AP8801

500mA LED Step-down Converter

AP8801 Rev. 4

4 of 11

DECEMBER 2009

DS31765

www.diodes.com

Absolute Maximum Ratings

Symbol

Parameter

Rating

Unit

VIN pin voltage

-0.3~50

V

SW voltage

-0.3~50

V

Junction Temperature

150

Lead Temperature Soldering

300

Storage Temperature Range

-65 to +150

Caution:

The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not

be exceeded under any condition.

Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken

when handling and transporting these devices

Recommended Operating Conditions

Symbol

Parameter

Min

Max

Unit

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 specified. Duty cycle accuracy is also dependent on

propagation delay. Smaller size inductors can be used 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

Symbol

Parameter

Conditions

Min

Typ.

Max

Unit

Operating Input Voltage

8.0

-

48

V

Continuous switch current

(Note 4)

500

mA

Quiescent Current

-

78

120

μA

Switching Frequency

-

-

0.5

MHz

Internal Threshold Voltage

184

200

216

mV

Internal Reference Voltage

-

1.25

-

V

SET

SET pin input current

-

7

-

μA

Rds(on)

On Resistance of MOSFET

0.7

1.15

Ω

-

-

8

μA

EN

Voltage High

ON

1.25

-

-

V

EN

Voltage Low

OFF

-

-

0.2

V

θ

JA

Thermal Resistance

Junction-to-Ambient

SOP-8L (Note 5)

-

88

-

°C/W

MSOP-8L (Note 5)

-

128

-

°C/W

θ

JC

Thermal Resistance

Junction-to-Case

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.