MP24971DN [MPS]
1.5A, 50V, 100kHz, 5V Fixed Output Step- Down Converter with Programmable Current Limit and Output Line-Drop Compensation;
| 型号： | MP24971DN |
| 厂家： | 
MONOLITHIC POWER SYSTEMS |
| 描述： | 1.5A, 50V, 100kHz, 5V Fixed Output Step- Down Converter with Programmable Current Limit and Output Line-Drop Compensation |
| 文件： | 总14页 (文件大小：420K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MP24971
1.5A, 50V, 100kHz, 5V Fixed Output Step-
Down Converter with Programmable Current
Limit and Output Line-Drop Compensation
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP24971 is a monolithic, step-down,
switch-mode converter with a programmable
output-current limit. It has a fixed 5V/1.5A
continuous output over a wide input supply
range, and has excellent load and line
regulation. It has an internal 2ms-to-4ms soft-
start that prevents inrush current at start-up,
and compensates for output line drop.
Wide 8V-to-50V Operating Input Range
Output Over-Voltage Protection
5V Fixed Output
0.4Ω Internal Power MOSFET
Internal 4ms Soft-Start
Stable with Low-ESR Ceramic Output
Capacitors
Fixed 100kHz Frequency
Low EMI Signature
MP24971 achieves a low EMI signature with
well-controlled switching edges.
Thermal Shutdown
Output Line-Drop Compensation
Hiccup Circuit Limit and Short Circuit
Protection
It has fault-condition protections including
hiccup-mode current limit protection, short-
circuit
protection,
output
over-voltage
Available in SOIC8 and SOIC8E Package
protection, and thermal shutdown.
APPLICATIONS
The MP24971 requires a minimal number of
readily-available standard external components,
and is available in SOIC8 and SOIC8E
packages.
USB Power Supplies
Automotive Power Adapters
Power Supplies for Linear Chargers
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.
TYPICAL APPLICATION
Efficiency vs.
R1
0O
Output Current
V
=5V
OUT
L1
33µH
95
90
85
80
75
70
65
60
55
C4
0.1µF
C9
C8
C7
0.1µF
RSENSE
66mO
100µF 22µF
V
=12V
IN
C2
BST
SW
VOUT
+
2.2µF
VIN
C10
0.1µ F
VIN
Diode
C1
220µF
C3
0.1µF
V
=24V
=50V
VOC
IN
GND
R2
402kO
MP24971
ISP
ISN
C5
R3
1kO
GND
V
IN
10nF
VOS
C6
R4
1kO
R5
10nF
0O
0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5
OUTPUT CURRENT (A)
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
1
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
ORDERING INFORMATION
Part Number
MP24971DS*
MP24971DN**
Package
SOIC8
SOIC8E
Top Marking
MP24971
MP24971
Operating Temperature (TJ)
-40C to +125C
-40C to +125C
* For Tape & Reel, add suffix –Z (eg. MP24971DS–Z);
For RoHS, compliant packaging, add suffix –LF (eg. MP24971DS–LF–Z).
** For Tape & Reel, add suffix –Z (eg. MP24971DN–Z);
For RoHS, compliant packaging, add suffix –LF (eg. MP24971DN–LF–Z).
PACKAGE REFERENCE
SOIC8
SOIC8E
Recommended Operating Conditions (3)
Input Voltage VIN................................. 8V to 50V
Maximum Junction Temp. (TJ) ................ 125°C
ABSOLUTE MAXIMUM RATINGS (1)
Input Voltage VIN .......................................... 60V
VISN, VISP, VVOS........................................0V to 8V
Thermal Resistance (4)
SOIC8.....................................90...... 45... °C/W
θJA
θJC
|VISN -VISP| ...........................................0V to 0.4V
V
V
SW..................................... -0.3V to (VIN + 0.3V)
BST ................................................... VSW + 6.5V
SOIC8E ..................................50...... 10... °C/W
All Other Pins...............................-0.3V to +6.5V
Junction Temperature...............................150°C
Lead Temperature ....................................260°C
Storage Temperature............... -65°C to +150°C
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.
