Diodes AT5503 - Manual (Page 5)

Preliminary Datasheet
18V, 3A Synchronous DC-DC Buck Converter AT5503
Mar. 2013 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
5
Electrical Characteristics
V
IN
=V
EN
=12V, V
OUT
=3.3V, T
A
=25ºC, unless otherwise specified.
Parameter Symbol Conditions Min Typ Max Unit
SUPPLY VOLTAGE (IN PIN)
Input Voltage V
IN
4.5 18 V
Quiescent Current I
Q
V
FB
=1V,
V
EN
=3.3V
1.2 1.4 mA
Shutdown Supply Current I
SHDN
V
EN
=0V 0.1 1.0 µA
UNDER VOLTAGE LOCKOUT
Input UVLO Threshold V
UVLO
V
IN
Rising 3.65 4.0 4.25 V
Input UVLO Hysteresis V
HYS
0.2 V
ENABLE (EN PIN)
EN Shutdown Threshold
Voltage
1.1 1.5 2 V
EN Shutdown Threshold
Voltage Hysteresis (Note 2)
350 mV
EN Lockout Threshold Voltage 2.2 2.5 2.7 V
EN Lockout Hysteresis 210 mV
VOLTAGE REFERENCE (FB PIN)
Feedback Voltage V
FB
0.784 0.8 0.816 V
Feedback Over Voltage
Threshold
V
FBOV
1.1 V
Feedback Bias Current I
FB
V
FB
=1V -0.1 0.1 µA
MOSFET
High-side Switch On-resistance
(Note 3)
R
DSONH
I
SW
=0.2A&0.7A 100 mΩ
Low-side Switch On-resistance
(Note 3)
R
DSONL
I
SW
=-0.2A&-0.7A 100 mΩ
CURRENT LIMIT
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
4.3 5.6 A
Low-side Switch Current Limit I
LIML
From Drain to
Source
50 mA
SWITCHING REGULATOR
Oscillator Frequency f
OSC1
410 500 590 kHz
Short Circuit Oscillator
Frequency
f
OSC2
180 kHz