MIC29310 DATA SHEET (11/09/2015) DOWNLOAD

MIC29310/29312
Micrel
MIC29310/29312
3A Fast-Response LDO Regulator
General Description
Features
The MIC29310 and MIC29312 are low cost versions of
MIC29300 family low-dropout (LDO) regulators. Manufactured 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 transient recovery from input voltage surges and output load
current changes.
The MIC29310 is available in fixed 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.
•
•
•
•
•
•
•
•
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
Applications
•
•
•
•
•
•
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
For applications requiring even lower dropout
voltage, input voltage greater than 16V, or an
error flag, see the MIC29300/29301/29302/
29303.
Typical Application
MIC29312
On
Off
VIN
MIC29310-x.x
IN
VOUT
OUT
EN
R1*
VOUT
VIN
OUT
ADJ
IN
GND
R2*
GND
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
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MIC29310/29312
MIC29310/29312
Micrel
Ordering Information
Part Number
Voltage
Junction Temperature
Range
Package
MIC29310-3.3WT
3.3V
0°C to +125°C
TO-220
MIC29310-3.3BU
MIC29310-3.3WU
3.3V
0°C to +125°C
TO-263
MIC29310-5.0BT
MIC29310-5.0WT
5.0V
0°C to +125°C
TO-220
MIC29310-5.0BU
MIC29310-5.0WU
5.0V
0°C to +125°C
TO-263
MIC29312BT
MIC29312WT
Adj.
0°C to +125°C
TO-220
MIC29312BU
MIC29312WU
Adj.
0°C to +125°C
TO-263
Standard
RoHS Compliant(1)
MIC29310-3.3BT
Note:
1.
RoHS compliant with “high-melting solder” exemption.
Pin Configuration
TAB
TAB
3 OUT
2 GND
1
IN
OUT
2
GND
1
IN
MIC29310-x.xBU/WU
TO-263-3 (U)
MIC29310-x.xBT/WT
TO-220-3 (T)
5
4
3
2
1
TAB
5 ADJ
4 OUT
3 GND
2 IN
1 EN
TAB
3
ADJ
OUT
GND
IN
EN
MIC29312-x.xBU/WU
TO-263-5 (U)
MIC29312-x.xBT/WT
TO-220-5 (T)
Pin Description
Pin Number
MIC29310
Pin Number
MIC29312
Pin Name
Pin Function
1
EN
Enable (Input): Active-high, logic-level enable/shutdown control.
1
2
IN
Unregulated Input: +16V maximum supply.
2, TAB
3, TAB
GND
Ground: Ground pin and TAB are internally connected.
3
4
OUT
Regulator Output
5
ADJ
Ouput Voltage Adjust: 1.24V feedback from external resistive divider.
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Input Voltage (VIN) ..........................................–20V to +20V
Power Dissipation (PD) ............................. Internally Limited
Storage Temperature Range (TS) ............. –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ........................ 260°C
ESD, Note 3
Input Voltage (VIN) ........................................ +2.3V to +16V
Junction Temperature (TJ) ............................ 0°C to +125°C
Package Thermal Resistance
TO-263 (θJC) ......................................................... 2°C/W
TO-220 (θJC) ......................................................... 2°C/W
TO-220 (θJA) ....................................................... 55°C/W
MIC29310/29312
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November 2006
MIC29310/29312
Micrel
Electrical Characteristics(Note 11)
TJ = 25°C, bold values indicate 0°C ≤ TJ ≤ +125°C; unless noted
Parameter
Condition
Output Voltage
10mA ≤ IO ≤ IFL, (VOUT + 1V) ≤ VIN ≤ 8V, Note 4
Max
Units
2
%
Line Regulation
IO = 10mA, (VOUT + 1V) ≤ VIN ≤ 16V
Load Regulation
VIN = VOUT + 1V, 10mA ≤ IOUT ≤ IFULL LOAD, Notes 4, 8
0.06
0.5
%
0.2
1
%
ΔVO / ΔT
ppm/°C
Output Voltage Temperature Coefficient, Note 8
20
100
Dropout Voltage
ΔVOUT = –1%, Note 5
IO = 100mA
IO = 750mA
IO = 1.5A
IO = 3A
80
220
330
600
200
Ground Current
Min
IO = 750mA, VIN = VOUT + 1V
IO = 1.5A
IO = 3A
IGNDDO Ground Pin
Current at Dropout
VIN = 0.5V less than specified VOUT. IOUT = 10mA
Current Limit
VOUT = 0V, Note 6
3.0
Minimum Load Current
en, Output Noise Voltage
(10Hz to 100kHz) IL = 100mA
Typ
–2
1000
20
5
15
60
150
mA
mA
mA
2
3
mA
10
mA
3.8
A
7
CL = 10µF
CL = 33µF
mV
mV
mV
mV
400
260
µVRMS
µVRMS
Reference (MIC29312 only)
Reference Voltage
10mA ≤ IO ≤ IFL, VOUT + 1V ≤ VIN ≤ 8V, Note 4
1.215
Adjust Pin Bias Current
Reference Voltage
ppm/°C Temperature Coefficient
40
Note 9
1.265
VMAX
80
120
nA
nA
20
Adjust Pin Bias Current
Temperature Coefficient
0.1
nA/°C
Enable Input (MIC29312 only)
Input Logic Voltage
Enable Pin Input Current
Regulator Output
Current in Shutdown
Note 1.
