Diodes Incorporated PT8A3287PE

Overview

PT8A3287PE from Pericom Semiconductor is a mixed-signal CMOS heating controller IC designed for dual-voltage (120V/240V) AC-powered thermal appliances. It implements proportional temperature control using an external NTC sensor, includes NTC open-circuit protection, auto-off timer (1.2 hr @ 50 Hz), and drives TRIACs via a 160–240 µs pulse output. It operates in 8-pin DIP package with VDD = 3.5–5.5 V and supports curling irons and hair straighteners.

For engineers reviewing the PT8A3287PE datasheet, PT8A3287PE pinout, PT8A3287PE application, or PT8A3287PE equivalent, key selection criteria include its constant-mode LED2 output, TRIAC-compatible GATE trigger, NTC-based closed-loop regulation, internal Zener (4.5–5.5 V), and 50/60 Hz CLK-synchronized timing architecture.

Technical Context

The PT8A3287PE integrates a 5-bit ADC for NTC voltage sampling, a clock-synchronized heating timer (216,000 CLK cycles), and logic to generate proportional TRIAC gate pulses based on NTC input level and detected line voltage (via CLK amplitude). Its state machine transitions between Reset, Heating-On, and Heating-Off modes.

NTC open detection is implemented by monitoring NTC1 input while driving NTC2 as an output; if open, NTC1 is pulled low. The internal Zener (5.0 V typ.) regulates reference voltage, and power consumption remains ≤500 µA under static conditions with NTC1/CLK grounded.

Key Specifications

Pinout & Package

PT8A3287PE is housed in an 8-pin plastic DIP (JEDEC MS-001D/BA compliant) with 2.54 mm pitch, 9.2 mm width, and 6.4 mm body height. Lead-free (Pb-free) finish per RoHS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3285WE and PT8A3286PE, the PT8A3287PE uniquely combines DIP-8 through-hole mounting, constant-mode dual-LED indication, and TRIAC drive - making it optimal for cost-sensitive, manually assembled thermal appliances requiring unambiguous status signaling.

Availability

PT8A3287PE is available at Aetrix Electronics and suitable for curling irons, hair straighteners, and electric blanket controllers requiring stable component supply, long-lifecycle support, and RoHS-compliant lead-free packaging.

Supply support for PT8A3287PE 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 consumer and industrial applications before acquisition in 2017.

The PT8A328x series was developed specifically for low-cost, safety-certifiable thermal control in personal care appliances - integrating analog sensing, digital timing, and power switching in a single 8-pin device.

FAQ

What is the function of the NTC2 pin on PT8A3287PE?

NTC2 is an output pin used exclusively for NTC open-circuit detection. When the NTC sensor becomes disconnected, the IC pulls NTC2 low while simultaneously pulling NTC1 low to signal the fault. This hardware-level response occurs independently of software or external logic and initiates immediate heating shutdown.

Can PT8A3287PE drive a TRIAC directly without a driver transistor?

Yes - the GATE pin provides up to 5 mA sink current at 0.5 V, sufficient to trigger common snubberless TRIACs (e.g., BT136, TYN1025) used in <1 kW heating loads. No external driver is needed unless higher gate charge or isolation is required for safety-critical designs.

How does PT8A3287PE distinguish between 120V and 240V line operation?

It analyzes the amplitude of the CLK input signal derived from the AC line. High-amplitude CLK corresponds to 240V operation and triggers proportional control with reduced duty cycle; low-amplitude CLK selects 120V mode with higher effective power delivery - all without external configuration pins or resistors.

Is the internal Zener diode intended for primary voltage regulation?

Yes - the 4.5–5.5 V Zener (IDD = 500 µA–10 mA) serves as the main VDD regulator. It allows direct connection to a rectified and filtered AC-derived supply (e.g., via 1 MΩ resistor and 43 kΩ 2 W bleeder), eliminating the need for a separate linear or switching regulator in most implementations.