MP2459GJ-Z [MPS]
Switching Regulator, Current-mode, 1.5A, 580kHz Switching Freq-Max, PDSO6, TSOT-23, 6 PIN;
| 型号： | MP2459GJ-Z |
| 厂家： | 
MONOLITHIC POWER SYSTEMS |
| 描述： | Switching Regulator, Current-mode, 1.5A, 580kHz Switching Freq-Max, PDSO6, TSOT-23, 6 PIN 开关 光电二极管 输出元件 |
| 文件： | 总14页 (文件大小：916K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MP2459
0.5A, 55V, 480kHz
Step-Down Converter in a TSOT23-6
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP2459 is a monolithic, step-down, switch-
mode converter with a built-in power MOSFET.
It achieves a 0.5A peak-output current over a
wide input supply range with excellent load and
•
•
•
0.5A Peak Output Current
1Ω Internal Power MOSFET
Stable with Low-ESR Ceramic Output
Capacitors
Up to 90% Efficiency
0.1μA Shutdown Mode
Fixed 480kHz Frequency
Thermal Shutdown
Cycle-by-Cycle Over-Current Protection
Wide 4.5V-to-55V Operating Input Range
Output Adjustable from 0.81V to 0.95*VIN
Available in a TSOT23-6 Package
line
regulation.
Current-mode
operation
•
•
•
•
•
•
•
•
provides a fast transient response and eases
loop stabilization. Fault condition protections
include cycle-by-cycle current limiting and thermal
shutdown.
The MP2459 requires a minimal number of
readily-available external components. The
MP2459 is available in a TSOT23-6 package.
APPLICATIONS
•
•
•
•
•
Power Meters
Distributed Power Systems
Battery Chargers
Pre-Regulator for Linear Regulators
WLED Drivers
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
100
90
80
70
60
50
40
BST
VIN
IN
MP2459
U1
L1
GND
SW
FB
VOUT
GND
D1
EN
EN
30
0.0 0.1 0.2 0.3 0.4 0.5 0.6
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
1
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
ORDERING INFORMATION
Part Number*
Package
Top Marking
TSOT23-6
MP2459GJ
AEQ
* For Tape & Reel, add suffix –Z (eg. M2459GJ–Z);
PACKAGE REFERENCE
TOP VIEW
BST
GND
FB
1
2
3
6
5
4
SW
IN
EN
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance (4)
θJA θJC
Supply Voltage VIN ........................ −0.3V to 60V
TSOT23-6 ..............................220 ...110 °C/W
VSW ........................................−0.3V to VIN+0.3V
Notes:
VBS.......................................................VSW + 6V
All Other Pins................................ −0.3V to +6V
Continuous Power Dissipation (TA = +25°C) (2)
TSOT23-6..............................................0.568W
Junction Temperature..............................150°C
Lead Temperature ...................................260°C
Storage Temperature.............. −65°C to +150°C
Recommended Operating Conditions (3)
Supply Voltage VIN .......................... 4.5V to 55V
Output Voltage VOUT............... 0.81V to 0.95×VIN
Operating Junction Temp........−40°C to +125°C
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.
3) The device function is not guaranteed outside of the
recommended operating conditions.
4) Measured on JESD51-7, 4-layer PCB..
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
2
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
ELECTRICAL CHARACTERISTICS
VIN = 12V, TA = +25°C, unless otherwise noted.
Parameters
Symbol Condition
Min
Typ
Max
0.832
0.1
Units
V
Feedback Voltage
VFB
IFB
0.792
0.812
4.5V ≤ VIN ≤ 55V
Feedback Current
VFB = 0.85V
μA
Ω
Switch-On Resistance
Switch Leakage
RDS(ON)
1
ISW_LKG VEN = 0V, VSW = 0V
ILIM
fSW
fSW_F
1
μA
A
Current Limit
1.0
1.25
480
150
93.5
100
3.3
1.5
580
Oscillator Frequency
Foldback Frequency
Maximum Duty Cycle
Minimum ON-Time
VFB = 0.6V
VFB = 0V
380
kHz
kHz
%
DMAX
VFB = 0.6V
90
τON
ns
V
Under-Voltage Lockout Threshold, Rising
Under-Voltage Lockout Threshold, Falling
VUVLO_R
VUVLO_F
2.9
3.7
2.65
3.05
3.45
V
Under-Voltage Lockout Threshold,
Hysteresis
VUVLO_HYS
250
mV
EN Threshold, Rising
EN Threshold, Falling
EN Threshold, Hysteresis
VEN_R
VEN_F
1.35
1.17
180
3.1
V
V
VEN_HYS
mV
V
EN = 2V
EN Input Current
IEN
μA
VEN = 0V
0.1
Supply Current (Shutdown)
Supply Current (Quiescent)
Thermal Shutdown
IS
IQ
VEN = 0V
0.1
1.0
μA
mA
°C
VEN = 2V, VFB = 1V
0.73
165
20
0.85
TSD
Thermal Shutdown Hysteresis
TSD_HYS
°C
MP2459 Rev. 1.01
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6/19/2014
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© 2014 MPS. All Rights Reserved.
