EUP7903
EUP7903
300mA High PSRR LDO Regulators
DESCRIPTION
FEATURES
The EUP7903 is a high current, low-dropout (LDO) linear
regulator with fast transient response and high PSRR. It
offers high output accuracy, extremely low dropout voltage,
low quiescent current and fast start-up time.
The EUP7903 is designed to work with low-ESR ceramic
capacitors, reducing the amount of the PCB area necessary
for power applications. Only a 1uF ceramic output capacitor
can make the device stable over the whole load range.
EUP7903 can be externally set either fixed output mode or
adjustable output mode. Connect FB pin to GND to select
the fixed output mode. Its output is one of pre-set values:
1.25V~5V (50mV per step). Operated in the adjustable mode
when the FB pin is connected to an external resistors divider,
its output can be adjusted from 1.25V to 5V. Other key
features include over-current protection, thermal shutdown.
The device is available in the small SOT23-5 package.
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2.5V to 5.5V Input Voltage Range
[email protected] Dropout Voltage
Excellent Transient Response
Stable with 1uF Ceramic Output Capacitor
70dB PSRR at 1kHz
Low 90µA Quiescent Current
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Low Shutdown Current:<1µA
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Output Current Limit
Short Circuit Protection
Output Voltage With High Accuracy:
2% Initial Accuracy
Fixed Output Voltage:1.25V~5V (0.05V step)
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Adjustable Output Voltage: 1.25V~5V
Thermal Shutdown
Output Auto-Discharge in Shutdown
RoHS Compliant and 100% Lead (Fb)-Free
APPLICATIONS
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Cellular Phones
Bluetooth portable radios and Accessories
Battery-Powered Equipment
Laptop, Palmtops, Notebook Computer
PDAs
Digital still Camera and Video Recorders
Typical Application Circuit
Figure. 1 Adjustable Output
DS7903
Ver 1.0
Nov. 2008
1
EUP7903
Typical Application Circuit (continued)
Figure. 2 Fixed Output
Block Diagram
Figure. 3
DS7903
Ver 1.0
Nov. 2008
2
EUP7903
Pin Configurations
Package Type
Pin Configurations
SOT23-5
Pin Description
PIN
SOT23-5
DESCRIPTION
EN
1
Enable Pin. Connect this pin to ground or less than 0.4V to disable the device, connect EN
to 1.5V or above to enable the device.
GND
2
Signal Ground.
IN
3
Input Supply of the LDO.
OUT
4
Output of the LDO.
FB
5
Feedback pin. This pin is the anode terminal of the error amplifier. The FB pin compares
with internal reference voltage to regulate the output voltage. Connect to GND for fixed
output voltage version.
DS7903
Ver 1.0
Nov. 2008
3
EUP7903
Ordering Information
Order Number
Package Type
EUP7903-15VIR1
SOT23-5
EUP7903-18VIR1
SOT23-5
EUP7903-25VIR1
SOT23-5
EUP7903-28VIR1
SOT23-5
EUP7903-33VIR1
SOT23-5
EUP7903VIR1
SOT23-5
EUP7903-XXVIR1
SOT23-5
Marking
xxxxx
AD1C
xxxxx
AD1D
xxxxx
AD1B
xxxxx
AD1E
xxxxx
AD1H
xxxxx
AD1A
xxxxx
xxxx
Operating Temperature Range
-40 °C to +85°C
-40 °C to +85°C
-40 °C to +85°C
-40 °C to +85°C
-40 °C to +85°C
-40 °C to +85°C
-40 °C to +85°C
EUP7903 - □ □ □ □ □ □
Lead Free Code
1: Lead Free 0: Lead
Packing
R: Tape & Reel
Operating temperature range
I: Industry Standard
Package Type
V: SOT-23
Output Voltage
15:1.5V
18:1.8V 25:2.5V
28:2.8V
33:3.3V
XX: Voltage Options (1.25V to 5V, 0.05V per step)
Note:Every EUP7903 version can operate at adjustable mode by connecting FB pin to an external resistor divider.
DS7903
Ver 1.0
Nov. 2008
4
EUP7903
Absolute Maximum Ratings (1)
„
„
„
„
„
„
„
VIN,VEN --------------------------------------------------------------------------------------------0.3V to 6V
VOUT -------------------------------------------------------------------------------------- -0.3V to (VIN+0.3V)
Junction Temperature -------------------------------------------------------------------------------+150℃
Storage Temperature Range ----------------------------------------------------------------- -65℃ to +150℃
Lead Temperature ----------------------------------------------------------------------------------+260℃
Thermal Resistance θJA (SOT23-5) --------------------------------------------------------------220℃/W
ESD Rating
Human Body Model ------------------------------------------------------------------------2kV
Recommend Operating Conditions (2)
„
„
„
VIN ------------------------------------------------------------------------------------------------ 2.5V to 5.5V
VEN -----------------------------------------------------------------------------------------------0V to 5.5V
Operating Temperature Range --------------------------------------------------------------- -40℃ to +85℃
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℃, VIN=VOUT+1V, or VIN=2.5V for VOUT<1.5V unless otherwise specified.
