• LED driving current up to 500mA • Operating input voltage up to 48V • High efficiency up to 92%
• High switching frequency up to 500kHz • PWM/DC input for dimming control • Built-in output open-circuit protection
• SOP-8L and MSOP-8L are available in “Green” Molding Compound (No Br, Sb)
• Lead Free Finish/RoHS Compliant (Note 1)
The AP8801 is a step-down DC/DC converter designed to drive LEDs with a constant current. The device can drive up to thirteen LEDs, depending on the forward voltage of the LEDs, in ries from a voltage source of 8V to 48V. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The AP8801 switches at frequency up to 500kHz. This allows the u of small size external components, hence minimizing the PCB area needed.
Maximum output current of AP8801 is t via an external resistor connected between the V IN and SET input pins. Dimming is achieved by applying either a DC voltage or a PWM signal at the CTRL input pin. An input voltage of 0.2V or lower at CTRL shuts down the output at SW and puts the device into a low-current standby state.
• Commercial & industrial lighting • Small LCD panel backlight • Appliances interior lighting •
Architecture Detail lighting
Typical Application Circuit
D 1
C
Figure 1: Typical Application Circuit
Features
General Description
Applications
AP 8801 XX G - 13
Package Packing
S : SOP-8L Green 13 : Tape & Reel
G : Green
M8 : MSOP-8L
Device
Package Code Packaging (Note 2)
13”Tape and Reel
Quantity Part Number Suffix
AP8801SG-13 S SOP-8L 2500/Tape & Reel -13
AP8801M8G-13 M8 MSOP-8L 2500/Tape & Reel
-13
Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Plea visit our website at
/products/lead_free.html.
2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
/datasheets/ap02001.pdf.
(1) SOP-8L
(2) MSOP-8L
( Top View )
NC
SW CTRL SET SW
V IN GND GND ( Top View )
NC
SW CTRL SET SW
V IN GND GND Ordering Information
Pin Assignments
Pin Name Description
SW
Switch Pin. Connect inductor/freewheeling diode here, minimizing track length at this pin to
reduce EMI. GND GND pin SET Set Nominal Output Current Pin. Configure the output current of the device.
康熙王朝台词CTRL Dimming and On/Off Control Input. Input voltage of 0.2V or lower forces the device into low current standby mode and shuts off the output. A PWM signal allows the output current to be adjusted above or below the level t by the resistor connected to SET input pin. The input impedance is about 50k Ω, and if the pin is left open V CTRL = V REF V IN Input Supply Pin. Must be locally bypasd.
NC No connection
Block Diagram
武汉三大名胜
CTRL
V IN
GND
Figure 2: AP8801 Block Diagram
Pin Descriptions
Absolute Maximum Ratings
Symbol Parameter Rating Unit V IN VIN pin voltage -0.3~50 V
V SW SW voltage -0.3~50 V机械停车
T J Junction Temperature 150 o C
T LEAD Lead Temperature Soldering 300 o C
T ST Storage Temperature Range -65 to +150 o C
Caution: The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. The values must therefore not be exceeded under any condition.
Semiconductor devices are ESD nsitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken
when handling and transporting the devices
Recommended Operating Conditions
Symbol Parameter Min Max Unit T A Ambient
Temperature
Range -40 105 ºC
Duty Cycle Using Inductor ≥ 100µH (Note 3) 0.1 0.95
Notes: 3. For most applications the LED current will be within 8% over the duty cycle range specifi
ed. Duty cycle accuracy is also dependent on propagation delay. Smaller size inductors can be ud but LED current accuracy may be greater than 8% at extremes of duty cycle. This is
most noticeable at low duty cycles (less than 0.1) or when the input voltage is high and only one LED is being driven.
Electrical Characteristics (V IN =24V, T A=25o C, unless otherwi specified)
Symbol Parameter Conditions Min Typ. Max Unit V IN Operating
Input
Voltage 8.0 - 48 V
入党有用吗
I OUT Continuous switch current (Note 4) 500 mA男猪女兔婚姻怎么样
I Q Quiescent
Current - 78 120 μA
F OSC Switching
Frequency - - 0.5 MHz V THD Internal
Threshold
Voltage 184 200 216 mV V REF Internal Reference Voltage - 1.25 - V
SET SET pin input current V SET=V IN-0.2 -
7
-
μA
Rds(on) On Resistance of MOSFET I SW=0.4A
0.7
1.15
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I SW Leakage Switch leakage current - - 8 μA
EN Voltage
High ON 1.25 - - V EN Voltage
Low OFF - - 0.2 V
θJA Thermal Resistance
Junction-to-Ambient SOP-8L (Note 5) - 88 - °C/W MSOP-8L (Note 5) - 128 - °C/W
部门是什么意思θJC Thermal Resistance
Junction-to-Ca SOP-8L (Note 5) - 58 - °C/W MSOP-8L (Note 5) - 90 - °C/W
Notes: 4. Refer to figure 6 for the device derating curve.
5. Test condition for SOP-8L and MSOP-8L: Device mounted on FR-4 PCB, 2”x2”, 2oz copper, minimum recommended pad layout on top layer
and thermal vias to bottom layer ground plane. For better thermal performance, larger copper pad for heat-sink is needed.
艺术心理学LED Current Control
The LED current is controlled by the resistor RSET in Figure 1 connected between V IN and SET. The nominal average output current in the LED(s) is defined as:
SET THD LED R V I =
If the CTRL pin is driven by an external voltage (lower than 2.5V), the average LED current is:
SET THD REF CTRL LED R V V V I =
Figure 3: LED Current tting Vs R SET and V CTRL
Application Information
