概述
数据手册MPQ4560DN-AEC1-Z 概述
暂无描述
MPQ4560DN-AEC1-Z 数据手册
通过下载MPQ4560DN-AEC1-Z数据手册来全面了解它。这个PDF文档包含了所有必要的细节，如产品概述、功能特性、引脚定义、引脚排列图等信息。
PDF下载MPQ4560
Industrial-Grade, 2A, 2MHz, 55V
Step-Down Converter
Available in AEC-Q100
FEATURES
DESCRIPTION
Guaranteed Industrial Automotive
Temperature Range Limits
Wide 3.8V-to-55V Operating Input Range
250mΩ Internal Power MOSFET
Up to 2MHz Programmable Switching
Frequency
The MPQ4560 is a high-frequency, step-down,
switching regulator with an integrated, high-
side, high-voltage, power MOSFET. It provides
a 2A output with current mode control for fast
loop response and easy compensation.
The
wide
3.8V-to-55V
input
range
140μA Quiescent Current
Ceramic Capacitor Stable
Internal Soft-Start
accommodates
a
variety of step-down
applications, including those in automotive input
environment. A 12µA shutdown mode supply
current allows use in battery-powered
applications.
Up to 95% Efficiency
Output Adjustable from 0.8V to 52V
Available in QFN10 (3mmx3mm) and
SOIC8E Packages
High-power conversion efficiency over a wide
load range is achieved by scaling down the
switching frequency in light load conditions to
reduce the switching and gate driving losses.
AEC-Q100 Qualified
APPLICATIONS
High-Voltage Power Conversion
Automotive Systems
Industrial Power Systems
Distributed Power Systems
Battery Powered Systems
Frequency foldback prevents inductor current
runaway during startup and thermal shutdown
provides reliable, fault tolerant operation.
By switching at 2MHz, the MPQ4560 can
prevent electromagnetic interference problems,
such as those found in AM radio and ADSL
applications.
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Products, Quality Assurance page.
“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
The MPQ4560 is available in small 3mm x 3mm
QFN10 and SOIC8E packages.
TYPICAL APPLICATION
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
1
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
ORDERING INFORMATION
Part Number
MPQ4560DN*
Package
SOIC8E
Top Marking
MP4560DN
T8
Junction Temperature (TJ)
MPQ4560DQ**
QFN10 (3×3mm)
SOIC8E
–40°C to +125°C
MPQ4560DN-AEC1
MPQ4560DQ-AEC1
MP4560DN
T8
QFN10 (3×3mm)
* For Tape & Reel, add suffix –Z (e.g. MPQ4560DN-Z)
For RoHS Compliant Packaging, add suffix –LF, (e.g. MPQ4560DN-LF–Z)
** For Tape & Reel, add suffix –Z (e.g. MPQ4560DQ-Z)
For RoHS Compliant Packaging, add suffix –LF, (e.g. MPQ4560DQ-LF–Z)
PACKAGE REFERENCE
QFN10 (3x3mm)
SOIC8E
ABSOLUTE MAXIMUM RATINGS (1)
Supply Voltage (VIN).................... –0.3V to +60V
Switch Voltage (VSW)......... –0.5V to (VIN + 0.5V)
BST to SW.................................... –0.3V to +5V
All Other Pins................................ –0.3V to +5V
Continuous Power Dissipation .......(TJ = 25°C)(2)
QFN10 (3×3mm)........................................2.5W
SOIC8E .....................................................2.5W
Junction Temperature..............................150°C
Lead Temperature ...................................260°C
Storage Temperature.............. –65°C to +150°C
Thermal Resistance (4)
QFN10 (3x3mm).....................50 ......12 ...°C/W
θJA θJC
SOIC8E..................................50 ......10 ...°C/W
Notes:
1) Exceeding these ratings may damage the device
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ(MAX), the junction-to-
ambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD(MAX)=(TJ(MAX)-
TA)/ θJA. Exceeding the maximum allowable power dissipation
will cause excessive die temperature, and the regulator will go
into thermal shutdown. Internal thermal shutdown circuitry
protects the device from permanent damage.
Recommended Operating Conditions (3)
Supply Voltage VIN .......................... 3.8V to 55V
Output Voltage VOUT........................ 0.8V to 52V
Maximum Junction Temp. (TJ) ..............+125°C
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7 4-layer board.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
2
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
ELECTRICAL CHARACTERISTICS
VIN = 12V, VEN = 2.5V, VCOMP = 1.4V, TJ= –40°C to +125°C, unless otherwise noted. Typical Values
are at TJ=25°C.
