MP1477GTF-Z [MPS]
Switching Regulator,;
| 型号： | MP1477GTF-Z |
| 厂家： | 
MONOLITHIC POWER SYSTEMS |
| 描述： | Switching Regulator, 开关 光电二极管 |
| 文件： | 总19页 (文件大小：904K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MP1477
17V, 3A, 800kHz, High-Efficiency,
Synchronous, Step-Down Converter
with COT Control in SOT563 Package
DESCRIPTION
FEATURES
The MP1477 is a fully integrated, high-
frequency, synchronous, rectified, step-down,
switch-mode converter with internal power
MOSFETs. The MP1477 offers a very compact
solution that achieves 3A of continuous output
current with excellent load and line regulation
over a wide input range. The MP1477 uses
synchronous mode operation for higher
efficiency over the output current-load range.
Wide 4.2V to 17V Operating Input Range
58mΩ/27mΩ Low RDS(ON) Internal Power
MOSFETs
200µA Low IQ Current
High-Efficiency Synchronous Mode
Operation
Power Save Mode (PSM) at Light Load
Fast Load Transient Response
800kHz Switching Frequency
Internal Soft Start (SS)
Over-Current Protection (OCP) and Hiccup
Thermal Shutdown
Output Adjustable from 0.8V
Available in a SOT563 (1.6mmх1.6mm)
Package
Constant-on-time (COT) control operation
provides very fast transient response, easy loop
design, and very tight output regulation.
Full protection features include short-circuit
protection (SCP), over-current protection (OCP),
under-voltage protection (UVP), and thermal
shutdown.
APPLICATIONS
The MP1477 requires a minimal number of
Security Cameras
readily
available,
standard,
external
Digital Set-Top Boxes
Flat-Panel Televisions and Monitors
General Purposes
components and is available in a space-saving
SOT563 (1.6mmх1.6mm) package.
All MPS parts are lead-free, halogen-free, and adhere to the RoHS
directive. For MPS green status, please visit the MPS website under Quality
Assurance. “MPS” and “The Future of Analog IC Technology” are registered
trademarks of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
R4
10Ω
C3
1μF
12V
VIN
L1
2.2μH
3.3V/3A
VOUT
BST
VIN
SW
FB
R1
40.2kΩ
C1
22μF
C2
22μF x 2
MP1477
R2
13kΩ
R3
75kΩ
EN
EN
GND
MP1477 Rev. 1.0
9/12/2017
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
ORDERING INFORMATION
Part Number*
Package
Top Marking
MP1477GTF
SOT563 (1.6mmх1.6mm)
See Below
* For Tape & Reel, add suffix –Z (e.g. MP1477GTF–Z)
TOP MARKING
AUC: Product code of MP1477GTF
Y: Year code
LLL: Lot number
PACKAGE REFERENCE
TOP VIEW
SOT563 (1.6mmх1.6mm)
MP1477 Rev. 1.0
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
ABSOLUTE MAXIMUM RATINGS (1)
VIN ................................................ -0.3V to 18V
VSW ............................-0.6V (-6.5V for <10ns) to
VIN + 0.3V (19V for <10ns)
Thermal Resistance
SOT563
θJA
θJC
(5)
EV1477-TF-00A ................ 55.......21 ... °C/W
(6)
JESD51-7 ........................ 130......60 ... °C/W
VBST .....................................................VSW + 5V
(2)
NOTES:
VEN ..............................................-0.3V to 5V
1) Exceeding these ratings may damage the device.
2) For details on EN’s ABS max rating, please refer to the EN
Control section on page 11.
All other pins.................................... -0.3V to 5V
(3)(5)
Continuous power dissipation (TA = +25°C)
3) 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 produces an excessive die temperature, causing
the regulator to go into thermal shutdown. Internal thermal
shutdown circuitry protects the device from permanent
damage.
..................................................................2.2W
Junction temperature...............................150°C
Lead temperature ....................................260°C
Storage temperature..................-65°C to 150°C
Recommended Operating Conditions (4)
Supply voltage (VIN)....................... 4.2V to 17V
Output voltage (VOUT).........0.8V to VIN х DMAX or
10V max
4) The device is not guaranteed to function outside of its
operating conditions.
