M3TEK
Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
DESCRIPTION
FEATURES
The MT5031A devices provide a power supply
solution for products powered by either a one-cell
Li-Ion or Li-polymer battery. The converter
generates a stable output voltage that is either
adjusted by an external resistor divider or fixed
internally on the chip. It provides high efficient
power conversion and is capable of delivering
output currents up to 1.5A at 5V at a supply
voltage down to 3V. The maximum peak current
in the step-up switch is limited to a value of 3.5A.
The MT5031A operates at 800kHz switching
frequency and enters pulse-skip-mode (PSM)
operation at light load currents to maintain high
efficiency over the entire load current range.
During shutdown, the load is completely
disconnected from the battery.
L1
1.5uH
2.9V to
5V Input
C1
10uF
Synchronous Step-up Converter with 1.5A
Output Current From 3V Input
Wide VIN Range From 2.9V to 5.5V
Input Under-voltage Lockout Protection
Fixed and Adjustable Output Voltage
Built-in Output Over-voltage Protection
Light-Load Pulse Skip Mode
Load Disconnect During Shutdown
Output Short Circuit Protection
Thermal Shutdown Protection
Available in a SOP8 Packages
APPLICATIONS
SW
Power Bank
USB Charging Port (5V)
DC/DC Micro Modules
VOUT
VIN
EN
R3
MT5031A
C2
10uF
C3
10uF
5V output
up to 1.5A
FB
R4
GND
PGND
Figure 1. MT5031A Typical Application Circuit
Rev. 0.1
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M3TEK
Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
Ordering Information
Part No.
Marking
Temp. Range
Package
MT5031ANSRR
MT5031A
-40°C ~+85°C
SOP 8L 150 mils
Remark
xxxxx
Pin Configuration
MT5031A TOP View
Pin Description
NAME
PIN NO.
DESCRIPTION
VIN
1
Input Supply voltage
EN
GND
2
3
Enable input. (1/VIN enabled, 0/GND disabled)
Analog Ground pin. Connect GND to PGND under EP.
FB
4
Voltage feedback of adjustable versions.
VOUT
5
Step-up convert output
SW
PGND
Rev. 0.1
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6, 7
8
Step-up and rectifying switch input
Power Ground pin.
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Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
Absolute Maximum Rating (1)
Supply Voltage (VIN) …………………..
-0.3V to +6V
Lead Temperature…..………………………………260°C
Output Voltage (VOUT) …………………
-0.3V to +6V
Junction temperature range, TJ .……
-40°C
Input Voltage (EN, FB, SW) ……..……
-0.3V to +6V
Storage temperature range, Tstg ……
-55°C~+155°C
Peak Output Current
~+135°C
………………. Internally limited
Thermal Information
Maximum Power Dissipation(TA=+25°C )
…….1.38W
SOP8 Thermal resistance(θJA)
…………
72.4°C/W
Recommend Operating Conditions (2)
Input Voltage (VIN) ……………………
+2.9V to +5.5V
Output Voltage (VOUT) ………………..
+2.9V to +5.5V
Operating Temperature Range ……
-40°C to +85°C
Note (1): Stress beyond those listed under “Absolute Maximum Ratings” may damage the device.
Note (2): The device is not guaranteed to function outside the recommended operating conditions.
Electrical Characteristics
TA = +25°C, 2.9V ≤ VIN ≤ 5.5V, unless otherwise noted. Typical values are at VIN= VEN =3.6V and VOUT=5V.
PARAMETER
TEST CONDITIONS
Input voltage range VIN
MIN
TYP
2.5
MAX
UNIT
5.5
V
Input Under-voltage Lockout
2.2
V
Threshold VUVLO
Output voltage adjustable
2.5
5.5
V
range VOUT
Feedback voltage VFB
490
500
510
mV
Oscillator frequency fOSC
640
800
960
kHz
NCH Switch Current Limit
VOUT= 5V
3.5
A
NCH Switch on resistance
VOUT= 5V
90
mΩ
PCH Switch on resistance
VOUT= 5V
90
mΩ
Shutdown Current
VEN = 0V, VIN = 3.6V
0.1
Rev. 0.1
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µA
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M3TEK
Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
TEST CONDITIONS
PARAMETER
Quiescent Current
VIN
MIN
VFB =0.55V , VOUT=5V
TYP
MAX
UNIT
125
200
µA
0.4
V
EN logic low voltage
EN logic high voltage
EN leakage current
1.4
Clamped on GND or VIN
V
-1
1
µA
Thermal Shutdown
150
℃
Thermal Shutdown Hysteresis
20
℃
Functional Block Diagram
Figure 2. MT5031A Functional Block Diagram
Rev. 0.1
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Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.3V, MT5031A typical application circuit (Figure 1.), TA = +25°C, unless otherwise noted.
Efficiency vs. Load Current
Steady State
VIN=3.3V,VOUT=5.0V,ILOAD=0A
4 us/div
Steady State
VIN=4.19V, VOUT=5.0V, ILOAD=0.05A
4 us/div
Startup from Enable
Vin=3.3V,Vout=5.0V,Iload=1.5A
2 ms/div
Steady State
VIN =3.3V, VOUT=5.0V, ILOAD=0.1A
4 us/div
Shutdown from Enable
VIN =3.3V, VOUT=5.0V,
ILOAD=1.5A
400 us/div
Short Circuit
VIN =3.3V, VOUT=5V,
ILOAD=0.3A to Short Circuit
40 ms/div
Rev. 0.1
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M3TEK
Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
Detailed Description
The MT5031A is based on a fixed frequency current mode pulse width modulation topology. The peak current of the
NMOS switch is sensed to limit the maximum current flowing through the switch and the inductor. The typical peak
current limit is set to 3.5A. An internal temperature sensor prevents the device from getting overheated in case of
excessive power dissipation.
Application Information
Because of the high integration of MT5031A, the application circuit is simple. Only input capacitor CIN, output
capacitor COUT, inductor L, output feedback resistors R3, R4 need to be selected for the targeted applications
specifications.
Setting the Output Voltage
The MT5031Aoutput voltage can be adjusted with an external resistor divider (See Figure 1). The typical value of the
voltage on the FB pin is 500mV. The maximum allowed value for the output voltage is 5.5 V. Choose the bottom
resistor R4 in the 100kΩ~500kΩ range to set the divider current at 1 µA or higher. The value of resistor R3, depending
on the needed output voltage VOUT, can be calculated using Equation 1:
V

