Diodes Incorporated PT8A3512WEX

Overview

PT8A3512WEX from Princeton Technology is a CMOS smart iron controller IC designed for automatic thermal safety shutdown in electric irons operating on 50Hz AC mains. It integrates an on-chip shunt regulator (4.5–5.5V), ACCLK-synchronized 8-minute vertical-position timeout and 30-second horizontal-position timeout, and open-drain LED driver with 4Hz flash output upon timeout - deployed in household iron safety control circuits.

For engineers reviewing the PT8A3512WEX datasheet, PT8A3512WEX pinout, PT8A3512WEX application, or PT8A3512WEX equivalent, key selection criteria include AC frequency compatibility (50Hz only), relay drive capability (RELAYA active-high, 1mA source), DISC terminal discharge function, and SOIC-8 package suitability for compact PCB layouts in consumer appliance designs.

Technical Context

The PT8A3512WEX uses 50Hz AC line frequency as its primary timing reference via the ACCLK input, enabling precise 8-minute vertical and 30-second horizontal timeout functions without external crystal. Its sensor signal processor handles debounce and vibration immunity for mechanical tilt sensors connected to the SW pin.

Internal blocks include a shunt-regulated power supply (VCC = 4.5–5.5V), DPLL-based timing logic, power-on reset, and dual-output drivers: RELAYA (active-high, 1mA source) for heater control and DISC (active-high, 1mA source) for electrolytic capacitor discharge - both rated for 20mA max DC output current.

Key Specifications

Pinout & Package

PT8A3512WEX is supplied in a lead-free SOIC-8 package (JEDEC MS-012 AA), 3.9mm width, 1.27mm pitch, with gull-wing leads and 0.66mm max height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3512PE, PT8A3512WEX offers surface-mount compatibility and smaller footprint; compared with PT8A3511WE, it is functionally identical except for mandatory 50Hz clock dependency - making it the sole valid choice for EU/UK/Asia 230V/50Hz iron designs.

Availability

PT8A3512WEX is available at Aetrix Electronics and suitable for household appliance safety control, electric iron thermal management, and AC mains-synchronized timing applications requiring stable component supply across global 230V/50Hz markets.

Supply support for PT8A3512WEX 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

Princeton Technology Corporation is a Taiwan-based fabless semiconductor company specializing in mixed-signal ASICs for consumer electronics and home appliances.

The PT8A351x series belongs to Princeton's Smart Appliance Controller product line, engineered specifically for single-function, high-reliability thermal safety in electric irons - emphasizing AC-line synchronization, vibration immunity, and minimal external component count.

FAQ

What is the maximum allowable VCC voltage for PT8A3512WEX?

The absolute maximum VCC voltage is 5.5V, with recommended operation between 4.5V and 5.5V. Exceeding 5.5V risks permanent damage, as confirmed by the Absolute Maximum Ratings table in the datasheet. The on-chip shunt regulator maintains regulation within this range when powered from rectified AC-derived rails with appropriate series resistance.

Can PT8A3512WEX operate on 60Hz AC mains?

No - PT8A3512WEX is factory-configured for 50Hz ACCLK input only. Using 60Hz causes incorrect timeout durations: 30s and 8min thresholds will shorten by 17%, violating safety requirements. The PT8A3511 variant is the designated 60Hz counterpart and is not pin- or function-compatible.

How does the DISC pin function in the application circuit?

The DISC pin is an active-high output that discharges the external electrolytic capacitor (e.g., C1 in Figure 2) during standby or timeout. This prevents residual voltage buildup that could cause delayed or unsafe relay re-engagement. It sources up to 1mA and must be connected through a current-limiting resistor to the capacitor's positive terminal.

Is the LED pin compatible with common anode or common cathode indicators?

The LED pin is open-drain and active-low - it sinks current to ground. Therefore, it requires a common-anode LED configuration: LED anode tied to VCC (via current-limiting resistor), cathode to LED pin. When active, it sinks ≥10mA to produce visible flashing at ~4Hz; floating state enables steady illumination during normal heating.