ETC EUP2410

芯美电子
Preliminary
EUP2410
1.6A, 500KHz Synchronous
Step-up Converter
DESCRIPTION
The EUP2410 is a highly efficient, synchronous, fixed
frequency, current-mode step-up converter with output to
input disconnect. When EUP2410 is disabled, the internal
conduction path from SW to OUT is fully blocked and the
OUT pin is isolated from the battery. This output disconnect
feature reduces the shutdown current to typically only 50nA.
The 500KHz switching frequency allows for smaller external
components producing a compact solution for a wide range
of load currents. Highly integration and internal
compensation network minimizes as 5 external components,
N-Channel switch and P-Channel Synchronous switch
integration will greatly improve converter efficiency.
Internal soft-start function also reduce inrush current. The
EUP2410 regulates the output voltage up to 6V from either a
2-cell NiMH/NiCd or a single-cell Li-Ion battery.
The EUP2410 is offered in a thin SOT23-5 package.
FEATURES
z
z
z
z
z
z
z
z
z
z
z
Over 90% Efficiency
1.6A Typical Switch Current Limit
500KHz Fixed Switching Frequency
Output to Input Disconnect at Shutdown Mode
Internal Synchronous Rectifier
Internal Soft-Start
Internal Compensation
50nA Shutdown Current
Thermal Shutdown
5-Pin TSOT-23 Package
RoHS compliant and 100% lead(Pb)-free
APPLICATIONS
z
z
z
z
GPS PND
Handheld Digital Audio
Digital Still and Video Cameras
White LED Flash
Typical Application Circuit
Figure1.
DS2410
Ver 0.1
Feb. 2008
1
联系电话：１５９９９６４４５７９　８３１５１７１５
芯美电子
Preliminary
EUP2410
Pin Configurations
Package Type
Pin Configurations
TSOT23-5
Pin Description
PIN
NAME
DESCRIPTION
Regulation Feedback Input. Connect to an external resistive voltage divider from the
output to FB to set the output voltage.
1
FB
2
GND
Ground.
3
OUT
4
SW
5
EN
Supply Input for the EUP2410. Connect to the output of the converter.
Output Switching Node. SW is the drain of the internal low-side N-Channel MOSFET
and high-side P-Channel MOSFET. Connect the inductor to SW to complete the
step-up converter.
Regulator On/Off Control Input. A logic high input (VEN > 1.4V) turns on the
regulator. A logic low input (VEN < 0.4V) puts the EUP2410 into low current
shutdown mode.
Block Diagram
Figure.2
DS2410
Ver 0.1
Feb. 2008
2
联系电话：１５９９９６４４５７９　８３１５１７１５
芯美电子
Preliminary
EUP2410
Ordering Information
Order Number
Package Type
Marking
Operating Temperature range
EUP2410OIR1
TSOT23-5
n0XXXX
-40 °C to 85°C
EUP2410
□ □ □ □
Lead Free Code
1: Lead Free 0: Lead
Packing
R: Tape & Reel
Operating temperature range
I: Industry Standard
Package Type
O: TSOT
DS2410
Ver 0.1
Feb. 2008
3
联系电话：１５９９９６４４５７９　８３１５１７１５
芯美电子
EUP2410
Preliminary
Absolute Maximum Ratings
▓
▓
▓
▓
▓
▓
All Pins -------------------------------------------------------------------------------------------------------- -0.3V to 6V
Supply Voltage VIN --------------------------------------------------------------------------------------------- 2.2V to 6V
Output Voltage VOUT ------------------------------------------------------------------------------------------- 2.5V to 6V
Operating Temperature Rang --------------------------------------------------------------------------- -40°C to 85°C
Storage Temperature Rang, Tstg ----------------------------------------------------------------------- -65°C to 150°C
Thermal Resistance
θJA (TSOT) --------------------------------------------------------------------------------------------------- 220°C/W
Electrical Characteristics
VIN = 2.4V, VOUT = 3.5V, CIN=10uF, COUT = 10µF, L1=4.7µH, R1 =178KΩ, R2 =100KΩ,TA = -40°C to +85°C, unless
otherwise noted. Typical values are at TA = +25°C.)
Parameter
Conditions
EUP2410
Min
Typ
Max.