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
TYPICAL CHARACTERISTICS
VIN=12V, VOUT=5V, IOUT=0.5A, L=15μH, TA=25°C, unless otherwise noted.
80
60
40
20
0
180
120
60
80
60
40
20
0
180
120
60
1.3
1.1
0.9
0.7
0.5
0.3
0
0
-20
-40
-60
-80
-20
-40
-60
-60
-120
-60
-120
-180
-180 -80
10000 100000 1000000
100
1000
100
1000
10000 100000 1000000
5
15 25 35 45 55 65
Conduction EMI
Radiation EMI
80
70
60
50
40
30
20
60
55
50
45
40
35
30
25
20
15
EN 55022 Electric Field Strength
3 m QP
EN 55022 Voltage on Mains QP
EN 55022 Voltage on Mains AV
10
5
10
0
0
150k 300
8001M 2M 3M 5M 810M 20M 30M
30M 5060 80100M
200 300 400500 8001G
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
4
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
TYPICAL PERFORMANCE CHARACTERISTICS
VIN=12V, VOUT=5V, L=22μH, TA=25°C, unless otherwise noted.
Efficiency vs. Load Load Regulation
Line Regulation
I
=0.5A
OUT
100
90
80
70
60
50
40
30
2.0
1.6
2.0
1.6
1.2
0.8
1.2
0.8
0.4
0.4
0.0
0.0
-0.4
-0.8
-1.2
-1.6
-2.0
-0.4
-0.8
-1.2
-1.6
-2.0
0.0
0.2
0.4
0.6
0.8
1.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
LOAD CURRENT ( A )
6
16
26
36
46
56
LOAD CURRENT ( A )
INPUT VOLTAG ( V )
Load Regulation
V
=3.3V
OUT
2.0
1.6
100
90
80
70
60
50
40
30
2.0
1.6
1.2
1.2
0.8
0.8
0.4
0.4
0.0
0.0
-0.4
-0.8
-1.2
-1.6
-2.0
-0.4
-0.8
-1.2
-1.6
-2.0
6
16
26
36
46
56
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
LOAD CURRENT ( A )
0.0 0.2 0.4 0.6 0.8 1.0
LOAD CURRENT ( A )
INPUT VOLTAG ( V )
2.0
1.7
1.4
1.1
0.8
0.5
850
830
810
790
770
750
600
560
520
480
440
400
-40 -10 20 50 80 110 140
-40 -10 20 50 80 110 140
-40 -10 20 50 80 110 140
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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5
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=12V, VOUT=5V, L=22μH, TA=25°C, unless otherwise noted.
Steady State Steady State
Load Transient
V
=8V, I
=0.8A
I
=0.15A
I
=0.2A to 0.7A
OUT
IN OUT
OUT
V
V
V
IN
IN
IN
10V/div.
10V/div.
5V/div.
V
SW
10V/div.
V
V
SW
SW
V
OUT
10V/div.
5V/div.
200mV/div.
V
V
OUT
OUT
5V/div.
5V/div.
I
I
L
L
I
L
1A/div.
500mA/div.
500mA/div.
Steady State
Steady State
Load Transient
V
=6V, V
=3.3V, I
OUT
=0.1A
V
=60V, V
=3.3V, I
OUT
=0.9A
V
=3.3V, I =0.2A to 0.7A
OUT OUT
IN OUT
IN OUT
V
V
IN
IN
V
IN
10V/div.
5V/div.
50V/div.
V
SW
10V/div.
V
SW
V
SW
5V/div.
50V/div.
V
OUT
200mV/div.
V
V
OUT
OUT
2V/div.
2V/div.
I
I
L
I
L
L
200mA/div.
500mA/div.
1A/div.
Power Ramp Up
Power Ramp Down
Short Output
V
=60V, I
=0.5A
V
=60V, I
=0.5A
I
=0.65A
IN OUT
IN OUT
OUT
V
V
V
IN
IN
IN
50V/div.
50V/div.
10V/div.
V
SW
V
SW
V
SW
10V/div.
50V/div.
50V/div.
V
V
OUT
V
OUT
OUT
5V/div.
5V/div.