(2)
Continuous Power Dissipation (TA = 25°C)
SOIC8...................................................... 1.38W
SOIC8E...................................................... 2.5W
ESD Susceptibility
HBM (Human Body Mode).......................... 2kV
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
2
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
ELECTRICAL CHARACTERISTICS
VIN = 12V, TA = 25°C, unless otherwise noted.
Parameters
Symbol Condition
Min
Typ
Max
Units
Output Voltage
VOUT
VOVP
4.85
5
5.15
V
8V VIN 50V, RSENSE=0Ω
Output Over-Voltage
Protection
5.69
6
6.2
V
Switch-On Resistance
Switch Leakage
Current Limit
RDS(ON)
0.4
0.1
4.4
0.5
1(5)
5.2
Ω
μA
A
VISN = 6.5V, VSW = 0V
3.5
70
Oscillator Frequency
Bootstrap Voltage
Minimum On Time
SW Rising Edge
SW Falling Edge
fSW
VBST - VSW
tON
100
4
140
kHz
V
50
100
50
85
250
100
150
ns
ns
ns
tRISE
tFALL
Under-Voltage Lockout Threshold
Rising
2.8
3.5
4.2
V
Under-Voltage Lockout Threshold
Hysteresis
200
200
mV
VISP-VISN=50mV
VISP-VISN=100mV
330
450
Load-Line Compensation
Gain
VVOC
mV
500
90
620
100
-0.5
1.2
700
110
+1
Current Sense Voltage
VISP-VISN VISN=5V
mV
μA
Input Bias Current (ISN, ISP)
Supply Current (Quiescent)
IBIAS (ISN,ISP) VISP=VISN=5V
-1
VISN = VVOS = 5.5V
1.5
mA
Thermal Shutdown
150
°C
Note:
5) Guaranteed by design.
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
3
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
PIN FUNCTIONS
Package
Pin #
Name Description
Supply Voltage. Operates from an unregulated 8V-to-50V input. Requires decoupling
capacitor(s)—CIN—to limit voltage spikes. Drain of the internal power MOSFET; supplies
power to the whole chip.
1
VIN
Ground. Voltage reference of the regulated output voltage. GND node should be placed
outside of the diode-to-CIN ground path to prevent switching current spikes from inducing
voltage noise into the part. Connect exposed pad to GND plane for optimal thermal
performance.
GND
Exposed
Pad
2
3
4
VOS
VOC
Output Voltage Sense. Connect directly to the output.
Output Line Drop Compensator. Connect to GND through a resistor to compensate for the
output voltage drop.
Negative Current Sense Input. Used for limiting load current and for over-voltage
protection. Native 6V over-voltage protection threshold.
5
6
ISN
ISP
Positive Current Sense Input. Used for load current limiting.
Bootstrap. Requires a capacitor to drive the power MOSFET gate above the supply
voltage. Connected capacitor between SW and BST pins to form a floating supply across
the power MOSFET driver. An on-chip regulator charges the external bootstrap capacitor.
If the on-chip regulator is not powerful enough, add a diode from VIN or VOUT to charge the
external boot-strap capacitor.
7
8
BST
SW
Switch Output. Output power supply.
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
4
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
TYPICAL CHARACTERISTICS
I
vs.
Current Limit vs.
Temperature
V
vs. Temperature
VOS
BIAS(ISP,ISN)
Temperature
V
=V =5V
ISP ISN
5.4
5.3
5.2
5.1
5
-0.45
-0.5
4.96
4.9575
4.955
4.9525
4.95
-0.55
-0.6
4.9
4.8
4.7
4.6
4.5
4.4
-0.65
-0.7
4.9475
4.945
4.9425
4.94
-0.75
-0.8
-0.85
-50 -20
10
40 70 100 130
-50 -20
10 40 70 100 130
-50 -20 10 40 70 100 130
Frequency vs. Temperature
V
OVP
vs. Temperature
V
vs. Temperature
VOC
V
-V =100mV
ISP ISN
5.96
5.95
5.94
5.93
5.92
5.91
5.9
640
110
109
108
107
106
105
104
103
102
101
100
635
630
625
620
615
-50 -20
10
40 70 100 130
-50 -20
10
40
70 100 130
-50 -20
10
40
70 100 130
V
vs. Temperature
Quiescent Current vs.
