ETC LX8221-GIDU

LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
KEY FEATURES
DESCRIPTION
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Overall regulator efficiency has been
improved with a minimized operating
ground current (typ < 140µA per
regulator). Further, this ground current
is virtually eliminated in shutdown mode
(typ < 1µA).
Other safety features include channel
independent Thermal and Short Circuit
Current protection.
Separate Enable pins allow each
regulator to be switched on and off
independently by applying a TTL logic
level control signal to the Enable pin
further enhancing system level power
management.
These features combined with a small
footprint (i.e., 10-pin MSOP package)
make the LX8221 especially useful for
battery-operated equipment such as
cellular telephones, laptop computers
and PDA equipment.
The LX8221 family of dual output
linear regulators provide for the
selection of either fixed or adjustable
output voltages, and combine low
dropout
operation,
fast
transient
performance, tight output voltage
accuracy, and ultra-low ground current
within a very small package footprint.
The PMOS output transistor allows
for an ultra-low dropout characteristic
(e.g., typically less than 175mV at
100mA). The individual regulators can
be powered from either separate supply
voltages or the same supply voltage
between 2.8V to 6V allowing for
maximum system flexibility.
An optional ceramic or tantalum type
capacitor may be connected to each
Bypass pin separately to improve
performance in critical low-noise
applications.
! Compact regulators with
two 150 mA outputs
! Dropout Voltage typically
175mV @ 100mA
! Ultra low shutdown Current
typically less than 1µA
! Output trimmed to 0.5%
! Small MSOP-10 package
! Over Current &
Temperature protection
! Stable with ceramic or
tantalum capacitors
APPLICATIONS
!
!
!
!
!
Battery Operated Systems
Laptop, Notebook and PDA’s
Cellular Telephones/pagers
Instrumentation
Linear post regulators for
SMPS
IMPORTANT: For the most current data, consult MICRO Semi’s website: http://www.microsemi.com
PRODUCT HIGHLIGHT
5.0V
N/C
VIN2
EN1
VIN1
EN2
}
To Control Logic
5.0V
N/C
On
Off
3.3V
VIN2
EN1
VIN1
EN2
ADJ1
VOUT1
}
To Control Logic
On
Off
3.3V
CB1
VOUT1
ADJ
VOUT2
ADJ2
GND
VOUT2
GND
R1
R2
R1
R1
R2
R2
Adjustable / Adjustable Application
Fixed / Adjustable Application
PACKAGE ORDER INFO
VOUT1
VOUT2
-40 to 125
-40 to 125
-40 to 125
-40 to 125
Adjustable
2.5V
2.7V
3.0V
Adjustable
Adjustable
Adjustable
Adjustable
DU
Plastic MSOP
10-Pin
LX8221-AIDU
LX8221-BIDU
LX8221-DIDU
LX8221-GIDU
LX8221
TJ (°°C)
Package Marking
8221 AIDU LX
8221 BIDU LX
8221 DIDU LX
8221 GIDU LX
Contact Microsemi for additional / available options
Note: Available in Tape & Reel.
Append the letter “T” to the part number. (i.e. LX8221-AIDUT)
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
ABSOLUTE MAXIMUM RATINGS
PACKAGE PIN OUT
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to
Ground. Currents are positive into, negative out of specified terminal.
VOUT1
1
10
CB1
2
9
EN1
NC
3
8
GND
VIN1
EN2
4
7
ADJ
VIN2
5
6
VOUT2
DU PACKAGE
(Top View)
“NC” = No Internal Connection
THERMAL DATA
DU
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Input Voltage (VIN1, VIN2) ..........................................................................-0.3V to +7V
Output Current (IOUT1, IOUT2) ................................................................................. 150mA
Operating Temperature Range..................................................................... -40 to +125 °C
Maximum Junction Temperature (TJ).......................................................................150 °C
Storage Temperature (TJ) ............................................................................ -65 to +150 °C
FRONT MARKING
Plastic MSOP 8-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
THERMAL RESISTANCE-JUNCTION TO CASE, θJC
206°°C/W
39°°C/W
8221
xIDU
LX
Junction Temperature Calculation: TJ = TA + (PD x θJC).
The θJA numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
x = Voltage Combination
i.e. A = Adj/Adj
FUNCTIONAL PIN DESCRIPTION
PIN NAME
DESCRIPTION
VIN1/VIN2
Unregulated input supply voltage
GND
Ground Pin
EN1/EN2
Enable control input: Logic high = Enable; logic low or open = Shutdown
CB1
Reference bypass input. Adding an additional external capacitor reduces output noise.
VOUT1/VOUT2
Regulated output voltage. Regulator stability is achieved with external capacitor of 1uF
ADJ (1, 2)
Adjust pin. Connect a resistor divider to this pin to establish preferred output voltage.
BLOCK DIAGRAM
VIN1
EN1
EN2
VIN2
VOUT2
VOUT1
+
CB1
CURRENT
LIM IT
CURRENT
LIMIT
CONTROL
LOGIC
-
THERMAL
SENSOR
+
CONTROL
LOGIC
VREF
PACKAGE DATA
THERM AL
SENSOR
ADJ
-
VREF
GND
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
RECOMMENDED OPERATING CONDITIONS
Symbol
Input Operating Voltage Range (Note 1)
Enable Input Voltage Range
Continuous Output Current Range
Input Capacitor (VIN to GND)
Output Capacitor (VOUT to GND)
VIN1, VIN2
EN1/2
IOUT1, IOUT1
CIN
COUT
Min
LX8221
Typ
2.5
Units
Max
6
VIN + 0.3V
150
1.0*
1.0*
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Parameter
2.2
V
V
mA
µF
µF
Note 1: The minimum VIN has to meet two conditions VIN > 2.5V and VIN > VOUT + VDROPOUT.
* Size your output capacitor to meet the transient loading requirement. If you have a very dynamic load, a lower ESR and larger value capacitor will improve the response to
these load steps.
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, the following specifications apply over the operating ambient temperature -40°C ≤ TA ≤ 125°C except
where otherwise noted. Test conditions: VIN = VOUT + 0.5V; IOUT =10mA; CIN = 1µF; COUT = 1µF; TJ = TA using low duty cycle pulse
testing methods.
LX8221
Parameter
Symbol
Test Conditions
Units
Min
Typ
Max
Output Voltage (2.5, 2.7, 3.0, ADJ)
Adjust Reference Voltage
 ∆VO