5) Measured on EV1477-TF-00A, 2-layer PCB.
6) Measured on JESD51-7, 4-layer PCB.
Operating junction temp. (TJ) ...-40°C to +125°C
MP1477 Rev. 1.0
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
ELECTRICAL CHARACTERISTICS
VIN = 12V, TJ = -40°C to +125°C (7), typical value is tested at TJ = +25°C, unless otherwise noted.
Parameter
Symbol Condition
Min
Typ
Max
10
Units
μA
Supply current (shutdown)
Supply current (quiescent)
HS switch on resistance
LS switch on resistance
Switch leakage
IIN
IQ
VEN = 0V
VEN = 2V, VFB = 0.85V
170
200
58
240
μA
HSRDS(ON) VBST-SW = 3.3V
LSRDS(ON)
mΩ
mΩ
μA
27
SWLKG
ILIMIT
VEN = 0V, VSW = 12V
10
Valley current limit
VOUT = 0V
2.7
-250
600
4
5.8
A
VOUT = 3.3V, Lo = 2.2μH,
IOUT = 0A
ZCD
IZCD
20
250
mA
Oscillator frequency
Minimum on time (8)
Minimum off time (8)
fSW
VFB = 0.75V
800
45
1000
kHz
ns
TON_MIN
TOFF_MIN
180
805
805
10
ns
TJ = +25°C
793
789
817
821
100
mV
mV
nA
VREF
%
Feedback voltage
VREF
TJ = -40°C to 125°C
Feedback current
FB UV threshold (H to L)
Hiccup duty cycle (8)
EN rising threshold
EN hysteresis
IFB
VUV_th
Hiccup entry
VEN = 2V
75%
25
DHiccup
VEN_RISING
VEN_HYS
IEN
1.14
1.2
100
2
1.26
V
mV
µA
EN input current
VIN under-voltage lockout
threshold rising
INUVVth
3.7
1.6
4
4.18
3
V
VIN under-voltage lockout
threshold hysteresis
INUVHYS
330
mV
Soft-start period
Thermal shutdown (8)
Thermal hysteresis (8)
NOTES:
TSS
TSD
2.5
150
20
ms
°C
°C
TSDHYS
7) Guaranteed by over-temperature correlation, not tested in production.
8) Guaranteed by design and engineering sample characterization.
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 12V, VOUT = 3.3V, L = 2.2µH, TA = +25°C, unless otherwise noted.
MP1477 Rev. 1.0
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 12V, VOUT = 3.3V, L = 2.2µH, TA = +25°C, unless otherwise noted.
MP1477 Rev. 1.0
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 12V, VOUT = 3.3V, L = 2.2µH, TA = +25°C, unless otherwise noted.
MP1477 Rev. 1.0
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 12V, VOUT = 3.3V, L = 2.2µH, TA = +25°C, unless otherwise noted.
MP1477 Rev. 1.0
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
PIN FUNCTIONS
Package
Pin #
Name Description
Supply voltage. The MP1477 operates from a 4.2V to 17V input rail. A capacitor (C1) is
required to decouple the input rail. Connect VIN using a wide PCB trace.
1
2
3
VIN
SW
Switch output. Connect SW using a wide PCB trace.
System ground. GND is the reference ground of the regulated output voltage and requires
extra care during the PCB layout. Connect GND with copper traces and vias.
GND
Bootstrap. Connect a 1µF BST capacitor and a resistor between SW and BST to form a
floating supply across the high-side switch driver.
4
5
BST
EN
Enable. Drive EN high to enable the MP1477. For automatic start-up, connect EN to VIN
with a 100kΩ pull-up resistor.
Feedback. Connect FB to the tap of an external resistor divider from the output to GND to
set the output voltage. The frequency foldback comparator lowers the oscillator frequency
when the FB voltage drops below 600mV to prevent current-limit runaway during a short-
circuit fault.