Temperature
V
-V vs. Temperature
ISP ISN
BST
V
ISN=5V
4.1
4.05
4
1220
1210
1200
1190
1180
1170
1160
1150
1140
1130
105
104.5
104
103.5
103
3.95
3.9
102.5
102
101.5
101
3.85
3.8
100.5
100
-50 -20
10
40
70 100 130
-50 -20
10
40
70 100 130
-50 -20
10
40
70 100 130
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
5
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CHARACTERISTICS
C1=220μF, C2=2.2μF, C8=22μF, C9=100μF, L=33μH, RSENSE=66mΩ, TA=25°C, unless otherwise
noted.
Output Line Drop
Compensation
Loop Gain with
Phase Margin
Efficiency vs.
Output Current
V
=12V, V
=5V, I =1.5A
OUT
V
=5V
IN OUT
OUT
Resistor Load
4.96
4.95
4.94
4.93
4.92
4.91
4.9
200
160
120
80
50
40
95
90
85
80
75
70
65
60
55
V
=12V
IN
V
=12V
IN
30
V
=24V
IN
20
40
V
=24V
=50V
10
IN
V
=50V
IN
0
0
-40
-80
-120
-160
-200
-10
-20
-30
-40
-50
V
IN
0
0.2 0.4 0.6 0.8
(A)
1 1.2 1.4
0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5
(A)
0.1
1
10
100
1000
I
I
FREQUENCY(kHz)
OUT
OUT
Load Regulation
Connect ISP, ISN to GND
EMI Radiation
V
=12V, V
=5V, I =1.5A
OUT
IN OUT
Resistor Load
90
80
70
60
50
40
30
20
10
0
4.96
4.955
4.95
V
=12V
V
=24V
IN
IN
EN55022
4.945
4.94
V
=50V
IN
4.935
-10
4.93
0
0.2 0.4 0.6 0.8
1
1.2 1.4 1.6
30
100
1000
I
(A)
FREQUENCY(MHz)
OUT
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
6
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
C1=220μF, C2=2.2μF, C8=22μF, C9=100μF, L=33μH, RSENSE=66mΩ, TA=25°C，unless otherwise
noted.
Steady State
IN OUT
Steady State
IN OUT
Power Ramp Up
IN OUT
V
=12V, V
=5V, I
OUT
=1.5A E-Load
V
=50V, V
=5V, I
=1.5A E-Load
V
=12V, V
=5V, I =1.5A
OUT
OUT
Resistor Load
SW
10V/div
SW
50V/div
/AC
1V/div
V
IN
10V/div
V
/AC
IN
V
IN
500mV/div
/AC
SW
10V/div
V
OUT
V
/AC
50mV/div
OUT
20mV/div
V
OUT
5V/div
I
I
L
L
I
OUT
2A/div
2A/div
2A/div
Power Ramp Down
IN OUT
Short Circuit Enter
Short Circuit Steady
IN OUT
V
=12V, V
=5V, I
OUT
=1.5A
V
=12V, V
=5V, I
=0.5A
V
=12V, V =5V
IN OUT
OUT
Resistor Load
SW
10V/div
V
IN
SW
10V/div
10V/div
SW
10V/div
V
OUT
5V/div
V
OUT
500mV/div
V
OUT
5V/div
I
L
I
OUT
2A/div
I
OUT
2A/div
2A/div
Short Circuit Recovery
IN OUT
Load Transient Response
Over Voltage Protection
V
=12V, V
=5V, I
OUT
=0.5A
V
=12V, V
=5V, I
=0.3A-1.5A
V
=12V, V
=5V, I
=1.5A
IN OUT
OUT
IN OUT
OUT
Slew Rate=6.4mA/
s
Add an 6V External Power to ISN
V
V
OUT
200mV/div
SW
10V/div
ISN
5V/div
V
SW
OUT
5V/div
10V/div
V
OUT
5V/div
I
I
OUT
I
OUT
OUT
1A/div
2A/div
2A/div
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
7
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
FUNCTIONAL BLOCK DIAGRAM
VIN
CURRENT SENSE
AMPLIFIER
GND
Σ
63mO
REGULATOR
REFERENCE
BST
SW
RAMP
NMOSFET
DRIVER
REGULATOR
OSCILLATOR
RSENSE OUT
CLK
S
R
IN
Q
PWM
COMPARATOR
6.2uA
200mV
JFET
600mV
Hiccup
Current Limit
ISP
ISN
RS1
RS2
X6
VOS
1.23V
OVP
COMPARATOR
10000kO
RTOP
R1
300kO
C2
1704kO
50pF
10pF
JFET
C1
1pF
SS Circuit
VOC
ERROR
AMPLIFIER
800mV
RBOT
57.14kO
RC
Figure 1—Function Block Diagram
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
8
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
OPERATION
Main Control Loop
threshold, the current limit loop will turn off the
high-side MOSFET immediately. The internal
The MP24971 is a current-mode buck regulator
where the output voltage of the error amplifier
(EA) is proportional to the peak inductor
current.