∆VIN 

 ∆VO

Load Regulation 
∆I O 

Line Regulation
Dropout Voltage
(VIN
− VO )
(Note 2)
Ground Pin Current
Adjust Input Bias Current
Enable Pin Current
Enable Threshold
VADJ
TJ = 25°C
0mA ≤ IOUT1/2 ≤ 150mA, (VOUT1/2 + 0.5V) ≤ VIN ≤ 6V
TJ = 25°C
0mA ≤ IOUT1/2 ≤ 150mA, 2.85V ≤ VIN ≤ 6V
VRV
(VOUT1/2 + 0.5V) ≤ VIN ≤ 6V, IOUT1/2 = 0.1mA
VRI
0.5mA ≤ IOUT1/2 ≤ 100mA
VDO
IGND
ISTBY
IADJ
IEN
VEN(IH)
VEN(IL)
IOUT(SC)
PSRR
eN
TSD
-1
-2.5
1.163
1.152
1.175
0.04
ILOAD1/2 = 1mA, ∆VO = -1%
ILOAD1/2 = 50mA, ∆VO = -1%
ILOAD1/2 = 100mA, ∆VO = -1%
ILOAD1/2 = 150mA, ∆VO = -1%
EN1 = High, EN2 = High
EN1 = Low, EN2 = Low
VADJ = 1.25V
VEN1/2 = VIN
0.175
0.25
280
1
2.5
1.187
1.200
%/V
1.5
%VNOM
0.050
0.175
0.3
0.4
440
1
100
100
0.4
400
50
50
170
V
0.15
2.0
VOUT1 = 0V, VOUT2 = 0V
TJ = 25°C, f = 120Hz
TJ = 25°C, COUT = 10uF,CBYPASS = 470 pF
%
V
µA
nA
nA
V
mA
dB
µV
°C
Note 2: Dropout voltage is defined as the input to output differential at which the output voltage drops 1% below the nominal value. Dropout voltage specification
applies only to output voltages greater than 2.8 V. For output voltages below 2.8 V, the dropout voltage is nothing but the input to output differential, since the
minimum input voltage is 2.8 V.
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
ELECTRICALS
Short Circuit Current Limit
Power Supply Rejection Ratio
Output Noise
Thermal Shutdown Temperature
VOUT1/2
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
APPLICATIONS
Input Capacitor
To improve load transient response and noise rejection a
bypass capacitor is recommended (but it is not required for
stability). There are no requirements for the ESR
(Equivalent Series Resistor) on the input capacitor, but
tolerance and temperature coefficient must be considered
when selecting this capacitor to ensure that the capacitor’s
value will be around 1µF over the entire operating
temperature range. For the LX8221, a 1µF ceramic type
capacitor may be connected between both VIN1/2 and
ground.
Output Capacitor
The LX8221 uses an internal feedback loop to maintain a
constant output voltage. This feedback loop induces a
natural phase shift and the amount of phase shift
determines the loop’s stability. Therefore, like any lowdropout regulator, an output capacitor with low ESR
(Equivalent Series Resistance) is required between VOUT
and GND to stabilize the internal control loop. A ceramic,
tantalum or electrolytic capacitor with a minimum
recommended capacitance value of 1.0 µF and ESR
between 5mΩ and 1Ω will satisfy the stability for the entire
operating range.
Copyright  2000
Rev. 1.0, 2002-01-02