Unit
Supply Voltage
2.2
5
V
Output Voltage Range
2.5
6
V
1
µA
Supply Current (Shutdown)
VEN=VOUT=0V, VSW=5V
0.05
Supply Current
VFB=1.3V
0.39
Feedback Voltage
Feedback Input Current
1.2
VFB=1.2V
1.25
mA
1.3
50
V
nA
Switching Frequency
310
500
690
KHz
Maximum Duty Cycle
80
85
90
%
0.4
V
EN Input Low Voltage
EN Input High Voltage
1.4
EN Pull Down Resistor
Low-Side On Resistance
VOUT=3.3V by design
Low-Side Current Limit
1
V
1
MΩ
450
mΩ
1.6
2
A
High-Side On Resistance
VOUT=3.3V by design
650
mΩ
Thermal Shutdown
Note 1
160
°C
Thermal Shutdown Hysteresis
Note 1: Guaranted By Design .
Note 1
30
°C
DS2410
Ver 0.1
Feb. 2008
4
联系电话：１５９９９６４４５７９　８３１５１７１５
芯美电子
EUP2410
Preliminary
Typical Operating Characteristics
Operating Conditions： VIN = 2.4V, VOUT = 3.5V, CIN=10uF, COUT = 10µF, L1=4.7µH, R1 =178KΩ, R2 =100KΩ
Efficiency vs Load Current
Load Regulation
1
3.6
0.9
3.4
Output Voltage (V)
EFFICIENCY
0.8
0.7
0.6
0.5
0.4
Vin=2.4V
Vin=3.0V
0.3
1
10
100
3.2
3
2.8
2.6
2.4
0
1000
500
1000
Load Current (mA)
LOAD CURRENT(mA)
Continuous Mode Operation
Line Regulation
ILOAD=20mA
3.5
ILoad=0mA
ILoad=400mA
VSW
Vout(V)
3.495
VOUT
3.49
IINUCTOR
3.485
3.48
1.8
2.3
2.8
3.3
Vin(V)
Transient Response
Continuous Mode Operation
ILOAD=40mA to 400mA Step
ILOAD=400mA
VSW
ILOAD
VOUT
VOUT
IINUCTOR
DS2410
Ver 0.1
Feb. 2008
5
联系电话：１５９９９６４４５７９　８３１５１７１５
1500
芯美电子
EUP2410
Preliminary
Typical Operating Characteristics (continued)
Operating Conditions： VIN = 2.4V, VOUT = 3.5V, CIN=10uF, COUT = 10µF, L1=4.7µH, R1 =178KΩ, R2 =100KΩ
RLOAD=16Ω
Startup
Feedback Voltage vs Temperature
1.248
1.246
FB VOLTAGE (V)
VEN
VSW
1.244
1.242
1.24
1.238
VOUT
1.236
1.234
-40
-20
0
20
40
60
80
100
TEMPERATURE (℃ )
Maximum Duty Cycle vs Temperature
88
MAX DUTY CYCLE (%)
87.5
87
86.5
86
85.5
85
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (℃)
DS2410
Ver 0.1
Feb. 2008
6
联系电话：１５９９９６４４５７９　８３１５１７１５
120
芯美电子
EUP2410
Preliminary
Operation
Where VOUT is the output voltage, VFB is the 1.25V
feedback voltage and R2=100kΩ.
The EUP2410 uses a 500KHz fixed-frequency,
current-mode regulation architecture to regulate the
output voltage. The EUP2410 measures the output voltage
through an external resistive voltage divider and compares
that to the internal 1.25V reference to generate the error
voltage. The current-mode regulator compares the error
voltage to the inductor current to regulate the output
voltage. The use of current-mode regulation improves
transient response and control loop stability.
When the EUP2410 is disabled (EN = Low), both power
switches are off. There is no current path from SW to
OUT. Therefore, the output voltage discharges to ground.
When the EUP2410 is enabled (EN = High), a limited
start-current charges the output capacitor through the
P-Channel MOSFET until the output voltage rising to SW,
then the part operates in force PWM mode for regulating
the output voltage to the target value.
At the beginning of each cycle, the N-Channel MOSFET
switch is turned on, forcing the inductor current to rise.
The current at the source of the switch is internally
measured and converted to a voltage by the current sense
amplifier. That voltage is compared to the error voltage.
When the inductor current rises sufficiently, the PWM
comparator turns off the switch, forcing the inductor
current to the output capacitor through the internal
P-Channel MOSFET rectifier, which forces the inductor
current to decrease. The peak inductor current is
controlled by the error voltage, which in turn is controlled
by the output voltage. Thus the output voltage controls the
inductor current to satisfy the load.