low (off)
high (on)
0.8
V
V
2.4
VEN = VIN
15
30
75
µA
µA
VEN = 0.8V
–
2
4
µA
µA
Note 10
10
20
µA
µA
Exceeding the absolute maximum rating may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3.
Devices are ESD sensitive. Handling precautions recommended.
Note 4:
Full Load current is defined as 3A for the MIC29310/29312. For testing, VOUT is programmed to 5V.
Note 5:
Dropout voltage is defined as the input-to-output differential when the output voltage drops to 99% of its nominal value with VOUT + 1V applied
to VIN.
Note 6:
For this test, VIN is the larger of 8V or VOUT + 3V.
Note 7:
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.
Note 8:
Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
Note 9:
VREF ≤ VOUT ≤ (VIN – 1V), 2.4V ≤ VIN ≤ 16V, 10mA < IL ≤ IFL, TJ ≤ TJ(max).
Note 10: VEN ≤ 0.8V and VIN ≤ 8V, VOUT = 0.
Note 11: Specification for packaged product only.
November 2006
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MIC29310/29312
MIC29310/29312
Micrel
Block Diagram
IN
OUT
*EN
Bias
On/Off
O.V.
ILIMIT
16V
Reference
Feedback
ADJ*
Thermal
Shutdown
GND
MIC29310/29312
MIC29310/29312
* MIC29312 only.
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November 2006
MIC29310/29312
Micrel
Typical Characteristics
MIC29312 Line Transient Response
with 3A Load, 100F Output Capacitance
VIN = VOUT + 1V
EN
OUT
IN
ADJ
GND
0.1µF
49.9k
1%
INPUT VOLTAGE
VOUT
3.525V nominal
MIC29312
93.1k
1%
4 × 330µF
AVX
TPSE337M006R0100
tantalum
6.525V
4.525V
200s/division
OUTPUT VOLTAGE
VOUT load (not shown):Intel® Power Validato
r
MIC29312 Load Transient Response Test Circuit
+20mV
3.525V
–20mV
MIC29312 Load Transient Response
(See Test Circuit Schematic)
OUTPUT VOLTAGE
6.525V
4.525V
LOAD CURRENT
3.525V
–20mV
DROPOUT VOLTAGE (V)
0.60
MIC2931x Dropout Voltage
vs. Output Current
1
0.50
0.40
0.30
0.20
0.10
0.00
0
1
2
OUTPUT CURRENT (A)
November 2006
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3.525V
–20mV
1ms/division
IOUT = 3A
COUT =10F
DROPOUT VOLTAGE (mV)
OUTPUT VOLTAGE
200s/division
+20mV
3A
200mA
0mA
MIC2931x Dropout Voltage
vs. Temperature
0.8
0.6
0.4
ILOAD = 3A
0.2
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
5
MIC29310-3.3
Dropout Characteristics
5.0
OUTPUT VOLTAGE (V)
INPUT VOLTAGE
MIC29312 Line Transient Response
with 3A Load, 10F Output Capacitance
+20mV
IOUT = 3A
COUT = 100F
4.0
ILOAD = 10mA
3.0
2.0
ILOAD = 3A
1.0
0.0
0
2
4
INPUT VOLTAGE (V)
6
MIC29310/29312
MIC29310/29312
20
2.0
1.0
0.0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
40
30
20
10
0
40
ENABLE CURRENT (µA)
OUTPUT VOLTAGE (V)
50
0
1
2
OUTPUT CURRENT (A)
3
30
25
20
VEN = 5V
15
10
VEN = 2V
5
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
10
IOUT = 1.5A
5
20
MIC2931x Ground Current
vs. Temperature
80
IOUT = 3A
60
40
20
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
MIC29310-3.3 Output Voltage
vs. Temperature
MIC2931x Short Circuit
Current vs. Temperature
6
5
3 DEVICES
3.24
3.22
3.20
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
MIC29312 Enable Current
vs. Temperaure
35
15
100
3.40
3.38
3.36
3.34
3.32
3.30
3.28
3.26
4
3
VOUT = 0V
2
1
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
MIC29312 Adjust Pin Current
vs. Temperature
50
ADJUST PIN CURRENT (nA)
GROUND CURRENT (mA)
60
MIC2931x Ground Current
vs. Output Current
MIC2931x Ground Current
vs. Temperature
-10
0
10
INPUT VOLTAGE (V)
10
40
30
ILOAD = 10mA
20
10
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
