Diodes Incorporated PT8A3247WE

Overview

PT8A3247WE from Pericom Semiconductor is a mixed-signal CMOS LSI heating controller IC for single-key hair curlers, featuring constant LED indication, NTC-based auto temperature control, 1-hour auto power-off timer (at 60 Hz), dual-voltage operation (110/220 VAC), and direct SCR gate drive. It implements NTC open-circuit protection and operates across –20°C to +85°C ambient.

For engineers reviewing the PT8A3247WE datasheet, PT8A3247WE pinout, PT8A3247WE application, or PT8A3247WE equivalent, this device supports precise thermal regulation in low-cost AC-powered personal care appliances with integrated safety logic and voltage-adaptive power control.

Technical Context

The PT8A3247WE integrates a 2-bit ADC for NTC voltage sampling, internal clock synchronization to AC line frequency (50/60 Hz), and state-machine-based thermal control logic that dynamically adjusts SCR firing angle based on NTC resistance and input voltage level. It distinguishes four NTC voltage thresholds (VNTC0–VNTC2) to modulate heating power.

Its dual-voltage capability is implemented via automatic detection of CLK amplitude and scaling of GATE output duty cycle - delivering ~100% conduction at 110 VAC and ~25% at 220 VAC under nominal NTC conditions - preventing overheating across global mains standards.

Key Specifications

Pinout & Package

PT8A3247WE is housed in a lead-free, RoHS-compliant SOIC-8 package (JEDEC MS-012E/AA), measuring 4.7–5.1 mm × 3.8–4.0 mm × 1.35–1.75 mm, with 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3245WE and PT8A3246WE, PT8A3247WE uniquely combines constant LED indication with mandatory 1-hour auto-shutoff - making it the only variant certified for IEC 60335-1–compliant hair styling tools requiring both visual feedback and hard-timed thermal safety.

Availability

PT8A3247WE is available at Aetrix Electronics and suitable for hair curlers, flat irons, hot air brushes, and waving irons requiring stable component supply, dual-voltage support, and IEC 60335-1–aligned thermal safety features.

Supply support for PT8A3247WE 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 Corporation was a fabless semiconductor company specializing in high-performance interface, timing, and power management solutions before its acquisition by Diodes Incorporated in 2016.

The PT8A324x series belongs to Pericom's dedicated heating controller product line, designed specifically for cost-sensitive, AC-mains–powered personal care appliances with integrated thermal safety and minimal external component count.

FAQ

What is the function of Pin 2 (NTC2) on the PT8A3247WE?

Pin 2 (NTC2) is an open-drain output used exclusively for NTC open-circuit detection. When the NTC sensor becomes disconnected, this pin pulls low, triggering GATE disable and LED2 flash at 1/8 CLK frequency. It is not used for analog measurement or biasing - its sole role is fail-safe signaling.

Does PT8A3247WE require an external crystal or oscillator?

No. The PT8A3247WE uses the AC mains-derived CLK signal (50/60 Hz) as its sole timing reference. Pin 3 accepts a zero-crossing waveform from a resistive divider or optocoupler - no crystal, ceramic resonator, or external oscillator is needed, reducing BOM cost and board space.

How does PT8A3247WE adapt to 110 VAC versus 220 VAC operation?

The device detects line voltage level via CLK input amplitude and adjusts SCR conduction duty cycle accordingly: ~100% at 110 VAC and ~25% at 220 VAC under identical NTC conditions. This maintains consistent thermal output without user intervention or hardware configuration changes.

Can PT8A3247WE drive a triac directly, or is an SCR mandatory?

PT8A3247WE's GATE output is optimized for direct SCR triggering (2.5 mA sink capability). While it can drive small triacs with low gate threshold current (e.g., < 2 mA), most triacs require higher peak gate current or snubber networks. For robust triac interfacing, a discrete transistor buffer is recommended - unlike SCR, which works reliably without added components.