MIC49300
Micrel
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 1
µ
F 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
Load Transient Response
IN
OUT
R1
V
BIAS
= 3.3V
C
BIAS
= 1
µF
Ceramic
C
IN
= 1
µF
Ceramic
BIAS
ADJ
R2 C
OUT
=
10µF
Ceramic
V
OUT
20mV/div
V
IN
= 1.5V
MIC49300BR
V
OUT
= 1.0V
GND
V
BIAS
= 5V
V
IN
= 2.5V
V
OUT
= 1.8V
C
OUT
= 10µF Ceramic
Low Voltage,
Fast Transient Response Regulator
I
OUT
2A/div
TIME (20µs/div.)
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
October 2003
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MIC49300
MIC49300
Micrel
Ordering Information
Part Number
MIC49300-0.9BR
MIC49300-1.2BR
MIC49300-1.5BR
MIC49300-1.8BR
MIC49300BR
Output Current
3A
3A
3A
3A
3A
Voltage
0.9V
1.2V
1.5V
1.8V
ADJ.
Temperature Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
S-Pak-5
S-Pak-5
S-Pak-5
S-Pak-5
S-Pak-5
Other voltages available. Contact Micrel for details.
Pin Configuration
5
4
3
2
1
VOUT
VIN
GND
VBIAS
EN/ADJ.
TAB
5-Lead S-Pak (R)
Pin Description
Pin Number
1
Pin Name
Enable
ADJ.
4
5
2
3
VIN
VOUT
VBIAS
GND
Pin Function
Enable (Input): CMOS compatible input. Logic high = enable, logic low =
shutdown.
Adjustable regulator feedback input. Connect to resistor voltage divider.
Input voltage which supplies current to the output power device.
Regulator Output.
Input Bias Voltage for powering all circuitry on the regulator with the excep-
tion of the output power device.
Ground (TAB is connected to ground on S-Pak).
MIC49300
2
October 2003
MIC49300
Micrel
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
IN
) ....................................................... 8V
Bias Supply Voltage (V
BIAS
) ............................................ 8V
Enable Input Voltage (V
EN
) ............................................. 8V
Power Dissipation .................................... Internally Limited
ESD Rating,
Note 3
...................................................... 2kV
Operating Ratings
(Note 2)
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
IN
Junction Temperature Range ............. –40°C
≤T
J
≤
+125°C
Package Thermal Resistance
S-PAK(θ
JC
) ............................................................ 2°C/W
Electrical Characteristics
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,
Note 4;
unless otherwise specified.
Parameter
Output Voltage Accuracy
Line Regulation
Load Regulation
Dropout Voltage (V
IN
– V
OUT
)
Dropout Voltage (V
BIAS
– V
OUT
)
Note 4
Ground Pin Current,
Note 5
Conditions
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
Ground Pin Current in Shutdown
Current thru V
BIAS
Current Limit
Enable Input, Note 6
Enable Input Threshold
(Fixed Voltage only)
Enable Pin Input Current
Reference
Reference Voltage
Note 1.
Note 2.
Note 3.
Note 4.
Note 5.
Note 6.
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
V
EN
≤
0.6V, (I
BIAS
+ I
CC
),
Note 6
I
L
= 0mA
I
L
= 3A
V
OUT
= 0V
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
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
For V
OUT
≤1V,
V
BIAS
dropout specification does not apply due to a minimum 3V V
BIAS
input.
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
.
Fixed output voltage versions only.
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MIC49300
MIC49300
Micrel
Functional Diagram
V
BIAS
V
IN
Ilimit
V
EN
/
ADJ
Fixed
Enable
Bandgap
Adj.
V
IN
Open
Circuit
Fixed
V
OUT
R1
R2
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October 2003
MIC49300
Micrel
Typical Characteristics
V
IN
Dropout
vs. Output Current
V
BIAS
Dropout
vs. Output Current
Dropout vs.
Temperature (Input Supply)
400
350
V
IN
DROPOUT (mV)
300
1.7
1.6
V
BIAS
DROPOUT (V)
V
IN
DROPOUT (mV)
250
200
150
100
50
0
0
0.5
1
1.5
2
2.5
OUTPUT CURRENT (A)
3
1.5
1.4
1.3
1.2
1.1
1
0
0.5 1.0 1.5 2.0 2.5
OUTPUT CURRENT (A)
3.0
300
250
200
150
100
50
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Dropout Characteristics
2.0
OUTPUT VOLTAGE (V)
BIAS CURRENT (mA)
Bias Current
vs. Input Supply
25
I
OUT
= 100mA
Bias Current
vs. Supply Voltage
1000
900
BIAS CURRENT (mA)
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
I
OUT
= 2A
100mA
3A
20
I
OUT
= 0mA
15
10
5
V
OUT
= 1.8V
V
BIAS
= 5V
800
700
600
500
400
300
200
100
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
SUPPLY VOLTAGE (V)
I
OUT
= 3A
I
OUT
= 1A
V
BIAS
= 5V
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
SUPPLY VOLTAGE (V)
0
0 0.5 1 1.5 2 2.5 3 3.5 4
INPUT SUPPLY (V)
Bias Current
vs. Output Current
35
35
BIAS CURRENT (mA)
30
25
20
15
10
5
3.0
30
25
20
15
10
5
0
0
V
BIAS
= 5V
V
IN
= 2.5V
0.5 1.0 1.5 2.0 2.5
OUTPUT CURRENT (A)
Bias Current
vs. Temperature
60
I
OUT
= 500mA
BIAS CURRENT (mA)
I
OUT
= 100mA
Bias Current
vs. Temperature
50
40
30
20
10
I
OUT
= 1A
BIAS CURRENT (mA)
I
OUT
= 3A
I
OUT
= 2A
I
OUT
= 100µA
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Output Voltage
vs. Temperature
SHORT CIRCUIT CURRENT (A)
1.834
9
8
7
6
5
4
3
2
1
Short Circuit
vs. Temperature
OUTPUT VOLTAGE (V)
1.824
1.814
1.804
1.794
1.784
1.774
1.764
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE(°C)
October 2003
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MIC49300
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