|
|
PDF AT1799 Data sheet ( Hoja de datos )
| Número de pieza | AT1799 | |
| Descripción | Step-Down Voltage Regulator | |
| Fabricantes | Aimtron Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de AT1799 (archivo pdf) en la parte inferior de esta página. Total 14 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
AT1799
2A Step-Down Voltage Regulator
Feature
Description
‧ 4.75V to 16V Supply Voltage Operating
AT1799 is a voltage-mode PWM step-down
Range.
‧ 380KHz 15% Fixed Switching Frequency.
‧ Voltage-Mode PWM Step-Down Regulator.
‧ Built-in Power MOSFET, Rds(on) 100m .
DC-DC converter capable of driving up to 2A
loads over a wide input supply range with excellent
line and load regulation characteristics. High
efficiency is obtained through the use of a low
Rds(on) P-channel power switch.
‧ 2A Output Current, Up to 91.9% Efficiency
‧ 1.215V 1.5% Internal Reference
‧ Shutdown Current less than 20uA.
‧ Thermal-Shutdown and Built-in Soft-Start.
‧ Cycle-by-Cycle Current-Limit Protection.
‧ Short Circuitry Protection.
It uses a fixed switching frequency up to 380KHz
thus allowing smaller sized components. The
output voltage level is user-programmable via an
external resistive voltage divider. The built-in
soft-start can reduce inrush current on the input
source at turn on.
‧ Under-Voltage Lockout Protection.
‧ Output Voltage Adjustable From 1.215V to
16V.
‧ SOP-8 Package.
The device also has built-in cycle-by-cycle
current-limit, thermal shutdown, under-voltage
lockout and an ON/OFF logic-control that can
power down the regulator to a shutdown mode. In
shutdown mode the regulator draws less than 20uA
Application
of supply current. When a short circuit is detected
‧ Distributed Power Systems
‧ Battery Charger.
‧ Palmtop Computers, PDAs.
on the output , the device immediately change
switching frequency to 42 KHz and duty cycle is
limited to 5% to protect IC from damage.
‧ DSL Modems
AT1799 is available in SOP-8 package.
Block Diagram
Aimtron reserves the right without notice to change this circuitry and specifications.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
8/23/2006 REV:1.1
Email: [email protected]
1
1 page  
Typical characteristics
AT1799
2A Step-Down Voltage Regulator
Efficiency vs. O utput C urrent and Voltage
95
VIN=10V
90
85
80
75
5.0V
3.3V
70
0.1 0.2 0.3 0.5 0.7 1 1.3 1.5 1.7 2
O utput Current (A)
1.22
Reference Voltage vs Temperature
1.219
1.218
1.217
1.216
1.215
-20
-10
0
10 25 40 70 80
Temperature (OC)
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
8/23/2006 REV:1.1
Email: [email protected]
5
5 Page 
maximum load current.
AT1799
2A Step-Down Voltage Regulator
Feedback Resistor Network
An external resistor divider is required to divide the output voltage down to the
nominal reference voltage. Current drawn by the resistor network should be limited to
maintain the overall converter efficiency. The maximum value of the resistor network
is limited by the feedback input bias current and the potential for noise being coupled
into the feedback pin. A resistor network in the order of 100kΩ is recommended. The
buck converter output voltage is determined by the following relationship:
VO
= VREF
× ⎜⎜⎝⎛1 +
R3
R2
⎟⎟⎠⎞
where VREF =1.215V as specified.
Input capacitor
An input capacitor helps to provide additional current to the power supply as well as
smooth input voltage variations in high current switching regulators. When selecting
an input capacitor, a low ESR capacitor is required to keep the noise at the IC to a
minimum. Ceramic capacitors are preferred, but tantalum or low-ESR electrolytic
capacitors may also suffice. Choose an input capacitor who’s maximum voltage rating
is 1.3 times greater than the maximum input voltage, and who’s RMS current rating is
equal to one-half of the maximum dc load current. It may be necessary in some
designs to add a small valued ceramic type capacitor in parallel with the input
capacitor to prevent any ring.
Output Capacitor
The output capacitor acts to smooth the dc output voltage and also provides energy
storage. Selection of an output capacitor, with an associated equivalent series
resistance (ESR), impacts both the amount of output ripple voltage and stability of the
control loop. Low ESR capacitors are preferred to keep the output voltage ripple low.
The output voltage ripple is estimated to be:
∆Vripple
=
(1 − D) ×VO
8×
L × COUT
×
f2
OSC
For low ESR ceramic capacitors, the output ripple is dominated by the charging or
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
8/23/2006 REV:1.1
Email: [email protected]
11
11 Page | ||
| Páginas | Total 14 Páginas | |
| PDF Descargar | [ Datasheet AT1799.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| AT1793 | 2-Channel Step-Down PWM Controller | Aimtron Technology |
| AT1796 | Step-Down Switching Regulator | Aimtron Technology |
| AT1799 | Step-Down Voltage Regulator | Aimtron Technology |
| 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 |