Diodes Incorporated
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PT8A2641 (Obsolete)

Triac driver

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Product Description

The PT8A264X is a CMOS LSI chip designed for use in automatic PIR lamp control. It can operate with a 2-wire configuration for triac applications or with a 3-wire configuration for relay applications. The chip is equipped with operational amplifiers, a comparator, timer, a zero crossing detector, control circuit, a voltage regulator, a system oscillator, and an output timing oscillator.

Its PIR sensor detects infrared power variations induced by the motion of a human body and transforms it to a voltage variation. If the PIR output voltage variation conforms to the criteria (refer to the functional description), the lamp is turned on with an adjustable duration. The PT8A264X offers three operating modes (ON, AUTO, OFF) which can be set through the MODE pin. While the chip is working in the AUTO mode the user can override it and switch to the quickly install mode, or manual ON mode, or return to the AUTO mode by switching the power switch.


  • Operating voltage: 5V (Typ.)
  • Average supply current: 120μA (Typ.)
  • 2 stage op-amp for filter.
  • Build-in noise rejection circuit.
  • On-chip regulator.
  • Adjustable output duration
  • Override function.
  • ON/AUTO/OFF selectable by MODE pin
  • Apply to AC 220V/50Hz and 110V/60Hz.
  • Auto-reset if the ZC signal disappears over 3 seconds
  • Output pulse (PT8A2641/5/7) to drive triac or output level (PT8A2642/6/8) to drive relay.
  • CDS to enable/disable output.
  • 40 second warm-up.
  • Quick check mode for installation.

Product Specifications

Product Parameters

Driver Type Triac

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Technical Documents

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Additional Technical Documents are available upon request:
Application information, Evaluation board, and Other technical documents

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Product Change Notices (PCNs)

A PCN may only apply to specific orderable part numbers in this datasheet. Please refer to the corresponding PCN to see the exact orderable part number(s) affected.

PCN # Issue Date Implementation Date Subject
PCN-2602 2023-01-31 2023-07-31 Device End of Life (EOL)


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