Diodes Incorporated PT8A3305HWE

Overview

PT8A3305HWE from Pericom Semiconductor is a ceramic heating controller IC designed for direct SCR-triggered temperature-regulated alumina heater systems. It integrates PTC-based self-sensing temperature detection, 5V zener regulation, line-synchronized clock input (50/60 Hz), LED driver output, and auto power-off timer (1.2 hr @ 50 Hz). It operates across -20°C to +85°C with 4.0–5.0 V supply and supports one-key ON/OFF toggle functionality in SOIC-8 package.

For engineers reviewing the PT8A3305HWE datasheet, PT8A3305HWE pinout, PT8A3305HWE application, or PT8A3305HWE equivalent, key selection considerations include its integrated heater sensing without external thermistor, high-current SCR gate pulse (200 µs, >15 mA), dual-voltage AC compatibility (120/240 VAC), internal 5 V zener, and fixed constant-LED indication mode for one-key operation.

Technical Context

The PT8A3305HWE implements a line-synchronized analog temperature control loop: CLK pin locks to AC zero-crossing (50/60 Hz), PTC pin senses heater resistance change directly, and internal comparator with ±3 mV offset compares VB–REF voltage to set VT and VTH thresholds. Its GATE output delivers a 120–300 µs active-high SCR trigger pulse with ≥15 mA peak drive capability.

It embeds a POR circuit (2.0–3.0 V threshold), a 1.2-hour auto-shutoff timer referenced to 50 Hz clock cycles (216,000 counts), and a 100 µA–100 mA VB switch with R_ON ≤15 Ω and R_OFF ≥5 MΩ. The device requires no external temperature sensor and maintains stable operation across environmental temperature variations.

Key Specifications

Pinout & Package

PT8A3305HWE is supplied in an 8-pin SOIC package (JEDEC MS-012E/AA compliant), measuring 4.7–5.1 mm × 3.8–4.0 mm × 1.35–1.75 mm, with 1.27 mm pitch and Pb-free/Green compliance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3305LWE, PT8A3305HWE delivers faster initial heat-up at the cost of higher preheat overshoot; versus PT8A3301HPE, it reduces mechanical BOM count and simplifies UI but sacrifices independent button control and dynamic LED signaling.

Availability

PT8A3305HWE is available at Aetrix Electronics and suitable for electric kettle control, ceramic cooktop heater systems, industrial hot plates, and medical warming trays requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for PT8A3305HWE 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 electronics.

The PT8A330x series was developed specifically for cost-sensitive, microcontroller-free ceramic heating applications-emphasizing integration of sensing, timing, and power control in a single SOIC/DIP package.

FAQ

What is the function of the VB pin on PT8A3305HWE?

The VB pin serves as a switched bias voltage source that connects to the heater network. With R_ON ≤15 Ω and R_OFF ≥5 MΩ, it supplies a stable reference point for the internal comparator to measure PTC resistance changes. It is not a power rail but a precision sampling node essential for self-sensing temperature control without external components.

Can PT8A3305HWE drive a 20 A SCR directly?

Yes-its GATE output delivers ≥15 mA peak current in a 120–300 µs pulse, which meets the gate trigger requirements of standard 20 A SCRs (e.g., BT139, TYN2025) under worst-case junction temperatures. No external transistor buffer is needed, though proper PCB layout and gate resistor selection remain critical for noise immunity.

How does the auto power-off timer work without a crystal or RC oscillator?

The timer counts AC line cycles using the CLK input: 216,000 clock periods equal 1.2 hours at 50 Hz (or ~1 hour at 60 Hz). It relies entirely on zero-crossing synchronization-not internal oscillators-ensuring accuracy and eliminating timing drift due to temperature or voltage variation.

Is the LED output active-high or active-low?

The LED pin is an open-drain output configured for active-low sinking. When enabled, it pulls down to GND with ≥5 mA drive capability-requiring an external current-limiting resistor and anode-connected LED. In PT8A3305HWE's constant-mode configuration, it remains continuously asserted during heating.