MIC29310/29312
Micrel
MIC29310/29312
3A Fast-Response LDO Regulator
General Description
The MIC29310 and MIC29312 are low cost versions of
MIC29300 family low-dropout (LDO) regulators. Manufac-
tured on Micrel’s proprietary Super beta PNP™ process,
the MIC29310/2 is a 3A LDO regulator with very low-dropout
voltage (600mV over the full load) and low ground current.
Along with a total accuracy of ±2% (over temperature, line
and load regulation) these regulators feature very fast tran-
sient recovery from input voltage surges and output load
current changes.
The MIC29310 is available in
fi
xed 3.3V and 5V outputs
voltages; the MIC29312 has an adjustable output which can
be set by two external resistors to a voltage between 1.24V
to 15V. In addition, all versions are fully protected against
overcurrent faults, reversed input polarity, reversed lead
insertion, and overtemperature operation.
A TTL logic enable (EN) pin is available in the MIC29312 to
shutdown the regulator. When not used, the device can be set
to continuous operation by connecting EN to the input (IN).
The MIC29310/2 is available in the standard 3- and 5-pin
TO-220 and TO-263 packages with an operating junction
temperature range of 0°C to +125°C.
For applications requiring even lower dropout
voltage, input voltage greater than 16V, or an
error flag, see the MIC29300/29301/29302/
29303.
Features
•
•
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•
•
•
•
•
•
•
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Low cost versions of MIC29300 family
Fast transient response
3A current over full temperature range
600mV dropout voltage at full load
Low ground current
Accurate 1% guaranteed tolerance
“Zero” current shutdown mode (MIC29312)
Fixed voltage and adjustable versions
Processor peripheral and I/O supplies
PC add-in cards
High-efficiency “green” computer systems
High-efficiency linear power supplies
High-efficiency switching supply post regulator
Battery-powered equipment
Applications
Typical Application
On
Off
MIC29312
EN
IN
GND
OUT
R1*
ADJ
R2*
V
OUT
V
IN
MIC29310-x.x
IN
OUT
GND
V
OUT
V
IN
V
OUT
= 1.240
R1
+1
R2
* For best performance, total series resistance
(R1 + R2) should be small enough to pass
the minimum regulator load current of 10mA.
Fixed Regulator Configuration
Adjustable Regulator Configuration
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
November 2006
1
MIC29310/29312
MIC29310/29312
Micrel
Ordering Information
Part Number
Standard
MIC29310-3.3BT
MIC29310-3.3BU
MIC29310-5.0BT
MIC29310-5.0BU
MIC29312BT
MIC29312BU
Note:
1.
RoHS compliant with “high-melting solder” exemption.
RoHS Compliant
(1)
MIC29310-3.3WT
MIC29310-3.3WU
MIC29310-5.0WT
MIC29310-5.0WU
MIC29312WT
MIC29312WU
Voltage
3.3V
3.3V
5.0V
5.0V
Adj.
Adj.
Junction Temperature
Range
0°C to +125°C
0°C to +125°C
0°C to +125°C
0°C to +125°C
0°C to +125°C
0°C to +125°C
Package
TO-220
TO-263
TO-220
TO-263
TO-220
TO-263
Pin Configuration
3 OUT
TAB
3
TAB
OUT
GND
IN
2 GND
1
IN
2
1
MIC29310-x.xBT/WT
TO-220-3 (T)
MIC29310-x.xBU/WU
TO-263-3 (U)
5 ADJ
4 OUT
3 GND
2 IN
1 EN
5
4
3
2
1
ADJ
OUT
GND
IN
EN
TAB
TAB
MIC29312-x.xBT/WT
TO-220-5 (T)
MIC29312-x.xBU/WU
TO-263-5 (U)
Pin Function
Enable (Input): Active-high, logic-level enable/shutdown control.
Unregulated Input: +16V maximum supply.
Ground: Ground pin and
TAB
are internally connected.
Regulator Output
Ouput Voltage Adjust: 1.24V feedback from external resistive divider.
