NCP3020: 300kHz / 9V-18V / 10A DC-DC Buck PWM Controller + MOSFET

ON Semiconductor Confidential
Design Note – DN06072/D
9-18V Input, 10A DC-DC PWM Buck Controller + FET
Device
NCP3020
Application
Input
Voltage
Output
Voltage
Output
Current
Topology
Test Equipment
9-18V
3.3V
0.01-10A
Buck
Table 1: Buck Power Supply
Characteristic
Input Voltage
Output Voltage
Output Current
Oscillator Frequency
Output Voltage Ripple
Load Regulation
Iout = 0.02-10A) Vin= 9V NCP3020
Iout = 0.02-10A) Vin= 18V NCP3020
Min
9
3.25
.01
270
Typ
12
3.265
1
300
86
Max
18
3.28
10
330
0.99
0.78
Unit
V
V
A
kHz
mVpk-pk
mV/A
Key Features
Circuit Description
This circuit is proposed for a wide
varying +12V input (9V-18V) where there is a
need to step-down the voltage to +3.3V @
10A. The requirement specified a large
electrolytic input capacitance and also to
utilize electrolytic capacitors on the output.
Target efficiency is >85%.
The PCB for the NCP3020 is a 2-layer
board for use in applications up to 50W. The
synchronous buck converter uses voltage
mode control, which can be compensated
externally with a transconductance amplifier.
The soft start time is fixed. The NCP3020
demonstration board is a flexible design
allowing the use of electrolytic capacitors or
ceramic capacitors. It also allows the use of
SO8-FL or D-PAK MOSFETs.
 High Efficiency
 Adjustable Current Limit
 Output Overvoltage and Output Undervoltage
protection
 Short Circuit Protection
 Fixed Switching Frequency
Rev 0, January 2011
ON Semiconductor Confidential
Performance
The following figures show typical performance of the NCP3020 demonstration boards.
Efficiency (%)
Efficiency Vs I-Out
95
90
85
80
75
70
65
60
9 V-In
12 V-In
15 V-In
18 V-In
0
2
4
6
8
10
I-Out (A)
Figure 1: NCP3020 Efficiency at 9V-18.0V with a 3.3V Output Voltage
V-Out (V)
Load Regulation
3.3
3.29
3.28
3.27
3.26
3.25
3.24
3.23
3.22
9 V-In
12 V-In
15 V-In
18 V-In
MIN
MAX
0
2
4
6
8
I-Out (A)
Figure 2: NCP3020 Load Regulation
Rev 0, January 2011
10
ON Semiconductor Confidential
0A
Line Regulation
1A
3.3
2A
3.29
3A
V-Out (V)
3.28
4A
3.27
5A
3.26
6A
3.25
7A
3.24
8A
3.23
9A
3.22
10A
9
10
11
12
13
14
15
16
V-In (V)
Figure 3: NCP3020 Line Regulation
Rev 0, January 2011
17
18
MAX
MIN
ON Semiconductor Confidential
Schematics
Figure 4: NCP3020 Schematic
Rev 0 - January, 2011
ON Semiconductor Confidential
Table 2: NCP3020 BOM
© 2011 ON Semiconductor.
Disclaimer: ON Semiconductor is providing this design note “AS IS” and does not assume any liability arising from its use; nor does ON Semiconductor convey any license
to its or any third party’s intellectual property rights. This document is provided only to assist customers in evaluation of the referenced circuit implementation and the
recipient assumes all liability and risk associated with its use, including, but not limited to, compliance with all regulatory standards. ON Semiconductor may change any of
its products at any time, without notice.
Design note created by Tim Kaske and Jim Hill, e-mail: [email protected] ; [email protected]
Rev 0 - January, 2011