Diodes Incorporated PT8A3231PE

Overview

PT8A3231PE from Pericom Semiconductor is a mixed-signal CMOS LSI heating controller IC for automatic temperature regulation in 120V/240V AC appliances, featuring dual-voltage operation, NTC-based thermal sensing, auto-off timer (1.2 hr @ 50 Hz), direct SCR gate drive, and multi-mode LED indication. It integrates 2-bit ADC, NTC open-circuit protection, and clock-synchronized power control - deployed in hair curlers and similar portable heating devices.

For engineers reviewing the PT8A3231PE datasheet, PT8A3231PE pinout, PT8A3231PE application, or PT8A3231PE equivalent, key selection considerations include NTC input voltage thresholds (0.29–0.41×VDD), GATE output current (2.5 mA sink), 50/60 Hz line-synchronous timing, 8-pin DIP-8 package compatibility, and dual-key ON/OFF control logic with LED feedback.

Technical Context

The PT8A3231PE implements line-frequency-synchronized state machine control: CLK input locks timing to AC mains (50/60 Hz), enabling precise 1.2-hour auto-shutoff at 50 Hz (1.0 hour at 60 Hz). Internal 2-bit ADC digitizes NTC voltage across three thresholds (VNTC0–VNTC2) to determine heating duty cycle and LED flash pattern.

It provides direct high-side SCR triggering via active-high GATE output (2.5 mA sink capability), while NTC1/NTC2 pins implement open-circuit detection - pulling GATE low and flashing LED1 at 1/8 CLK frequency when NTC resistance exceeds 20 MΩ. ON/OFF pins support two-key discrete control with integrated LED1/LED2 drive.

Key Specifications

Pinout & Package

PT8A3231PE is housed in a lead-free 8-pin DIP package per JEDEC MS-001D/BA, with 2.54 mm pitch and 9.0–9.4 mm body width. Pin 1 (NTC1) is located at the top-left corner of the notch-marked side.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3231PE, PT8A3231WE offers identical functionality in a smaller footprint for SMT lines, while PT8A3235PE trades dual-key flexibility for simpler control logic and constant LED behavior - both require no schematic redesign beyond pin mapping and layout adjustments.

Availability

PT8A3231PE 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-lifecycle availability in consumer appliance programs.

Supply support for PT8A3231PE 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 interface, timing, and power management ICs, focused on signal integrity and system-level integration.

The PT8A323x series belongs to Pericom's dedicated heating controller product line, designed specifically for cost-sensitive, safety-critical AC-powered thermal appliances with minimal external components.

FAQ

What is the function of the NTC2 pin on PT8A3231PE?

NTC2 is an open-drain output that pulls low when the NTC sensor is disconnected (R > 20 MΩ), forcing GATE to inactive state and initiating LED1 flash at 1/8 CLK frequency. It does not source current and must be externally pulled up to VDD for proper fault signaling - confirmed in DC Electrical Characteristics table and Function Description section.

Can PT8A3231PE operate with a 24 VDC supply instead of AC-derived 5 V?

No - PT8A3231PE requires a regulated 3.5–5.5 V DC supply referenced to GND. Its CLK input expects 50/60 Hz AC waveform derived from mains, not DC. Using 24 VDC would exceed absolute maximum ratings and damage the IC. A separate AC-to-DC converter and line-synchronized CLK extraction circuit are mandatory for non-AC-supplied systems.

How does the device distinguish between 120 V and 240 V line voltages?

PT8A3231PE does not measure RMS voltage directly. Instead, it uses the same 50/60 Hz CLK input for timing and adjusts SCR firing phase based on detected NTC voltage range - higher line voltage yields higher NTC divider voltage, shifting duty cycle automatically. This behavior is defined in the "Effect of NTC and CLK input voltage on GATE and LED indication" table on page 3.

Is the GATE output capable of driving a 1 A triac directly?

No - GATE delivers 2.5 mA sink current at VOUT = 0.5 V, sufficient for triggering small-signal triacs (e.g., Z0103MN, BT134) but inadequate for 1 A main triacs requiring ≥10 mA gate current. A discrete NPN transistor buffer stage (e.g., MMBT3904) is required to amplify GATE output for higher-current loads, as implied by the "Direct drive SCR" feature applying only to low-power SCRs.