MIC2931x Output Impedance
vs. Frequency
1
0.1
0.01
0.001
1x106
IOUT = 750mA
3.0
10
100x103
4.0
RLOAD = 100Ω
-0.5
-20
10x103
5.0
2
4
6
8
INPUT VOLTAGE (V)
0.0
1x103
MIC2931x Ground Current
vs. Temperature
0
0.5
100x100
10
1.0
10x100
6.0
2
4
6
8
INPUT VOLTAGE (V)
0
VOUT = 3.3V
1.5
CURRENT (A)
0
50
OUTPUT IMPEDANCE (Ω)
0.5
100
MIC2931x Ground Current
vs. Input Voltage
2.0
GROUND CURRENT (mA)
GROUND CURRENT (mA)
1.0
IOUT = 3A
150
GROUND CURRENT (mA)
GROUND CURRENT (mA)
IOUT = 10mA
1.5
0.0
MIC2931x Ground Current
vs. Input Voltage
200
GROUND CURRENT (mA)
MIC2931x Ground Current
vs. Input Voltage
2.0
GROUND CURRENT (mA)
Micrel
FREQUENCY (Hz)
MIC29310/29312
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November 2006
MIC29310/29312
Micrel
Applications Information
PD = IOUT × (1.02VIN – VOUT)
The MIC29310 and MIC29312 are high performance low-dropout voltage regulators suitable for all moderate to high-current
voltage regulator applications. Their 600mV of dropout voltage
at full load make them especially valuable in battery powered
systems and as high efficiency noise filters in “post-regulator”
applications. Unlike older NPN-pass transistor designs, where
the minimum dropout voltage is limited by the base-emitter
voltage drop and collector-emitter saturation voltage, dropout
performance of the PNP output of these devices is limited
merely by the low VCE saturation voltage.
A trade-off for the low dropout voltage is a varying base
drive requirement. But Micrel’s Super ßeta PNP™ process
reduces this drive requirement to merely 2% to 5% of the
load current.
MIC29310/312 regulators are fully protected from damage
due to fault conditions. Current limiting is provided. This
limiting is linear; output current under overload conditions
is constant. Thermal shutdown disables the device when
the die temperature exceeds the maximum safe operating
temperature. Transient protection allows device (and load)
survival even when the input voltage spike above and below
nominal. The output structure of these regulators allows voltages in excess of the desired output voltage to be applied
without reverse current flow. The MIC29312 version offers a
logic level ON/OFF control: when disabled, the devices draw
nearly zero current.
An additional feature of this regulator family is a common
pinout: a design’s current requirement may change up or down
yet use the same board layout, as all of Micrel’s high-current
Super ßeta PNP™ regulators have identical pinouts.
Where the ground current is approximated by 2% of IOUT.
Then the heat sink thermal resistance is determined with
this formula:
TJ MAX – TA
θSA = —————— – (θJC + θCS)
PD
Where TJ MAX ≤ 125°C and θCS is between 0 and 2°C/W.
The heat sink may be significantly reduced in applications
where the minimum input voltage is known and is large compared with the dropout voltage. Use a series input resistor to
drop excessive voltage and distribute the heat between this
resistor and the regulator. The low dropout properties of Micrel
Super ßeta PNP regulators allow very significant reductions
in regulator power dissipation and the associated heat sink
without compromising performance. When this technique is
employed, a capacitor of at least 0.1µF is needed directly
between the input and regulator ground.
Please refer to Application Note 9 for further details and examples on thermal design and heat sink specification.