Pin Description
Pin Number
MIC29310
1
2,
TAB
3
Pin Number
MIC29312
1
2
3,
TAB
4
5
Pin Name
EN
IN
GND
OUT
ADJ
Absolute Maximum Ratings
(Note 1)
Input Voltage (V
IN
) ..........................................–20V to +20V
Power Dissipation (P
D
) ............................. Internally Limited
Storage Temperature Range (T
S
) ............. –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ........................ 260°C
ESD,
Note 3
MIC29310/29312
2
Operating Ratings
(Note 2)
Input Voltage (V
IN
) ........................................ +2.3V to +16V
Junction Temperature (T
J
) ............................ 0°C to +125°C
Package Thermal Resistance
TO-263
(θ
JC
) ......................................................... 2°C/W
TO-220 (θ
JC
) ......................................................... 2°C/W
TO-220 (θ
JA
) ....................................................... 55°C/W
November 2006
MIC29310/29312
Micrel
Electrical Characteristics
(Note 11)
T
J
= 25°C,
bold
values indicate 0°C
≤
T
J
≤
+125°C; unless noted
Parameter
Output Voltage
Line Regulation
Load Regulation
ΔV
O
/
ΔT
ppm/°C
Dropout Voltage
Condition
10mA
≤
I
O
≤
I
FL
, (V
OUT
+ 1V)
≤
V
IN
≤
8V,
Note 4
I
O
= 10mA, (V
OUT
+ 1V)
≤
V
IN
≤
16V
V
IN
= V
OUT
+ 1V, 10mA
≤
I
OUT
≤
I
FULL LOAD
,
Notes 4, 8
Output Voltage Temperature Coefficient,
Note 8
ΔV
OUT
= –1%,
Note 5
I
O
= 100mA
I
O
= 750mA
I
O
= 1.5A
I
O
= 3A
I
O
= 750mA, V
IN
= V
OUT
+ 1V
I
O
= 1.5A
I
O
= 3A
V
IN
= 0.5V less than specified V
OUT
. I
OUT
= 10mA
V
OUT
= 0V,
Note 6
C
L
= 10µF
C
L
= 33µF
10mA
≤
I
O
≤
I
FL
, V
OUT
+ 1V
≤
V
IN
≤
8V,
Note 4
1.215
40
Note 9
20
0.1
nA/°C
3.0
Min
–2
0.06
0.2
20
Typ
Max
2
0.5
1
100
Units
%
%
%
80
220
330
600
5
15
60
2
3.8
7
400
260
200
1000
20
150
3
mV
mV
mV
mV
mA
mA
mA
mA
A
Ground Current
I
GNDDO
Ground Pin
Current at Dropout
Current Limit
Minimum Load Current
e
n
, Output Noise Voltage
(10Hz to 100kHz) I
L
= 100mA
Reference (MIC29312 only)
Reference Voltage
Adjust Pin Bias Current
Reference Voltage
ppm/°C Temperature Coefficient
Adjust Pin Bias Current
Temperature Coefficient
Enable Input (MIC29312 only)
Input Logic Voltage
Enable Pin Input Current
10
mA
µV
RMS
µV
RMS
1.265
80
120
V
MAX
nA
nA
low (off)
high (on)
V
EN
= V
IN
V
EN
= 0.8V
0.8
2.4
15
–
10
20
30
75
2
4
V
V
µA
µA
µA
µA
µA
µA
Regulator Output
Current in Shutdown
Note 1.
Note 2.
Note 3.
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Note 10
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.
Full Load current is defined as 3A for the MIC29310/29312. For testing, V
OUT
is programmed to 5V.
Dropout voltage is defined as the input-to-output differential when the output voltage drops to 99% of its nominal value with V
OUT
+ 1V applied
to V
IN
.
For this test, V
IN
is the larger of 8V or V
OUT
+ 3V.
Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the load current plus the ground
pin current.
Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
V
REF
≤
V
OUT
≤
(V
IN
– 1V), 2.4V
≤
V
IN
≤
16V, 10mA < I
L
≤
I
FL
, T
J
≤
T
J(max).
Note 10:
V
EN
≤
0.8V and V
IN
≤
8V, V
OUT
= 0.
Note 11:
Specification for packaged product only.
November 2006
3
MIC29310/29312
MIC29310/29312
Micrel
Typical Characteristics
MIC29312 Line Transient Response
with 3A Load, 100F Output Capacitance
MIC29312
EN
V
IN
= V
OUT
+ 1V
IN
GND
OUT
ADJ
49.9k
1%
0.1µF
93.1k
1%
INPUT VOLTAGE
V
OUT
3.525V nominal
4
×
330µF
AVX
TPSE337M006R0100
tantalum
6.525V
4.525V
200s/division
V
OUT
load (not shown):
Intel® Power Validato
r
OUTPUT VOLTAGE
MIC29312 Load Transient Response Test Circuit
+20mV
3.525V
–20mV
I
OUT
= 3A
C
OUT
= 100F
MIC29312 Line Transient Response
with 3A Load, 10F Output Capacitance
MIC29312 Load Transient Response
(See Test Circuit Schematic)
INPUT VOLTAGE
6.525V
4.525V
OUTPUT VOLTAGE
+20mV
3.525V
–20mV
1ms/division
200s/division
I
OUT
= 3A
C
OUT
=10F
OUTPUT VOLTAGE
3.525V
–20mV
LOAD CURRENT
+20mV
3A
200mA
0mA
0.60
DROPOUT VOLTAGE (V)
MIC2931x Dropout Voltage
vs. Output Current
DROPOUT VOLTAGE (mV)
1
0.8
0.6
0.4
0.2
MIC2931x Dropout Voltage
vs. Temperature
OUTPUT VOLTAGE (V)
5.0
4.0
MIC29310-3.3
Dropout Characteristics
0.50
0.40
0.30
0.20
0.10
0.00
0
1
2
OUTPUT CURRENT (A)
3
I
LOAD
= 10mA
3.0
2.0
I
LOAD
= 3A
1.0
0.0
I
LOAD
= 3A
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
0
2
4
INPUT VOLTAGE (V)
6
November 2006
5
MIC29310/29312
PCB设计
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