Parameter
Symbol Condition
Min
Typ
Max Units
TJ=25°C
0.780 0.797 0.820
4.5V < VIN <
55V
Feedback Voltage
VFB
−40°C ≤ TJ ≤85°C
−40°C ≤ TJ ≤125°C
0.772
0.766
0.829
0.829
1.0
V
Feedback Leakage Current
Upper Switch On Resistance (5)
Upper Switch Leakage
Current Limit
IFB
0.1
μA
mΩ
μA
A
TJ=25°C
=
175
160
250
330
VBST – VSW
5V
RDS(ON)
ISW
400
VEN = 0V, VSW = 0V
TJ=25°C
1
2.6
2.2
3.2
4.5
4.7
ILIM
Duty Cycle ≤ 60%
COMP to Current Sense
Transconductance (5)
GCS
5.7
A/V
Error Amp Voltage Gain (6)
Error Amp Transconductance
Error Amp Min Source current
Error Amp Min Sink current
400
120
10
V/V
µA/V
µA
ICOMP = ±3µA
VFB = 0.7V
VFB = 0.9V
TJ=25°C
−10
3.0
µA
2.7
2.4
3.3
3.6
V
VIN UVLO Threshold
VIN UVLO Hysteresis
Soft-Start Time (5)
0.35
0.5
1
V
0V < VFB < 0.8V
0.19
0.8
ms
TJ=25°C
1.2
1.3
20
MHz
RFREQ
=
Oscillator Frequency
fSW
95kΩ
0.7
Shutdown Supply Current
Quiescent Supply Current
Thermal Shutdown (5)
Minimum Off Time (5)
Minimum On Time (5)
IS
VEN < 0.3V
12
µA
µA
°C
ns
ns
V
IQ
No load, VFB = 0.9V (no switching)
Hysteresis = 20°C
140
150
100
100
1.55
200
tOFF
tON
TJ=25°C
1.4
1.3
1.7
1.8
EN Rising Threshold
EN Threshold Hysteresis
320
mV
Note:
5) Derived from bench characterization. Not tested in production.
6) Guaranteed by design. Not tested in production.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
3
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
PIN FUNCTIONS
QFN SOIC8
Pin # Pin #
Name Description
Switch Node. Output from the high-side switch. A low VF Schottky rectifier to ground
is required. The rectifier must be close to the SW pins to reduce switching spikes.
1, 2
3
1
2
3
SW
EN
Enable Input. Pull this pin below the specified threshold to shutdown the chip. Pull it
up above the specified threshold or leaving it floating to enable the chip.
Compensation. Output of the GM error amplifier. Control loop frequency
compensation is applied to this pin.
4
COMP
Feedback. Input to the error amplifier. Sets the regulator voltage by comparing the
tap of an external resistive divider connected between the output and GND to the
internal +0.8V reference.
5
4
FB
GND, Ground. Connect as close as possible to the output capacitor and avoid the high-
Exposed current switch paths. Connect exposed pad to GND plane for optimal thermal
6
7
5
6
7
8
pad
performance.
Switching Frequency Program Input. Connect a resistor from this pin to ground to set
the switching frequency.
FREQ
Input Supply. This supplies power to all the internal control circuitry, both BS
regulators, and the high-side switch. Place a decoupling capacitor to ground close to
this pin to minimize switching spikes.
8, 9
10
VIN
Bootstrap. Positive power supply for the internal floating high-side MOSFET driver.
Connect a bypass capacitor between this pin and SW pin.
BST
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
4
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
TYPICAL CHARACTERISTICS
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
5
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
TYPICAL CHARACTERISTICS (continued)
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
6
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 12V, VOUT =3.3V, C1 = 4.7µF, C2 = 22µF, L1 = 10µH and TA = 25°C, unless otherwise noted.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
7
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 12V, VOUT =3.3V, C1 = 4.7µF, C2 = 22µF, L1 = 10µH and TA = 25°C, unless otherwise noted.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
8
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
BLOCK DIAGRAM
Figure 1: Functional Block Diagram
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
9
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
Enable Control
The MPQ4560 has a dedicated enable control
pin (EN) that can enable or disable the chip when
the input voltage exceeds an upper threshold. Its
falling threshold (turn-off) is 1.2V, and its rising
threshold (turn-on) is 1.5V (300mV higher).
