Microsemi LX8610-25CDM 1a bicmos very low dropout regulator Datasheet

A
M I C R O S E M I
LX8610-xx
1A BiCMOS Very Low Dropout Regulators
C O M P A N Y
P RELIMINARY D ATASHEET
Dropout Voltage Typically
The LX8610 family are positive
very low dropout regulators. They are
designed to provide a power supply for
very low headroom applications, such as
3.3V– 2.5V.
BiCMOS technology allows an
effective series pass element resistance,
RDS(ON) of 250m dropout voltage of 250mV at 1A.
Low Quiescent Current and LogicControlled Shutdown help conserve
battery life and increase system
efficiency. Typical quiescent current is
under 400µA irrespective of load
current, while the shutdown current is
only 10µA.
The device will enter
shutdown mode when the ENABLE pin
is pulled low.
Thermal & Short-Circuit Current
Limiting: the LX8610 limits the current
when the output is shorted, so protecting
sensitive load circuits. The device will
also turn off if the junction temperature
exceeds 155°C.
Available in small outline SOT-223
and 8-pin SOIC: Adjustable versions
use the 8-pin SOIC and fixed output
voltage devices are supplied in the 3-lead
SOT-223.
250mA At 1A And 50mV At
10mA
Low Quiescent Current,
Under 400µA, Irrespective
Of Load
Shutdown Current 10µA
Adjustable Output Version In
8-pin SOIC Package
Fixed Outputs Of 2.5V, 3.3V
Available In 3-Pin SOT-223
Package
Low Reverse Leakage
Current
Short-Circuit And Thermal
Shutdown Protection
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
W W W . Microsemi . COM
3.3V & 2.5V Supplies For
Memory, Microprocessors,
Clock Circuits, Etc.
Portable Equipment
L X 86 1 0 -xx S im p lified B lock D ia gram
V OUT
V IN
Current
Lim it
Reference
Current
RA
Charge
P um p
A D J*
1 .2 5 V
RB
E N A B LE *
GND
V IN /2
RA
Reverse
V oltage
S ense
Therm al
S hutdown
RB
L X 8 6 1 0-0 0
-
-
L X 8 6 1 0-2 5
25K
25K
L X 8 6 1 0-3 3
41K
25K
LX8610-XX
* A d ju sta b le 8 le a d ve rsio n on ly
TJ (°C)
0 to 125°C
OUTPUT ST PLASTIC SOT-233 DM Plastic SOIC
8-PIN
VOLTAGE
3-PIN
3.3
2.5
ADJ (00)
LX8610-33CST
LX8610-25CST
–
LX8610-33CDM
LX8610-25CDM
LX8610-00CDM
Note: Available in Tape & Reel.
Append the letter “T” to the part number. (i.e. LX8610CDMT)
Copyright  2000
Rev. 0.6f,2000-09-15
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
C O M P A N Y
LX8610-xx
1A BiCMOS Very Low Dropout Regulators
P RELIMINARY D ATASHEET
Input Voltage (VIN) ......................................................................................................6.5V
Enable Pin ..............................................................................................-0.3V to V IN+0.3V
Operating Junction Temperature Plastic (ST & DM) Packages .................................125°C
Storage Temperature ................................................................................... -65°C to 150°C
Lead Temperature (Soldering, 10 Seconds) ...............................................................300°C
Note:
T A B IS G N D
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.
ST
GND/
H E A T S IN K
GND/
H E A T S IN K
E N A B LE
PLASTIC SOT-223 PACKAGE
THERMAL RESISTANCE-JUNCTION TO TAB, θJT
15°C/W*
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
DM
θJLD
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
30°C/W
V OU T
2
GND
1
V IN
1
8
ADJ
2
7
GND/
H E A T S IN K
3
6
GND/
H E A T S IN K
4
5
V IN
DM PACKAGE
(Top View)
150°C/W
PLASTIC SOIC PACKAGE
3
ST PACKAGE
(Top View)
V O UT
W W W . Microsemi . COM
90°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
θJA can be improved with package soldered copper area over backside ground plane or
internal power plane. θJA can vary from 45°C/W > 75°C/W depending on mounting
technique. See table below for thermal resistance guidelines:
Copper Area
(Topside)*
Copper Area
(Backside)*
2.0 sq” (1290mm2)
1.0 sq” (645 mm2)
0.5 sq” (323 mm2)
0.25 sq” (161 mm2)
1.0 sq” (645 mm2)
0.5 sq” (323 mm2)
0.1 sq” (65 mm2)
0.1 sq” (65 mm2)
Thermal
Resistance
(θJA)
Board Area
Possible Heat Sink Approaches
using PCB Copper
ST (SOT-223)
45°C/W
50°C/W
60°C/W
70°C/W
DM (SOIC)
2
2.0 sq” (1290mm )
1.0 sq” (645 mm2)
0.5 sq” (323 mm2)
0.25 sq” (161 mm2)
2
1.0 sq” (645 mm )
0.5 sq” (323 mm2)
0.1 sq” (65 mm2)
0.1 sq” (65 mm2)
2
2.0 sq” (1290mm )
1.0 sq” (645 mm2)
0.5 sq” (323 mm2)
0.25 sq” (161 mm2)
60°C/W
67°C/W
70°C/W
75°C/W
1
8
2
7
3
6
4
5
PACKAGE DATA
2.0 sq” (1290mm2)
1.0 sq” (645 mm2)
0.5 sq” (323 mm2)
0.25 sq” (161 mm2)
*Tab of device attached to topside copper, or leads 2,3,5,6 of SOIC package
Copyright  2000
Rev. 0.6f,2000-09-15
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
P RELIMINARY D ATASHEET
1A BiCMOS Very Low Dropout Regulators
C O M P A N Y
VIN
Positive supply input for the regulator. Bypass to GND with at least 2.2µF of low ESR, ESL capacitance if
supply source is further than 1 inch from the device.
