ape3061 APEC, ape3061 Datasheet - Page 4

• Manufacturer Part Number: ape3061
• Description: Step-up Pwm Dc/dc Converter Description
• Manufacturer: APEC

Setting the Output Voltage
Current Limiting Setting
Inductor Selection
Input Capacitor Selection
APPLICATION INFORMATION
adjustable output version. The external resistor sets the output voltage according to
the following equation:
from SENSE pin to GND (refer the application circuit). The internal current limit
compared voltage is 60mV. When the SENSE voltage is larger than 60mV, an over-
current condition is triggered. Please refer to the formula for setting the minimum current
limit value:
switching, which results in some efficiency loss. The inductor value can be derived from
the following equation:
small value inductors result in high ripple currents. Choose inductor ripple current
approximately 15% of the maximum input current 3A, ∆IL=0.45A.
current plus half the ripple current to prevent core saturation (3A+0.25A).
noise from the device. The input capacitor impedance at the switching frequency shall be
less than input source impedance to prevent high frequency switching current passing to
the input. A low ESR input capacitor sized for maximum RMS current must be used.
and often much higher voltage ratings are needed to satisfy.
Table 2 Inductor select for output voltage setting (V
Note: ISW(MAX) is the maximum N-MOSFET current
The capacitor voltage rating should be at least 1.5 times greater than the input voltage,
The input capacitor reduces the surge current drawn from the input and switching
Advanced Power
Electronics Corp.
Application circuit item shows the basic application circuit with APE3061
The current limit threshold is setting by the external resistor (RSENSE) connecting
For most designs, Low inductance values are physically smaller but require faster
Where is inductor Ripple Current. Large value inductors lower ripple current and
The DC current rating of the inductor should be at least equal to the maximum load
V
I
L = [V
SW(MAX)
OUT
L1 Value
V
=1V x (1+R1/R2)
IN
OUT
= 60m / RSENSE
x (V
OUT
- V
18uH
9V
IN
CC
)] / (V
=5V)
OUT
15uH
12V
x ∆I
L
x f
10uH
15V
IX
)
10uH
18V
Table 1 Resistor select for output voltage setting
V
12V
15V
18V
24V
OUT
1.5K
1.3K
R2
1K
1K
APE3061
11K
21K
17K
30K
R1
4