soft-start circuit resets after the VOS voltage
drops below 1.9V and VCOMP rises above 3V; at
this point, the high side switch turns on and
MP24971 restarts with a full soft start. This
hiccup process repeats until the device stops
detecting a fault.
When a cycle starts, SW is disconnected and
the EA output voltage is higher than the current
sense amplifier (CSA) output. The rising edge
of the 100kHz CLK signal sets the RS flip-flop,
which connects SW and the inductor to the
input supply.
The current limit value can be lowered by an
internal current source and external resistors
connected to ISN and ISP pins when the output
voltage drops below 200mV. This feature can
greatly reduce the average short circuit current.
The CSA amplifies the rising inductor current.
The PWM comparator (PWMCOMP) compares
sum of the CSA output and the ramp
compensation (positive input) against the EA
output (negative input). When the positive
PWMCOMP input exceeds the negative PWMCOMP
input, the RS flip-flop resets and the MP24971
reverts to its initial SW off state: Otherwise, the
falling edge of the CLK resets the flip-flop.
Output Over-Voltage Protection
The MP24971 has output over-voltage
protection to prevent the output voltage from
rising above a threshold of 6V—such as if the
output sense is left open—and prevents any
voltage damage to the circuit load. If the output
voltage—as sensed by the ISN pin—rises
above 6V, the high-side MOSFET will turn off
immediately and part will be lathed off after a
timer delay.
The EA amplifies the voltage difference
between VOUT (connected through the VOS pin)
and the 800mV reference: Because VOUT
connects to the negative input of the EA, when
VOUT drops below 5V, the EA output increases.
Since the EA output voltage is proportional to
the peak inductor current, an increase in
inductor voltage increases current delivered to
the output. An external Schottky Diode
dissipates the inductor current when SW is off.
Output-Line–Drop Compensation
MP24971 is capable of compensating an output
voltage drop—such as high impedance caused
by a very long trace—to keep a constant 5V
load-side voltage. Compensation feedback
comes from the VOS pin and through the RTOP
resistor. Program the load line compensation
gain using a resistor connected to VOC pin,
selected based on RSENSE and RTRACE (Figure 2)
values.
Hiccup-Mode Current Limit Protection
The ISP and ISN pins sense the output current
information for current limit protection. Once the
VSENSE exceeds the 100mV voltage limit
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
9
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
APPLICATION INFORMATION
Setting the Output Line Drop Compensation
Long traces to the circuit load induce a voltage
drop between VOUT and VLOAD. that can be
described as:
VOUT
RSENSE
RTRACE1
SW
RTRACE2
VLOAD
RTRACE
ISP
ISN
VDROP IOUT RTRACE
(1)
Load
X 6
Where RTRACE RTRACE1 RTRACE2 as seen in
Figure 2. Then, the VLOAD is:
VOS
VOC
RTOP
VLOAD VOUT IOUT RTRACE
(2)
VFB
RC
Supplying an accurate and consistent load
voltage over current-dependant trace resistance
necessitates line-drop compeonsation.
RBOT
MP24971 offers a compensation method that
adjusts the FB voltage slightly according to the
load current.
Hiccup
Current Limit
600mV
10000kO
10pF
The relation between VOUT and VFB can be
described by:
0.8V
ERROR
AMPLIFIER
VOUT VFB
VFB IOUT RSENSE 6
(3)
Internal Block
RTOP
RBOT
RC
Figure 2—Output Line Drop Compensation
Where, VFB is 0.8V.
