LX8942
TM
廬
Low Dropout Dual Regulator
P
RODUCTION
D
ATA
S
HEET
DESCRIPTION
The Microsemi LX8942 is a dual
8.2V/5V positive voltage regulator. One
output is a high current (up to 1000mA)
regulator that can be turned on or off by a
high impedance low current TTL
compatible switch. The second or standby
output remains on regardless. The on/off
switch not only shuts off the high current
output but actually puts the IC in a
micropower
mode,
achieving
low
quiescent
current.
This
unique
characteristic coupled with an extremely
low dropout, (0.55V for output current of
10mA) makes the LX8942 well suited for
power systems that require standby
memory. The LX8942 includes other
features which were originally designed
for automotive applications. These include
protection
from
reverse
battery
installations, double battery jumps and
load dump (transients).
The high current regulator has over
voltage shutdown to protect both the internal
circuitry and the load during line transients,
such as load dump (60V). In addition, the
high current regulator design also has built-
in protection for short circuit and thermal
overload. During these fault conditions of
the primary output, the standby regulator
will continue to power its load.
The LX8942 is the 8.2 volt, 鹵5% version
of a family of dual regulators with a standby
output voltage of 5V. Other high-current
outputs programmed for 5V and 12V
regulation are available in the SG29055,
SG29125 devices. They are designed to
function over the full automotive ambient
temperature range of -40擄C to 85擄C.
KEY FEATURES
2% Internally Trimmed Output
Two regulated outputs
Output current in excess of
1000mA
Low quiescent current standby
regulator
Drop-out Voltage, Input-output
differential <0.6V at 0.5A
Reverse battery protection
60V load dump protection
-50V reverse transient protection
Short circuit protection
Internal thermal overload
protection
ON/OFF switch for high current
output
Surface Mount TO-252
APPLICATIONS
WWW .
Microsemi
.C
OM
IMPORTANT:
For the most current data, consult
MICROSEMI鈥檚
website:
http://www.microsemi.com
Automotive electronics for
controls, entertainment and
safety functions
Continuous operation systems
PRODUCT HIGHLIGHT
Input Voltage
(VIN)
* Required close to regulator package.
** Required for stability. May be increased without bound.
Capacitor must be rated to operate at the minimum
temperature expected for the regulator system.
C1*
0.1碌F
1
2
Over Voltage
Thermal
Shutdown
C2 **
47碌F
Output Voltage (VOUT1)
(8.2V, 1000mA)
+
-
Regulator
Bias
1.23V
Reference
5V Standby
Regulator
5
ON/OFF Switch (for
output voltage only)
4
Standby Output (VSB)
(5V, 60mA)
LX8942
3
C3**
100碌F
LX8942
LX8942
Ground
PACKAGE ORDER INFO
T
J
(擄C)
-40 to 85
DT
Plastic TO-252
5-Pin
RoHS Compliant / Pb-free
LX8942IDT
Note: Available in Tape & Reel. Append the letters 鈥淭R鈥?to the part number. (i.e. LX8942IDT-TR)
Copyright
漏
2005
Rev. 1.2, 2006-01-20
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
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