OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

MP20048DJ-LF-P

P1-P3P4-P6P7-P9P10-P10
MP20048 – CAPACITOR-FREE, 250mA, LOW DROPOUT VOLTAGE REGULATOR
MP20048 Rev. 0.91 www.MonolithicPower.com 7
4/6/2010 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2010 MPS. All Rights Reserved.
TYPICAL PERFORMANCE CHARACTERISTICS(continued)
V
IN
=3V, V
OUT
=2.5V, V
EN
=1.7V, C
1
=1uF,C
2
=0.1uF, no C
3
,T
A
=25
o
C, unless otherwise noted.
V
IN
1V/div.
V
OUT
1V/div.
I
OUT
200mA/div.
V
IN
1V/div.
V
OUT
1V/div.
I
OUT
200mA/div.
V
IN
2V/div.
V
OUT
2V/div.
I
OUT
200mA/div.
V
IN
2V/div.
V
OUT
2V/div.
I
OUT
200mA/div.
V
IN
1V/div.
V
OUT
1V/div.
I
OUT
200mA/div.
V
EN
1V/div.
V
OUT
1V/div.
I
OUT
200mA/div.
V
EN
1V/div.
V
OUT
2V/div.
V
IN
1V/div.
V
OUT/AC
100mV/div.
I
OUT
200mA/div.
V
OUT/AC
500mV/div.
I
OUT
200mA/div.
2ms/div. 2ms/div. 40us/div.
2us/div.
MP####-TPC##
200us/div. 40us/div.
1s/div. 40ms/div. 200ms/div.
Input Power Start Up
with Resistive Load
I
OUT
=250mA
EN Start Up
with Resistive Load
I
OUT
=250mA
EN Shut Down
with Resistive Load
I
OUT
=250mA
Input Power Shut Down
with Resistive Load
I
OUT
=250mA
Line Transient
with Resistive Load
V
IN
=3.5V-4.5V, V
OUT
=2.50V,
C
1
=0, I
OUT
=250mA
Load Transient
with Resistive Load
I
OUT
=10mA-250mA
Over Current Protection
Entry
Over Current Protection
Steady State
Over Current Protection
Recovery
MP20048 – CAPACITOR-FREE, 250mA, LOW DROPOUT VOLTAGE REGULATOR
MP20048 Rev. 0.91 www.MonolithicPower.com 8
4/6/2010 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2010 MPS. All Rights Reserved.
BLOCK DIAGRAM
Bandgap
+
+
Ref
Charge
Pump
Thermal
Protection
Current
Limit
Error
Amp
Error Amp
GND
EN
IN
OUT
4k
FB
Figure1—Functional Block Diagram
OPERATION
The MP20048 is a kind of new low-dropout
(LDO) voltage regulators which uses an NMOS
as the pass element in a voltage-follower
configuration. The highlight of this topology is
the stability even without outside capacitor. It
can get any value of output between 1.234V to
5V.
The MP20048 uses an advanced BICMOS
process to yield high precision. It also delivers
very low dropout voltages and low ground pin
current and features the thermal-off and current
limit block to protect the devices from damage.
Dropout Voltage
Dropout voltage is the minimum input to output
differential voltage required for the regulator to
maintain an output voltage within 100mV of its
nominal value. Because the NMOS pass
element behaves as a low-value resistor, the
dropout voltage of MP20048 is very low.
Enable Pin and Shutdown
The MP20048 can be switched ON or OFF by a
logic input at the EN pin. A high voltage at this
pin will turn the device on. When the EN pin is
low, the regulator output is off. The EN pin
should be tied to V
IN
to keep the regulator
output always on if the application does not
require the shutdown feature. Do not float the
EN pin.
Current Limit
The MP20048 includes a current limit structure
which monitors and controls NMOS’s gate
voltage to limit the guaranteed maximum output
current to 450mA.
Thermal Protection
Thermal protection turns off the NMOS when
the junction temperature exceeds +140ºC,
allowing the IC to cool. When the IC’s junction
temperature drops by 10ºC, the NMOS will be
turned on again. Thermal protection limits total
power dissipation in the MP20048. For reliable
operation, junction temperature should be
limited to 125 ºC maximum.
MP20048 – CAPACITOR-FREE, 250mA, LOW DROPOUT VOLTAGE REGULATOR
MP20048 Rev. 0.91 www.MonolithicPower.com 9
4/6/2010 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2010 MPS. All Rights Reserved.
APPLICATION INFORMATION
Setting the Output Voltage
The output voltage of MP20048 can get any
value of output between 1.234V to 5V. The
voltage divider divides the output voltage down
to the feedback voltage by the ratio:
2R1R
2R
VV
OUTFB
+
=
Where V
FB
is the feedback threshold voltage
(V
FB
= 1.234V), and V
OUT
is the output voltage.
Thus the output voltage is:
R2
R2R1
1.234V
OUT
+
×=
R2 can be as high as 100kΩ, but a typical value
is 10kΩ. Using that value, R1 is determined by:
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
−
×=
FB
FBOUT
V
VV
2R1R
For example, for a 2.5V output voltage, R2 is
10kΩ, and R1 is 10.2kΩ. You can select a
standard 10.2kΩ (±1%) resistor for R1.
Power Dissipation
The power dissipation for any package depends
on the thermal resistance of the case and circuit
board, the temperature difference between the
junction and ambient air, and the rate of air flow.
The power dissipation across the device can be
represented by the equation:
()
OUTOUTIN
IVVP ×−=
The allowable power dissipation can be
calculated using the following equation:
()
JAAmbientJunction(MAX)
TTP θ−= /
Where (T
Junction
− T
Ambient
) is the temperature
difference between the junction and the
surrounding environment, θ
JA
is the thermal
resistance from the junction to the ambient
environment.
Output Capacitor Selection
The MP20048 does not require the output
capacitor for stable operation. It is specifically
designed to be stable with any type and value
capacitor including ceramic and electrolytic.
Although an output capacitor is not required for
stability, the output capacitor, C2, is optional to
be connected at the output side. (Figure 2)
Output capacitor of larger values will help to
improve load transient response and reduce
output noise with the drawback of increasing
size.
Output Noise
A precision bandgap reference is used to
generate the internal reference voltage, VREF,
which is the dominant noise source within the
MP20048. It is optional to connect a feed
forward capacitor, C3, from the output to
feedback to improve load transient performance.
This capacitor, C3, should be limited to be less
than 0.1uF. (Figure 2)
IN
EN
(optional)
(optional)
OUT
FB
GND
VIN
C1
R1
R2
C3
C2
VOUT
MP20048
Figure2. Typical Application Circuit with
optional output cap and feedforward cap
P1-P3P4-P6P7-P9P10-P10

MP20048DJ-LF-P

Mfr. #:
Buy MP20048DJ-LF-P
Manufacturer:
Monolithic Power Systems (MPS)
Description:
LDO Voltage Regulators Capless Low Noise 250mA Linear Reg
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet