MIC49300
3A Low Voltage LDO Regulator with Dual
Input Voltages
General Description
The MIC49300 is a high-bandwidth, low-dropout, 3.0A
voltage 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.
Datasheets and support documentation are available on
Micrel’s web site at:
www.micrel.com.
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 of –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
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
January 22, 2014
Revision 3.0
Micrel, Inc.
MIC49300
Ordering Information
Part Number
(1,
2)
Output Current
3A
3A
3A
3A
3A
Voltage
0.9V
1.2V
1.5V
1.8V
Adj.
Temperature Range
–40° to +125°C
–40° to +125°C
–40° to +125°C
–40° to +125°C
–40° to +125°C
Package
S-PAK-5
S-PAK-5
S-PAK-5
S-PAK-5
S-PAK-5
MIC49300-0.9WR
MIC49300-1.2WR
MIC49300-1.5WR
MIC49300-1.8WR
MIC49300WR
Note:
1. Other voltages are available. Contact Micrel for details.
2. RoHS-compliant with ‘high-melting solder’ exemption.
Pin Configuration
5-Pin S-Pak (R)
Pin Description
Pin Number
1
2
3
4
5
Pin Name
EN
ADJ
VBIAS
GND
VIN
VOUT
Pin Function
Enable (input): CMOS-compatible input. Logic high = enable, logic low = shutdown.
Adjustable regulator feedback input. Connect to resistor voltage divider.
Input bias voltage for powering all circuitry on the regulator with the exception of the output power
device.
Ground (TAB is connected to ground on S-Pak).
Input voltage that supplies current to the output power device.
Regulator output.
January 22, 2014
2
Revision 3.0
Micrel, Inc.
MIC49300
Absolute Maximum Ratings
(3)
Supply Voltage (V
IN
) ....................................................... +8V
Bias Supply Voltage (V
BIAS
) ............................................ +8V
Enable Input Voltage (V
EN
) ............................................. +8V
Power Dissipation ..................................... Internally Limited
(5)
ESD Rating .................................................................. 2kV
Operating Ratings
(4)
Supply Voltage (V
IN
) ..................................... +1.4V to +6.5V
Bias Supply Voltage (V
BIAS
) ............................. +3V to +6.5V
Enable Input Voltage (V
EN
) .................................. 0V to V
BIAS
Junction Temperature Range .............–40°C ≤ T
J
≤ +125°C
Package Thermal Resistance
S-PAK (
JC
) .......................................................... 2°C/W
Electrical Characteristics
(6)
T
A
= 25°C with V
BIAS
= V
OUT
+ 2.1V; V
IN
= V
OUT
+ 1V;
bold
values indicate –40°C≤ T
J
≤ +125°C, unless noted.
Parameter
Output Voltage Accuracy
Line Regulation
Load Regulation
Dropout Voltage (V
IN
– V
OUT
)
Dropout Voltage (V
BIAS
– V
OUT
),
Note 7
Ground Pin Current,
Note 8
Ground Pin Current in Shutdown
Current through V
BIAS
Current Limit
Enable Input,
Note 9
Enable Input Threshold (fixed voltage only)
Enable Pin Input Current
Reference
Reference Voltage
Notes:
3. Exceeding the absolute maximum ratings may damage the device.
4. The device is not guaranteed to function outside its operating ratings.
5. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
6. Specification for packaged product only.
7. For V
OUT
≤1V, V
BIAS
dropout specification does not apply due to a minimum 3V V
BIAS
input.
8. I
GND
= I
BIAS
+ (I
IN
– I
OUT
). At high loads, input current on V
IN
will be less than the output current, due to drive current being supplied by V
BIAS
.
9. Fixed output voltage versions only.
Condition
At 25°C, fixed voltage options
Over temperature range
V
IN
= 2.0V to 6.5V
I
L
= 0mA to 3A
I
L
= 1.5A
I
L
= 3A
I
L
= 3A
I
L
= 0mA
I
L
= 3A
V
EN
≤ 0.6V, (I
BIAS
+ I
CC
), Note 8
I
L
= 0mA
I
L
= 3A
V
OUT
= 0V
Min.
-1
-2
-0.1
Typ.
Max.
1
2
Units
%
%
%/V
%
mV
mV
V
mA
0.01
0.2
125
280
1.5
25
25
0.07
20
50
6.5
0.1
0.5
200
400
2.1
50
5
35
150
9
mA
µA
mA
mA
A
Regulator enable
Regulator shutdown
1.6
0.6
0.1
1.0
V
V
µA
Adjustable option only
0.891
0.882
0.9
0.909
0.918
V
V
January 22, 2014
3
Revision 3.0
Micrel, Inc.
MIC49300
Functional Diagram
January 22, 2014
4
Revision 3.0
Micrel, Inc.
MIC49300
Typical Characteristics
January 22, 2014
5
Revision 3.0
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