Design Specification
300mA Low Noise Dual LDO
PL2211
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 200
mV at 300mA. The other features of PL2211 include short-
circuit protection and thermal-shutdown protection.
The PL2211 is designed especially for battery-powered
portable devices. Its low noise feature makes PL2211 ideal
for noise-sensitive personal communication 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.
FEATURES
Guaranteed 300mA load/ LDO
Ultra low output noise: 100µV
RMS
Low ground current: 200µA
Very low dropout: 180mV @300mA
Zero shutdown supply current
TTL-logic-controlled independent enable input
Thermal and current limit protections
Low ESR capacitor compatibility to achieve
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
APPLICATIONS
Cellular and cordless phones
Wireless LAN cards
Palmtop computers
Personal communication equipment
TYPICAL APPLICATION
Power IC Ltd.
Version 1.0
-1-
www.picsemi.com
Mar 4, 2007
Design Specification
300mA Low Noise Dual LDO
PL2211
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
℃
℃/W
℃
℃
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
℃
ELECTRICAL CHARACTERISTICS
(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.)
Symbol
V
IN
∆V
OUT
∆V
load
∆Vl
LINE
V
DP
I
O
ILIM
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
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. Unit
5.5
1.0
0.5
0.05
V
%
%
%/V
mV
mV
mA
RMS
mA
180
80
300
350
350
600
600
0.02
200
75
70
100
165
20
220
100
I
Q
I
G
PSRR
PSRR
Standby Current
Ground pin current
Ripple Rejection, I
OUT
= 10mA,
Output voltage noise
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
1
300
µA
µA
dB
dB
µV
RMS
°C
°C
V
V
IH
V
IL
I
EN
Logic Input High Voltage (EN)
Logic Input Low Voltage (EN\)
Logic Input Current (SHDN\)
( both regulator )
( both regulator )
( both regulator )
1.2
0.4
-1
1
V
µA
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.
Power IC Ltd.
Version 1.0
-4-
www.picsemi.com
Mar 4, 2007
Design Specification
300mA Low Noise Dual LDO
PL2211
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
= +155°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
15°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.
Operating Region and Power Dissipation
The PL2211 maximum power dissipation depends on 1)
the thermal resistance of the case and circuit board, 2) the
temperature difference between the die junction and
ambient, and 3) the rate of airflow. The power dissipation
across the device is:
P = Iout ( Vin – Vout )
The maximum power dissipation is:
Pmax = (Tj – Ta) / (θjc +
θca)
Where (Tj – Ta) is the temperature difference between
the PL2211 die junction and the ambient air;
θjc
is the
thermal resistance of the package; and
θca
is the thermal
www.picsemi.com
Mar 4, 2007
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 550mA (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
Power IC Ltd.
Version 1.0
-5-
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