iW3612
AC/DC Digital Power Controller for
Dimmable LED Drivers
1.0 Features
● Isolated AC/DC offline 100VAC /230VAC LED driver
● Line frequency ranges from 45Hz to 66Hz
● Intelligent wall dimmer detection
2.0 Description
The iW3612 is a high performance AC/DC offline power
supply controller for dimmable LED luminaires, which uses
advanced digital control technology to detect the dimmer
type and phase. The dimmer conduction phase controls
the LED brightness. The LED brightness is modulated by
PWM-dimming. iW3612’s unique digital control technology
eliminates visible flicker.
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Leading-edge dimmer
Trailing-edge dimmer
No-dimmer detected
Unsupported dimmer
iW3612 can operate with all dimmer schemes including:
leading-edge dimmer, trailing-edge dimmer, as well as
other dimmer configurations such as R-type, R-C type or
R-L type. When a dimmer is not present, the controller can
automatically detect that there is no dimmer.
● Hybrid dimming scheme
● Wide dimming range from 1% up to 100%
● Optimized for PF > 0.7
iW3612 operates in quasi-resonant mode to provide
high efficiency. The iW3612 provides a number of key
built-in features. The iW3612 uses iWatt’s advanced primary-
● No visible flicker
● Resonant control to achieve high efficiency, 85% without side sensing technology to achieve excellent line and load
dimmer
regulation without secondary feedback circuitry. In addition,
iW3612’s pulse-by-pulse waveform analysis technology
allows accurate LED current regulation. The iW3612
maintains stability over all operating conditions without the
need for loop compensation components. Therefore, the
iW3612 minimizes external component count, simplifies EMI
design and lowers overall bill of materials cost.
● Temperature compensated LED current
● Small size design
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Small size input bulk capacitor
Small size output capacitor
Small transformer
3.0 Applications
● Dimmable LED luminaires
● Primary-side sensing eliminates the need for
opto-isolator feedback and simplifies design
● Tight LED current regulation ± 5%
● Fast start-up, typically 10µA start-up current
● Hot-plug LED module support
● Optimized for 3W - 25W output power
● Capable of higher output power with enhanced external
driver
● Multiple protection features:
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LED open circuit protection
Single-fault protection
Over-current protection
LED short circuit protection
Current sense resistor short circuit protection
Over-temperature protection
Input over-voltage protection
● Up to 25W output power
Rev. 1.6
iW3612
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