VOUT
Output for the regulator. It is recommended to bypass to GND with at least 10µF although this is not required
for regulation, rather it is needed for transient response. Size your output capacitor to meet the transient
loading requirement. If you have a very dynamic load, a larger capacitor will improve the response to these
load steps.
GND
Reference ground. The input and output bypass capacitors should be connected to this pin. In addition the tab
on the SOT-223 package and pins 2,3,6, and 7 on the SOIC package are also used for heat sinking the device.
ADJ
Feedback pin for the regulator. For the LX8610-00, the output voltage can be set by two external resistors with
the following relationship: VOUT = 1.25V * (1 + RA / RB) where RA is the resistor connected between VOUT and
ADJ, and RB is the resistor connected between ADJ and GND.
ENALBE
Enable input. This pin has a threshold of about VIN / 2, it should be actively pulled high to enable the regulator.
This can be accomplished with a resistive pull-up. When low, it turns off the regulator and puts the device in a
low current shutdown state.
W W W . Microsemi . COM
LX8610-xx
VIN
5
IN
OUT
LX8610-00
CIN
ENABLE
4
GND
2,3
6,7
VOUT
1
RA
ADJ
8
VREF
COUT
RB

RA 

RB 
VOUT = VREF 1 +

PIN DESCRIPTION
Figure 1 – Typical Application
Copyright  2000
Rev. 0.6f,2000-09-15
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
C O M P A N Y
LX8610-xx
1A BiCMOS Very Low Dropout Regulators
P RELIMINARY D ATASHEET
Parameter
Symbol
Input Voltage
Load Current (with adequate heatsinking)
Input Capacitor (VIN to GND)
Output Capacitor (VOUT to GND)
VIN
Min
3
10
2.2
10
LX8610
Typ
Units
Max
5.5
V
mA
µF
µF
1000
10
22*
* Size your output capacitor to meet the transient loading requirement. If you have a very dynamic load, a larger capacitor will improve the response to
these load steps.
W W W . Microsemi . COM
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 125°C except where
otherwise noted. Test conditions: VIN = VOUT + 1.5V; IOUT = 10mA; CIN = 10µF; COUT = 22µF; TJ = TA.
Parameter
Symbol
Test Conditions
Min
LX8610-xx
Typ
Max
Units
LX8610-33 FIXED 3.3V, 1A
Output Voltage
VOUT
Line Regulation
Load Regulation
VREG
IREG
Dropout Voltage (VDO = VIN–VOUT)
VDO
Short Circuit Current
Quiescent Current
ISC
IQ
Reverse Leakage Current
IREV
Shutdown Threshold *
Shutdown Current *
VSD
ISD
TJ = 25°C
Over Temperature
VIN = 3.45V to 5.5V
IOUT = 10mA to 1A
IOUT = 1A, VOUT OUT –1%
IOUT = 0.5A, VOUT OUT – 1%
IOUT = 10mA, VOUT OUT – 1%
VOUT = 0V
IOUT = 10mA to 1A
0V < VIN < VOUT, VOUT <3.4V (at VOUT)
OV < VIN < VOUT, VOUT <3.4V (at VIN)
3.25
3.22
-50
0.8
ENABLE < 0.8V
3.3
4
5
0.25
0.15
0.05
1.25
400
400
0
VIN / 2
10
3.35
3.38
8
10
0.4
0.25
0.15
1.7
600
650
25
V
mV
mV
V
A
µA
µA
mA
V
µA
LX8610-25 FIXED 2.5V, 1A
VOUT
Line Regulation
Load Regulation
VREG
IREG
Dropout Voltage (VDO = VIN–VOUT)
VDO
Short Circuit Current
Quiescent Current
ISC
IQ
Reverse Leakage Current
IREV
Shutdown Threshold
Shutdown Current
VSD
ISD
Copyright  2000
Rev. 0.6f,2000-09-15
TJ = 25°C
Over Temperature
VIN = 3.1V to 5.5V, IOUT = -10mA
IOUT = 10mA to 1A
IOUT = 1A, VOUT OUT –1%