OPERATION
The MPQ4560 is an asynchronous, step-down,
switching regulator with an integrated high-side,
high-voltage,
power
MOSFET
and
a
programmable frequency. It provides a single
highly-efficient solution with current-mode control
for fast loop response and easy compensation. It
features a wide input voltage range, internal soft-
start control, and precise current limiting. Its very
low operational quiescent current makes it
suitable for battery-powered applications.
When floating, an internal 1µA current source
pulls EN up to ~3.0V to enable the chip. Pull-
down requires a 1µA current.
When EN is pulled below 1.2V, the chip enters its
lowest shutdown current mode. When EN
exceeds 0V but remains lower than its rising
threshold, the chip remains in shutdown mode
but the shutdown current increases slightly.
PWM Control
The MPQ4560 operates in a fixed-frequency,
peak-current-control mode to regulate the output
voltage at moderate-to-high output current. The
internal clock initiates a PWM cycle. The power
MOSFET turns ON and remains ON until its
current reaches the value set by the COMP
voltage. When the power switch is OFF, it
remains OFF for at least 100ns before the next
cycle starts. If the current in the power MOSFET
does not reach the COMP-set current value
within one PWM period, the power MOSFET
remains ON, saving a turn-off operation.
Under-Voltage Lockout
Under-voltage lockout (UVLO) protects the chip
from operating at insufficient supply voltage. The
UVLO rising threshold is about 3.0V while its
falling threshold is a consistent 2.6V.
Internal Soft-Start
Soft-start prevents the converter output voltage
from overshooting during startup and short-circuit
recovery. When the chip starts, the internal circuit
generates a soft-start voltage (SS) ramping up
Pulse-Skipping Mode
from 0V to 2.6V. When it is less than the VREF
,
Under light-load condition the switching
frequency stretches the zero-voltage period to
reduce the switching loss and driving loss.
SS overrides VREF so the error amplifier uses SS
as the reference. When SS exceeds VREF, VREF
regains control.
Error Amplifier
Thermal Shutdown
The error amplifier compares the FB pin voltage
(VFB) to the internal reference (VREF) and outputs
a current proportional to the difference. This
Thermal shutdown prevents the chip from
operating at exceedingly high temperatures.
When the silicon die temperature exceeds its
upper threshold, the whole chip shuts down.
When the temperature is less than its lower
threshold, the chip is enabled again.
output
current
charges
the
external
compensation network to form VCOMP, which
controls the power MOSFET current.
During operation, the minimum VCOMP is clamped
to 0.9V and its maximum is clamped to 2.0V.
COMP is internally pulled down to GND in
shutdown mode. Do not pull VCOMP above 2.6V.
Floating Driver and Bootstrap Charging
An external bootstrap capacitor powers the
floating power MOSFET driver. This floating
driver has its own UVLO protection. This UVLO’s
rising threshold is 2.2V with a hysteresis of
150mV. The driver’s UVLO is soft-start related:
When the bootstrap voltage hits its UVLO
threshold, the soft-start circuit resets. To prevent
noise, there is 20µs delay before the reset action.
When bootstrap UVLO is gone, the reset is off
and then the soft-start process resumes.
Internal Regulator
An internal 2.6V regulator powers most of the
internal circuits. This regulator takes the VIN
input and operates in the full VIN range. When VIN
exceeds 3.0V, the output of the regulator is in full
regulation. When VIN is less than 3.0V, the output
decreases.
The dedicated internal bootstrap regulator
regulates and charges the bootstrap capacitor to
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
10
MPQ4560 – 2A, 2MHz, 55V STEP-DOWN CONVERTER
~5V. When the voltage between the BST and SW
During a short circuit, the VFB voltage is low and
pulls down VSS to ~100mV above VFB. Removing
the short circuit causes the output voltage to
recover with VSS. When VFB is high enough, the
frequency and current limit return to normal
values.
nodes is less than its regulation, a PMOS pass
transistor from VIN to BST turns ON. The
charging current path is from VIN, BST and then
to SW. An external circuit must provide enough
voltage headroom to facilitate charging.