Symbol
Parameter
Input Voltage
VIN
Input Voltage
IQ
Quiescent Current
ISHDN Shutdown Current
Power Supply Ripple
PSRR
Rejection
VFB FB Pin Voltage
Enable
VENH Enable High Voltage
VENL Disable Low Voltage
IEN
EN Input Current
TST
Start-up Time
Output voltage
VOUT
Output Voltage Accuracy
VLNR
Output Line Regulation
VLDR
Output Load Regulation
Conditions
EUP7903
Min. Typ. Max.
2.5
VEN=3.5V, IOUT=0mA
VEN=0V
VIN=VNOM+1VP-P,f=100Hz,
ILOAD=10mA
90
0.1
75
1.225
1.25
Nov. 2008
dB
1.275
V
0.4
1
V
V
µA
µs
1.5
VIN=VOUT+1V, IOUT=10mA
VIN=VOUT+1V, IOUT=10mA,
TA =-40℃ to +85℃
VOUT+0.5V<VIN<5.5V, IOUT=10mA
1mA < IOUT <300mA,
VIN=VNOM+1.0V
-2
+2
%
-3
+3
%
0.01
0.1
%/V
10
16
mV
240
mV
-1
0.2
40
Dropout Voltage (3)
180
IOUT=300mA
(Applied for VOUT≥2.3V)
IOUTMAX Maximum Output Current
300
Protection
ILIMIT Current Limit
330
500
TSD Thermal Shutdown Temperature No Load, VIN=VEN=5V
155
TSDHYS Thermal Shutdown Hysteresis
No Load, VIN=VEN=5V
30
Note (3): Dropout is defined as VIN-VOUT when VOUT is 2% below the value of VOUT for VIN=VOUT+0.5V.
Ver 1.0
V
µA
µA
Over temperature range
Over temperature range
VIN=3.5V, VEN=3.5V or 0V
VIN=3.5V, VOUT=2.5V
VDROP
DS7903
5.5
130
1
Unit
5
mA
mA
℃
℃
EUP7903
Typical Characteristics
Time (4ms/div)
Time (40µs/div)
DS7903
Ver 1.0
Nov. 2008
6
EUP7903
Typical Characteristics (continued)
Thermal Shutdown Cycle
Time (40ms/div)
Time (100µs/div)
Time (400µs/div)
DS7903
Ver 1.0
Nov. 2008
7
EUP7903
Detailed Function Description
The EUP7903 is a high output current, low dropout
linear regulator with fast transient response and high
PSRR. It offers high output accuracy, extremely low
dropout voltage, low quiescent current and fast start-up
time. It is designed to work with low-ESR ceramic
capacitor, reducing the amount of the PCB area. Only a
1uF ceramic capacitor can make the device stable over
the whole load range.
As shown in the function block diagram, the EUP7903
is composed of the bandgap reference voltage, the error
amplifier, P-channel MOSFET pass transistor, internal
resistor divider and some additional protection circuits.
The reference voltage, connected to the cathode
terminal of the error amplifier, compares with the
feedback voltage to regulate the output voltage to make
it constant over the whole load range. If the feedback
voltage is lower than the reference voltage, the pass
transistor gate is pulled low to increase its conductivity.
This allows more current to flow to the output and
increases the output voltage. If the feedback voltage is
higher than the reference voltage, the pass transistor
allows less current to flow to the output. The feedback
point is the output of the internal or external resistor
divider connected to the VOUT pin.
Enable/Shutdown
The EUP7903 is disabled when the EN pin is connected
to ground or the voltage less than 0.4V, and the
quiescent current is less than 1uA. Connect EN pin to
1.5V or higher to enable the device.
Output Soft stop
When the regulator is disabled, an internal 400Ω resistor
is connected between VOUT and GND. To discharge
output capacitor COUT.
Adjustable Output Voltage
EUP7903 has a wide output voltage range. The output
voltage is programmed by an external resistor divider as
shown in Figure 1. The output voltage can be calculated
by the following equation:
VOUT = (1 +
R1
) × VREF
R2
Figure. 4 Output Voltage Select Circuit
Fixed Output Voltage
When the FB voltage is less than 220mV, EUP7903 will
operate in the fixed output mode, its output is one of
pre-set values: 1.25V~5V. There is no external
component needed to set the output voltage.