Then, the VOUT can be calculated by:
Selecting the Inductor
For most applications, use a 10µH to 47µH
inductor with a DC current rating of at least
125% of the maximum load current. For best
efficiency, select an inductor with a DC
resistance less than 200mꢀ. For most designs,
the inductance value can be determined by.
IOUT RSENSE 6RTOP
(4)
(5)
VOUT 5V
RC
The VLOAD is determined by:
IOUT RSENSE 6RTOP
VLOAD 5V
RC
VOUT (VIN VOUT
VIN IL fOSC
)
IOUT RTRACE
L
(8)
To maintain a VLOAD that is not variable with load
current, balance the equation below:
Where ΔIL is the inductor ripple current.
Choose inductor current ripple to equal
approximately 30% of the maximum load
current, 1.5A. Then maximum inductor peak
current is:
IOUT RSENSE 6RTOP
IOUT RTRACE (6)
RC
Where RTOP is 300kΩ. Simplifying, we find that
RC comes out to:
IL
IL(MAX) ILOAD
RSENSE 6300k
2
(9)
RC
(7)
Under light-load conditions below 100mA, use a
larger inductor to improve efficiency.
RTRACE
Where RSENSE is known and RTRACE can be
tested or evaluated
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
10
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
Selecting the Input Capacitor
The current limit at output short condition is:
An input capacitor reduces the surge current
drawn from the input and any switching noise
from the device. Chose a capacitor with a
switching-frequency impedance less than the
input source impedance. Use ceramic
capacitors with X5R or X7R dielectrics for their
low ESR and small temperature coefficients. A
capacitor value of 4.7µF will suffice for most
applications.
100mV 6.2A RS1
IOUT _ SL
RSENSE
(13)
SW
Ra
RS1
Ca
ISP
ISN
RS2
Selecting the Output Capacitor
An output capacitor limits the output voltage
and ensures regulator loop stability. Chose an
output capacitor with a low impedance at the
switching frequency; preferably ceramic with
X5R or X7R dielectrics.
(a)
RSENSE
SW
Setting the Current Limit
The inductor’s DC resistance (DCR) sets the
hiccup current limit. Use a sense resistor with
high precision and accuracy for accurate sense
measurement.
RS1
ISP
ISN
RS2
In Figure 3a, the output current limit is:
100mV
(b)
IOUT _L
DCR
Where Ra and Ca form a low pass filter.
(10)
Figure 3—Current Sensing Methods
In Figure 3b, the output current limit is set as:
100mV
RSENSE
SW
IOUT _L
RSENSE
(11)
Programming the Short Circuit Current Limit
The hiccup current limit at output short
condition can be programmed to be lower by
external resisters (RS1, RS2, RS1=RS2), as shown
in figure 4.
ISP
RS1
ISN
RS2
When output voltage is lower than 200mV, the
current limit is described by:
6.2uA
200mV
IOUT _ SL RSENSE 6.2A RS1 100mV
(12)
Figure 4—Short Circuit Current Limit
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
11
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
5V
PC Board Layout
The high frequency paths for VIN, SW and
GND should be routed very close to the device
with short, direct, and wide traces. Place the
input capacitor as close as possible to the IN
and GND pins. Place the external feedback
resistors next to the FB pin. Keep the switching
node SW short and away from the feedback
network.
BS
MP24971
10nF
SW
Figure 5—External Bootstrap Diode
Design Example
External Bootstrap Diode
An external bootstrap diode helps improve the
efficiency of the regulator when the system has
a 5V fixed input or the power supply generates
a 5V output. The bootstrap diode can be low-
cost, such as an IN4148 or a BAT54.
Below is a sample design that follows the
application guidelines for the specifications
below:
Parameter
Symbol Value Units
Input Voltage
Output Voltage
Output Current Limit
Output OVP
VIN
8 - 50
5
1.5
6
V
V
A
V
Add a diode for high duty-cycle operation (when
VOUT
IOUT-L
VOVP
VOUT
>65%).
V
IN
Figure
schematic.
Characteristics
6
shows the detailed application
The Typical Performance
performance and circuit
waveforms are all based on this design. For
additional implentations, consult the Evaluation
Board Data Sheets.
