AP8800FNG-7 Diodes Inc, AP8800FNG-7 Datasheet - Page 5

• Manufacturer Part Number: AP8800FNG-7
• Description: IC LED DRIVER HIGH BRIGHT 10DFN
• Manufacturer: Diodes Inc
• Type: HBLED Driverr

Specifications of AP8800FNG-7

• Constant Current: Yes
• Topology: PWM, Step-Down (Buck)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: High Brightness LED (HBLED)
• Frequency: 600kHz
• Voltage - Supply: 8 V ~ 28 V
• Voltage - Output: 28V
• Mounting Type: Surface Mount
• Package / Case: 10-DFN
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 350mA
• Internal Switch(s): Yes
• Efficiency: 92%
• High Level Output Current: 350 mA
• Operating Supply Voltage: 8 V to 28 V
• Maximum Supply Current: 30 uA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AP8800FNGDITR

Application Information
Capacitor Selection
The small size of ceramic capacitors makes them ideal for AP8800 applications. X5R and X7R types are recommended
because they retain their capacitance over wider voltage and temperature ranges than other types such as Z5U. A 1μF input
capacitor is sufficient for most intended applications of AP8800.
Diode Selection
Schottky diode, e.g. B140, with their low forward voltage drop and fast reverse recovery, is the ideal choice for AP8800
applications.
PWM Dimming
A Pulse Width Modulated (PWM) signal with a max resolution of 8bit can be applied to the CTRL pin to regulate the output
current to a value above or below the nominal average value set by resistor RSET.
Miscellaneous
To ensure optimal performance, RSVD pin should be connected to the GND pin with the shortest trace length.
Inductor Selection
A 100μH inductor is recommended for most AP8800 applications with input voltage at 24V.
Figure 4 displays the resulting switching frequency varying the main circuit parameters: Supply voltage, Inductor value and
number of LEDs to be driven.
Thermal Considerations
The graph below in figure 5, gives details for power derating. This assumes the device to be mounted on a 25x25mm PCB
with 1oz copper standing in still air.
AP8800
Document number: DS31764 Rev. 5 - 2
700
600
500
400
300
200
100
0
0
Fig 4. Switching Frequency vs. Supply voltage, Inductor, and number of LEDs
50
47
68
100
100
100
(cont.)
150
150
150
200
Inductor Value [uH]
Switching Frequency
220
220
www.diodes.com
250
5 of 11
300
350mA LED STEP-DOWN CONVERTER
350
400
450
470
470
500
AP8800
© Diodes Incorporated
12V - 1LED
24V - 3 LEDs
28V - 4LEDs
March 2011