Diodes Incorporated PT8A3307HWE

Overview

PT8A3307HWE from Pericom Semiconductor is a ceramic heating controller IC designed for direct SCR-triggered temperature regulation in high-watt-density alumina heaters. It integrates PTC-based temperature sensing, 5V zener regulation, line-synchronized clock input (50/60 Hz), auto power-off timer (1.2 hr @ 50 Hz), and LED driver - eliminating external sensors and discrete timing components. Used in compact ceramic space heaters and portable warming devices.

For engineers reviewing the PT8A3307HWE datasheet, PT8A3307HWE pinout, PT8A3307HWE application, or PT8A3307HWE equivalent, this page delivers verified functional identity, DIP-8/SOIC-8 package mapping, dual-voltage AC compatibility (120/240 VAC), SCR gate pulse timing (200 µs typ.), and one-key toggle control with constant LED indication.

Technical Context

The PT8A3307HWE implements a dedicated analog control loop for ceramic heaters: it samples heater resistance via the PTC pin, compares against internal reference (REF), and drives the GATE pin with high-current pulses to trigger SCRs. Its CLK input synchronizes timing to AC line frequency, enabling precise 50/60 Hz–locked heating cycles and auto-shutoff at 216,000 clock counts.

It features built-in POR (2.0–3.0 V threshold), input hysteresis for key detection (VKON = 0.8–1.1 V), comparator offset voltage ≤ ±3 mV, and VB switch R_ON ≤ 15 Ω - ensuring reliable operation across –20°C to +85°C ambient without external biasing or calibration.

Key Specifications

Pinout & Package

PT8A3307HWE is available in lead-free, RoHS-compliant SOIC-8 (JEDEC MS-012E/AA) package: 4.7–5.1 mm width, 3.8–4.0 mm body height, 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3307HWE, PT8A3307LWE offers lower thermal overshoot at startup but identical control architecture, while PT8A3305HWE trades constant LED for flash indication and shortens auto-off to 1 hour - making it better suited for 60 Hz regions with user feedback requirements.

Availability

PT8A3307HWE is available at Aetrix Electronics and suitable for compact ceramic space heaters, portable warming pads, and industrial benchtop heaters requiring stable component supply, lead-free compliance, and SOIC-8 surface-mount integration.

Supply support for PT8A3307HWE 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 consumer, industrial, and computing applications.

The PT8A330x family was developed specifically for ceramic heating systems - integrating sensorless temperature control, SCR drive, and safety timers to replace multi-component discrete designs in cost-sensitive thermal appliances.

FAQ

What is the function of the VB pin on PT8A3307HWE?

The VB pin provides a regulated bias voltage for the PTC temperature sensor network. Internally, it connects to a low-R_ON (≤15 Ω) switch that supplies current to the PTC element. In one-key configurations, it also supports ON/OFF toggle functionality by modulating bias path impedance - enabling direct heater resistance measurement without external components.

Does PT8A3307HWE require an external crystal or oscillator?

No. PT8A3307HWE derives timing from the AC mains via the CLK pin, accepting 50 Hz or 60 Hz zero-crossing signals. This eliminates the need for crystals, RC oscillators, or external timing ICs - reducing BOM count and improving reliability in thermally demanding environments where crystal aging or drift could affect performance.

How does the auto power-off timer work, and is it configurable?

The timer counts 216,000 CLK cycles: at 50 Hz, this equals 1.2 hours; at 60 Hz, 1.0 hour. It activates automatically upon ON-key press and cannot be disabled or extended via pins or registers. The timing is hard-coded in silicon and requires no external components - meeting IEC 60335-1 thermal safety requirements for unattended operation.

Can PT8A3307HWE drive SCRs rated above 20 A?

PT8A3307HWE's GATE output delivers ≥15 mA peak current with 200 µs pulse width - sufficient to trigger standard 20 A SCRs. For higher-current SCRs (e.g., 40 A), a small external buffer transistor (e.g., MMBT3904) is recommended between GATE and SCR gate to ensure reliable turn-on under worst-case junction temperature and gate charge conditions.