|
|
PDF MPQ4561 Data sheet ( Hoja de datos )
| Número de pieza | MPQ4561 | |
| Descripción | 1.5A 2MHz 55V Step-Down Converter Available | |
| Fabricantes | MPS | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MPQ4561 (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
MPQ4561
1.5A, 2MHz, 55V
Step-Down Converter
Available in AEC-Q100
DESCRIPTION
The MPQ4561 is a high-frequency, step-down,
switching regulator with an integrated internal
high-side high voltage power MOSFET. It
provides up to a 1.5A output with current mode
control for fast loop response and easy
compensation.
The wide 3.8V-to-55V input range accommodates
a variety of step-down applications, including
those in automotive input environment. A 12µA
shutdown mode supply current makes it suitable
for battery-powered applications.
A scaled-down switching frequency in light-load
conditions provides high power-conversion
efficiency over a wide load range while reducing
switching and gate driver losses.
The frequency foldback prevents inductor current
runaway during startup and thermal shutdown
provides reliable, fault tolerant operation.
By switching at 2MHz, the MPQ4561 is able to
prevent EMI (Electromagnetic Interference) noise
problems, such as those found in AM radio and
ADSL applications.
The MPQ4561 is available in a 3mm x 3mm
QFN10 package with an exposed pad.
TYPICAL APPLICATION
FEATURES
Guaranteed Industrial/Automotive
Temperature Range Limits
Wide 3.8V to 55V Operating Input Range
300mΩ Internal Power MOSFET
Up to 2MHz Programmable Switching
Frequency
140μA Quiescent Current
Stable with Ceramic Capacitor
External Soft-Start
Up to 95% Efficiency
Output Adjustable from 0.8V to 52V
Available in QFN10 (3mmx3mm) package
AEC-Q100 Qualified
APPLICATIONS
High-Voltage Power Conversion
Automotive Systems
Industrial Power Systems
Distributed Power Systems
Battery Powered Systems
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Quality Assurance.
“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
MPQ4561 Rev. 1.11
www.MonolithicPower.com
3/29/2013
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
1
http://www.Datasheet4U.com
1 page  
MPQ4561 – 1.5A, 2MHz, 55V STEP-DOWN CONVERTER
TYPICAL CHARACTERISTICS
MPQ4561 Rev. 1.11
www.MonolithicPower.com
3/29/2013
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
5
5 Page 
MPQ4561 – 1.5A, 2MHz, 55V STEP-DOWN CONVERTER
provide enough voltage headroom to facilitate
charging.
As long as VIN is sufficiently higher than SW, the
bootstrap capacitor will charge. When the power
MOSFET is ON, VIN is about equal to SW so the
bootstrap capacitor cannot charge. When the
external diode is on, the difference between VIN
and SW is at its largest, thus making it the best
period to charge. When there is no current in the
inductor, SW equals the output voltage VOUT so
the difference between VIN and VOUT can charge
the bootstrap capacitor.
Under higher duty-cycle operation conditions, the
time period available for bootstrap charging is
smaller so the bootstrap capacitor may not
sufficiently charge.
In case the internal circuit does not have
sufficient voltage and the bootstrap capacitor is
not charged, extra external circuitry can ensure
the bootstrap voltage is in the normal operational
region. Refer to the External Bootstrap Diode in
Application section.
The DC quiescent current of the floating driver is
about 20µA. Make sure the bleeding current at
the SW node is higher than this value, such that:
IO
VO
(R1 R
2)
20μA
Current-Comparator and Current Limit
A current-sense MOSFET accurately senses the
current in the power MOSFET. This signal is then
fed to the high speed current comparator for
current-mode–control purposes, which uses it as
one of its inputs with the COMP voltage. When
the power MOSFET turns on, the comparator is
first blanked until the end of the turn-on transition
to avoid noise issues. When the sensed current
exceeds the COMP voltage, the comparator
output is low and the power MOSFET turns off.
The cycle-by-cycle maximum current of the
internal power MOSFET is internally limited.
Short Circuit Protection
When the output is shorted to the ground, the
switching frequency folds back and the current
limit falls to reduce the short circuit current. When
the FB voltage equals 0V, the current limit falls to
about 50% of its full current limit. The FB voltage
reaches its 100% of its current limit when it
exceeds 0.4V
When the short-circuit FB voltage is low, the SS
drops by VFB and SS ≈ VFB + 100mV. If the short
circuit is removed, the output voltage recovers at
the SS rate. When FB is high enough, the
frequency and current limit return to normal
values.
Startup and Shutdown
If both VIN and VEN exceed their appropriate
thresholds, the chip starts. The reference block
starts first, generating stable reference voltage
and currents, and then the internal regulator is
enabled. The regulator provides stable supply for
the remaining circuits.
While the internal supply rail is up, an internal
timer blanks the power MOSFET OFF for about
50µs to avoid start-up glitches. When the internal
soft-start block is enabled, it first holds its SS
output low to ensure the other circuits are ready
and then slowly ramps up.
Three events can shut down the chip: EN low,
VIN low and thermal shutdown. In the shutdown
procedure, power MOSFET is turned off first to
avoid any fault triggering. The COMP voltage and
the internal supply rail are then pulled down.
Programmable Oscillator
An external resistor (RFREQ) connected from the
FREQ pin to GND sets the MPQ4558 oscillating
frequency. Calculate the value of RFREQ from:
RFREQ
(k)
100000
fS(k Hz)
5
For fSW=500kHz, RFREQ=195kΩ.
Soft-Start
Soft-start prevents the converter output voltage
from overshooting during startup and short circuit
recovery phases. Internally the soft-start voltage
(VSS) is the voltage at SS pin offset by about 1V.
VSS is applied on the error amplifier in parallel
with the internal reference voltage REF. VSS or
REF (whichever is lower) controls the error
amplifier . When VSS ramps up from 0 to high, the
controller tries to regulate FB from zero to REF at
the VSS ramp-up pace.
A 5μA current source pulls up the SS pin. Given
the soft-start capacitor (CSS), the soft-start time is
about the time CSS voltage changes by 0.8V. So
the soft-start time can be estimated as:
MPQ4561 Rev. 1.11
www.MonolithicPower.com
3/29/2013
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet MPQ4561.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MPQ4560 | Industrial-Grade 2A 2MHz 55V Step-Down Converter Available | MPS |
| MPQ4561 | 1.5A 2MHz 55V Step-Down Converter Available | MPS |
| 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 |