Dual Low Noise LDO
in 3mm×3mm MLF
TM
FEATURES
•
•
•
•
•
•
•
•
•
•
•
300mA+300mA dual channel high accuracy
LDO
Ultra low output noise: 140
μ
V
RMS
Low ground current: 200
μ
A
Very low dropout: 150mV @300mA
Zero shutdown supply current
TTL-logic-controlled independent enable
input
Thermal and current limit protections
Ultra low droop load transient response
Ultra fast line transient response
Tiny 10pin 3mm x 3mm MLF (10L-TDLMF )
package
Fixed options 1.5V, 1.8V, 2.5V, 2.8V, 3.0V
and 3.3V
DESCRIPTION
The PL2211 is a dual CMOS low dropout linear
regulator with ultra-low-noise output, very low
dropout voltage and very low ground current.
The PL2211 operates from a 2.5V to 5.5V input
voltage range and delivers up to 300mA, with low
dropout of 150 mV at 300mA. The other features of
PL2211 include short-circuit protection and thermal-
shutdown protection.
Its dual channel and low noise feature is ideal for
microcontroller
and
DSP
based
handheld
applications.
Other key application areas for PL2211 also include
palmtop computers, PCMCIA cards and WLAN
cards.
The PL2211 has a special feature that if both EN
pin is enabled simultaneously the output of LDO2
delays 20us from output of LDO1 which helps to
minimize inrush startup current.
The PL2211 is available in tiny 10pin 3mm x 3mm
MLF (10L-TDLMF) package with fixed output
voltage versions.
APPLICATIONS
•
•
•
•
•
•
•
•
Dual supply handheld products
Cellular and cordless phones
Wireless LAN cards
Digital camera
MP3 / MP4 / CD player
Pen drives
USB Hubs and USB 2.0
Mini PCI & PCI express cards
TYPICAL APPLICATION
July 2007
www.picsemi.com
© 2007 Power IC. All Rights Reserved.
1
ABSOLUTE MAXIMUM RATINGS
Symbol
V
IN
V
EN
P
D
T
STG
R
θJA
T
J,MAX
T
L
ESD
Parameter
DC Supply Voltage at Pin 1
Enable Input Voltage at Pin 2 and Pin 3
Continuous Power Dissipation
Storage Temperature Range
Thermal Resistance, Junction-To-Air
Operating Junction Temperature
Lead Temperature (Soldering, 5sec)
ESD Capability, HBM model
Value
-0.3 to +6.0
-0.3 to +6.0
Internally limited
-65 to +150
235
-40 to +125
260
2
Unit
V
V
W
°c
°c
/W
°c
°c
kV
RECOMMENDED OPERATING CONDITIONS
Symbol
V
IN
V
EN
T
A
Parameter
DC Supply Voltage at Pin 1
Enable Input Voltage at Pin 2 and Pin 3
Operating Ambient Temperature
Value
+2.5 to 5.5
0 to V
IN
-40 to +85
Unit
V
V
°c
ELECTRICAL CHARACTERISTICS
Symbol
V
IN
ΔV
OUT
ΔV
LOAD
ΔVl
LINE
VDP
I
O
ILIM
IQ
IG
PSRR
PSRR
(V
IN
=V
OUT(NOMINAL)
+1V or 2.5V (whichever is greater), V
EN
=V
IN,
C
IN
=C
OUT
=1µF, I
O
=1mA, T
A
=25°C, unless otherwise noted.)
Parameter
Supply Voltage
Output Voltage Accuracy
Load Regulation
Line Regulation
dV
OUT
/( dV
IN
*V
OUT(NOMINAL)
)*100%
Dropout Voltage (Note 1)
Maximum Output Current
Current Limit/Output Current
Standby Current
Ground pin current
Ripple Rejection, I
OUT
= 10mA,
Output voltage noise
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Logic Input High Voltage (EN)
Logic Input Low Voltage (EN\)
Logic Input Current (SHDN\)
Test Conditions
I
O
= 1mA ( both regulator )
I
O
=1mA to 300mA ( both regulator )
V
IN
=V
OUT(NOMINAL)
+0.1V (or 2.5V,
whichever is greater) to 5.5V, I
O
=1mA
( both regulator )
I
LOAD
= 300mA ( both regulator )
I
LOAD
= 100mA ( both regulator )
Continuous
V
IN
-V
OUT
=1.3V ( regulator 1 )
V
IN
-
V
OUT
=1.3V ( regulator 2 )
V
EN
= 0V
I
LOAD1
= I
LOAD2
=1mA ( both regulator
active)
f = 100Hz, Cout= 1µF, Cbyp=10nF
f = 10KHz, Cout= 1µF, Cbyp =10nF
C
OUT
= 1µF, C
BYP
= 10nF,
F = 10Hz to 100K Hz (Vp-p/2/√2)
Min.