6
FB
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
BLOCK DIAGRAM
VIN
Bias &
Voltage
Reference
Bootstrap
Regulator
BST
EN
1MΩ
VCC
Regulator
Main Switch
(NCH)
HS
Driver
On
Timer
Iss
SW
Logic
Control
VCC
PWM
FB
LS
Driver
Synchronous
Current
Modulator
Rectifier (NCH)
Current Sense
Amplifier
GND
Figure 1: Functional Block Diagram
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
shorter, and the HS-FET turns on more
OPERATION
frequently. The switching frequency increases
in turn. The output current reaches the critical
level when the current modulator time is zero
and can be determined with Equation (1):
The MP1477 is fully integrated, synchronous,
rectified, step-down, switch-mode converter.
Constant-on-time (COT) control is employed to
provide fast transient response and ease loop
stabilization. At the beginning of each cycle, the
high-side MOSFET (HS-FET) is turned on when
the FB voltage (VFB) drops below the reference
voltage (VREF). The HS-FET is turned on for a
fixed interval determined by the one-shot on-
timer. The on-timer is determined by both the
output voltage and input voltage to make the
switching frequency fairly constant over the
input voltage range.
(VIN VOUT) VOUT
2LFSW VIN
IOUT
(1)
The device reverts to pulse-width modulation
(PWM) mode once the output current exceeds
the critical level. Afterward, the switching
frequency remains fairly constant over the
output current range.
Enable (EN) Control
EN is a digital control pin that turns the
regulator on and off. Drive EN high to turn on
the regulator. Drive EN low to turn off the
regulator. An internal 1MΩ resistor from EN to
GND allows EN to be floated to shut down the
chip.
After the on period elapses, the HS-FET is
turned off until the next period. By repeating
operation this way, the converter regulates the
output voltage.
Continuous conduction mode (CCM) is when
the output current is high and the inductor
current is always above zero amps. The low-
side MOSFET (LS-FET) is turned on when the
HS-FET is off to minimize conduction loss.
There is a dead short between the input and
GND if both the HS-FET and LS-FET are
turned on at the same time. This is called a
shoot-through. To prevent shoot-through, a
dead time is generated internally between the
HS-FET off and LS-FET on period or the LS-
FET off and HS-FET on period.
EN is clamped internally using a 2.8V series
Zener diode (see Figure 2). Connecting the EN
input through a pull-up resistor to VIN limits the
EN input current to less than 100μA, preventing
damage to the Zener diode.
For example, when connecting 12V to VIN,
RPULLUP ≥ (12V - 2.8V) / (100kΩ + 35kΩ) = 68µA.
EN
35kΩ
1MΩ
EN
When the MP1477 works in pulse-frequency
modulation (PFM) mode during light-load
operation, the MP1477 reduces the switching
frequency automatically to maintain high
efficiency, and the inductor current drops
almost to zero. When the inductor current
reaches zero, the low-side driver goes into tri-
state (Hi-Z). Therefore, the output capacitors
discharge slowly to GND through R1 and R2.
When VFB drops below VREF, the HS-FET is
turned on. This operation improves device
efficiency greatly when the output current is low.
Logic
2.8V
GND
Figure 2: Zener Diode between EN and GND
Under-Voltage Lockout (UVLO)
Under-voltage lockout (UVLO) protects the chip
from operating at an insufficient supply voltage.
The MP1477 UVLO comparator monitors the
output voltage of the internal regulator (VCC).
The UVLO rising threshold is about 4V, while its
falling threshold is 3.67V consistently.
Internal Soft Start (SS)
Light-load operation is also called skip mode
because the HS-FET does not turn on as
frequently as it does during heavy-load
conditions. The frequency at which the HS-FET
turns on is a function of the output current. As
the output current increases, the current
modulator regulation time period becomes
Soft start (SS) prevents the converter output
voltage from overshooting during start-up.