5V/div.
I
I
L
OUT
I
OUT
1A/div.
500mA/div.
500mA/div.
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
6
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=12V, VOUT=5V, L=22μH, TA=25°C, unless otherwise noted.
Enable On Enable Off
Short Output Recovery
I
=0.5A
OUT
I
=0.5A
I
=0.65A
OUT
OUT
V
V
V
IN
EN
EN
10V/div.
2V/div.
2V/div.
V
V
V
SW
SW
SW
10V/div.
10V/div.
10V/div.
V
V
V
OUT
OUT
OUT
5V/div.
5V/div.
5V/div.
I
I
I
L
L
L
1A/div.
500mA/div.
500mA/div.
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
7
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
PIN FUNCTIONS
Pin # Name Description
Bootstrap. Connect a capacitor between the SW and BS pins to form a floating supply across
the power switch driver. This capacitor drives the power switch’s gate above the supply voltage.
1
2
BST
Ground. Voltage reference for the regulated output voltage. Requires special layout
GND considerations. Isolate this node from the D1 to C1 ground path to prevent switching current
spikes from inducing.
Feedback. Sets the output voltage. Connect to the tap of an external resistor divider from the
3
FB
output to GND. The frequency foldback comparator lowers the oscillator frequency when the FB
voltage is below 250mV to prevent current-limit runaway during a short-circuit fault.
On/Off. Pull EN above 1.2V to turn the device ON. For automatic enable, connect to VIN using a
100kΩ resistor.
4
5
6
EN
IN
Supply Voltage. The MP2459 operates from a 4.5V-to-55V unregulated input. Requires C1 to
prevent large voltage spikes from appearing at the input.
SW Switch Output.
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
8
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
OPERATION
The MP2459 is a current mode buck regulator.
That is, the EA output voltage is proportional to
the peak inductor current.
If the sum of the Current Sense Amplifier output
and the Slope Compensation signal does not
exceed the EA output for a whole cycle, then
the falling edge of the CLK resets the Flip-Flop.
At the beginning of a cycle, M1 is off. The EA
output voltage is higher than the current sense
amplifier output, and the current comparator’s
output is low. The rising edge of the 480kHz
CLK signal sets the RS Flip-Flop. Its output
turns on M1 thus connecting the SW pin and
inductor to the input supply.
The output of the Error Amplifier integrates the
voltage difference between the feedback and
the 0.81V bandgap reference. The polarity is
such that lower than 0.81V FB pin voltage
increases the EA output voltage. Since the EA
output voltage is proportional to the peak
inductor current, an increase in its voltage also
increases current delivered to the output.
The increasing inductor current is sensed and
amplified by the Current Sense Amplifier. Ramp
compensation is summed to the Current Sense
Amplifier output and compared to the Error
Amplifier output by the PWM Comparator.
When the sum of the Current Sense Amplifier
output and the Slope Compensation signal
exceeds the EA output voltage, the RS Flip-
Flop is reset and M1 is turned off. The external
Schottky rectifier diode (D1) conducts the
inductor current.
Figure 1: Functional Block Diagram
MP2459 Rev. 1.01
6/19/2014
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MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
APPLICATION INFORMATION
Setting Output Voltage
Selecting the Inductor
The external resistor divider sets the output
voltage (see the Typical Application schematic).
Table 1 lists resistors for common output
voltages. The feedback resistor (R2) also sets
the feedback loop bandwidth with the internal
compensation capacitor (see Figure 1). R1 is:
Use an inductor with a DC current rating at
least 25% percent higher than the maximum
load current for most applications. For best
efficiency, the inductor’s DC resistance should
be less than 200mꢀ. Refer to Table 2 for
suggested surface-mount inductors.
R2
VOUT
R1=
−1
0.812V
Table 1: Resistor Selection for Common
Output Voltages
VOUT (V)
1.8
R1 (kΩ)
102 (1%)
59 (1%)
R2 (kΩ)
124 (1%)
124 (1%)
124 (1%)
124 (1%)
2.5
3.3
40.2 (1%)
23.7 (1%)
5
Table 2: Inductor Selection Guide
Inductance
Max DCR
Current Rating
(A)
Part Number
Dimensions L x W x H (mm3)
(µH)
(ꢀ)
Wurth
744042100
744052150
10
15
22
0.15
0.19
0.12
1.3
0.95
1.15
4.8x4.8x1.8
5.8x5.8x1.8
5.8x5.8x2.8
744053220
ABC
SH4018100YL
SH4028150YL
SH5028220YL
TDK
10
15
22
0.15
0.15
0.12
1.3
1.03
1.15
4.8x4.8x1.8
4.8x4.8x2.8
5.8x5.8x2.8
VLCF5020T-100MR87
VLCF5024T-150MR71-2
VLCF5028T-220MR71-2
Coilcraft
10
15
22
0.182
0.152
0.14
1.56
1.66
1.66
5x5x2.0
5x5x2.4
5x5x2.8
LPS5030-103MRC
LPS5030-153MRC
LPS5030-223MRC
10
15
22
0.127
0.16
0.19
1.5
1.4
1.25
5x5x3
5x5x3
5x5x3
MP2459 Rev. 1.01
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6/19/2014
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MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
For most designs, the required inductance
value can be derived from the following
equation.