As long as VIN is sufficiently higher than VSW, the
bootstrap capacitor can charge. When the power
MOSFET is ON, VIN≈VSW so the bootstrap
capacitor cannot charge. When the external
diode is ON, the difference between VIN and VSW
is at its largest, thus making it the best period to
charge. When there is no current in the inductor,
VSW=VOUT so the difference between VIN and VOUT
can charge the bootstrap capacitor.
Startup and Shutdown
If both VIN and VEN exceed their respective
thresholds, the chip starts. The reference block
initiates to generate a stable reference voltage
and currents, and then the internal regulator is
enabled. The regulator provides a stable supply
for the remaining circuitries.
While the internal supply rail is up, an internal
timer holds the power MOSFET OFF for about
50µs to blank the startup noise. When the
internal soft-start block is enabled, it first holds its
SS output low to ensure the remaining circuitries
are ready and then slowly ramps up.
At higher duty cycles, the time period available
for bootstrap charging is shorter so the bootstrap
capacitor may not sufficiently charge. If the
internal circuit does not have sufficient voltage
and the bootstrap capacitor is not charged, extra
external circuitry can ensure the bootstrap
voltage is within the normal operational region.
Three events can shut down the chip: VEN LOW,
VIN LOW and thermal shutdown. During
shutdown, the power MOSFET turns OFF first to
avoid any fault triggering. Then VCOMP and the
internal supply rail drop.
The DC quiescent current of the floating driver is
about 20µA. Make sure the bleeding current at
the SW node exceeds this value, such that:
Programmable Oscillator
VO
An external resistor (RFREQ) from the FREQ pin to
ground sets the MPQ4560 oscillating frequency.
The value of RFREQ can be calculated from:
IO
20A
(R1 R2)
Current Comparator and Current Limit
100000
A current-sense MOSFET accurately senses the
power MOSFET’s current. The result goes to the
high-speed current comparator for current-mode
control.: When the power MOSFET turns ON, the
comparator is first blanked till the end of the turn-
on transition to avoid noise issues. The
comparator then compares the power switch
current to VCOMP. When the sensed current
exceeds VCOMP, the comparator output is LOW,
turning OFF the power MOSFET. The
cycle-by-cycle maximum current of the internal
power MOSFET is internally limited.
RFREQ(kΩ) =
-5
fS(kHz)
For example, for fSW=500kHz, RFREQ=195kΩ.
Short Circuit Protection
When the output is shorted to the ground, the
switching frequency folds back and the current
limit falls to lower the short-circuit current. When
VFB is zero, the current limit drops to about 50%
of its full current limit. When VFB exceeds 0.4V,
current limit reaches 100%.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
11
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
APPLICATION INFORMATION
To determine the inductance, allow the inductor’s
peak-to-peak ripple current to approximately
equal 30% of the maximum switch current limit.
Make sure that the peak inductor current is less
than the maximum switch current limit. The
inductance value can be calculated by:
COMPONENT SELECTION
Setting the Output Voltage
A resistive voltage divider from the output voltage
to FB pin sets the output voltage. The voltage
divider divides the output voltage down to the
feedback voltage by the ratio:
VOUT
VOUT
R2
L1=
(1-
)
VFB=VOUT
fs ΔIL
V
IN
R1+R2
Where VOUT is the output voltage, VIN is the input
voltage, fS is the switching frequency, and ∆IL is
the peak-to-peak inductor ripple current.
Thus the output voltage is:
R1+R2
R2
VOUT =VFB
Choose an inductor that will not saturate under
the maximum inductor peak current. The peak
inductor current can be calculated by:
For example, the value for R2 can be 10kΩ. With
this value, R1 is:
VOUT
VOUT
R1=12.5(VOUT -0.8)(KΩ)
ILP ILOAD
1
2 fS L1
V
IN
So for a 3.3V output voltage, R2 is 10kΩ, and R1
is 31.6kΩ.
Where ILOAD is the load current.
Table 1 lists several suitable inductors from
various manufacturers. The different inductor
choices include price vs. size requirements and
any EMI requirements.