When the chip starts up, the internal circuitry
generates a soft-start voltage (SS) that ramps
up from 0V to 1.2V. When SS is lower than
REF, SS overrides REF so the error amplifier
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
uses SS as the reference. When SS exceeds
Floating Driver and Bootstrap Charging
REF, the error amplifier uses REF as the
reference. The SS time is set to 2.5ms
internally.
An external bootstrap capacitor powers the
floating power MOSFET driver. This floating
driver has its own UVLO protection with a rising
threshold of 2.2V and a hysteresis of 150mV.
VIN regulates the bootstrap capacitor voltage
internally through D1, M1, C3, L1, and C2 (see
Figure 3). If VIN - VSW exceeds 3.3V, U2
regulates M1 to maintain a 3.3V BST voltage
across C3.
Over-Current Protection (OCP) and Short-
Circuit Protection (SCP)
The MP1477 has a valley current-limit control.
During the LS-FET on state, the inductor
current is monitored. When the sensed inductor
current reaches the valley current limit, the low-
side limit comparator turns over, and the
MP1477 enters over-current protection (OCP)
mode. The HS-FET waits until the valley current
limit disappears before turning on again.
Meanwhile, the output voltage drops until VFB is
below the under-voltage (UV) threshold
(typically 75% below the reference). Once UV is
triggered, the MP1477 enters hiccup mode to
restart the part periodically.
During OCP, the device tries to recover from
the over-current fault with hiccup mode. During
hiccup mode, the chip disables the output
power stage, discharges the soft start, and
attempts to soft start again automatically. If the
over-current condition still remains after the soft
start ends, the device repeats this operation
cycle until the over-current condition disappears
and the output rises back to the regulation level.
OCP is a non-latch protection.
Figure 3: Internal Bootstrap Charger
Start-Up and Shutdown Circuit
If both VIN and EN exceed their respective
thresholds, the chip starts up. The reference
block starts first, generating a stable reference
voltage and current, and then the internal
regulator is enabled. The regulator provides a
stable supply for the remaining circuits.
Three events can shut down the chip: EN low,
VIN low, and thermal shutdown. The shutdown
procedure starts by blocking the signaling path
to avoid any fault triggering. The internal supply
rail is then pulled down.
Pre-Bias Start-Up
The MP1477 has been designed for monotonic
start-up into pre-biased loads. If the output is
pre-biased to a certain voltage during start-up,
the BST voltage is refreshed and charged, and
the voltage on the soft start is charged as well.
If the BST voltage exceeds its rising threshold
voltage and the soft-start voltage exceeds the
sensed output voltage at FB, the MP1477 starts
working normally.
Thermal Shutdown
Thermal shutdown prevents the chip from
operating at exceedingly high temperatures.
When the silicon die temperature exceeds
150°C, the entire chip shuts down. When the
temperature falls below its lower threshold
(typically 130°C), the chip is enabled again.
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
the peak-to-peak ripple current in the inductor
APPLICATION INFORMATION
Setting the Output Voltage
to be between 30% to 60% of the maximum
output current and ensure that the peak
inductor current is below the maximum switch
current limit. The inductance value can be
calculated with Equation (3):
The external resistor divider is used to set the
output voltage. First, choose a value for R2. R2
should be chosen reasonably, since a small R2
value leads to considerable quiescent current
loss, but a large R2 value makes FB noise-
sensitive. R2 is recommended to be within 5 -
100kΩ. Typically, an R2 value between 5 -
30µA provides a good balance between system
stability and no-load loss. R1 can then be
determined with Equation (2):
VOUT
SW IL
VOUT
(3)
L
(1
)
F
V
IN
Where ∆IL is the peak-to-peak inductor ripple
current.
The inductor should not saturate under the
maximum inductor peak current. The peak
inductor current can be calculated with
Equation (4):
VOUT VREF
R1
R2
(2)
VREF
VOUT
VOUT
The feedback circuit is shown in Figure 4.
(4)
ILP IOUT
(1
)
2FSW L
V
VOUT
IN
MP1477
Selecting the Input Capacitor
The input current to the step-down converter is
discontinuous and therefore requires
R1
RT
FB
a
R2
capacitor to supply AC current to the step-down
converter while maintaining the DC input
voltage. For the best performance, place
ceramic capacitors as close to VIN as possible.