3) Ensure all feedback connections are short
and direct. Place the feedback resistors
and compensation components as close to
the chip as possible.
VOUT × (VIN − VOUT
VIN × ΔIL × fSW
)
L =
4) Route SW away from sensitive analog
areas such as FB.
Where ΔIL is the inductor ripple current.
5) Connect IN, SW, and especially GND to
large copper areas to cool the chip for
improved thermal performance and long-
term reliability. For single layer PCBs, avoid
soldering the exposed pad
Choose the inductor ripple current to be 30% of
the maximum load current. The maximum
inductor peak current is:
ΔIL
IL(MAX) = ILOAD
+
2
.
Under light-load conditions (below 100mA), use
a larger inductance to improve efficiency.
Selecting the Input Capacitor
The input capacitor reduces the surge current
drawn from the input supply and the switching
noise from the device. The input capacitor
impedance at the switching frequency should be
less than the input source impedance to prevent
high-frequency-switching current from passing
through the input. Use ceramic capacitors with
X5R or X7R dielectrics for their low ESRs and
small temperature coefficients. For most
applications, a 4.7µF capacitor will sufficient.
Selecting the Output Capacitor
The output capacitor keeps the output voltage
ripple small and ensures feedback loop stability.
The output capacitor impedance should be low
at the switching frequency. Use ceramic
capacitors with X5R or X7R dielectrics for their
low ESR characteristics. For most applications,
a 22µF ceramic capacitor will sufficient.
Figure 2: PCB Layout
PCB Layout Guide
PCB layout is very important to stability. Please
follow these guidelines and use Figure 2 as
reference.
1) Keep the path of switching current short
and minimize the loop area formed by the
input capacitor, high-side MOSFET, and
Schottky diode.
2) Keep the connection from the power
ground→Schottky diode→SW pin as short
and wide as possible.
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
11
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
External Bootstrap Diode
An external bootstrap diode may enhance
regulator efficiency under the following
conditions:
MP2459
z
z
VOUT=5V or 3.3V; and
VOUT
Figure 3: Optional Bootstrap Diode for Enhanced
Efficiency
High duty cycle: D=
>65%
VIN
In these cases, add an external BST diode from
the output of the voltage regulator to the BST
pin, as shown in Figure 3.
The recommended external BST diode is
IN4148, and the BST capacitor is 0.1µF-1µF.
MP2459 Rev. 1.01
6/19/2014
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© 2014 MPS. All Rights Reserved.
12
MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
TYPICAL APPLICATION CIRCUIT
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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MP2459 – 0.5A, 55V, 480kHz, STEP-DOWN CONVERTER IN A TSOT23-6
PACKAGE INFORMATION
TSOT23-6
0.95
BSC
0.60
TYP
2.80
3.00
6
4
1.20
TYP
See Note 7
EXAMPLE
TOP MARK
1.50
1.70
2.60
3.00
2.60
TYP
AAAA
PIN 1
1
3
TOP VIEW
RECOMMENDED LAND PATTERN
0.84
0.90
1.00 MAX
0.09
0.20
SEATING PLANE
0.30
0.50
0.00
0.10
0.95 BSC
SEE DETAIL "A"
SIDE VIEW
FRONT VIEW
NOTE:
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSION OR GATE BURR.
GAUGE PLANE
0.25 BSC
3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH
OR PROTRUSION.
4) LEAD COPLANARITY(BOTTOM OF LEADS AFTER FORMING
SHALL BE0.10 MILLIMETERS MAX.
)
0.30
0.50
0o-8o
5) DRAWING CONFORMS TO JEDEC MO-193, VARIATION AB.
6) DRAWING IS NOT TO SCALE.
7) PIN 1 IS LOWER LEFT PIN WHEN READING TOP MARK FROM
LEFT TO RIGHT, (SEE EXAMPLE TOP MARK)
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.
MP2459 Rev. 1.01
6/19/2014
www.MonolithicPower.com
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© 2014 MPS. All Rights Reserved.
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