Diodes Incorporated PT8A3286PEX

Overview

PT8A3286PEX from Pericom Semiconductor is a mixed-signal CMOS heating controller IC designed for 120V/240V AC-powered thermal appliances. It implements proportional temperature control using an external NTC sensor, features NTC open-circuit protection, auto power-off after 1.15–1.25 hour timer timeout (50/60 Hz), and drives TRIACs with 160–240 µs trigger pulses up to 15 mA. Used in hair straighteners and curling irons.

For engineers reviewing the PT8A3286PEX datasheet, PT8A3286PEX pinout, PT8A3286PEX application, or PT8A3286PEX equivalent, key selection criteria include its dual-voltage auto-adaptation, NTC-based closed-loop regulation, TRIAC-compatible gate drive, LED2 flash mode (1/8 clock), and DIP-8 lead-free package compatibility with thermal appliance safety standards.

Technical Context

The PT8A3286PEX integrates a 5-bit ADC for NTC voltage sampling, internal Zener regulator (4.5–5.5 V), and programmable heating timer synchronized to AC line frequency (50/60 Hz). Its control logic automatically selects proportional output mode based on NTC voltage and CLK amplitude level (120V vs. 240V detection).

It operates across –20°C to +85°C, draws ≤500 µA supply current, and delivers 5 mA low-side GATE sink current for TRIAC triggering. NTC2 serves as open-detection output, while LED1/LED2 are configurable I/O pins supporting flash or constant illumination per function table.

Key Specifications

Pinout & Package

PT8A3286PEX is supplied in an 8-pin lead-free PDIP package (JEDEC MS-001D/BA), 9.0–9.4 mm wide, 6.2–6.6 mm body width, with 2.54 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3284PEX and PT8A3285PEX, PT8A3286PEX uniquely disables LED2 flash while retaining full NTC-based proportional control, open-detection, and 1.2-hour auto-off-making it optimal for cost-sensitive, minimal-indicator thermal devices.

Availability

PT8A3286PEX is available at Aetrix Electronics and suitable for hair straighteners, curling irons, and electric blanket controllers requiring stable component supply, RoHS-compliant packaging, and long-term industrial availability.

Supply support for PT8A3286PEX 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 2016.

The PT8A328x series belongs to Pericom's dedicated thermal control product line, engineered specifically for low-cost, single-chip heating management in AC-powered personal care and home appliances.

FAQ

What is the function of the NTC2 pin on PT8A3286PEX?

NTC2 is an open-drain digital output that goes low when the NTC sensor is disconnected or open-circuited. During normal operation with a valid NTC, NTC2 remains in high-impedance state. This signal is used externally to disable the TRIAC gate or trigger system-level fault handling, ensuring fail-safe thermal shutdown.

Does PT8A3286PEX require an external crystal or clock source?

No. PT8A3286PEX uses the AC mains frequency as its timing reference via the CLK pin, which accepts direct connection to a scaled-down line voltage signal (e.g., via resistive divider). It internally detects 50 Hz or 60 Hz and adapts heating control parameters accordingly-no external oscillator or crystal is needed.

How does PT8A3286PEX differentiate between 120V and 240V line voltages?

It analyzes the amplitude of the CLK input signal: high-amplitude CLK indicates 240V operation and adjusts proportional control gain downward to avoid excessive heating; low-amplitude CLK triggers higher gain for 120V lines. This auto-detection occurs at power-on and requires no configuration or external components.

Can PT8A3286PEX drive a TRIAC directly without a driver transistor?

Yes. The GATE pin provides up to 5 mA sink current with 160–240 µs pulse width-sufficient to trigger sensitive-gate TRIACs (e.g., MAC97A6, BT134) commonly used in sub-1 kW heating loads. For higher-current TRIACs, a small bipolar transistor buffer is recommended per application circuit guidelines.