Capacitors with X5R and X7R ceramic
dielectrics are recommended because they are
fairly stable with temperature fluctuations.
Figure 4: Feedback Network
Table 1 lists the recommended resistor values
for common output voltages.
Table 1: Resistor Selection for Common Output
Voltages, COUT = 22µF*2 (9)
The capacitors must also have a ripple current
rating greater than the maximum input ripple
current of the converter. The input ripple current
can be estimated with Equation (5):
VOUT (V) R1 (kΩ) R2 (kΩ) RT (kΩ) L (μH)
5
40.2
40.2
40.2
40.2
40.2
40.2
20.5
7.68
13
19.1
32.4
45.3
82
75
75
3.3
2.2
2.2
1.5
1.5
1
3.3
2.5
1.8
1.5
1.2
1
100
110
147
147
249
VOUT
VOUT
(5)
ICIN IOUT
(1
)
V
V
IN
IN
The worst-case condition occurs at VIN = 2VOUT
shown in Equation (6):
,
84.5
1
NOTE:
9) For a detail design circuit, please refer to the Typical
Application Circuits on page 16 to page 18.
IOUT
ICIN
(6)
2
Selecting the Inductor
An inductor is necessary for supplying constant
current to the output load while being driven by
the switched input voltage. A larger-value
inductor results in less ripple current and a
lower output ripple voltage but also has a larger
physical footprint, higher series resistance, and
lower saturation current. A good rule for
determining the inductance value is to design
For simplification, choose an input capacitor
with an RMS current rating greater than half of
the maximum load current.
The input capacitance value determines the
input voltage ripple of the converter. If there is
an input voltage ripple requirement in the
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
system, choose an input capacitor that meets
the specification.
Selecting a larger output capacitor can also
achieve a better load transient response, but
the maximum output capacitor limitation should
be also considered in the design application. If
the output capacitor value is too high, the
output voltage cannot reach the design value
during the soft-start time and will fail to regulate.
The input voltage ripple can be estimated with
Equation (7):
IOUT
SW CIN
VOUT
VOUT
(7)
V
(1
)
IN
F
V
V
IN
IN
The maximum output capacitor value (Co_max
can be limited approximately with Equation (12):
)
The worst-case condition occurs at VIN = 2VOUT
shown in Equation (8):
,
(12)
CO_MAX (ILIM_ AVG IOUT )T / VOUT
ss
IOUT
4 FSW CIN
Selecting the Output Capacitor
1
(8)
V
IN
Where ILIM_AVG is the average start-up current
during the soft-start period, and Tss is the soft-
start time.
An output capacitor is required to maintain the
DC output voltage. Ceramic or POSCAP
capacitors are recommended. The output
voltage ripple can be estimated with Equation
(9):
PCB Layout Guidelines
Efficient layout of the switching power supplies
is critical for stable operation. A poor layout
design can result in poor line or load regulation
and stability issues. For best results, refer to
Figure 5 and follow the guidelines below.
VOUT
V
1
(9)
)
VOUT
(1 OUT )(RESR
FSW L
V
8FSW COUT
IN
1) Place the high-current paths (GND, VIN,
and SW) very close to the device with short,
direct, and wide traces.
In the case of ceramic capacitors, the
impedance at the switching frequency is
dominated by the capacitance. The output
voltage ripple is mainly caused by the
capacitance. For simplification, the output
voltage ripple can be estimated with Equation
(10):
2) Place the input capacitor as close to VIN
and GND as possible (recommended within
1mm).
3) Place the external feedback resistors next
to FB.
VOUT
VOUT
(10)
VOUT
(1
)
8F 2 LCOUT
V
4) Keep the switching node SW short and
away from the feedback network.
SW
IN
The output voltage ripple caused by the ESR is
very small. In the case of POSCAP capacitors,
the ESR dominates the impedance at the
switching frequency. For simplification, the
output ripple can be approximated with
Equation (11):
VOUT
V
(1 OUT )RESR
(11)
VOUT
FSW L
V
IN
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
Design Example
Table 2 shows a design example when ceramic
capacitors are applied.