2.5
-1.0
Typ.
Max.
5.5
1.0
0.5
0.05
Unit
V
%
%
%/V
mV
mV
mA
RMS
mA
150
80
300
350
350
600
600
0.02
200
75
70
140
165
20
220
100
1
300
µA
µA
dB
dB
µV
RMS
°C
°C
V
V
µA
VIH
VIL
IEN
( both regulator )
( both regulator )
( both regulator )
1.2
-1
0.4
1
Note 1: The Dropout Voltage is defined as V
IN
- V
OUT
, when V
OUT
is
2%
below the value of V
OUT
measured for
V
IN
=V
OUT(nominal)
+1V.
July 2007
www.picsemi.com
© 2007 Power IC. All Rights Reserved.
4
OPERATION DESCRIPTION
The PL2211 are ultra-low-noise, low-dropout, low-
quiescent current linear regulators designed for
space-restricted applications. These devices can
supply loads up to 300mA. As shown in the Block
Diagram, the PL2211 consists of a highly accurate
band gap core, noise bypass circuit, error amplifier,
P-channel pass transistor and an internal feedback
voltage divider. The 1.0V band gap reference is
connected to the error amplifier’s inverting input.
The error amplifier compares this reference with
the feedback voltage and amplifies the difference.
If the feedback voltage is lower than the reference
voltage, the pass transistor gate is pulled low. This
allows more current to pass to the output and
increases the output voltage. If the feedback
voltage is too high, the pass transistor gate is
pulled high, allowing less current to pass to the
output. The output voltage is feedback through an
internal resistor voltage divider connected to the
OUT pin. An external bypass capacitor connected
to BYP reduces noise at the output. Additional
blocks include a current limiter, over temperature
protection, and shutdown logic.
Internal P-Channel Pass Transistor
The PL2211 feature a 1Ω (typ) P-channel MOSFET
pass transistor. This provides several advantages
over similar designs using a PNP pass transistor,
including longer battery life. The P-channel MOSFET
requires no base drive, which considerably reduces
quiescent current. PNP-based regulators waste
considerable current in dropout when the pass
transistor saturates. They also use high base-drive
current under heavy loads. The PL2211 does not
suffer from these problems and consume only
200μA of quiescent current in light load.
Current Limit
The PL2211 includes a current limiter. It monitors
the output current and controls the pass transistor’s
gate voltage to limit the output current under
600mA (typ). The output can be shorted to ground
for an indefinite amount of time without damaging
the part.
Enable Input
The PL2211 features an active-high Enable input
(EN) pin that allows on/off control of the regulator.
The PL2211 bias current reduces to less than
microampere of leakage current when it is
shutdown. The Enable input is TTL/CMOS
compatible threshold for simple logic interfacing.
When EN is ‘H,’ the output voltage startup rising
time is 35us typically at 300mA output current.
Connect EN pin to IN pin for normal operation
Under Voltage Lockout
When the input supply goes too low (below 2.0V)
the PL2211 produces an internal UVLO (under
voltage lockout) signal that generates a fault signal
and shuts down the chip. This mechanism protects
the chip from producing false logic due to low input
supply.
Quick Charging Mode
The PL2211 has a quick charge block to get the
reference up very quickly by charging the BYP
capacitor with very high current when the chip
comes out of shut down. This quick charge block
stops charging the BYP capacitor when the
reference reaches 95% of its nominal value and
then the chip switches out of quick charging mode
to normal operating mode.
Over Temperature Protection
Over temperature protection limits total power
dissipation in the PL2211. When the junction
temperature exceeds T
j
= +165°C, the thermal
sensor signals the shutdown logic and turns off the
pass transistor. The thermal sensor turns the pass
transistor on again after the IC’s junction
temperature drops by 20°C, resulting in a pulsed
output
during
continuous
thermal-overload
conditions.
Thermal-Overload protection is design to protect
the PL2211 in the event of a fault condition. For
continual operation, do not exceed the absolute
maximum junction temperature rating of Tj =
+150°C.
July 2007
www.picsemi.com
© 2007 Power IC. All Rights Reserved.
5
DSP 与 ARM 处理器
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