IOUT = 0.5A, VOUT OUT – 1%
IOUT = 10mA, VOUT OUT – 1%
VOUT = 0V
IOUT = 10mA to 1A
0V < VIN < VOUT, VOUT < 2.6V (at VOUT)
0V < VIN < VOUT, VOUT <2.6V (at VIN)
2.46
2.44
-50
0.8
ENABLE < 0.8V
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
2.5
2.5
3
5
0.25
0.15
0.05
1.25
300
400
0
VIN / 2
10
2.54
2.56
6
10
0.4
.025
0.1
1.7
600
650
25
V
mV
mV
V
A
µA
µA
mA
V
µA
Page 4
ELECTRICALS
Output Voltage
A
M I C R O S E M I
LX8610-xx
1A BiCMOS Very Low Dropout Regulators
C O M P A N Y
P RELIMINARY D ATASHEET
Parameter
Symbol
Test Conditions
Min
LX8610-xx
Typ
Max
Units
LX8610-00 ADJUSTABLE OUTPUT,
1A
Reference Voltage
VREF
Line Regulation
Load Regulation
Short Circuit Current
VREG
IREG
ISC
Dropout Voltage (VDO = VIN–VOUT)
VDO
Quiescent Current
IQ
Reverse Leakage Current
IREV
Bias Current at ADJ Pin
Shutdown Threshold
Shutdown Current
IBIAS
VSD
ISD
TJ = 25°C
Over Temperature
VIN = VOUT + 150mV to 5.5V, IOUT = 10mA
IOUT = 10mA to 1A
VOUT = 0V
IOUT = 1A, VIN > 4V
IOUT = 0.5A, VIN > 3V
IOUT = 10mA, VIN > 3V
IOUT = 10mA to 1A, VIN = 5.5V
0V < VIN < VOUT, VOUT < 5.5V (at VOUT)
0V < VIN < VOUT, VOUT <5.5V (at VIN)
1.23
1.22
-50
0.8
ENABLE < 0.8V
1.22
1.25
2
7
1.25
0.25
0.15
0.05
400
400
0
100
(VIN / 2)
10
1.27
1.28
4
15
1.7
0.4
0.25
0.15
600
650
V
mV
mV
A
V
W W W . Microsemi . COM
µA
µA
mA
nA
V
µA
25
* Note: Enable threshold and Shutdown Current apply only to 8-Pin SOIC package outline versions
L X 8 6 1 0 D ro p o u t vs L o a d v s T e m p
350
300
250
0
25
75
100
125
200
150
100
ELECTRICALS
50
0
0
0 .2 5
0 .5
0 .7 5
1
FIGURE 2 – Dropout Voltage Vs. Output Current (Typical – LX8610-25CST)
Copyright  2000
Rev. 0.6f,2000-09-15
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
A
M I C R O S E M I
LX8610-xx
1A BiCMOS Very Low Dropout Regulators
C O M P A N Y
P RELIMINARY D ATASHEET
ST
W W W . Microsemi . COM
3-Pin Plastic SOT-223
D
Dim
B1
A
B
B1
C
D
E
F
G
H
I
J
K
L
E
H
2
1
3
B
F
G
L
K
A
J
MILLIMETERS
MIN
MAX
1.55
1.80
0.65
0.85
2.95
3.15
0.25
0.35
6.30
6.70
3.30
3.70
2.30 BSC
4.60 BSC
6.71
7.29
–
0.91
0.02
0.10
10° MAX
.084
1.04
INCHES
MIN
MAX
0.061
0.071
0.026
0.033
0.116
0.124
0.010
0.014
0.248
0.264
0.130
0.146
0.0905 BSC
0.181 BSC
0.264
0.287
–
0.036
.0008
.004
10° MAX
0.033
0.041
MILLIMETERS
MIN
MAX
4.83
5.00
3.81
3.94
1.35
1.75
0.33
0.51
–
0.77
1.27 BSC
0.19
0.25
0.13
0.25
4.80
5.21
–
8°
5.79
6.20
–
0.10
INCHES
MIN
MAX
0.190
0.197
0.150
0.155
0.053
0.069
0.013
0.020
–
0.030
0.050 BSC
0.007
0.010
0.005
0.010
0.189
0.205
–
8°
0.228
0.244
–
0.004
I
C
8-Pin Plastic SOIC
DM
Dim
A
P
B
G
L
M
C
D
K
J
F
*Lead Coplanarity
Note:
1. 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.
Preliminary Data – Information contained in this document is pre-production data and is proprietary to LinFinity. It
may not be modified in any way without the express written consent of LinFinity. Product referred to herein is offered
in sample form only and LinFinity reserves the right to change or discontinue this proposed product at any time.
Copyright  2000
Rev. 0.6f,2000-09-15
Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
MECHANICALS
A
B
C
D
F
G
J
K
L
M
P
*LC
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