|
|
PDF AP65550 Data sheet ( Hoja de datos )
| Número de pieza | AP65550 | |
| Descripción | 650kHz ADAPTIVE COT STEP-DOWN CONVERTER | |
| Fabricantes | Diodes | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de AP65550 (archivo pdf) en la parte inferior de esta página. Total 14 Páginas | ||
|
No Preview Available !
AP65550
5A, 18V, 650kHz ADAPTIVE COT STEP-DOWN CONVERTER
Description
Pin Assignments
The AP65550 is an adaptive constant on-time mode synchronous
buck converter providing high efficiency, excellent transient response
and high DC output accuracy for low-voltage regulation in digital TV
and monitor.
The constant-on-time control scheme handles wide input/output
voltage ratios and provides low external component count. The
internal proprietary circuit enables the device to adopt both low
equivalent series resistance (ESR) output capacitors, such as SP-
CAP or POSCAP and ultra-low ESR ceramic capacitors.
The adaptive on-time control supports seamless transition between
continuous conduction mode (CCM) at higher load conditions and
discontinuous conduction mode (DCM) at lighter load conditions.
DCM allows AP65550 maintain high efficiency at light load conditions.
The AP65550 also features programmable soft-start, UVLO, OTP and
OCP to protect the circuit.
This IC is available in SO-8EP package.
Features
Fixed Frequency Emulated Constant On-time Control
Good Stability Independent of the Output Capacitor ESR
Fast Load Transient Response
Synchronous Rectification: 65mΩ Internal High-side Switch and
36mΩ Internal Low-side Switch
Wide Input Voltage Range: 4.5V to 18V
Output Voltage Range: 0.76V to 6V
5A Continuous Output Current
650kHz Switching Frequency
Built-in Over Current Limit
Built-in Thermal Shutdown Protection
Programmable Soft-start
Pre-biased Start-up
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
( Top View )
EN 1
FB 2
VREG5 3
SS 4
8
7
6
5
SO-8EP
Applications
Gaming Consoles
Flat Screen TV sets and Monitors
Set Top Boxes
Distributed power systems
Home Audio
Consumer electronics
Network Systems
FPGA, DSP and ASIC Supplies
Green Electronics
VIN
BS
SW
GND
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
Typical Applications Circuit
INPUT
VIN
12V
C1
20μF
8
IN
ON 1
OFF
EN
C4
8.2nF
4
SS
7
BST
6
SW
AP65550
5
GND
2
FB
3
VREG5
C5 L1
0.1µF 1.5μH
R1
8.25kΩ
R2
22.1kΩ
C3
1µF
OUTPUT
VOUT
1.05V
C2
44μF
Figure 1. Typical Application Circuit
AP65550
Document number: DS36336 Rev. 2 - 2
1 of 14
www.diodes.com
April 2014
© Diodes Incorporated
http://www.Datasheet4U.com
1 page  
AP65550
Typical Performance Characteristics (@TA = +25°C, VIN = 12V, VOUT = 3.3V, unless otherwise specified.)
85˚C
25˚C
-40˚C
-40˚C
25˚C
85˚C
25˚C
85˚C
-40˚C
IO=3A
IO=4A
IO=5A
IO=2A
AP65550
Document number: DS36336 Rev. 2 - 2
5 of 14
www.diodes.com
April 2014
© Diodes Incorporated
http://www.Datasheet4U.com
5 Page 
AP65550
Application Information (cont.)
Inductor
Calculating the inductor value is a critical factor in designing a buck converter. For most designs, the following equation can be used to calculate
the inductor value;
L
VOUT (VIN
VIN ΔIL
VOUT )
fSW
Where ΔIL is the inductor ripple current.
And fSW is the buck converter switching frequency.
Choose the inductor ripple current to be 30% of the maximum load current. The maximum inductor peak current is calculated from:
IL(MAX)
ILOAD
ΔIL
2
Peak current determines the required saturation current rating, which influences the size of the inductor. Saturating the inductor decreases the
converter efficiency while increasing the temperatures of the inductor and the internal MOSFETs. Hence choosing an inductor with appropriate
saturation current rating is important.
A 1µH to 3.3µH inductor with a DC current rating of at least 25% percent higher than the maximum load current is recommended for most
applications. For highest efficiency, the inductor’s DC resistance should be less than 100mΩ. Use a larger inductance for improved efficiency
under light load conditions.
The phase boost can be achieved by adding a additional feed forward capacitor (C4) in parallel with R1.
Output Voltage (V)
1
1.05
1.2
1.5
1.8
2.5
3.3
5
C10(pF)
—
—
—
—
5-22
5-22
5-22
5-22
L1(µH)
1.0-1.5
1.0-1.5
1.0-1.5
1.5
1.5
2.2
2.2
3.3
Table 2. Recommended Component Selection
C5+C9(µF)
22-68
22-68
22-68
22-68
22-68
22-68
22-68
22-68
Input Capacitor
The input capacitor reduces the surge current drawn from the input supply and the switching noise from the device. The input capacitor has to
sustain the ripple current produced during the on time on the upper MOSFET. It must hence have a low ESR to minimize the losses.
The RMS current rating of the input capacitor is a critical parameter that must be higher than the RMS input current. As a rule of thumb, select an
input capacitor which has RMs rating that is greater than half of the maximum load current.
Due to large dI/dt through the input capacitors, electrolytic or ceramics should be used. If a tantalum must be used, it must be surge protected.
Otherwise, capacitor failure could occur. For most applications, greater than 10µF ceramic capacitor is sufficient.
Output Capacitor
The output capacitor keeps the output voltage ripple small, ensures feedback loop stability and reduces the overshoot of the output voltage. The
output capacitor is a basic component for the fast response of the power supply. In fact, during load transient, for the first few microseconds it
supplies the current to the load. The converter recognizes the load transient and sets the duty cycle to maximum, but the current slope is limited
by the inductor value.
AP65550
Document number: DS36336 Rev. 2 - 2
3 of 14
www.diodes.com
April 2014
© Diodes Incorporated
http://www.Datasheet4U.com
11 Page | ||
| Páginas | Total 14 Páginas | |
| PDF Descargar | [ Datasheet AP65550.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| AP65550 | 650kHz ADAPTIVE COT STEP-DOWN CONVERTER | Diodes |
| AP65552 | 650kHz ADAPTIVE CCM/COT STEP-DOWN CONVERTER | Diodes |
| 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 |