Cirrus Logic AN352 User Manual
An352, Introduction
Copyright
Cirrus Logic, Inc. 2011
(All Rights Reserved)
http://www.cirrus.com
Application Note
DRIVING MOSFETs WITH THE CS1501 & CS1601
1. Introduction
The CS1501 & CS1601 are high-performance digital power factor correction (PFC) controllers designed for switching mode pow-
er supply (SMPS) & lighting applications. This papers discusses the basics of driving power MOSFETs, including some guide-
lines for layout & component choices.
2. CS1501 & CS1601 Gate Drive
The CS1501 & CS1601 internal gate driver is a dual MOSFET between VDD & GND.
The CS1501 & CS1601 parameters for its internal gate drive are listed below.
1.
C
L
is defined as the capacitive load that the IC drives. For test purposes, load capacitance (C
L
) is 1 nF and is
connected as shown in the following diagram.
Parameter
Condition
Symbol
Min
Typ
Max
Unit
PFC Gate Drive
Output Source Resistance
I
GD
= 100 mA, V
DD
= 13 V
R
OH
-
9
-
Ω
Output Sink Resistance
I
GD
= -200 mA, V
DD
= 13 V
R
OL
-
6
-
Ω
Rise Time
1
C
L
= 1 nF, V
DD
= 13 V
t
r
-
32
45
ns
Fall Time
1
C
L
= 1 nF, V
DD
= 13 V
t
f
-
15
25
ns
Output Voltage Low State
I
GD
= -200 mA, V
DD
= 13 V
Vol
-
0.9
1.3
V
Output Voltage High State
I
GD
= 100 mA, V
DD
= 13 V
Voh
11.3
11.8
-
V
CS1501
CS1601
8
VDD
V
DD
7
GD
6
GND
GD OUT
GD
GND
CS
VDD
Buffer
S
1
R
1
R
2
R
3
TP
C
L
1nF
+15V
-15V
S
2
V
D D
AN352
MAR ‘11
AN352REV1