DA9123.007
3 May 2004
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: 0.23 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 (with
bypass capacitor 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 very wide. This ESR range from a few mΩ up to a
couple of Ohms combined with no minimum output
FEATURES
• Optimized for Fast Start-up
• Very Low Noise
• Internal Thermal Shutdown
• Short Circuit Protection
• Functionally and Pin Compatible with
LP2982/LP2985/LP3985
• Small SOT23-5 or tiny WL-CSP Package
• Output Voltage Options: 2.8, 3.0 and 3.3 V,
see Ordering Information p. 12
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.
MAS9123 also includes an auto-discharge function,
wherein a shutdown transistor turns on and
discharges the output capacitor, when MAS9123 is
turned off.
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
• GPS Systems
• RF Section of Wireless Systems
• RF Section of Cellular Phones
• Oven Oscillators
• RF Section of Cordless Phones
• Battery Powered Systems
• Portable Systems
• Radio Control Systems
1 (12)