Instruction Manual

Preliminary Datasheet
380kHz, 3A Asynchronous DC - DC Buck Converter AP3203
Mar. 2011 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
5
Electrical Characteristics
V
IN
=V
EN
=12V, V
OUT
=3.3V, T
A
=25
o
C, unless otherwise specified. And those in boldface type apply over
the full operating temperature rang (T
A
=-40ºC to +85ºC).
Parameter Symbol Conditions Min Typ Max Unit
Input Voltage V
IN
4.75 18 V
Quiescent Current I
Q
V
EN
=2V,
V
FB
=1.35V
1.0 1.5 mA
Shutdown Supply Current I
SHDN
V
EN
=0V 1 10
µA
Feedback Voltage V
FB
1.185 1.222 1.258
V
Feedback Over Voltage
Threshold
V
FBOV
1.48 V
Feedback SCP Voltage Threshold V
FB_SCP
0.6 V
Feedback Bias Current I
FB
V
FB
= 1V -0.1 0.1
µA
Upper Switch On-resistance R
DSONH
I
SW
=0.5A
0.12
Ω
Lower Switch On-resistance R
DSONL
I
SW
=0.05A
10
Ω
High-side Switch Leakage
Current
I
LEAKH
V
IN
=18V, V
EN
=0V
V
SW
=0V
0.1 10
µA
High-side Switch Current Limit I
LIMH
4 5.2 A
Low-side Switch Current Limit I
LIML
From Drain to
Source
0.15 A
V
ENH
1.5 V
EN Pin Threshold
V
ENL
0.5 V
EN Pull-up Current I
EN_PH
V
EN
=0V 1.0
µA
Input UVLO Threshold V
UVLO
V
IN
Rising 3.55 3.85 4.15 V
Input UVLO Hysteresis V
HYS
0.3 V
Oscillator Frequency f
OSC1
380 kHz
Short Circuit Oscillator
Frequency
f
OSC2
80 kHz
Maximum Duty Cycle D
MAX
V
FB
=1.0V 90 %
Minimum Duty Cycle D
MIN
V
FB
=1.35V 0 %
Error Amplifier Voltage Gain (Note 3) A
EA
400 V/V
Error Amplifier Transconductance G
EA
700 950 1200
µA/V
COMP to Current Sense
Transconductance
G
CS
5.4 A/V
Thermal Shutdown (Note 3) T
OTSD
160 ºC
Thermal Shutdown Hysteresis (Note
3)
T
HYS
30 ºC
Soft-start Time (Note 3) t
SS
C4=0.1µF,
I
OUT
=500mA
10 ms
Soft-start Current I
SS
6
µA