Current Limit
The EUP7903 includes a current limit circuit to monitor
the gate voltage of the pass transistor to limit the output
current. When the output current is higher than the
over-current limit, the circuit will clamp the gate voltage
of the pass transistor to limit the output current. The
typical output current limit is 500mA.
Thermal Shutdown
The EUP7903 monitors internal temperature. When the
junction temperature exceeds 155℃, the over
temperature protection (OTP) circuit turn off the pass
transistor until the device is cooled down by 30℃. Then
the pass transistor resumes. For continue operation, do
not exceed absolute maximum junctiqwk iknf on
temperature.
Application Information
Resistor Select
Choose R2=100k to optimize accuracy, power supply
rejection, noise and power consumption. And the R1 can
be chosen by:
R1 = R 2 (
Ver 1.0
Nov. 2008
(EQ.2)
where VREF is the internal reference voltage, which is
1.25V in EUP7903.
External Capacitor
The EUP7903 requires external capacitors for stability.
It is specifically designed to work with low-ESR
capacitors requiring minimum PCB area.
Input capacitor
A 1uF ceramic capacitor or higher is required between
the VIN pin and the GND pin. Place it as close as
possible to the device. There are no requirements for the
ESR on the input capacitor, but the tolerance and
temperature coefficient must be considered when
selecting the capacitor to ensure the capacitance is 1uF
over the whole operating temperature range.
(EQ.1)
Where VREF is the internal reference voltage, which is
1.25V in EUP7903.
DS7903
VOUT
− 1)
VREF
8
EUP7903
Output capacitor
The EUP7903 is designed specifically to work with very
small ceramic output capacitors. A 1uF to 10uF
capacitor with 5mΩ to 500mΩ ESR range is suitable
for the most EUP7903 applications. The ESR of a
typical 1uF ceramic capacitor is around 20mΩ, which
easily meets the ESR requirement for stability.
Capacitor characteristics
More consideration should be taken when selecting the
capacitor because its capacitance can vary with
temperature. The capacitor type X7R or X5R, which
operates over a temperature range of -40℃ to +85℃, will
only vary within ±15%. However Z5U or T5V
temperature characteristics. Their capacitance can drop
by more than 50% as the temperature goes from 25℃ to
85℃. Therefore the capacitor type X7R or X5R is
recommended in applications where the ambient
temperature will change significantly above or below
25℃.
No load Stability
The EUP7903 will remain stable and in regulation with
no external load. This is special important in CMOS
RAM keep-alive applications.
PD ( MAX ) = (125°C − 25°C) / 220 = 0.445W (EQ.5)
for SOT23-5 package
The maximum power dissipation depends on operating
ambient temperature for fixed TJ(MAX) and thermal
resistance θJA. For EUP7903 packages, the Figure 5 of
derating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
allowed.
Maximum Power Dissipation(W)
0.6
(EQ.3)
(EQ.4)
Where TJ(MAX) is the maximum operation junction
temperature 125°C, TA is the ambient temperature and
the θJA is the junction to ambient thermal resistance.
For recommended operating conditions specification of
EUP7903, where TJ(MAX) is the maximum junction
temperature of the die (125°C) and TA is the operated
ambient temperature. The junction to ambient thermal
resistance θJA is layout dependent. For SOT-23-5
package, the thermal resistance θJA is 220°C/W on the
standard thermal test board. The maximum power
dissipation at TA = 25°C can be calculated by following
formula :
Nov. 2008
0.2
0.1
0
25
50
75
100
o
125
150
Figure. 5. Power Dissipation for EUP7903 Package
The EUP7903 is available in the SOT23-5 package.
PD ( MAX) = (TJ ( MAX) − TA ) θ JA
Ver 1.0
0.3
Ambient Temperature( C)
The maximum power dissipation depends on the thermal
resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference
between junction and ambient. The maximum power
dissipation can be calculated by following formula :
DS7903
SOT23-5
0.4
0.0
Thermal Considerations
Thermal protection limits power dissipation in
EUP7903.When the device junction temperature exceeds
155°C, the OTP circuit starts the thermal shutdown
function and turns the pass transistor off. The pass
transistor turns on again after the junction temperature
cools down 30°C.
For continuous operation, do not exceed absolute
maximum junction temperature 150°C. The power
dissipation definition in device is:
PD = ( VIN − VOUT ) × I OUT + VIN × I Q
0.5
9
EUP7903
Packaging Information
SOT23-5
SYMBOLS
A
A1
D
E1
E
L
b
e
DS7903
Ver 1.0
Nov. 2008
MILLIMETERS
MIN.
MAX.
1.30
0.00
0.15
2.90
1.60
2.60
3.00
0.30
0.60
0.30
0.50
0.95
10
INCHES
MIN.
0.000
MAX.
0.052
0.006
0.114
0.063
0.102
0.012
0.012
0.118
0.024
0.020
0.037
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