R 
VOUT = VADJ  1 + 1 
R

2 
Enable
The Enable pin allows the LX8221 to be independently
turned on and off. The Enable pins are compatible with
standard TTL-CMOS levels. A logic zero (0.4V) on the En1/
En2 pins shuts the LX8221 off and reduces the supply
current to less than 1µA (typ). Pulling the Enable inputs high
(2.0V) causes normal operation to resume. If the Enable
feature is not used, this pin can be connected to VIN.
Minimum Load Requirement
Although line regulation is improved with a minimum load
of 100µA, the LX8221 does not have a minimum load
current in order to maintain stability. This is an especially
important feature in certain applications.
Temperature Protection
The thermal protection shuts the LX8221 down when the
junction temperature exceeds approximately 1500C; there is
no appreciable thermal hysteresis.
Short Circuit Current Protection
The LX8221 includes over-current protection, when the
output load current exceeds about 400mA. When this
occurs, the protection circuit forces the regulator to decrease
its output current.
Thermal Consideration
Thermal shutdown protects the integrated circuit from
thermal overload caused from a rise in junction temperature
during power dissipation. This type of protection is intended
for fault protection only and not as a means of current (or,
power) limiting during normal application usage. Proper
thermal evaluation should be done to ensure that the junction
temperature dose not exceed it’s maximum rating. Operating
at the maximum TJ of 150°C can impact reliability. Due to
variation in individual device electrical characteristics and
thermal resistance, the built in thermal overload protection
may be activated at power levels slightly above or below the
rated dissipation. Power dissipation for each regulator can
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 4
APPLICATION
Optional Bypass Capacitor
The fixed/adjustable voltage version of the LX8221
includes a separate Bypass pin (CB1) for the fixed
regulator that allows for further reduction of output noise.
If the regulator’s output noise performance meets system
design specifications without the capacitor, omit it. The
bypass capacitor impacts the start up time, which is
inversely proportional to the size of bypass capacitor.
Further, the bypass capacitor reduces the regulator phase
margin. Hence, implementing the bypass capacitor will
require the use of a larger output capacitor to maintain the
LDO’s stability. The LX8221-x adjustable regulator’s
output voltage can be externally set by connecting the ADJ
pin/s to an external resistor divider (See Figure 1 and 2).
The output voltage can be calculated using the formula:
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Description
The LX8221 family of LDO linear regulators is available
in a 10-pin MSOP Package and provides a cost effective
power management solution for battery driven applications.
The regulator family includes both fixed/adjustable and
adjustable/adjustable output voltage versions. The internal
PMOS power device provides low dropout regulation with
a fast line and load transient response. It also includes
internal current limiting and thermal shutdown circuitry. In
this section you will find information about capacitor,
thermal, and layout design considerations.
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
APPLICATIONS
calculate the
temperature:
PD = (VIN ( MAX ) − VOUT ( MIN ) )× I OUT ( MAX )
For the MSOP package, thermal resistance, θJA is 2200C/W
when mounted on a FR4 copper clad PCB. Junction
temperature of the integrated circuit can be calculated
using:
Where:
TRISE = (PD × Θ JA )
Example: Given the following conditions:
