MIC49200
2A Low Voltage LDO
with Dual Input Voltages
General Description
The MIC49200 is a high-bandwidth, low-dropout, 2A
voltage regulator ideal for powering core voltages of low-
power microprocessors. The MIC49200 implements a
dual supply configuration allowing for very low output
impedance and very fast transient response.
The MIC49200 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 MIC49200 offers
fixed
output
voltages from 0.9V to 1.8V and adjustable output voltages
down to 0.9V.
The MIC49200 requires a minimum of output capacitance
for stability, working optimally with small ceramic
capacitors.
The MIC49200 is available in a 5-pin S-Pak. Its operating
temperature range is –40°C to +125°C.
Data sheets and support documentation can be found 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 output capacitors
•
±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
•
Junction temperature range: –40°C to 125°C
Applications
•
•
•
•
•
•
•
Set-top box
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
Output Voltage
(50mV/div)
V
IN
= 2.8V
V
OUT
= 1.8V
Output Current
(1A/div)
V
BIAS
= 4V
C
OUT
= 1µF
Low Voltage, Fast Transient Response Regulator
Time (40µs/div)
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 2006
M9999-011306
(408) 955-1690
Micrel, Inc.
MIC49200
Ordering Information
Part Number
RoHS Compliant
MIC49200-1.0WR*
MIC49200-1.8WR*
MIC49200WR*
Output
Current
2A
2A
2A
Voltage
1.0V
1.8V
Adj
Junction
Temperature Range
–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
* RoHS compliant with ‘high-melting solder’ exemption.
Pin Configuration
5-Pin S-Pak (R)
Pin Description
Pin Number
S-Pak-5
1
Pin Name
EN
ADJ
2
3
4
5
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 which supplies current to the output power device.
Regulator Output.
January 2006
2
M9999-011306
(408) 955-1690
Micrel, Inc.
MIC49200
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) ................................................ 8V
Bias Supply Voltage (V
BIAS
) ..................................... 8V
Enable Input Voltage (V
EN
)...................................... 8V
Power Dissipation............................. Internally Limited
ESD Rating
(3)
.........................................................3kV
Operating Ratings
(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 6.5V
Junction Temperature ...................-40°C
≤
T
J
≤
+125°C
Package Thermal Resistance
S-Pak (θ
JA
) ................................................. 2°C/W
Electrical Characteristics
(4)
T
A
= 25°C with V
BIAS
= V
OUT
+ 2.2V; V
IN
= V
OUT
+ 1V;
bold
values indicate –40°C
≤
T
J
≤
+125°C
(5)
, unless noted.
Parameter
Output Voltage Accuracy
Line Regulation
Load Regulation
Dropout Voltage (V
IN
– V
OUT
)
(Note 5)
I
L
= 1.5A
I
L
= 2A
Dropout Voltage (V
BIAS
– V
OUT
)
(Note 5)
I
L
= 750mA
I
L
= 1.5A
I
L
= 2A
Ground Current
(Note 6)
I
L
= 0mA
I
L
= 2A
Ground Pin Current in Shutdown
Current thru V
BIAS
V
EN
≤
0.6V, (V
BIAS
+ I
INPUT
)
(Note 7)
I
L
= 0mA
I
L
= 2A
Current Limit
Enable Input Threshold
Enable Pin Input Current
Reference
Reference Voltage
Adjustable version
0.891
0.882
0.9
0.909
0.918
V
V
V
OUT
= 0V
Regulator enable
Regulator shutdown
Independent of state
0.1
2.5
1.6
0.6
1
280
400
1.3
1.65
1.75
15
15
0.5
9
40
3.5
25
30
1
2
15
25
120
5.3
6
1.9
2.1
2.0
2.2
Conditions
At 25°C
Over temperature range (I
OUT
= 10mA)
V
IN
= V
OUT
+ 1V to 6.5V
I
L
= 10mA to 2A
I
L
= 750mA
Min
-1
-2
-0.1
0.01
0.2
130
Typ
Max
+1
+2
+0.1
1
1.5
200
300
400
500
530
625
Units
%
%
%/V
%
%
mV
mV
mV
mV
mV
mV
V
V
V
V
V
mA
mA
mA
µA
µA
mA
mA
mA
A
A
V
V
µA
January 2006
3
M9999-011306
(408) 955-1690
Micrel, Inc.
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating range.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
4. Specification for packaged product only.
MIC49200
5. For V
OUT
≤
1.1V, V
BIAS
dropout specification does not apply due to a minimum 3V V
BIAS
input. Dropout voltage is defined as the input-to-output
differential at which the output voltage drops 2% below its nominal value measured at 1V differential for V
IN
and 2.2V differential for V
BIAS
.
For outputs below 1.4V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 1.4V.
6. I
GND
= I
BIAS
+ (I
IN
– I
OUT
). At high loads, input current on V
IN
will be less then the output current, due to drive current being supplied by V
BIAS
.
7. Fixed output voltage versions only.
January 2006
4
M9999-011306
(408) 955-1690
Micrel, Inc.
MIC49200
Functional Diagram
V
BIAS
V
IN
Ilimit
V
EN
/
ADJ
Fixed
Enable
Bandgap
Adj.
R1
Fixed
V
OUT
R2
January 2006
5
M9999-011306
(408) 955-1690
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