A
M I C R O S E M I
L
INFINITY
C O M P A N Y
LX8816
Dual Channel 1A Low Dropout Regulator
P
RELIMINARY
DESCRIPTION
KEY FEATURES
W W W.
Microsemi
.COM
The LX8816 is a dual channel
positive-voltage linear regulator. This
dual regulator has one fixed output
coupled with an adjustable output.
Each channel features low-dropout
and high accuracy.
The LX8816 provides designers
with a flexible power management
solution, minimal printed circuit board
area and shorter design cycles.
Each channel can supply up to one
amp independently with a regulator
design optimized for system efficiency
by consuming minimal ground current
and directing quiescent current to the
load.
The LX8816 features on-chip
trimming of the internal voltage
enabling precise output voltages,
typically
±1%
of it’s specified value,
while the BiPolar output transistor has a
low dropout voltage even at full output
current (V
DO
< 1.2V typ. @ 1A).
Thermal and Short Circuit Current
Protection are integrated on-chip and
operate independently for each regulator
output.
The LX8816 regulator is stable with a
low-value output capacitor, typically
2.2µF on the outputs, allowing designers
flexibility in external component
selection.
Linfinity’s S-PAK power package
enables maximum power dissipation and
ease of assembly using surface mount
technology.
!
Two Independent Regulated
Outputs
!
Accurate Output Voltages
!
Typical Dropout of 1.2V at 1A
and 1.1V at 500mA
!
Independent Thermal and
Current Limit Protection
!
Low Profile 5 Lead SMT Power
Package
!
Low Tolerance Load Regulation
(0.4%)
!
Wide DC Supply Voltage of 4.3V
to 13.2V
!
Loop Stability Independent of
Output Capacitor Type
APPLICATIONS/BENEFITS
APPLICATIONS/BENEFITS
!
!
!
!
!
!
5V to 3.3V/2.5V Regulators
Hard Disk Drives, CD-ROMs
ADSL and Cable Modems
Battery Charging Circuits
Instrumentation
PC Peripherals
IMPORTANT:
For the most current data, consult
MICROSEMI’s
website:
http://www.microsemi.com
APPLICATION CIRCUITS
V
IN
= 5V
V
IN
V
2
10 µF
V
IN
= 5V
V
IN
2.5V @ 1.0A
22µF
V
2
10 µF
22µF
LX8816-01
GND
ADJ
V
1
LX8816-03
GND
V
1
ADJ
3.3V @ 1.0A
R1
634
R2
511
2.8V* @ 1.0A
10µF
R1
499
R2
1150
1.8V* @ 1.0A
10µF
*
V
1
=
V
REF
1
+
+
I
ADJ
R
1
R
2
R
1
R
1
*
V
1
=
V
REF
1
+
R
2
+
I
ADJ
R
1
LX8816
LX8816
T
J
(°C)
°
0 to 125
PACKAGE ORDER INFO
O
UTPUT
V
1
O
UTPUT
V
2
(PIN 4)
(PIN 5)
Adj.
2.5V
Adj.
3.3V
DF
Plastic S-PAK
5-PIN
LX8816-01CDF
LX8816-03CDF
Note: Available in Tape & Reel.
Append the letter “T” to the part number. (i.e. LX8816-01CDFT)
Copyright
2000
Rev. 0.6, 2001-09-12
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
A
M I C R O S E M I
L
INFINITY
C O M P A N Y
LX8816
Dual Channel 1A Low Dropout Regulator
P
RELIMINARY
ABSOLUTE MAXIMUM RATINGS
Input Voltage (V
BAT
).................................................................................................. 13.5V
Load Current (Internally Limited)................................................................................... 1A
Power Dissipation ................................................................................... Internally Limited
Short-Circuit Protection ....................................................................................... Indefinite
Operating Junction Temperature ................................................................................150°C
Lead Temperature (Soldering 180 seconds) ...............................................................235°C
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.
PACKAGE PIN OUT
TAB is GND
5
4
3
2
1
W W W.
Microsemi
.COM
V
2
V
1
G ND
ADJ
V
IN
DF P
ACKAGE
(Top View)
THERMAL DATA
DF
Plastic S-Pak 5-Pin
4.5°C/W
24.5°C/W
T
HERMAL
R
ESISTANCE
-J
UNCTION TO
T
AB
,
θ
JT
T
HERMAL
R
ESISTANCE
-J
UNCTION TO
A
MBIENT
,
θ
J
A
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
The
θ
JA
numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
θ
JA
can vary from 25°C/W to >
40°C/W depending on mounting technique. (See Application Notes Section: Thermal
considerations)
FUNCTIONAL PIN DESCRIPTION
P
IN
N
AME
V
IN
ADJ
GND
V
1
D
ESCRIPTION
Positive unregulated supply input for the regulator. Bypass to GND with at least 2.2µF of low ESR and ESL
capacitance.
Adjustable Input
.
