Электронные компоненты → ИНТЕГРАЛЬНЫЕ МИКРОСХЕМЫ → Схемы контроля питания → ШИМ-регуляторы
EZBuckTM 4A Synchronous Buck Regulator
AOZ1024D
General Description
The AOZ1024D is a synchronous high efficiency, simple to use, 4A buck regulator. The AOZ1024D works from a 4.5V to 16V input voltage range, and provides up to 4A of continuous output current with an output voltage adjustable down to 0.8V. The AOZ1024D comes in a DFN 5 x 4 package and is rated over a -40°C to +85°C ambient temperature range.
Features
4.5V to 16V operating input voltage range Synchronous rectification: 100m internal high-side switch and 20m internal low-side switch High efficiency: up to 95% Internal soft start 1.5% initial output accuracy Output voltage adjustable to 0.8V 4A continuous output current Fixed 500kHz PWM operation Cycle-by-cycle current limit Pre-bias start-up Short-circuit protection Thermal shutdown Small size DFN 5 x 4 packages
Applications
Point of load DC/DC conversion PCIe graphics cards Set top boxes DVD drives and HDD LCD panels Cable modems Telecom/networking/datacom equipment
Typical Application
VIN
C1 22µF Ceramic
VIN EN
L1 4.7µH
AOZ1024D
LX
R1
VOUT
C2, C3 22µF Ceramic
COMP
RC CC
FB AGND PGND
R2
Figure 1. 3.3V/4A Synchronous Buck Regulator
Rev. 1.3 September 2009
www.aosmd.com
Page 1 of 16
AOZ1024D
Ordering Information
Part Number
AOZ1024DI
Ambient Temperature Range
-40°C to +85°C
Package
DFN-8
Environmental
Green
All AOS products are offered in packages with Pb-free plating and compliant to RoHS standards. Please visit www.aosmd.com/web/quality/rohs_compliant.jsp for additional information.
Pin Configuration
PGND VIN AGND FB
1 8
LX LX EN COMP
LX
2 3 7 6
GND
4 5
5 x 4 DFN
(Top Thru View)
Pin Description
Pin Number
1 2 3 4 5 6 7, 8
Pin Name
PGND VIN AGND FB COMP EN LX
Pin Function
Power ground. Electrically needs to be connected to AGND. Supply voltage input. When VIN rises above the UVLO threshold the device starts up. Reference connection for controller section. Also used as thermal connection for controller section. Electrically needs to be connected to PGND. The FB pin is used to determine the output voltage via a resistor divider between the output and GND. External loop compensation pin. The enable pin is active high. Connect in to VIN if not used and do not leave it open. PWM output connection to inductor.
Rev. 1.3 September 2009
www.aosmd.com
Page 2 of 16
AOZ1024D
Block Diagram
VIN
EN
UVLO & POR
5V LDO Regulator
Internal +5V
OTP
+
ISen Reference & Bias
Softstart ILimit
Q1
+
0.8V
+
EAmp
+
FB
PWM Comp
PWM Control Logic
Level Shifter + FET Driver
LX
Q2
COMP
+
Frequency Foldback Comparator
500kHz/68kHz Oscillator
0.2V
AGND
PGND
Absolute Maximum Ratings
Exceeding the Absolute Maximum ratings may damage the device.
Recommend Operating Ratings
The device is not guaranteed to operate beyond the Maximum Operating Ratings.
Parameter
Supply Voltage (VIN) LX to AGND EN to AGND FB to AGND COMP to AGND PGND to AGND PGOOD to AGND Junction Temperature (TJ) Storage Temperature (TS) ESD Rating
(1)
Rating
18V -0.7V to VIN+0.3V -0.3V to VIN+0.3V -0.3V to 6V -0.3V t ...
