Ap2008, Electrical characteristics, Typical application circuit – Diodes AP2008 User Manual
Page 5: Pwm buck controller
AP2008
PWM BUCK CONTROLLER
AP2008 Rev. 2
5 of 8
FEBRUARY 2009
©
Diodes Incorporated
Electrical Characteristics
(Continued) (T
A
=25ºC, V
CC
=6V, f=200 Khz)
Output section
Symbol
Parameter
Conditions
Min
Typ.
Max
Unit
I
LEAK
Leakage
current
V
O
= 20V
10
µA
I
DRV
Sink current
V
IN
=
12V
200 mA
Source current
V
IN
=
12V
200 mA
V
SAT
Output saturation voltage
I
O
= 10 mA
1.0
1.5
V
I
SC
Short-circuit
output
current
V
O
=
6V
120 mA
PWM comparator
Symbol
Parameter
Conditions
Min
Typ.
Max
Unit
V
T0
Input threshold voltage at f = 10 KHz
(COMP)
CT=6800pF
0.6
0.7
V
V
T100
Maximum duty cycle
1.2
1.3
V
Total device
Symbol
Parameter
Conditions
Min
Typ.
Max
Unit
I
CCA
Average supply current
C
T
= 270pF
6
10
mA
Soft Start
Symbol
Parameter
Conditions
Min
Typ.
Max
Unit
V
SS
Soft-start
Voltage
2.3 V
I
SS
Constant Charge Current
20
µA
Typical Application Circuit
L1
10uH
R1
R2
C3
470uF
Output
Step-Down DC/DC converter
C2
10nF
(Optional)
Vcc = 12V
P mos
Q1
1
2
3
8
7
6
5
4
OUT
FB
VCC
COMP
GND
SCP
SS
CT
C6 220nF
C5 50nF
C4 270pF
1K
4K
C1
470uF
5A
R3 30K
C4
50nF
(Optional)
1V/5A