MIC49300_05 Datasheet, PDF (1/8 Pages) Micrel Semiconductor – 3.0A Low Voltage LDO Regulator w/Dual Input Voltages

MIC49300
3.0A Low Voltage LDO Regulator w/Dual Input Voltages
General Description
The MIC49300 is a high-bandwidth, low-dropout, 3.0A volt-
age regulator ideal for powering core voltages of low-power
microprocessors. The MIC49300 implements a dual supply
configuration allowing for very low output impedance and
very fast transient response.
The MIC49300 requires a bias input supply and a main input
supply, allowing for ultra-low input voltages on the main supply
rail. The input supply operates from 1.4V to 6.5V and the bias
supply requires between 3V and 6.5V for proper operation.
The MIC49300 offers fixed output voltages from 0.9V to 1.8V
and adjustable output voltages down to 0.9V.
The MIC49300 requires a minimum of output capacitance for
stability, working optimally with small ceramic capacitors.
The MIC49300 is available in a 5-pin S-Pak. It operates over
a junction temperature range of –40°C to +125°C.
Features
• Input Voltage Range:
V_IN: 1.4V to 6.5V
V_BIAS: 3.0V to 6.5V
• Stable with 1µF ceramic capacitor
• ±1% initial tolerance
• Maximum dropout voltage (V_IN-V_OUT) of 500mV over
temperature
• Adjustable output voltage down to 0.9V
• Ultra fast transient response (Up to 10MHz bandwidth)
• Excellent line and load regulation specifications
• Logic controlled shutdown option
• Thermal shutdown and current limit protection
• Power S-Pak package
• Junction temperature range: –40°C to 125°C
Applications
• Graphics processors
• PC Add-In Cards
• Microprocessor core voltage supply
• Low voltage digital ICs
• High Efficiency Linear power supplies
• SMPS post regulators
Typical Application
V_IN = 1.5V
V_BIAS = 3.3V
C_BIAS = 1µF
Ceramic
MIC49300BR
IN
OUT
BIAS ADJ
GND
V_OUT = 1.0V
R1
R2 ^COUT ^{= 10µF}
Ceramic
C_IN = 1µF
Ceramic
Low Voltage,
Fast Transient Response Regulator
Load Transient Response
V_BIAS = 5V
V_IN = 2.5V
V_OUT = 1.8V
C_OUT = 10µF Ceramic
TIME (20µs/div.)
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
August 2005
1
M9999-082605-B