Diodes Incorporated PT8A3304LWE

Overview

PT8A3304LWE from Pericom Semiconductor is a ceramic heating controller IC designed for direct SCR-triggered temperature regulation in alumina heater systems. It integrates PTC-based self-sensing temperature control, 50/60Hz line-synchronized clock input, internal 5V zener regulation, and auto power-off timing (1.2 hr @50Hz). It operates across -20°C to +85°C with dual-voltage AC support (120/240VAC) and is packaged in lead-free, green SOIC-8.

For engineers reviewing the PT8A3304LWE datasheet, PT8A3304LWE pinout, PT8A3304LWE application, or PT8A3304LWE equivalent, key selection considerations include its one-key toggle interface, VB-biased PTC sensing architecture, GATE output pulse width (120–300 µs), REF bias resistor tolerance (20–80 kΩ), and immunity to ambient temperature drift.

Technical Context

The PT8A3304LWE implements a line-synchronized, comparator-based thermal control loop where the PTC input serves as both temperature sensor and push-button interface. Its internal oscillator locks to CLK input derived from AC zero-crossing, enabling precise 50/60Hz timing for heating cycles and auto-shutoff.

It features dual-mode SCR triggering: high-current (≥15 mA) GATE pulses ensure reliable turn-on of 20A SCRs, while short pulse width (≤300 µs) minimizes false triggering from SCR leakage at elevated temperatures. The VB pin provides programmable bias for PTC resistance measurement, and REF sets comparator reference voltage (0.7 V typical).

Key Specifications

Pinout & Package

PT8A3304LWE is housed in an 8-pin SOIC package per JEDEC MS-012E/AA, with 1.27 mm pitch, 4.7–5.1 mm width, and 3.8–4.0 mm body height. Thermal pad not present; RoHS-compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3304HWE, the PT8A3304LWE offers lower preheat overshoot for tighter thermal control; versus PT8A3300LPE, it reduces mechanical complexity with one-key operation and SOIC packaging for higher-density PCBs.

Availability

PT8A3304LWE is available at Aetrix Electronics and suitable for electric kettle control, ceramic cooktop heater, and medical warming cabinet applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant green packaging.

Supply support for PT8A3304LWE 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, with emphasis on industrial and consumer control applications.

The PT8A330x series was developed specifically for cost-sensitive, microcontroller-free ceramic heating systems-delivering integrated sensing, timing, and SCR drive in a single SOIC/DIP package.

FAQ

What is the function of the VB pin on PT8A3304LWE?

The VB pin supplies a regulated bias current to the external PTC thermistor, converting its resistance change into a measurable voltage at the PTC input. It operates as a current source with R_ON ≤15 Ω and R_OFF ≥5 MΩ, enabling precise ratiometric temperature sensing without external op-amps or references.

Can PT8A3304LWE drive a 40A SCR directly?

No-PT8A3304LWE's GATE output delivers up to 15 mA peak current with 200 µs pulse width, sufficient for 20A SCRs per datasheet validation. Driving a 40A SCR requires an external gate driver stage (e.g., MOC3021 optocoupler + BJT buffer) to meet gate charge and dv/dt requirements.

How does the auto power-off timer behave with unstable AC frequency?

The timer counts CLK input edges, so deviations from nominal 50/60Hz cause proportional timing error-e.g., 49Hz extends shutoff to ~1.22 hr. The IC does not compensate for frequency drift; stable line frequency is required for accurate 1.2-hour cutoff.

Is the REF pin internally connected to a fixed voltage?

No-REF is an open-drain comparator reference node requiring an external resistor (20–80 kΩ) between REF and GND to set the 0.7 V threshold. This resistor forms a voltage divider with the PTC/VB network, enabling programmable temperature setpoints without trimming.