Inductor
The inductor provides constant current to the
output load while being driven by the switched
input voltage. A larger-value inductor will result in
lower ripple current that will lower the output
ripple voltage. However, a larger inductor value
will be physically larger, have higher series
resistance, or lower saturation current.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
12
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
Table 1: Inductor Selection Guide
Inductance
Max DCR
(Ω)
Current Rating
(A)
Dimensions
Part Number
(µH)
L × W × H (mm3)
Wurth Electronics
7447789004
744066100
744771115
744771122
TDK
4.7
10
15
22
0.033
0.035
0.025
0.031
2.9
3.6
7.3×7.3×3.2
10×10×3.8
12×12×6
3.75
3.37
12×12×6
RLF7030T-4R7
SLF10145T-100
SLF12565T-150M4R2
SLF12565T-220M3R5
Toko
4.7
10
15
22
0.031
0.0364
0.0237
0.0316
3.4
3
7.3×6.8×3.2
10.1×10.1×4.5
12.5×12.5×6.5
12.5×12.5×6.5
4.2
3.5
FDV0630-4R7M
919AS-100M
919AS-160M
919AS-220M
4.7
10
16
22
0.049
0.0265
0.0492
0.0776
3.3
4.3
3.3
3
7.7×7×3
10.3×10.3×4.5
10.3×10.3×4.5
10.3×10.3×4.5
Output Rectifier Diode
Choose a diode whose maximum reverse voltage
rating exceeds the maximum input voltage, and
whose current rating exceeds the maximum load
current. Table 2 lists example Schottky diodes
and manufacturers.
The output rectifier diode supplies the current to
the inductor when the high-side switch is OFF.
Use a Schottky diode to reduce losses from the
diode forward voltage and recovery times.
Table 2: Diode Selection Guide
Voltage/
Current
Rating
Diodes
Manufacturer
B290-13-F
B380-13-F
90V, 2A
80V, 3A
100V, 2A
100V, 3A
Diodes Inc.
Diodes Inc.
Central Semi
Central Semi
CMSH2-100M
CMSH3-100MA
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
13
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
Input Capacitor
VOUT
VOUT
ΔVOUT
1
RESR
The input current to the step-down converter is
discontinuous and requires a capacitor to supply
the AC current to the step-down converter while
maintaining the DC input voltage. Use capacitors
with low equivalent series resistances (ESR) for
the best performance. Ceramic capacitors are
best, but tantalum or low-ESR electrolytic
capacitors may also suffice.
fS L
VIN
The characteristics of the output capacitor also
affect the stability of the regulation system. The
MPQ4560 can be optimized for a wide range of
capacitances and ESR values.
Compensation Components
MPQ4560 employs current-mode control for easy
compensation and fast transient response. The
COMP pin controls the system stability and
transient response. The COMP pin is the output
of the internal error amplifier. A series capacitor-
For simplification, choose the input capacitor with
an RMS current rating greater than half of the
maximum load current. The input capacitor (C1)
can be electrolytic, tantalum, or ceramic.
resistor
combination
sets
a
pole-zero
When using electrolytic or tantalum capacitors,
place a small, high-quality, ceramic capacitor
(0.1μF) as close to the IC as possible. When
using ceramic capacitors, make sure that they
have enough capacitance to provide sufficient
charge to prevent excessive voltage ripple at the
input. The input voltage ripple caused by
capacitance is approximately:
combination to control the control system’s
characteristics. The DC gain of the voltage
feedback loop is:
VFB
AVDC RLOAD GCS AVEA
VOUT
Where
AVEA is the error-amplifier voltage gain,
400V/V;
ILOAD
VOUT
VOUT
VIN
1
fS C1
VIN
V
IN
GCS is the current-sense transconductance,
5.6A/V; and
Output Capacitor
The output capacitor (C2) maintains the DC
output voltage. Use ceramic, tantalum, or low-
ESR electrolytic capacitors. Low-ESR capacitors
are preferred to keep the output voltage ripple
low. The output voltage ripple can be estimated
as:
RLOAD is the load resistor value.
The system has two important poles: One from
the compensation capacitor (C3) and the output
resistor of error amplifier, and the other due to
the output capacitor and the load resistor. These
poles are located at:
VOUT
VOUT
VIN
1
RESR
VOUT
1
fS L
8 fS C2
GEA
fP1
2πC3 AVEA
Where L is the inductor value and RESR is the
ESR value of the output capacitor.
1
fP2
For ceramic capacitors, the capacitance
dominates the impedance at the switching
frequency and contributes the most to the output
voltage ripple. For simplification, the output
voltage ripple can be estimated by:
2πC2RLOAD
Where,
transconductance, 120μA/V.