Capacitor Requirements
For stability and minimum output noise, a capacitor on the
regulator output is necessary. The value of this capacitor
is dependent upon the output current; lower currents allow
smaller capacitors. MIC29310/2 regulators are stable with a
minimum capacitor value of 10µF at full load.
This capacitor need not be an expensive low ESR type:
aluminum electrolytics are adequate. In fact, extremely low
ESR capacitors may contribute to instability. Tantalum capacitors are recommended for systems where fast load transient
response is important.
Where the regulator is powered from a source with a high
AC impedance, a 0.1µF capacitor connected between Input
and GND is recommended. This capacitor should have good
characteristics to above 250kHz.
Transient Response and 5V to 3.3V Conversion
The MIC29310/2 have excellent response to variations in
input voltage and load current. By virtue of their low dropout
voltage, these devices do not saturate into dropout as readily
as similar NPN-based designs. A 3.3V output Micrel LDO will
maintain full speed and performance with an input supply as
low as 4.2V, and will still provide some regulation with supplies down to 3.8V, unlike NPN devices that require 5.1V
or more for good performance and become nothing more
than a resistor under 4.6V of input. Micrel’s PNP regulators
provide superior performance in “5V to 3.3V” conversion
applications than NPN regulators, especially when all tolerances are considered.
Minimum Load Current
The MIC29310/2 regulators are specified between finite loads.
If the output current is too small, leakage currents dominate
VOUT
IN
OUT
GND
Figure 3. The MIC29310 regulator requires only two
capacitors for operation.
Thermal Design
Linear regulators are simple to use. The most complicated
design parameters to consider are thermal characteristics.
Thermal design requires the following application-specific
parameters:
• Maximum ambient temperature, TA
• Output Current, IOUT
• Output Voltage, VOUT
• Input Voltage, VIN
First, we calculate the power dissipation of the regulator
from these numbers and the device parameters from this
datasheet.
November 2006
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MIC29310/29312
MIC29310/29312
Micrel
VOUT
R1 = R2 × ( –—— – 1 )
1.240
and the output voltage rises. A 10mA minimum load current
is necessary for proper regulation.
Adjustable Regulator Design
Where VO is the desired output voltage. Figure 4 shows
component definition. Applications with widely varying load
currents may scale the resistors to draw the minimum load
current required for proper operation (see the table below).
Enable Input
The MIC29312 version features an enable (EN) input that
allows ON/OFF control of the device. Special design allows “zero” current drain when the device is disabled—only
microamperes of leakage current flows. The EN input has
TTL/CMOS compatible thresholds for simple interfacing with
logic, or may be directly tied to VIN. Enabling the regulator
requires approximately 20µA of current into the EN pin.
Figure 4. Adjustable Regulator with Resistors
The adjustable regulator version, MIC29312, allows programming the output voltage anywhere between 1.25V and the
15V maximum operating rating of the family. Two resistors
are used. Resistors can be quite large, up to 1MΩ, because
of the very high input impedance and low bias current of the
sense comparator. The resistor values are calculated by:
Resistor Value Table for the MIC29312 Adjustable Regulator
Voltage
2.85
2.9
3.0
3.1
3.15
3.3
3.45
3.6
3.8
4.0
4.1
Standard (Ω)
R1
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
R2
76.8k
75.0k
69.8k
66.5k
64.9k
60.4k
56.2k
52.3k
48.7k
45.3k
43.2k
Min. Load (Ω)
R1
162
165
174
187
191
205
221
237
255
274
287
R2
124
124
124
124
124
124
124
124
124
124
124
Note: This regulator has a minimum load requirement. “Standard” values assume the load meets this requirement. “Minimum
Load” values are calculated to draw 10mA and allow regulation with an open load (the minimum current drawn from the load
may be zero).
MIC29310/29312
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November 2006
MIC29310/29312
Micrel
Package Information
3-Pin TO-220 (T)
3-Pin TO-263 (U)
November 2006
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MIC29310/29312
MIC29310/29312
Micrel
5-Pin TO-220 (T)
5-Pin TO-263 (U)
MIC29310/29312
10
November 2006
MIC29310/29312
November 2006
Micrel
11
MIC29310/29312
MIC29310/29312
Micrel
MICREL, INC.
2180 FORTUNE DRIVE
SAN JOSE, CA 95131
USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s
use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser’s own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2005 Micrel, Incorporated.
MIC29310/29312
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November 2006