AP8801SG-13 Diodes Zetex, AP8801SG-13 Datasheet - Page 5

• Manufacturer Part Number: AP8801SG-13
• Description: Conv DC-DC Single Step Down 8V to 48V 8-Pin SOP T/R
• Manufacturer: Diodes Zetex
• Type: Step Downr

Specifications of AP8801SG-13

• Package: 8SOP
• Number Of Outputs: 1
• Minimum Input Voltage: 8 V
• Maximum Input Voltage: 48 V
• Switching Frequency: 500 KHz
• Maximum Output Current: 0.5 A
• Output Type: Fixed
• Output Voltage: -0.3 to 50 V
• Switching Regulator: Yes
• Efficiency: 92 %
• Operating Temperature: -40 to 105 °C

Application Information
LED Current Control
The LED current is controlled by the resistor RSET in Figure 1 connected between V
average output current in the LED(s) is defined as:
If the CTRL pin is driven by an external voltage (lower than 2.5V), the average LED current is:
AP8801 Rev. 4
DS31765
I
I
LED
LED
600
500
400
300
200
100
=
=
0
R
V
V
0
V
THD
CTRL
SET
REF
0.15 0.3 0.45 0.6 0.75 0.9 1.05 1.2 1.35 1.5 1.65 1.8 1.95 2.1 2.25 2.4 2.55 2.7 2.85
R
V
THD
SET
0.4
0.47
0.47
0.56
0.68
0.68
Figure 3: LED Current setting Vs R
0.82
0.82
0.82
1
1
1
LED current Versus RSET and VCTRL
1.2
1.2
RSET value [Ohms ]
1.2
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1.5
1.5
1.5
5 of 11
2
2
2
500mA LED Step-down Converter
SET
and V
CTRL
3
3
3
3
IN
and SET. The nominal
DECEMBER 2009
LED current @
VCTRL = 1.25V
LED current @
VCTRL = 2.5V
LED current @
VCTRL = 0.625V
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AP8801
Diodes Incorporated