Rev. 1.00

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Rev. 1.00

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HT7L4091

Universal Step-Down PWM Control

For High Brightness LED Lighting Control

Typical Performance Characteristics

There are many different factors to influence efficiency of the application, such as the output power,

working frequency, power supply circuit of the HT7L4091 and so on. The following are some

measured results.

Efficiency vs. Power Supply Circuit – Working Frequency

There are several different power supply circuits for the device. Reference to the “Application

circuit” for some examples. The different circuits provide different advantages, such as high

efficiency or low cost.

Follow are some efficiency compare for different power supply circuits. The condition

efficiency.

efficiency compare in different application circuits

(freq,min=50kHz)

78

80

82

84

86

88

90

92

80

130

180

230

280

Vac (V)

auxiliary circuit

typical circuit

BJT circuit

frequency) to >=30 KHz.

efficiency compare with different frequency in two application

circuits

81

83

85

87

89

91

93

80

130

180

230

280

Vac (V)

auxiliary circuit 50kHz

BJT circuit 50kHz

auxiliary circuit 30kHz

BJT circuit 30kHz