Diodes Incorporated PT8A3230WEX

Overview

PT8A3230WEX from Pericom Semiconductor is a mixed-signal CMOS LSI heating controller IC for automatic temperature regulation in 120V/240V appliances, featuring dual-voltage operation, NTC-based closed-loop thermal control, NTC open-circuit protection, 1-hour auto-off timer (at 60Hz), and direct SCR gate drive. It operates from 3.5–5.5V supply, supports 50/60Hz line-synchronized clock input, and delivers 2.5mA GATE output current for triac/SCR triggering.

For engineers reviewing the PT8A3230WEX datasheet, PT8A3230WEX pinout, PT8A3230WEX application, or PT8A3230WEX equivalent, key selection considerations include its dual-voltage line sensing, on-chip 2-bit ADC for NTC voltage discrimination, LED indicator logic with flash modes, SCR trigger timing alignment to AC zero-crossing, and DIP-8/SOIC-8 package compatibility for hair curler and similar portable heating systems.

Technical Context

The PT8A3230WEX integrates a 2-bit ADC to digitize NTC voltage across three thresholds (VNTC0–VNTC2) and maps them to SCR duty-cycle modulation-enabling 12.5% to 100% power delivery depending on line voltage (120V vs. 240V) and sensed temperature. Its internal state machine transitions between Reset, Heating-On, and Heating-Off states based on ON/OFF button inputs and timer expiration.

CLK input synchronizes all timing functions-including the 216,000-clock auto-off timer (≈1.2h @50Hz, ≈1h @60Hz)-and gates SCR firing to AC half-cycles. NTC2 pin provides open-detection feedback, forcing GATE disable and LED2 flash at 1/8 CLK frequency when NTC resistance exceeds 20MΩ.

Key Specifications

Pinout & Package

PT8A3230WEX is available in lead-free, RoHS-compliant SOIC-8 (JEDEC MS-012E/AA) package, 4.7–5.1mm wide, 3.8–4.0mm body width, 1.27mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3230WEX, the PEX variant offers mechanical ruggedness at the cost of PCB area, while PT8A3234WEX reduces front-panel complexity by merging controls-both retain identical thermal regulation accuracy, NTC protection, and auto-off timing.

Availability

PT8A3230WEX is available at Aetrix Electronics and suitable for hair curlers, flat irons, travel dryers, and electric blankets requiring stable component supply, RoHS-compliant packaging, and long-term thermal safety certification support.

Supply support for PT8A3230WEX 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) designs high-performance interface, timing, and power management ICs for consumer, computing, and industrial markets.

The PT8A323x series belongs to Pericom's dedicated heating controller product line, engineered specifically for cost-sensitive, safety-critical thermal appliances with dual-voltage AC mains compatibility and integrated NTC protection.

FAQ

What is the function of the NTC2 pin?

NTC2 is an open-drain output that pulls low when the NTC sensor resistance exceeds 20MΩ, indicating an open circuit. This condition forces GATE disable and activates LED2 flash at 1/8 CLK frequency-providing immediate visual fault indication and preventing unsafe heating operation.

Can PT8A3230WEX operate with a 50Hz AC line only?

Yes. The device accepts 50Hz or 60Hz CLK input and scales its auto-off timer accordingly: 216,000 clock cycles equal 1.2 hours at 50Hz and 1 hour at 60Hz. All thermal control logic, including SCR duty adjustment and LED flash rates, remains fully functional at either frequency.

How does the IC differentiate between 120V and 240V line voltages?

It does not measure RMS voltage directly. Instead, it analyzes CLK input amplitude-higher amplitude indicates 240V line, lower amplitude indicates 120V-and adjusts SCR conduction window to deliver appropriate power without external voltage sensing circuitry.

Is external decoupling required on VDD?

Yes. A minimum 0.1µF ceramic capacitor must be placed between VDD and GND, as close as possible to pins 4 and 8. This suppresses high-frequency noise from SCR switching and ensures stable internal oscillator and comparator operation under load transients.