|
|
PDF AX3803 Data sheet ( Hoja de datos )
| Número de pieza | AX3803 | |
| Descripción | 500KHz Synchronous Rectified Step-Down Converter | |
| Fabricantes | AXElite | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de AX3803 (archivo pdf) en la parte inferior de esta página. Total 8 Páginas | ||
|
No Preview Available !
AX3803
3A, 23V, 500KHz Synchronous Rectified
Step-Down Converter
GENERAL DESCRIPTION
The AX3803 is a monolithic synchronous buck regulator. The device integrates two
110mΩ MOSFETs, and provides 3A of continuous load current over a wide input voltage of
4.75V to 23V. Current mode control provides fast transient response and cycle-by-Cycle
current limit.
Internal soft-start prevents inrush current at turn-on, and in shutdown mode the supply
current drops to 5μA.
This device, available in SOP-8L-EP package, provides a very compact solution with
minimal external components.
FEATURES
- 3A Output Current
- Wide 4.75V to 23V Operating Input Range
- Integrated 110mΩ Power MOSFET Switches
- Output adjust from VFB to 20V
- Internal compensation
- Up to 94% Efficiency
- Stable with Low ESR Ceramic Output Capacitors
- Fixed 500KHz Frequency
- Cycle-by-Cycle Over Current Protection
- Thermal shutdown and short circuit protections
BLOCK DIAGRAM
FB 5
OSCILLATOR
140/500KHz
RAMP
CLK
NC 8
0.925V
-
+
+
ERROR
AMPLIFIER
6μA
NC 6
EN 7
+
1.5V -
SHUTDOWN
COMPARATOR
CURRENT
SENSE
AMPLIFIER
+ SQ
RQ
- CURRENT
COMPARATOR
2 IN
+
5V
-
1 BS
M1
110mΩ
3 SW
M2
110mΩ
4 GND
EN
IN
INTERNAL
REGULATORS
5V
1/8
Axelite Confidential Materials, do not copy or distribute without written consent.
Rev.1.0 Nov.22, 2012
1 page  
AX3803
FUNCTION DESCRIPTIONS
The AX3803 is a synchronous rectified, current-mode, step-down regulator. It regulates
input voltages from 4.75V to 23V down to an output voltage as low as 0.925V, and supplies
up to 3A of load current.
The AX3803 uses current-mode control to regulate the output voltage. The output
voltage is measured at FB through a resistive voltage divider and amplified through the
internal Tran conductance error amplifier.
The converter uses internal N-Channel MOSFET switches to step-down the input
voltage to the regulated output voltage. Since the high side MOSFET requires a gate voltage
greater than the input voltage, a boost capacitor connected between SW and BS is needed to
drive the high side gate. The boost capacitor is charged from the internal 5V rail when SW is
low.
APPLICATION INFORMATION
COMPONENT SELECTION
Setting the Output Voltage
The output voltage is set using a resistive voltage divider from the output voltage to FB
pin. The voltage divider divides the output voltage down to the feedback voltage by the ratio:
VFB=VOUT × R2
R1 R2
Where VFB is the feedback voltage and VOUT is the output voltage.
Thus the output voltage is:
VOUT=0.925 × R1 R2
R2
R2 can be as high as 100kΩ, but a typical value is 10kΩ. Using the typical value for R2, R1 is
determined by:
R1= 10.811 × (VOUT － 0.925) (kΩ)
For example, for a 3.3V output voltage, R2 is 10kΩ, and R1 is 25.7kΩ.
5/8
Axelite Confidential Materials, do not copy or distribute without written consent.
Rev.1.0 Nov.22, 2012
5 Page | ||
| Páginas | Total 8 Páginas | |
| PDF Descargar | [ Datasheet AX3803.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| AX3803 | 500KHz Synchronous Rectified Step-Down Converter | AXElite |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |