4.0–5.5 V supply and drives SCR gate with 200 µs high-current pulse (≥15 mA).

For engineers reviewing the PT8A3307HPEX datasheet, PT8A3307HPEX pinout, PT8A3307HPEX application, or PT8A3307HPEX equivalent, key selection considerations include its one-key toggle ON/OFF function, constant LED indication mode, high-overshoot preheat threshold (VTH – VT), DIP-8 package compatibility, and dual-voltage AC support (120/240 VAC) without external sensor.

Technical Context

The PT8A3307HPEX implements line-frequency synchronized timing via CLK pin to coordinate SCR triggering and thermal cycle control. Its internal comparator monitors PTC voltage relative to REF (0.7 V nominal), enabling self-calibrating temperature detection without thermistor biasing circuitry.

It features dual-mode operation: one-key toggle (PTC pin functions as ON/OFF toggle) and constant LED output (non-flashing). The GATE output delivers 200 µs active-high pulses with ≥15 mA peak current to reliably trigger 20 A SCRs, while VB pin provides programmable bias for PTC network configuration.

Key Specifications

Pinout & Package

PT8A3307HPEX is supplied in an 8-pin DIP (Dual In-line Package) per JEDEC MS-001D/BA, with 2.54 mm pitch, body width 6.2–6.6 mm, and height 3.71–4.31 mm. Lead-free (Pb-free) construction complies with RoHS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3307LPEX and PT8A3305HPEX, the PT8A3307HPEX uniquely combines constant LED indication, high-overshoot preheat tuning, and one-key toggle - making it optimal for cost-sensitive, single-button consumer appliances where thermal responsiveness outweighs minimal overshoot.

Availability

PT8A3307HPEX is available at Aetrix Electronics and suitable for electric cooktops, medical warming pads, industrial ceramic heaters, and commercial food warmers requiring stable component supply, RoHS-compliant lead-free packaging, and long-term lifecycle continuity.

Supply support for PT8A3307HPEX 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) is a fabless provider of high-performance analog and mixed-signal ICs, specializing in timing, interface, and power management solutions for industrial and consumer markets.

The PT8A330x series was developed specifically for sensorless ceramic heating control - targeting applications where reliability, simplicity, and AC mains synchronization supersede programmability or digital communication.

FAQ

What is the function of the VB pin on PT8A3307HPEX?

The VB pin is a switched bias voltage output used to energize the PTC thermistor network. It operates as a low-resistance source (RON ≤15 Ω) when enabled and high-impedance (>5 MΩ) when off. Its voltage tracks VDD and provides stable excitation for accurate PTC resistance measurement without external bias components.

Does PT8A3307HPEX require an external crystal or oscillator?

No. PT8A3307HPEX derives timing from the AC mains via the CLK pin, which accepts 50 Hz or 60 Hz zero-crossing signals. This eliminates need for external timing components and ensures intrinsic synchronization with line frequency for clean SCR phase control and reduced EMI.

Can PT8A3307HPEX drive a TRIAC directly?

No. PT8A3307HPEX is designed for active-high SCR gate triggering with 200 µs pulses and ≥15 mA peak current. TRIACs typically require bidirectional gate drive or AC-coupled triggering; using this IC with a TRIAC would require additional interface circuitry and is not supported per datasheet specifications.

How does the auto power-off timer behave if the heater is cycled ON/OFF manually?

The timer resets on every OFF command (VDD pulled low or PTC pressed for OFF in two-key mode). In PT8A3307HPEX's one-key mode, the timer starts only after ON press and runs uninterrupted until expiration or manual OFF press - ensuring safety even during repeated short-duration heating cycles.