DA9123.005
31 March 2003
MAS9123
80 mA LDO Voltage Regulator IC
• Very Low Noise: 9.5 µVrms
• Very Short Start-up Time: 20 µs
• Excellent Ripple Rejection: 68 dB
• Stable with Low-ESR Output
Capacitors
• Low Minimum Output Capacitance
Requirement: 0.22 µF
• Regulator Enable/Disable Control
DESCRIPTION
MAS9123 is a low dropout voltage regulator with an
enable/disable pin, which allows device to be turned
off or on by pulling control to low or high.
Due to the very low noise level of only 9.5 µVrms
MAS9123 is highly suitable for very sensitive
circuits, e.g., in portable applications. In addition to
the noise level, MAS9123 excels in dropout voltage
(95 mV typical at 50 mA) and in start-up time
(typically 20 µs from start-up to within ±1% of
VOUT(NOM)). Also its ripple rejection ability of 68 dB at
10 kHz exceed that of competition.
The Equivalent Series Resistance (ESR) range of
output capacitors that can be used with MAS9123 is
FEATURES
• Optimized for Fast Start-up
• Very Low Noise
• Internal Thermal Shutdown
• Short Circuit Protection
• SOT23-5 Package (Pin Compatible with LP2982)
• WL-CSP Package (Pin Compatible with LP3985)
• Output Voltage Options: 2.8, 3.0 and 3.3 V,
see Ordering Information p. 12
very wide. This ESR range from a few mΩ up to a
couple of Ohms combined with no minimum output
current requirement makes the usage of MAS9123
easier and low in cost. Also the minimum output
capacitance requirement is very low. This combined
with very short start-up time makes it possible to
switch the regulator off and on even in timing critical
and/or noise sensitive applications.
An internal thermal protection circuit prevents the
device from overheating. Also the maximum output
current is internally limited. In order to save power
the device goes into sleep mode when the regulator
is disabled.
APPLICATIONS
• RF Oscillators
• Wireless Systems
• Cellular Phones
• Cordless Phones
• Pagers
• Battery Powered Systems
• Portable Systems
• Radio Control Systems
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