The output voltage can be set by two external resistors with the following relationship: V
1
= V
REF
* (1 + R1 / R2) + I
ADJ
* R1 where R1 is the resistor connected between V
1
and ADJ, and R2 is the resistor
connected between ADJ and GND..
Common terminal for ground reference.
The input and output bypass capacitors should be connected to this
pin. In addition the tab on the S-Pak package and pin 3 are also used for heat sinking the device.
Adjustable regulator output (Regulator #1) It is recommended to bypass to GND with at least 1uF. Size your
output capacitor to meet the transient loading requirement. If you have a very dynamic load, a lower ESR
capacitor will improve the response to these load steps.
Fixed regulator output (Regulator #2) 1 It is recommended to bypass to GND with at least 1µF. Size your output
capacitor to meet the transient loading requirement. For dynamic loads, a lower ESR capacitor will improve the
response to these load steps.
P
ACKAGE
D
ATA
P
ACKAGE
D
ATA
V
2
Copyright
2000
Rev. 0.6, 2001-09-12
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
A
M I C R O S E M I
L
INFINITY
C O M P A N Y
LX8816
Dual Channel 1A Low Dropout Regulator
P
RELIMINARY
RECOMMENDED OPERATING CONDITIONS
Parameter
Input Voltage
Load Current each output (with adequate heat sinking)
Input Capacitor (V
IN
to GND)
Output Capacitor (V
OUT
to GND)
improve the response to these load steps.
W W W.
Microsemi
.COM
Symbol
V
IN
Min
4.3
0
2.2
1.0
LX8816-xx
Typ
Max
13.2
1000
Units
V
mA
µF
µF
20
10*
*
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
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C
≤
T
A
≤
125°C except where
otherwise noted and the following test conditions: V
IN
= 5V, I
OUT
= 10mA, C
1
= 10µF (Tantalum), C
2
= C
3
= 4.7µF (Tant.), & T
J
= T
A
using
low duty cycling methods.
LX8816-01
Parameter
Symbol
Test Conditions
Units
Min
Typ
Max
!
Adjustable Output (Output 1)
Reference Voltage
Line Regulation
Line Regulation
Load Regulation
Dropout Voltage
Dropout Voltage
Current Limit
Minimum Load Current
Adjust Pin Bias Current
V
REF
∆V
1
(V
IN
)
∆V
1
(V
IN
)
∆V
REF
(I
1
)
∆V
∆V
I
OUT (MAX)
I
L
I
ADJ
V
IN
= 5V, I
OUT
= 10mA, T
J
= 25°C
5mA < I
1
< 1A, 4.50V < V
IN
< 10V
4.5V < V
IN
< 5.5V, I
OUT
= 5mA
4.5V < V
IN
< 10V, I
OUT
= 5mA
5mA < I
1
< 1A, V
IN
= 4.75V
I
LOAD
= 1A,
∆V
1
= -1%
I
LOAD
= 0.5A,
∆V
1
= -1%
(V
IN
– V
1
) = 5V
Note 1, The external resistor divider current can be
included in this requirement.
Bias current flows into part.
V
IN
= 5V, I
OUT
= 5mA, T
J
= 25°C
5mA < I
1
< 1A, 4.50V < V
IN
< 10V
4.5V < V
IN
< 5.5V, I
OUT
= 5mA
4.5V < V
IN
< 10V, I
OUT
= 5mA
5mA < I
1
< 1A, V
IN
= 4.75V
I
LOAD
= 1A,
∆V
1
= -1%
I
LOAD
= 0.5A,
∆V
1
= -1%
(V
IN
– V
1
) = 5V
Note 1
V
IN
< 10V, I
1
= 5mA, I
2
= 5mA
V
IN
< 10V, I
1
= 1A, I
2
= 1A
f=120Hz, V
IN
= 5V
10Hz < f < 10kHz
60
1.8
4
75
0.003
140
1.0
1.0
1.237
1.219
1.25
1.25
3
0.2
0.01
1.2
1.1
1.4
1
0.12
2.462
2.437
2.50
2.50
7
0.2
3
1.2
1.1
1.4
0
4.5
8
2
1
2.537
2.563
10
0.25
5
1.3
1.2
1.263
1.281
6
0.35
0.4
1.3
1.2
V
mV
%/V
%V
1
V
V
A
mA
µA
!
Fixed Output (Output 2)
Output Voltage
Line Regulation
Line Regulation
Load Regulation
Dropout Voltage
Dropout Voltage
Current Limit
Minimum Load Current
V
2
∆V
2
(V
IN
)
∆V
2
(V
IN
)
∆V
2
(I
2
)
∆V
∆V
I
OUT (MAX)
I
L
I
Q
IQ
PSRR
V
OUT (RMS)
T
JSD
V
mV
%/V
mV
V
V
A
mA
mA
mA
dB
%V
°C
E
LECTRICALS
E
LECTRICALS
!
