AP1533
PWM CONTROL 1.8A STEP-DOWN CONVERTER
AP1533 Rev. 4 4 of 9 JULY 2009
DS31192 www.diodes.com © Diodes Incorporated
Electrical Characteristics
(V
IN = 12V, T
A
= 25°C, unless otherwise specified)
Symbol Parameter Conditions Min Typ. Max Unit
V
FB
Feedback Voltage I
OUT
= 0.1A 0.784 0.8 0.816 V
I
FB
Feedback Bias Current I
OUT
= 0.1A - 0.1 0.5 µA
I
SHDN
Current Consumption During
Power Off
V
EN
= 0V - 10 - µA
∆V
OUT
/ V
IN
Line Regulation V
IN
= 5V~23V - 1 2 %
∆V
OUT
/ V
OUT
Load Regulation I
OUT
= 0.1 to 1.8A - 0.2 0.5 %
f
OSC
Oscillation Frequency Measure waveform at SW pin 240 300 400 KHz
f
OSC1
Frequency of Current Limit or
Short Circuit Protection
Measure waveform at SW pin - 50 - KHz
V
IH
EN Pin Input Voltage
Evaluate oscillation at SW pin 2.0 - -
V
V
IL
Evaluate oscillation stop at SW pin - - 0.8
I
SH
EN Pin Input Leakage Current
EN Pin High - 20 - µA
I
SL
EN Pin Low - -10 - µA
I
OCSET
OCSET Pin Bias Current -- 75 90 105 µA
R
DS(ON)
Internal MOSFET R
DS(ON)
V
IN
=5V, V
FB
=0V - 110 150
mΩ
V
IN
=12V, V
FB
=0V - 80 110
EFFI Efficiency
V
IN
=12V, V
OUT
= 5V
I
OUT
=1.8
- 91 - %
T
SHDN
Thermal shutdown threshold - 150 - °C
T
HYS
Thermal shutdown hysteresis - 55 - °C
θ
JA
Thermal Resistance
Junction-to-Ambient
SOP-8L (Note 3) - 134 -
o
C/W
θ
JC
Thermal Resistance
Junction-to-Case
SOP-8L (Note 3) - 22 -
o
C/W
Notes: 3. Test condition: Device mounted on FR-4 PCB, 2”x2”, 2oz copper, minimum recommended pad layout, single side.
For better thermal performance, larger copper pad for heatsink is needed.
