17W调光调光LED驱动器参考设计驱动器参考设计
Cypress 公司的CY8CLEDAC02是高性能离线LED驱动器,AC离线输入从80V到277VAC,输出功率高达25W,调光
效率从2%到100%,主要用在可调光的离线LED驱动器,LED替代灯以及LED照明.本文介绍CY8CLEDAC02主要特
性,方框图, 简化和典型的应用电路图,以及采用CY8CLEDAC02的 220VAC 17W可调光LED驱动器参考设计系统
指标,电路图,材料清单和变压器指标.
Cypress 公司的CY8CLEDAC02是高性能离线
The CY8CLEDAC02 is a high performance offline LED driver, designed to interface directly with most conventional phase
cut based wall dimmers. The device uses proprietary digital control technology to provide automatic detection of dimmer
type
(leading or trailing edge). It automatically generates dimming signals for LED loads and has the ability to dim down to 2%. It
modulates LED brightness using a linear dimming scheme and switches to a
At the heart of a CY8CLEDAC02 based system is the chopping circuit which provides the load necessary to enable correct
wall dimmer operation. It also improves PF when there is no dimmer on the line.
The devices’ proprietary primary side sensing enables tight LED current regulation and eliminates the need for secondary
feedback circuitry. No opto-couplers are necessary to meet UL isolation requirements; enabling flyback conversion with
automatic isolation.
The CY8CLEDAC02 operates in quasi-resonant mode to achieve high efficiency. This mode of operation helps minimize
external component count and simplifies EMI design, lowering the total bill of material cost.
The device’s cycle-by-cycle adaptive digital regulation uses critical discontinuous conduction mode (CDCM) when driving
LED loads. The control algorithm for cycle-by-cycle regulation has internal compensation for guaranteed system phase and
gain margins; requiring no external components for loop compensation.
The CY8CLEDAC02 has full featured circuit protection not normally available with other primary-side control solutions. The
built-in protection includes output overvoltage protection (OOVP), output short circuit protection (OSCP), overtemperature
protection (OTP), current-sense resistor short protection (CSSP), and peak current limit protection (PCLP). It also enables
automatic LED brightness adjustment to compensate for temperature drift by simply connecting a NTC resistor to the VT
pin.
CY8CLEDAC02主要特性:
■ AC offline input range from 80 to 277 VAC
■ Up to 25W output power range
■ Intelligent wall dimmer detection:
❐ Leading edge (R, RL) dimmers
❐ Trailing edge (RC, RLC) dimmers
❐ No dimmer
■ Wide dimming range from 2 to 100%
■ Resonant control to achieve high efficiency (85% without dimmer)
■ Meets harmonic requirement with high power factor (0.7 without dimmer)
■ Primary-side sensing eliminates opto-isolators
■ Tight LED current regulation (typically < + 2.5%)
■ Low startup current (typically 10A)
■ Low startup time (typically 0.5s with active startup)
■ Multiple protection features:
❐ Output overvoltage protection (OOVP)
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