GEA
is the error-amplifier
The system has one important zero due to the
compensation capacitor and the compensation
resistor (R3). This zero is located at:
VOUT
VOUT
ΔVOUT
1
8 fS2 L C2
V
IN
1
For tantalum or electrolytic capacitors, the ESR
dominates the impedance at the switching
frequency. For simplification, the output ripple is
approximately:
fZ1
2πC3R3
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
14
MPQ4560 – 2A, 2MHz, 55V STEP-DOWN CONVERTER
The system may have another significant zero if
the output capacitor has a large capacitance or a
high ESR value. This zero is located at:
values, set the compensation zero (fZ1) <0.25 ×fC
to provide sufficient phase margin. C3 is then:
4
C3
1
2πR3 fC
fESR
2πC2RESR
3. C5 is required if the ESR zero of the output
capacitor is located at <0.5 ×fSW , or the following
relationship is valid:
In this case, a third pole set by the compensation
capacitor (C5) and the compensation resistor can
compensate for the effect of the ESR zero. This
pole is located at:
fS
2
1
2πC2RESR
1
fP3
If this is the case, use C5 to set the pole (fP3) at
the location of the ESR zero. Determine the C5:
2πC5R3
The goal of compensation design is to shape the
converter transfer function for a desired loop
gain. The system crossover frequency where the
feedback loop has unity gain is important: Lower
crossover frequencies result in slower line and
load transient responses, while higher crossover
frequencies lead to system instability. Generally,
set the crossover frequency to ~0.1×fSW.
C2RESR
C5
R3
High-Frequency Operation
The switching frequency of MPQ4560 can be
programmed up to 2MHz by an external resistor.
The minimum on time of MPQ4560 is about
100ns (typ). Pulse-skipping occurs more readily
at higher switching frequencies due to the
minimum ON time.
Table 3: Compensation Values for Typical
Output Voltage/Capacitor Combinations
VOUT
(V)
C2
(µF)
R3
(kΩ)
C3
(pF)
C6
(pF)
L (µH)
4.7
Since the internal bootstrap circuitry has higher
impedance, which may not sufficiently charge the
bootstrap capacitor during each (1−D)×τS
charging period, add an external bootstrap
charging diode if the switching frequency is about
2MHz (see External Bootstrap Diode section for
detailed implementation information).
1.8
2.5
3.3
5
33
22
22
33
22
32.4
26.1
68.1
47.5
16
680
680
220
330
470
None
None
None
None
2
4.7 - 6.8
6.8 -10
15 - 22
10
With higher switching frequencies, the capacitors’
inductive reactances (XL) dominate so that the
ESL of input/output capacitors determine the
input/output ripple voltages at higher switching
frequencies. As a result, use high-frequency
ceramic capacitors as input decoupling
capacitors and output filtering capacitors for high-
frequency operation.
12
To optimize the compensation components for
conditions not listed in Table 3, follow these
steps:
1. Choose R3 to set the desired crossover
frequency:
External Bootstrap Diode
An external bootstrap diode from the 5V rail to
the BST pin may enhance the efficiency under
the following conditions:
2πC2 f VOUT
R3
C
GEAGCS
VFB
There is a 5V rail available in the system;
VIN ≤5V;
Where fC is the desired crossover frequency.
2. Choose C3 to achieve the desired phase
margin. For applications with typical inductor
3.3V<VOUT<5V; and
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
15
MPQ4560 – 2A, 2MHz, 55V STEP-DOWN CONVERTER
for high duty-cycle operation (when VOUT/VIN >
65%).
The bootstrap diode can be a low cost one such
as IN4148 or BAT54.
Figure 2: External Bootstrap Diode
At no-load or light-load, the converter may
operate in pulse-skipping mode in order to
maintain output-voltage regulation. Thus there is
less time to refresh the BS voltage. For sufficient
gate voltage during pulse-skipping, VIN–VOUT>3V.
For example, if the VOUT=3.3V, VIN must be
exceed 3.3V+3V=6.3V to maintain sufficient BST
voltage at no-load or light-load. To meet this
requirement, the EN pin can program the input
UVLO voltage to VOUT+3V.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
16
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
TYPICAL APPLICATION CIRCUITS
Figure 3: Typical Application, 1.8V Output
Figure 4: Typical Application, 5V Output
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
17
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
3) Route SW away from sensitive analog
areas such as FB.
PCB LAYOUT GUIDE
PCB layout is very important for stable
operation. Try to duplicate the EVB layout for
optimum performance.
