RT7257D
Current Limit vs. Temperature
8
7
6
Output Current Limit vs. Input Voltage
6
5
4
3
Output Current Limit (A)
5
4
3
2
1
Current Limit (A)
V
OUT
= 1.2V
V
OUT
= 3.3V Add Bootstrap Diode
V
OUT
= 3.3V
V
IN
= 12V, V
OUT
= 3.3V
2
-50
-25
0
25
50
75
100
125
0
4.5
7
9.5
12
V
IN
= 12V
14.5
17
Temperature (°C)
Input Voltage (V)
Load Transient Response
Load Transient Response
V
OUT
(100mV/Div)
V
OUT
(100mV/Div)
I
OUT
(2A/Div)
V
IN
= 12V, V
OUT
= 3.3V, I
OUT
= 0.2A to 3A
I
OUT
(2A/Div)
V
IN
= 12V, V
OUT
= 3.3V, I
OUT
= 1.5A to 3A
Time (100μs/Div)
Time (100μs/Div)
Switching
V
OUT
(5mV/Div)
V
OUT
(5mV/Div)
Switching
V
SW
(10V/Div)
V
SW
(10V/Div)
I
L
(2A/Div)
V
IN
= 12V, V
OUT
= 3.3V, I
OUT
= 1.5A
I
L
(2A/Div)
V
IN
= 12V, V
OUT
= 3.3V, I
OUT
= 3A
Time (500ns/Div)
Time (500ns/Div)
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS7257D-04
September 2012
www.richtek.com
7
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
