ncp3101c ON Semiconductor, ncp3101c Datasheet - Page 21
ncp3101c
Manufacturer Part Number
ncp3101c
Description
Ncp3101c Wide Input Voltage Synchronous Buck Converter
Manufacturer
ON Semiconductor
Datasheet
1.NCP3101C.pdf
(26 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
NCP3101C
Manufacturer:
ON/安森美
Quantity:
20 000
C
CIN
t
V
starts to switch and a second inrush current can be
calculated:
C
C
D
I
I
t
V
is dependant on the type of load that is connected to the
output. Two types of load are considered in Figure 33: a
resistive load and a stepped current load.
increase with soft start linearly which can be quantified in
Equation 54.
DELAY_TOTAL
SS
CL
OCinrush_RMS
Inrush
Current
I
5.92 A +
IN
CC
I
OUT
LOAD
OUT
Once the t
From the above equation, it is clear that the inrush current
If the load is resistive in nature, the output current will
ICin_RMS
OCinrush_RMS
Figure 33. Load Connected to the Output Stage
ESR
+
0.1 W
12 V
DELAY_TOTAL
CINESR
= Total converter output capacitance
= Total load capacitance
= Duty ratio of the load
= Applied load at the output
= RMS inrush current during start−up
= Soft start interval
= Output voltage
+
V
= Input capacitor
= Input capacitor ESR
= Total delay interval
= Input voltage
*
IN
I
120 A +
C
ICinrush_PK
D
* 0.316 *
3
OUT
) I
*
) C
CL
0.316 *
0.1
12
has expired, the buck converter
* D
t
LOAD
SS
+
5 * 0.1 W * 330 mF
CIN
V
* V
6.76 ms
IN
ESR
5 * CIN
t
OUT
DELAY_TOTAL
ESR
* C
Load
OR
IN
(eq. 51)
(eq. 52)
(eq. 53)
http://onsemi.com
21
R
V
I
I
turns on at a defined voltage level, and draws a consistent
current, then the RMS connected load current is:
I
V
V
CLR_RMS
CR_PK
OUT
I
191 mA +
OUT
OUT
OUT
OUT_TO
Alternatively, if the output has an under voltage lockout,
CLR
_RMS +
835 mA +
Figure 34. Resistive Load Current
I
1
CLKI
3
= Output resistance
= Output voltage
= RMS resistor current
= Peak resistor current
= Output current
= Output voltage
= Output voltage load turn on
*
1
3
3.3 V
10 W
+
*
R
V
OUT
OUT
3.3 V * 1.0 V
V
OUT
tss
3.3 V
Voltage
Current
Output
Output
* V
V
I
330 mA +
CR_PK
OUT
OUT_TO
+
* 1 A
V
R
3.3 V
10 W
3.3V
OUT
* I
OUT
OUT
(eq. 54)
(eq. 55)