Table 2: Design Example
VIN
VOUT
IOUT
12V
3.3V
3A
Detailed application schematics are shown in
Figure 6 through Figure 12. The typical
performance and waveforms are shown in the
Typical Performance Characteristics section.
For more devices applications, please refer to
the related evaluation board datasheet.
Top Layer
Bottom Layer
Figure 5: Recommended Layout
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MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
TYPICAL APPLICATION CIRCUITS
R4
10Ω
C1
NS
C1A
22µF
C1B
0.1µF
C3
1µF
MP1477
L1
3.3µH
5V/3A
C2A
C2
22µF
22µF
R5
100kΩ
15pF
40.2kΩ
75kΩ
R2
7.68kΩ
Figure 6: VIN = 12V, VOUT = 5V/3A
R4
10Ω
C1A
C1B
22µF
0.1µF
C3
1µF
MP1477
2.2µH
3.3V/3A
C2A
C2
22µF
22µF
R5
15pF
100kΩ
40.2kΩ
75kΩ
R2
13kΩ
Figure 7: VIN = 12V, VOUT = 3.3V/3A
R4
10Ω
C1A
22µF
C1B
0.1µF
C3
1µF
MP1477
L1
2.2µH
2.5V/3A
C2
C2A
22µH
22µH
R5
100kΩ
15pF
40.2kΩ
100kΩ
R2
19.1kΩ
Figure 8: VIN = 12V, VOUT = 2.5V/3A
MP1477 Rev. 1.0
9/12/2017
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2017 MPS. All Rights Reserved.
16
MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
TYPICAL APPLICATION CIRCUITS (continued)
R4
10Ω
C1A
C1B
22µF
0.1µF
C3
1µF
MP1477
L1
1.5µH
1.8V/3A
C2
C2A
22µH
22µH
R5
100kΩ
15pF
40.2kΩ
110kΩ
R2
32.4kΩ
Figure 9: VIN = 12V, VOUT = 1.8V/3A
R4
10Ω
C1A
22µF
C1B
0.1µF
C3
1µF
MP1477
1.5µH
1.5V/3A
C2
C2A
22µF
22µF
R5
100kΩ
15pF
40.2kΩ
147kΩ
R2
45.3kΩ
Figure 10: VIN = 12V, VOUT = 1.5V/3A
R4
10Ω
C1A
22µF
C1B
0.1µF
C3
1µF
MP1477
L1
1µH
1.2V/3A
C2
C2A
22µF
22µF
R5
100kΩ
15pF
40.2kΩ
147kΩ
R2
82kΩ
Figure 11: VIN = 12V, VOUT = 1.2V/3A
MP1477 Rev. 1.0
9/12/2017
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2017 MPS. All Rights Reserved.
17
MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
TYPICAL APPLICATION CIRCUITS (continued)
R4
10Ω
C1A
C1B
22µF
0.1µF
C3
1µF
MP1477
L1
1µH
1V/3A
C2
C2A
22µF
22µF
R5
100kΩ
15pF
20.5kΩ
249kΩ
R2
84.5kΩ
Figure 12: VIN = 12V, VOUT = 1V/3A
MP1477 Rev. 1.0
9/12/2017
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2017 MPS. All Rights Reserved.
18
MP1477 – SYNCHRONOUS, STEP-DOWN CONVERTER WITH INTERNAL MOSFETS
PACKAGE INFORMATION
SOT563 (1.6mmх1.6mm)
PIN 1 ID
BOTTOM VIEW
TOP VIEW
SIDE VIEW
FRONT VIEW
NOTE:
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSION OR GATE BURR.
3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH
OR PROTRUSION.
4) LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING)
SHALL BE 0.10 MILLIMETERS MAX.
5) DRAWING IS NOT TO SCALE.
RECOMMENDED LAND PATTERN
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.
MP1477 Rev. 1.0
9/12/2017
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2017 MPS. All Rights Reserved.
19
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