Diodes Incorporated PT8A3516APEX

Overview

PT8A3516APEX from Pericom Semiconductor is a dedicated smart electric iron controller IC with integrated shunt regulator, sensor signal processor, RC oscillator, and programmable 30s/15min timer. It detects iron orientation (horizontal/vertical) via external sensor input, drives relay and buzzer outputs, and supports both 120V/60Hz and 240V/50Hz AC mains-synchronized timing. Used in automatic shut-off safety systems for household irons.

For engineers reviewing the PT8A3516APEX datasheet, PT8A3516APEX pinout, PT8A3516APEX application, or PT8A3516APEX equivalent, key selection criteria include AC clock synchronization capability, horizontal/vertical timeout configuration (30s/15min), open-drain LED drive, 4kHz buzzer output, and DIP-8 lead-free packaging for high-reliability appliance control.

Technical Context

The PT8A3516APEX uses AC line frequency (50Hz) as its primary timing reference, enabling ±1% timer accuracy without crystal. Its sensor interface processes SW input with debounce immunity and interprets logic level to determine iron orientation-high = horizontal, low = vertical-triggering distinct timeout modes.

Internal blocks include a 5V shunt regulator (4.5–5.5V output), power-on reset, logic control circuit generating active-high RELAY and DISC/BUZ signals, and an open-drain LED driver that toggles at ~1Hz during timeout. System standby power dissipation is <1W per recommended circuit.

Key Specifications

Pinout & Package

DIP-8 package (JEDEC MS-001D/BA compliant), lead-free, 9.0–9.4 mm width, 6.2–6.6 mm body width, 3.71–4.31 mm height. Pin 1 marked by notch or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PT8A3516BPEX, this part targets 50 Hz regions and requires no circuit redesign beyond ACCLK source; versus PT8A3519APEX, it delivers continuous buzzer tone for stronger user notification during timeout-critical in noisy domestic environments.

Availability

PT8A3516APEX is available at Aetrix Electronics and suitable for automatic iron safety shutdown, AC-mains-synchronized timer modules, and smart appliance sensor interface applications requiring stable component supply and long-lifecycle support.

Supply support for PT8A3516APEX 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) is a fabless provider of high-performance interface, timing, and power management ICs for consumer, computing, and industrial markets.

The PT8A351x series belongs to Pericom's Smart Appliance Controller product line, engineered specifically for contactless, low-cost, and ultra-reliable automatic shut-off in electric irons and similar thermal appliances.

FAQ

What is the function of the TEST pin on PT8A3516APEX?

The TEST pin enables fast functional verification: when held low, it scales all internal timeouts to 1/10 real-time (e.g., 15 min becomes 9.6 s). This allows rapid validation of relay cutoff, buzzer activation, and LED flashing behavior without waiting for full operational durations-critical during factory testing and prototype bring-up.

How does PT8A3516APEX achieve ±1% timer accuracy without a crystal?

It locks its internal timer to the 50 Hz AC mains frequency via the ACCLK pin. Because utility grid frequency is tightly regulated (typically ±0.05 Hz), using it as a timing reference yields ±1% accuracy over temperature and voltage variations-eliminating crystal cost, board space, and calibration overhead while maintaining safety-critical precision.

Can PT8A3516APEX drive a relay directly, or is external buffering required?

Yes-it drives relays directly: the RELAY pin delivers active-high output with 5 mA sink capability, matching the 24VDC/1.6kΩ coil specification in the reference design. No transistor buffer is needed when used with compliant relays; external flyback diode is mandatory per application note to suppress inductive kickback.

What is the role of the DISC/BUZ pin during normal operation versus timeout?

During normal operation, DISC/BUZ discharges external electrolytic capacitors to stabilize VCC regulation. At timeout, it switches to 4 kHz square-wave output to drive a 20 mm buzzer continuously-providing audible alert while maintaining capacitor discharge functionality through duty-cycle modulation.