D1
NS
Vcc
C4
R1
0.1µF
0O
L1
C9
C8
C7
0.1µF
R6
100mO
33µH
100µF 22µF
VOUT
C2
BST
SW
2.2µF
+
C11
0.1µF
VIN
VIN
R7
165O
D2
B360A
C1
100µF
C3
0.1µF
R5
100O
VOC
GND
C10
NS
R2
402kO
MP24971
GND
ISP
ISN
C5
10nF
R3
1kO
GND
VOS
C6
R4
R8
0O
10nF
1kO
Figure 6—Detailed Sample Application Schematic
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
12
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
PACKAGE INFORMATION
SOIC8
0.189(4.80)
0.197(5.00)
0.050(1.27)
0.024(0.61)
0.063(1.60)
8
5
0.150(3.80)
0.157(4.00)
0.228(5.80)
0.244(6.20)
0.213(5.40)
PIN 1 ID
1
4
TOP VIEW
RECOMMENDED LAND PATTERN
0.053(1.35)
0.069(1.75)
SEATING PLANE
0.004(0.10)
0.010(0.25)
0.0075(0.19)
0.0098(0.25)
0.013(0.33)
0.020(0.51)
SEE DETAIL "A"
0.050(1.27)
BSC
SIDE VIEW
FRONT VIEW
0.010(0.25)
0.020(0.50)
x 45o
NOTE:
1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN
BRACKET IS IN MILLIMETERS.
GAUGE PLANE
0.010(0.25) BSC
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSIONS OR GATE BURRS.
3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH
OR PROTRUSIONS.
4) LEAD COPLANARITY(BOTTOM OF LEADS AFTER FORMING)
SHALL BE0.004" INCHES MAX.
0.016(0.41)
0.050(1.27)
0o-8o
5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION AA.
6) DRAWING IS NOT TO SCALE.
DETAIL "A"
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
13
MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
PACKAGE INFORMATION
SOIC8E (EXPOSED PAD)
0.189(4.80)
0.197(5.00)
0.124(3.15)
0.136(3.45)
8
5
0.150(3.80)
0.157(4.00)
0.228(5.80)
0.244(6.20)
0.089(2.26)
0.101(2.56)
PIN 1 ID
1
4
TOP VIEW
BOTTOM VIEW
SEE DETAIL "A"
0.051(1.30)
0.067(1.70)
SEATING PLANE
0.000(0.00)
0.006(0.15)
0.0075(0.19)
0.0098(0.25)
0.013(0.33)
0.020(0.51)
SIDE VIEW
0.050(1.27)
BSC
FRONT VIEW
0.010(0.25)
0.020(0.50)
x 45o
GAUGE PLANE
0.010(0.25) BSC
0.024(0.61)
0.063(1.60)
0.050(1.27)
0.016(0.41)
0.050(1.27)
0o-8o
DETAIL "A"
0.103(2.62)
0.213(5.40)
NOTE:
1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN
BRACKET IS IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSIONS OR GATE BURRS.
3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH
OR PROTRUSIONS.
0.138(3.51)
4) LEAD COPLANARITY(BOTTOM OF LEADS AFTER FORMING)
SHALL BE0.004" INCHES MAX.
5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION BA.
6) DRAWING IS NOT TO SCALE.
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications.
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.
MP24971 Rev. 1.01
1/6/2012
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2012 MPS. All Rights Reserved.
14
相关型号：
MP24971DS
1.5A, 50V, 100kHz, 5V Fixed Output Step- Down Converter with Programmable Current Limit and Output Line-Drop Compensation
MPS
MP2498DV-LF
Switching Regulator, Current-mode, 4.7A, 1300kHz Switching Freq-Max, 4 X 5 MM, ROHS COMPLIANT, MO-220VHGD-3, QFN-28
MPS
MP2498DV-LF-Z
Switching Regulator, Current-mode, 4.7A, 1300kHz Switching Freq-Max, 4 X 5 MM, ROHS COMPLIANT, MO-220VHGD-3, QFN-28
MPS
MP2498DV-Z
Switching Regulator, Current-mode, 4.7A, 1300kHz Switching Freq-Max, 4 X 5 MM, MO-220VHGD-3, QFN-28
MPS
MP2499
Integrated 100V Load Dump Protection 2A, 100kHz Step Down Regulator with Programmable Output Current
MPS
©2020 ICPDF网 联系我们和版权申明