|
|
PDF FR9809 Data sheet ( Hoja de datos )
| Número de pieza | FR9809 | |
| Descripción | 500KHz Synchronous PWM-Buck DC/DC Converter | |
| Fabricantes | Fiti | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de FR9809 (archivo pdf) en la parte inferior de esta página. Total 13 Páginas | ||
|
No Preview Available !
fitipower integrated technology lnc.
FR9809
21V, 5A, 500KHz Synchronous PWM-Bu8c5kT
DC/DC Converter
Description
FR9809 is a high-efficiency synchronous step-down
DC/DC converter that employs a special process
technique to obtain very low RDS(ON) for the internal
metal–oxide–semiconductor field-effect transistor
(MOSFET). The input operation voltage is in a wide
range from 4.75V to 21V, and continuous load
current capability is 5A. Control circuit is designed
by a particular current mode which provides fast
transient response and eases loop stabilization.
This product has a very low standby current less
than 1μA in shutdown mode. When the
pin voltage is less than 0.4V, FR9809 will turn off.
Fault protection includes over current protection
(OCP), under voltage lockout protection (UVLO) and
over temperature protection (OTP) function.
This high-efficiency current mode step-down “Green
Power Converter” offers the standard SOP-8
package with an exposed pad.
Pin Assignments
SP Package (SOP-8 Exposed Pad)
VIN
LX
LX
BST
18
297
3 GND 6
45
GND
VCC
FB
SHDN/S
Features
High Efficiency up to 90%
Internal MOSFET RDS(ON): 110mΩ 20mΩ
Internal Compensation
Input Operation Voltage Range: 4.75V to 21V
5A Continuous Output Current
Output Voltage down to 0.805V
500KHz Oscillation Frequency
Sync to External Clock from 300KHz to 800KHz
Cycle-by-Cycle Current Limit
Under Voltage Lockout
Over-Temperature Protection with Auto Recovery
<1μA Shutdown Current
Thermal Enhanced SOP-8 (Exposed Pad)
Package
RoHS Compliant
Applications
Networking Equipment
OLPC, Netbook
Distributed Power System
LCD Monitor, TV, STB
External HDD
Security System
Ordering Information
FR9809□□□
TR: Tape/Reel
G: Green
C: Green
Package Type
SP: SOP-8 (Exposed Pad)
Figure 1. Pin Assignment of FR9809
FR9809-Preliminary 0.4-OCT-2012
1
1 page  
fitipower integrated technology lnc.
Electrical Characteristics
(VIN=12V, TA=25°C, unless otherwise specified.)
Parameter
Symbol
Conditions
Input Supply Voltage
VIN Shutdown Supply Current
VIN Quiescent Supply Current
VIN
ISD
IDDQ
=0V
=2V, VFB=1V
Feedback Voltage
VFB 4.75V≦VIN≦21V
High-Side MOSFET RDS(ON) (Note2)
HSRDS(ON)
Low-Side MOSFET RDS(ON) (Note2)
LSRDS(ON)
MOSFET Leakage Current
High-Side MOSFET Current
(Note2)
Maximum Duty Cycle
Limit
ILX(Leak)
ILIMIT
DMAX
=0V, VLX=0V
VFB=0.7V
Oscillation frequency
FLX
Short-Circuit Oscillation Frequency
FLX(Short) VFB=0.3V
Sync Frequency Range
FSYNC
Input UVLO Threshold
Under Voltage Lockout
Hysteresis
Input Low Voltage
VUVLO(Vth) VIN Rising
Threshold VUVLO(Hys)
(L)
Input High Voltage
(H)
Input Current
=2V
VCC Regulator
VCC
Soft-Start Time
TSS
Thermal Shutdown Threshold (Note 2)
Note 2：Guarantee by design.
TSD
FR9809
85T
Min Typ Max Unit
4.75 21 V
1 μA
1.5 mA
780 805 830 mV
110 mΩ
20 mΩ
0 10 μA
8A
90 %
350 500 650 KHz
150 KHz
300 800 KHz
4V
200 mV
0.4 V
2.0
2
V
μA
4.5 V
600 μs
170 °C
FR9809-Preliminary 0.4-OCT-2012
5
5 Page 
fitipower integrated technology lnc.
Application Information (Continued)
FR9809
85T
+
VNOISE (t)
=
VRIPPLE(t)
(t)
R PPL ( R, p p = F
T
L
L
R PPL ( L, p p = L+ L
1
T
R
R PPL ( , p p = 8 F
T
2L
1
T
T
Where FOSC is the switching frequency, L is the
inductance value, VIN is the input voltage, ESR is the
equivalent series resistance value of the output
capacitor, ESL is the equivalent series inductance
value of the output capacitor and the COUT is the
output capacitor.
Low ESR capacitors are preferred to use. Ceramic,
tantalum or low ESR electrolytic capacitors can be
used depending on the output ripple requirements.
When using the ceramic capacitors, the ESL
component is usually negligible.
It is important to use the proper method to eliminate
high frequency noise when measuring the output
ripple. The figure shows how to locate the probe
across the capacitor when measuring output ripple.
Remove the scope probe plastic jacket in order to
expose the ground at the tip of the probe. It gives a
very short connection from the probe ground to the
capacitor and eliminates noise.
Probe Ground
Inductor Selection
The output inductor is used for storing energy and
filtering output ripple current. But the trade-off
condition often happens between maximum energy
storage and the physical size of the inductor. The
first consideration for selecting the output inductor
is to make sure that the inductance is large enough
to keep the converter in the continuous current
mode. That will lower ripple current and result in
lower output ripple voltage. The Δ L is inductor
peak-to-peak ripple current:
L= F
T
L
1
T
The following diagram is an example to graphical
represent Δ L equation.
L=1.8μ
L=2.2μ
L=4.7μ
VIN=12V, FOSC=500KHz
A good compromise value between size and
efficiency is to set the peak-to-peak inductor ripple
current Δ L equal to 30% of the maximum load
current. But setting the peak-to-peak inductor
ripple current Δ L between 20%~50% of the
maximum load current is also acceptable. Then
the inductance can be calculated with the following
equation:
L=0.
T(MA
L=
T
F
T
L
To guarantee sufficient output current, peak inductor
current must be lower than the FR9809 high-side
MOSFET current limit. The peak inductor current
is shown as below:
P AK=
T(MA
+
L
2
VOUT
GND
Ceramic Capacitor
FR9809-Preliminary 0.4-OCT-2012
11
11 Page | ||
| Páginas | Total 13 Páginas | |
| PDF Descargar | [ Datasheet FR9809.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| FR9801 | 600KHz Synchronous Step-Down DC/DC Converter | Fiti |
| FR9801E | 600KHz Synchronous Step-Down DC/DC Converter | Fiti |
| FR9802 | 1.2MHz Synchronous Step-Down DC/DC Converter | Fiti |
| FR9806 | 500KHz Synchronous PWM-Buck DC/DC Converter | Fiti |
| 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 |