ST EVL6566A-75WADP User Manual

19 V - 75 W laptop adapter with tracking boost

PFC pre-regulator, using the L6563 and the L6566A

Features

■ Universal input mains range: 90÷264Vac -

Frequency 45 ÷ 65 Hz

■ Output voltage: 19 V@4 A continuous

operation

■ Mains harmonics: Acc. to EN61000-3-2

Class-D

■ ST-by mains consumption: Less than 0.25 W

@265Vac

■ Overall efficiency: Better than 86%

■ EMI: According to EN55022-Class-B

■ Safety: According to EN60950

■ Low profile design: 25 mm maximum height

■ PCB single layer: single side, 70 µm, CEM-1,

78x174 mm, Mixed PTH/SMT

EVL6566A-75WADP

Data Brief

Description

In this data brief of the EVL6566A-75WADP demo
board, the main characteristics and features of a
75 W adapter wide-range input mains, power­factor-corrected AC-DC adapter using the new
L6566A controller and the L6563 dedicated to the
PFC stage are described.

High efficiency and the very low standby input
consumption are highlighted in the following
figures and tables. The board is programmed for
working at fixed frequency (65 kHz) under
nominal condition (19 V at 4 A).

On the secondary side the TSM1014 with a
precise voltage reference and the optocoupler
SFH617A-4 to transfer the error amplifiers
information to the primary side have been used.

September 2007 Rev 1 1/8

For further information contact your local STMicroelectronics sales office.

www.st.com

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Efficiency EVL6566A-75WADP

1 Efficiency

Tab l e 1 below shows the efficiency with two different input voltages. The table begins with

the nominal load at 80 W on the output and it displays the efficiency at every power
decrease of 5 W.

Table 1. Efficiency measurements

230 V-50 Hz 115 V-60 Hz

Pin Pout Eff. Pin Pout Eff.

85.73 75.05 87.5% 87.24 75.06 86.0%

80.56 70.00 86.9% 80.73 70.00 86.7%

74.91 65.01 86.8% 74.34 65.01 87.4%

68.68 59.97 87.3% 68.95 60.00 87.0%

62.40 55.01 88.2% 63.80 55.02 86.2%

56.96 50.00 87.8% 58.03 50.04 86.2%

52.31 45.02 86.1% 51.80 45.05 87.0%

47.03 40.00 85.1% 45.45 40.00 88.0%

41.01 35.05 85.5% 40.53 35.05 86.5%

34.40 30.00 87.2% 35.15 30.00 85.3%

29.60 25.02 84.5% 29.00 25.02 86.3%

24.70 20.00 81.0% 23.07 20.00 86.7%

17.86 14.94 83.7% 18.36 15.05 82.0%

11.98 10.00 83.5% 11.88 10.00 84.2%

6.64 5.01 75.5% 6.10 5.05 82.8%

2.73 1.99 72.9% 2.53 1.99 78.7%

Above the 20 W power output, the efficiency is constant over 85%.

Figure 1. Overall efficiency versus output power at nominal mains voltages

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EVL6566A-75WADP Full load

2 Full load

Figure 2 and Figure 3 below show the drain and gate fly-back waveforms and the relevant

switching frequency at full load.

Figure 2. L6566A fly-back stage

waveforms at 115 V-60 Hz full load

CH1: drain 6566A
CH2: gate 6566A

Figure 3. L6566A fly-back stage

waveforms at 230 V-50 Hz full load

CH1: drain 6566A
CH2: gate 6566A

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