4) Connect IN, SW, and especially GND to
large copper surfaces to cool the chip to
improve thermal performance and long-
term reliability.
For changes, please follow these guidelines
and use Figure 5 as reference.
5) Place the compensation components close
to the MPQ4560. Avoid placing the
compensation components close to or
under high dv/dt SW node, or inside the
high di/dt power loop. If necessary, add a
ground plane to isolate the loops.
1) Place the input decoupling capacitor and
the catch diode as close to the MPQ4560
(VIN pin, SW pin and PGND) as possible,
with traces that are very short and fairly
wide. This can help to greatly reduce the
voltage spike on SW node, and the EMI
noise.
6) Switching loss increases at higher
frequencies.
To
improve
thermal
2) Ensure all feedback connections are short
and direct. Place the feedback resistors
and compensation components as close to
the chip as possible. Try to run the
feedback trace as far from the inductor and
noisy power traces as possible. Run the
feedback trace on the side of the PCB
opposite of the inductor with a ground
plane separating the two.
conduction, add a grid of thermal vias
under the exposed pad. Use small vias
(15mil barrel diameter) so that the hole fills
during the plating process: larger vias can
cause solder-wicking during the reflow
process. The pitch (distance between the
centers) between these thermal vias is
typically 40mil.
MPQ4560 Typical Application Circuit
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
18
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
GND
L1
R1
SW
C4
D1
R6
C2
C1
Vin
GND
GND
Vo
TOP Layer
Bottom Layer
MPQ4560DN Layout Guide
GND
L1
R1
SW
C4
D1
R6
C2
C1
Vin
GND
GND
Vo
TOP Layer
Bottom Layer
MPQ4560DQ Layout Guide
Figure 5: MPQ4560 Typical Application Circuit and PCB Layout Guide
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
19
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
PACKAGE INFORMATION
3mm × 3mm QFN10 (EXPOSED PAD)
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
20
MPQ4560 – 2A, 2MHz, 55V, STEP-DOWN CONVERTER
SOIC8E
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MPQ4560 Rev. 1.1
3/29/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
21
MPQ4560DN-AEC1-Z 相关器件
| 型号 | 制造商 | 描述 | 价格 | 文档 |
| MPQ4560DN-LF | MPS | 暂无描述 | 获取价格 |
|
| MPQ4560DN-LF-Z | MPS | Switching Regulator, Current-mode, 4.7A, 2000kHz Switching Freq-Max, PDSO8, ROHS COMPLIANT, MS-012BA, SOIC-8 | 获取价格 |
|
| MPQ4560DN-Z | MPS | Switching Regulator, Current-mode, 4.7A, 1300kHz Switching Freq-Max, PDSO8, MS-012BA, SOIC-8 | 获取价格 |
|
| MPQ4560DN-Z-LF | MPS | 暂无描述 | 获取价格 |
|
| MPQ4560DN-Z-LF-Z | MPS | Switching Regulator, | 获取价格 |
|
| MPQ4560DQ | MPS | Industrial-Grade, 2A, 2MHz, 55V Step-Down Converter Available in AEC-Q100 | 获取价格 |
|
| MPQ4560DQ-AEC1 | MPS | Industrial-Grade, 2A, 2MHz, 55V Step-Down Converter Available in AEC-Q100 | 获取价格 |
|
| MPQ4560DQ-AEC1 -Z | MPS | 暂无描述 | 获取价格 |
|
| MPQ4560DQ-AEC1-LF-Z | MPS | IC REG BUCK ADJ 2A | 获取价格 |
|
| MPQ4560DQ-LF | MPS | Switching Regulator, Current-mode, 4.7A, 1300kHz Switching Freq-Max, PDSO10, 3 X 3 MM, ROHS COMPLIANT, MO-229VEED-5, QFN-10 | 获取价格 |
|
MPQ4560DN-AEC1-Z 相关文章
Bourns 密封通孔金属陶瓷微调电位计产品选型手册(英文版)
- 2024-09-20
- 6
Bourns 精密环境传感器产品选型手册(英文版)
- 2024-09-20
- 9
Bourns POWrTher 负温度系数(NTC)热敏电阻手册 (英文版)
- 2024-09-20
- 8
Bourns GMOV 混合过压保护组件产品选型手册(英文版)
- 2024-09-20
- 6