!
!
!
!
TA = 60°C
VIN= 4.2V
VOUT= 2.7V
IOUT= 100mA
power
dissipation
and
junction
Total Power Dissipation:
(Note: power dissipation resulting from quiescent current
is negligible)
TJ = TA + TRISE
total
PD = (4.2V − 2.7 V ) × 0.1A = 0.15 W
Junction Temperature:
TJ = 60o C + (0.15W × 220o C / W ) = 93o C
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be calculated using the following equation:
Layout Consideration:
The layout must be implemented with low impedance paths
for VIN, VOUT and Ground by creating sufficiently wide
traces to avoid voltage drops and pick up noise. Adding an
area of PCB copper to the GND pin (pin 8) will reduce the
overall θJA since it is thermally connected to the device
substrate. This will lower the device junction temperature
improving overall output voltage accuracy. The input/output
capacitors must be placed as close as possible to each
voltage regulator output pin.
APPLICATION
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
APPLICATION CIRCUITS
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Resistor Table
5.0V
N/C
VIN2
EN1
VIN1
EN2
R1 = 13.0k Ω
R2 = 10.0k Ω
3.3V
3.0V
CB1
VOUT1
ADJ
VOUT2
2.7V
GND
R1
R2
Figure 1. Fixed / Adjustable Output Application
5.0V
N/C
VIN2
EN1
VIN1
EN2
ADJ1
VOUT1
ADJ2
VOUT2
Resistor Table
VOUT1
R1 = 13.0k Ω
R2 = 10.0k Ω
VOUT2
R1 = 11.3k Ω
R2 = 10.0k Ω
3.3V
2.7V
2.5V
GND
R2
R1
R1
R2
APPLICATIONS
Figure 2 – Adjustable / Adjustable Output Application
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
OUTPUT VOLTAGE VS TEMPERATURE
DROPOUT VOLTAGE VS TEMPERATURE
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350
1.185
325
300
1.18
OUTPUT VOLTAGE (V)
275
IL =150mA
250
1.175
225
200
1.17
175
150
1.165
IL =100mA
125
100
1.16
75
1.155
50
-50
-25
0
25
50
75
100
125
-50
-25
0
25
50
TEMPERATURE ( °C)
TEMPERATURE (°C)
OUTPUT CURRENT VS SUPPLY VOLTAGE
75
100
125
SHORT CIRCUIT CURRENT VS TEMPERATURE
- 340
0
- 350
- 50
- 360
- 370
- 100
- 380
-40°C
- 390
25°C
- 150
5V
- 400
85°C
4V
- 410
- 200
115°C
3V
- 420
- 250
- 430
2.8
3.3
3.8
4.3
4.8
SUPPLY VOLTAGE ( V)
5.3
5.8
-40
6.3
PSRR VS FREQUENCY
-25
0
25
85
SUPPLY VOLTAGE ( V)
100
115
125
PSRR VS FREQUENCY IN DROPOUT
0
0
50
50
100
0.1
1
10
100
Fr equency ( kHz)
0.1
1
10
100
Fr equency ( kHz)
Typical performance characteristics, unless otherwise specified are: CIN = COUT = 1µF, CBY = 470pF, VIN = VOUT = 2.5V, TA = 25°C, ENABLE is tied to VIN.
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 7
PERFORMANCE
100
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
PACKAGE DIMENSIONS
10-Pin Plastic MSOP
Dim
G
D
A
B
C
D
F
G
H
J
P
*LC
B
MILLIMETERS
MIN
MAX
2.85
3.05
2.90
3.10
1.10
0.16
0.31
0.40
0.60
0.50 BSC
0.050
0.150
0.10
4.75
5.05
0.10
INCHES
MIN
MAX
0.112
0.120
0.114
0.122
0.043
0.006 0.0124
0.015
0.023
0.019 BSC
0.002
0.006
0.004
0.187
0.198
0.004
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DU
*Lead Coplanarity
A
J
C
H
F
P
Note: Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not
include solder coverage.
MECHANICALS
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 8
LX8221
Dual 150mA CMOS Low Dropout Regulator
P RODUCTION
W W W. Microsemi .COM
NOTES
NOTES
PRODUCTION DATA – Information contained in this document is proprietary to
Microsemi and is current as of publication date. This document may not be modified in
any way without the express written consent of Microsemi. Product processing does not
necessarily include testing of all parameters. Microsemi reserves the right to change the
configuration and performance of the product and to discontinue product at any time.
Copyright  2000
Rev. 1.0, 2002-01-02
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 9