Entire Regulator
Quiescent Current
Quiescent Current
Ripple Rejection
RMS Output Noise (% of V
OUT
)
Thermal Shutdown
Note 1: Minimum load current is defined as the amount of output current required to maintain regulation.
Copyright
2000
Rev. 0.6, 2001-09-12
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
A
M I C R O S E M I
L
INFINITY
C O M P A N Y
LX8816
Dual Channel 1A Low Dropout Regulator
P
RELIMINARY
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C
≤
T
A
≤
125°C except where
otherwise noted and the following test conditions: V
IN
= 5V, I
OUT
= 10mA, C
1
= 10µF (Tantalum), C
2
= C
3
= 4.7µF (Tant.), & T
J
= T
A
using
low duty cycling methods.
Parameter
Symbol
Test Conditions
LX8816-03
Min
Typ
Max
1.237
1.219
1.25
1.25
1.5
0.1
0.04
1.2
1.1
1.0
1.4
2
0.12
3.250
3.217
3.30
3.30
6
0.17
2.6
1.2
1.1
1.0
1.4
0
3
1
3.350
3.383
8
0.20
4
1.3
1.2
1.263
1.281
2
0.17
0.11
1.3
1.2
ELECTRICAL CHARACTERISTICS
W W W.
Microsemi
.COM
Units
!
Adjustable Output (Output 1)
Reference Voltage
Line Regulation
Line Regulation
Load Regulation
Dropout Voltage
Dropout Voltage
Current Limit
Minimum Load Current
Adjust Pin Bias Current
V
REF
∆V
1
(V
IN
)
∆V
1
(V
IN
)
∆V
REF
(I
1
)
∆V
∆V
I
OUT (MAX)
I
L
I
ADJ
V
IN
= 5V, I
OUT
= 10mA, T
J
= 25°C
5mA < I
1
< 1A, 4.50V < V
IN
< 10V
4.5V < V
IN
< 5.5V, I
OUT
= 5mA
4.5V < V
IN
< 10V, I
OUT
= 5mA
5mA < I
1
< 1A, V
IN
= 4.75V
I
LOAD
= 1A,
∆V
1
= -1%
I
LOAD
= 0.5A,
∆V
1
= -1%
(V
IN
– V
1
) = 5V
Note 1, The external resistor divider current can be
included in this requirement.
Bias current flows into part.
V
IN
= 5V, I
OUT
= 5mA, T
J
= 25°C
5mA < I
1
< 1A, 4.50V < V
IN
< 10V
4.5V < V
IN
< 5.5V, I
OUT
= 5mA
4.5V < V
IN
< 10V, I
OUT
= 5mA
5mA < I
1
< 1A, V
IN
= 4.75V
I
LOAD
= 1A,
∆V
1
= -1%
I
LOAD
= 0.5A,
∆V
1
= -1%
(V
IN
– V
1
) = 5V
Note 1
V
mV
%/V
%V
1
V
V
A
mA
µA
!
Fixed Output (Output 2)
Output Voltage
Line Regulation
Line Regulation
Load Regulation
Dropout Voltage
Dropout Voltage
Current Limit
Minimum Load Current
V
2
∆V
2
(V
IN
)
∆V
2
(V
IN
)
∆V
2
(I
2
)
∆V
∆V
I
OUT (MAX)
I
L
V
mV
%/V
mV
V
V
A
mA
!
Entire Regulator
Quiescent Current
Quiescent Current
Ripple Rejection
RMS Output Noise (% of V
OUT
)
Thermal Shutdown
I
Q
IQ
PSRR
V
OUT (RMS)
T
JSD
V
IN
< 10V, I
1
= 5mA, I
2
= 5mA
V
IN
< 10V, I
1
= 1A, I
2
= 1A
f=120Hz, V
IN
= 5V
10Hz < f < 10kHz
135
60
2.6
3.5
75
0.003
140
3.1
6
mA
mA
dB
%V
°C
E
LECTRICALS
E
LECTRICALS
Note 1: Minimum load current is defined as the amount of output current required to maintain regulation.
Copyright
2000
Rev. 0.6, 2001-09-12
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 4
A
M I C R O S E M I
L
INFINITY
C O M P A N Y
1
LX8816
Dual Channel 1A Low Dropout Regulator
P
RELIMINARY
BLOCK DIAGRAM
V
IN
C
1
20
µ
F
W W W.
Microsemi
.COM
5
V
2
C
2
10
µ
F
BIAS
+
-
V
1
=
V
REF
×
1
+
R
1
R
2
+
I
ADJ
×
R
1
1.25V
V
REF
V
IN
4
V
1
R1
+
-
2
C
3
10
µ
F
R2
GND
3
Note: Application circuit above using ceramic capacitors.
Figure 1
– Simplified Block Diagram
B
LOCK
D
IAGRAM
B
LOCK
D
IAGRAM
Copyright
2000
Rev. 0.6, 2001-09-12
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
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