Selecting the Input Capacitor
An input capacitor is required to supply the AC ripple
current to the inductor, while limiting noise at the input
source. Multi-layer ceramic capacitors are the best choice
as they have extremely low ESR and are available in
small footprints. Use an input capacitor value of 4.7µF or
greater. This capacitor must be placed physically close to
the device.
Selecting the Output Capacitor
A single 4.7µF to 10µF ceramic capacitor usually
provides sufficient output capacitance for most
applications. Larger values up to 22µF may be used to
obtain extremely low output voltage ripple and improve
transient response. The impedance of the ceramic
capacitor at the switching frequency is dominated by the
capacitance, and so the output voltage ripple is mostly
independent of the ESR. The output voltage ripple VRIPPLE
is calculated as:
VRIPPLE =
Where VIN is the input voltage, ILOAD is the load current,
C2 is the capacitance of the output capacitor and fSW is the
500KHz switching frequency.
Selecting the Inductor
The inductor is required to force the output voltage higher
while being driven by the lower input voltage. A good
rule for determining the inductance is to allow the
peak-to-peak ripple current to be approximately 30%-50%
of the maximum input current. Make sure that the peak
inductor current is below the minimum current limit at the
duty cycle used (to prevent loss of regulation due to the
current limit variations).
Calculate the required inductance value L using the
equations:
Soft-Start
The EUP2410 includes a soft-start timer that limits the
voltage at the error amplifier output during startup to
prevent excessive current at the input. This prevents
premature termination of the source voltage at startup due
to inrush current. This also limits the inductor current at
startup, forcing the input current to rise slowly to the
amount required to regulate the output voltage during
soft-start.
Application Information
L=
Component Selection
Setting the Output Voltage
Set the output voltage by selecting the resistive voltage
divider ratio. The voltage divider drops the output voltage
to the 1.25V feedback voltage. Use a 100kΩ resistor for
R2 of the voltage divider. Determine the high-side resistor
R1 by the equation:
R1 =
DS2410
Ver 0.1
Feb. 2008
I LOAD (VOUT − VIN )
VOUT × C 2 × f SW
V IN ×(VOUT − VIN )
VOUT × f sw × ∆I
I IN ( MAX ) =
VOUT × I LOAD ( MAX )
VIN × η
∆I = (30 % − 50 %) I IN ( MAX )
VOUT − VFB
 VFB 


 R2 
7
联系电话：１５９９９６４４５７９　８３１５１７１５
芯美电子
Preliminary
Where ILOAD(MAX) is the maximum load current, ∆I is the
peak-to-peak inductor ripple current and η is efficiency.
For the EUP2410, typically, 4.7µH is recommended for
most applications. Choose an inductor that does not
saturate at the peak switch current as calculated above with
additional margin to cover heavy load transients and
extreme startup conditions.
Layout Considerations
High frequency switching regulators require very careful
layout for stable operation and low noise. All components
must be placed as close to the IC as possible. All feedback
components must be kept close to the FB pin to prevent
noise injection on the FB pin trace. The ground return of
C1 and C2 should be tied close to the GND pin. See the
EUP2410 demo board layout for reference.
Selecting the Schottky Diode
A Schottky diode D1 in parallel with the high-side
P-Channel MOSFET is necessary to clamp the SW node to
a safe level for outputs of 4V or above. A 0.5A, 20V
Schottky diode can be used for this purpose. See Figure 3.
DS2410
EUP2410
Figure 3.
5V Typical Application Circuit with External Schottky Diode and
Output Disconnect Not Required
Figure 4.
5V Typical Application Circuit with External Schottky Diode and
Output Disconnect Required
Ver 0.1
Feb. 2008
8
联系电话：１５９９９６４４５７９　８３１５１７１５
芯美电子
EUP2410
Preliminary
Package Information
TSOT23-5
SYMBOLS
A
A1
D
E1
E
L
b
e
DS2410
Ver 0.1
Feb. 2008
MILLIMETERS
MIN.
MAX.
1.00
0.00
0.15
2.90
1.60
2.60
3.00
0.30
0.60
0.30
0.50
0.95
INCHES
MIN.
0.000
MAX.
0.039
0.006
0.114
0.063
0.102
0.012
0.012
0.118
0.024
0.020
0.037
9
联系电话：１５９９９６４４５７９　８３１５１７１５