Diodes Incorporated PT8A3290PEX

Overview

PT8A3290PEX from Pericom Semiconductor is a mixed-signal CMOS heating controller IC designed for dual-voltage (120V/240V) hair styling appliances. It implements NTC-based proportional temperature control, auto-off timing (1.15–1.25 hr), and 15mA TRIAC gate drive with internal Zener regulation (4.5–5.5V). Used in curlers and straighteners, it integrates 5-bit ADC, clock-synchronized pulse triggering, and dual LED indication.

For engineers reviewing the PT8A3290PEX datasheet, PT8A3290PEX pinout, PT8A3290PEX application, or PT8A3290PEX equivalent, key selection criteria include NTC open-detection logic, 50/60Hz line-synchronized CLK input handling, proportional GATE output width (160–240µs), and DIP-8 package compatibility with thermal management in compact consumer housings.

Technical Context

The PT8A3290PEX uses line-frequency CLK (50/60Hz) as its timing reference to synchronize heating cycles and LED flash patterns. Its 5-bit ADC digitizes NTC voltage for closed-loop proportional control, while internal logic detects NTC open-circuit by monitoring NTC1/NTC2 states.

It features dual-mode button interface (ON/OFF pins as I/O), automatic voltage adaptation via CLK amplitude sensing, and a dedicated GATE output capable of driving high-current SCR/TRIACs with 200µs typical pulse width - all operating within -20°C to +85°C ambient range and 3.5–5.5V supply.

Key Specifications

Pinout & Package

PT8A3290PEX is supplied in lead-free 8-pin DIP (JEDEC MS-001D/BA compliant), with 0.3" body width, 2.54mm pitch, and 9.0–9.4mm length. Thermal pad not present; PCB layout requires clearance from adjacent high-temp components.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3290PEX, PT8A3294WE trades DIP-8 robustness and dual-button flexibility for SOIC-8 density and simplified UI, while PT8A3270PE omits critical safety features like auto-off and NTC open detection - making PT8A3290PEX the only choice for certified consumer heating devices requiring IEC-compliant thermal protection.

Availability

PT8A3290PEX is available at Aetrix Electronics and suitable for hair curlers, straighteners, and travel-sized styling appliances requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support for consumer electronics production.

Supply support for PT8A3290PEX 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, computing, and communications markets before its 2017 acquisition.

The PT8A3290PEX belongs to Pericom's dedicated heating controller product line, engineered specifically for thermally regulated personal care appliances - emphasizing integrated safety, dual-voltage adaptability, and minimal external component count.

FAQ

What is the function of the NTC2 pin on PT8A3290PEX?

NTC2 is an open-drain output that actively pulls low when the NTC sensor is detected as open-circuited. It sinks up to 2.0mA at 0.5V and interfaces directly with external circuitry (e.g., MCU GPIO or LED driver) to signal fault condition. This hardware-level response occurs independently of software, ensuring immediate heating shutdown upon sensor disconnection.

Can PT8A3290PEX operate without an external AC line clock signal?

No - the PT8A3290PEX requires a 50/60Hz CLK input derived from the AC mains to synchronize heating pulses, timer counting, and LED flash patterns. The device does not include an internal oscillator; omitting CLK results in non-functional heating control and disabled auto-off timer, as timing is strictly line-locked for zero-crossing accuracy and regulatory compliance.

How does PT8A3290PEX distinguish between 120V and 240V line operation?

The IC measures CLK input amplitude: high-amplitude CLK indicates 240V operation and configures proportional control for higher power delivery; low-amplitude CLK triggers 120V mode with reduced heating output. This analog-level detection is performed internally without external resistors or configuration pins, enabling automatic global voltage adaptation in a single BOM.

What is the maximum recommended TRIAC gate current drive capability of PT8A3290PEX?

The GATE pin delivers a minimum sink current of 5.0mA at 0.5V output voltage, sufficient to trigger standard 25–40A random-phase TRIACs (e.g., BT139, TYN625) with 160–240µs pulse width. For higher-current loads (>50A), a small external buffer transistor is recommended to maintain reliable turn-on margin under worst-case junction temperature conditions.