 V

R3 = R 4 ×  OUT − 1 = 200kΩ×  OUT -1
 500mV 
 VFB

(Equation 1)
Inductor Selection
The MT5030A 800kHz high switching frequency allows for the use of small surface mount inductors. For high
efficiency, choose inductors with high frequency core material, such as ferrite, to reduce core losses. Also to improve
efficiency, choose inductors with bigger size for a given inductance. The inductor should have low DCR (copper-wire
resistance) to reduce I2R losses, and must be able to handle the peak inductor current without saturating. The
inductor DC current rating should be greater than the maximum input average current. For the full 1.5Amp output
current applications, the inductor shall have enough core volume to support peak inductor currents up to 3.5A range
and DCR less than 30mΩ. The highest peak current through the inductor and the switch depends on the output load,
converter efficiency η, the input voltage (VBAT), and the output voltage (VOUT). Estimation of the maximum average
inductor current can be done using Equation 3:
I L = I OUT ×
VOUT
VBAT ×η
(Equation 3)
For example, for an output current of 1.5A at 5V with 85% efficiency, at least 2.9A of average current flows through the
inductor at a minimum input voltage of 3V.
The MT5030 step-up converters can operate with an effective inductance in the range of 1µH to 2.2µH and with output
capacitors in the range of 20µF to 100µF. The internal compensation is optimized for an output filter of L = 1.5µH and
COUT = 20µF. To minimize radiated noise, use a toroidal or shielded inductor.
Rev. 0.1
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Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
Input Capacitor
Place at least a 10 µF input ceramic capacitor close to the IC is to improve transient behavior of the regulator and EMI
behavior of the total power supply circuit.
Output Capacitor
The output capacitor must completely supply the load during the charging phase of the inductor. A reasonable value of
the output capacitance depends on the speed of the load transients and the load current during the load change. It is
recommended to use X7R ceramic capacitors placed as close as possible to the VOUT and PGND pins of the IC. A
recommended output capacitance value is around 20~47µF.
Layout consideration
Use wide and short traces for the main current path and for the power ground tracks. The input capacitor, output
capacitor, and the inductor should be placed as close as possible to the IC. Use a common ground node for power
ground and a different one for analog ground to minimize the effects of ground noise. Connect these ground nodes at
any place close to the ground pins of the IC.
Thermal information
Implementation of integrated circuits in low-profile and fine-pitch surface-mount packages typically requires special
attention to power dissipation. Many system-dependent issues such as thermal coupling, airflow, added heat sinks
and convection surfaces, and the presence of other heat-generating components affect the power-dissipation limits of
a given component.
Three basic approaches for enhancing thermal performance are listed below:
High speed switching path (SW, PGND and VOUT with wide PCB traces) must be kept as short as possible.
Solder the MT5031A PGND and GND pins to the ground plane.
Choose a bigger size 1.5uH Inductor with the lowest DCR value for given PCB space
The maximum junction temperature (TJ) of the MT5031A devices is 125℃.The thermal resistance of the SOP8
package is RθJA = 72.4℃/W, if the Exposed PAD is soldered. Specified regulator operation is assured to a maximum
ambient temperature TA of +50℃. Therefore, the maximum power dissipation for the SOP8 package it is about 1.03W.
More power can be dissipated if the maximum ambient temperature of the application is lower.
PD ( MAX ) =
Rev. 0.1
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TJ ( MAX ) − TA
Rθ JA
=
125o C-50o C
= 1.03W
72.4o C / W
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M3TEK
Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
PACKAGING INFORMATION
MT5031A SOP 8L 150 mils Package Outline Dimensions
SYMBOLS
MILLIMETERS
INCHES
MIN.
MAX.
MIN.
MIN.
A
1.35
1.75
0.053
0.069
A1
0.00
0.25
0.000
0.010
D
4.90
0.193
E1
3.90
0.153
E
5.80
6.20
0.228
0.244
L
0.40
1.27
0.016
0.050
b
0.31
0.51
0.012
0.020
e
Rev. 0.1
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1.27
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M3TEK
Preliminary Datasheet
MT5031A
800kHz Synchronous Step-up Converter with 3.5A Switches
Datasheet Revision History
REVISION
REVISION
NUMBER
DATE
0.1
2013/09/25
Rev. 0.1
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DESCRIPTION
PAGES
CHANGED
Initial release
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