Diodes Incorporated PT8A3301APEX

Overview

PT8A3301APEX from Pericom Semiconductor is a ceramic heater controller IC with integrated SCR gate driver, PTC temperature sensing interface, and auto-shutdown timer. It operates at 4.0–5.0 V, delivers 15 mA high-current gate pulse (200 µs width), supports dual AC line frequencies (50/60 Hz), and includes internal 5 V zener regulation. It enables direct ceramic heater control without external temperature sensors in compact DIP-8 packaging.

For engineers reviewing the PT8A3301APEX datasheet, PT8A3301APEX pinout, PT8A3301APEX application, or PT8A3301APEX equivalent, key selection criteria include its built-in line-synchronized clock input (CLK), VB bias voltage generation for PTC sensing, GATE output timing specs, and thermal shutdown behavior at 85°C ambient.

Technical Context

The PT8A3301APEX implements a dedicated analog temperature control loop using an internal comparator with ±3 mV offset voltage, referenced to a stable 0.7 V on REF pin and biased via VB (80 kΩ typical series resistance to VDD). Its CLK input synchronizes all timing-including 1.2-hour auto-off at 50 Hz-to AC mains zero-crossing.

It integrates a POR circuit triggering at 2.0–3.0 V, drives LED indicators directly (5 mA sink capability), and provides two distinct thermal response modes: normal heat-up threshold (VT) and fast heat-up offset (VTH = VT + 0.4–0.8% × (VB − VREF)), configurable per part variant (A/B suffix).

Key Specifications

Pinout & Package

PT8A3301APEX is supplied in lead-free 8-pin DIP (JEDEC MS-001D/BA compliant) with 2.54 mm pitch, 9.2 mm body width, and 6.4 mm body depth. Package height is 3.3 mm max.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3301BPE and PT8A3300APEX, PT8A3301APEX uniquely combines constant LED indication with high-VTH fast preheat-making it optimal for industrial ceramic heaters needing immediate thermal response and unambiguous operational status.

Availability

PT8A3301APEX is available at Aetrix Electronics and suitable for ceramic hair dryers, industrial HVAC duct heaters, electric kettles, and medical warming pads requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for PT8A3301APEX 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 interface, timing, and power management ICs for computing, communications, and industrial applications before its 2016 acquisition.

The PT8A330x family was designed specifically for cost-sensitive, high-reliability ceramic heating systems-integrating sensing, timing, and power control in a single DIP/SOIC package to replace multi-chip discrete solutions.

FAQ

What is the purpose of the VB pin and how is it used in thermal sensing?

VB provides a regulated bias voltage (~1.2 V) through an internal 80 kΩ resistor to the PTC thermistor. This creates a ratiometric voltage divider with REF (0.7 V), enabling the comparator to detect temperature changes independent of VDD variation. No external bias components are needed.

Does PT8A3301APEX require an external crystal or oscillator?

No. The IC uses the CLK pin to accept zero-crossing pulses from the AC mains-either directly from a bridge rectifier or via optocoupler-generating all internal timing (including the 1.2-hour auto-off) from the 50/60 Hz line frequency. No crystal, RC network, or external clock source is required.

How does the auto power-off timer reset?

The timer resets only on power-on reset (POR). Once triggered, it runs continuously until expiration (1.15–1.25 hr at 50 Hz), then forces GATE low and disables heating. Recovery requires full power cycle-no software command or pin toggle can restart it mid-cycle.

Can PT8A3301APEX drive SCRs rated above 20 A?

Not directly. Its GATE output delivers 15 mA peak for 200 µs-sufficient for 20 A SCRs per datasheet validation. For >20 A devices, an external MOSFET or bipolar transistor buffer stage is required to amplify the trigger current while preserving timing integrity.