MIC39500_05 [MICREL]
5A μCap Low-Voltage Low-Dropout Regulator; 5A μCap低电压低压差稳压器
| 型号： | MIC39500_05 |
| 厂家： | 
MICREL SEMICONDUCTOR |
| 描述： | 5A μCap Low-Voltage Low-Dropout Regulator |
| 文件： | 总10页 (文件大小：1981K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
5A µCap Low-Voltage Low-Dropout Regulator
General Description
The MIC39500 and MIC39501 are 5A low-dropout linear
voltage regulators that provide a low-voltage, high-current
output with a minimum of external components. Utilizing
Micrel’s proprietary Super βeta PNP™ pass element, the
MIC39500/1 offers extremely low dropout (typically 400mV
at 5A) and low ground current (typically 70mA at 5A).
• 5A minimum guaranteed output current
• 400mV dropout voltage
Ideal for 3.0V to 2.5V conversion
Ideal for 2.5V to 1.8V conversion
• 1% initial accuracy
• Low ground current
• Current limiting and thermal shutdown
• Reversed-battery and reversed-lead insertion protection
• Reversed-leakage protection
• Fast transient response
• TO-263 and TO-220 packages
• TTL/CMOS compatible enable pin (MIC39501 only)
• Error flag output (MIC39501 only)
• Ceramic capacitor stable (See Application Information)
The MIC39500/1 is ideal for PC Add-In cards that need to
convert from standard 2.5V or 3.3V, down to new, lower
core voltages. A guaranteed maximum dropout voltage of
500mV over all operating conditions allows the MIC39500/1
to provide 2.5V from a supply as low as 3V or 1.8V from
2.5V. The MIC39500/1 also has fast transient response, for
heavy switching applications. The device requires only 47µF
of output capacitance to maintain stability and achieve fast
transient response
The MIC39500/1 is fully protected with overcurrent limiting,
thermal shutdown, reversed-battery protection, reversed-
lead insertion protection, and reversed-leakage protection.
The MIC39501 offers a TTL-logic-compatible enable pin and
an error flag that indicates undervoltage and overcurrent
conditions. Offered in a fixed voltages, 1.8V and 2.5V, the
MIC39500/1 comes in the TO-220 and TO-263 packages
and an ideal upgrade to older, NPN-based linear voltage
regulators.
Applications
• Low Voltage Digital ICs
• LDO linear regulator for PC add-in cards
• High-efficiency linear power supplies
• SMPS post regulator
• Multimedia and PC processor supplies
• Low-voltage microcontrollers
• StrongARM™ processor supply
For applications requiring input voltage
greater than 16V, see the
MIC29500/1/2/3 family. For applications
with input voltage 6V or below, see
MIC3750x LDOs.
Typical Application
100KΩ
MIC39501-2.5
Enable
Shutdown
ERROR
FLAG OUTPUT
EN
FLG
MIC39500-2.5
VIN
3.3V
VOUT
2.5V
IN
OUT
VIN
3.3V
VOUT
2.5V
OUT
IN
GND
GND
1.0µF
47µF
1.0µF
47µF
MIC39500
StrongARM is a trademark of Advanced RISC Machines, Ltd.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
August 2005
1
M9999-082605-B
MIC39500/39501
Micrel
Ordering Information
Part Number
Voltage
Junction Temp. Range
Package
Standard
RoHS Compliant*
MIC39500-2.5BT
MIC39500-2.5BU
MIC39501-2.5BT
MIC39501-2.5BU
MIC39500-1.8BT
MIC39500-1.8BU
MIC39501-1.8BT
MIC39501-1.8BU
MIC39500-2.5WT*
MIC39500-2.5WU*
MIC39501-2.5WT*
MIC39501-2.5WU*
MIC39500-1.8WT*
MIC39500-1.8WU*
MIC39501-1.8WT*
MIC39501-1.8WU*
2.5V
2.5V
2.5V
2.5V
1.8V
1.8V
1.8V
1.8V
-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
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
3-Lead TO-220
3-Lead TO-263
5-Lead TO-220
5-Lead TO-263
3-Lead TO-220
3-Lead TO-263
5-Lead TO-220
5-Lead TO-263
* RoHS compliant with high-melting solder exemption.
Pin Configuration
3
2
1
OUT
3
2
1
OUT
GND
IN
GND
IN
MIC39500-x.xBT
TO-220-3 (T)
MIC39500-x.xBU
TO-263-3 (U)
5
4
3
2
1
FLG
OUT
GND
IN
5
4
3
2
1
FLG
OUT
GND
IN
EN
EN
MIC39501-x.xBT
TO-220-5 (T)
TO-263-5 (U)
Pin Description
Pin Number
Pin Number
Pin Name
Pin Function
MIC39500
MIC39501
1
EN
Enable (Input): TTL/CMOS compatible input. Logic high = enable; logic low
or open = shutdown
1
2, TAB
3
2
3, TAB
4
IN
Unregulated Input: +16V maximum supply.
Ground: Ground pin and TAB are internally connected.
Regulator Output
GND
OUT
FLG
5
Error Flag (Ouput): Open collector output. Active low indicates an output
fault condition.
M9999-082605-B
2
August 2005
MIC39500/39501
Micrel
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Supply Voltage (V )
–20V to +20V
Supply Voltage (V )
+2.25V to +16V
+16V
IN
IN
Enable Voltage (V
)
+20V
–65°C to +150°C
260°C
Enable Voltage (V
)
EN
EN
Storage Temperature (T )
Maximum Power Dissipation (P
)
D(max)
Note 4
S
Lead Temperature (soldering, 5 sec.)
Junction Temperature (T )
–40°C to +125°C
J
ESD, Note 3
Package Thermal Resistance
TO-263 (θ
)
2°C/W
2°C/W
JC
JC
TO-220 (θ
)
Electrical Characteristics
TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted
Symbol
Parameter
Condition
Min
Typ
Max
Units
VOUT
Output Voltage
10mA
–1
–2
1
2
%
%
10mA ≤ IOUT ≤ 5A, VOUT + 1V ≤ VIN ≤ 16V
IOUT = 10mA, VOUT + 1V ≤ VIN ≤ 16V
VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 5A
Line Regulation
0.06
0.2
20
0.5
1
%
%
Load Regulation
∆VOUT/∆T
ppm/°C
Output Voltage Temp. Coefficient,
100
Note 5
VDO
Dropout Voltage, Note 6
IOUT = 250mA, ∆VOUT = –2%
IOUT = 2.5A, ∆VOUT = –2%
125
320
400
15
250
mV
mV
mV
mA
mA
mA
A
IOUT = 5A, ∆VOUT = –2%
575
50
IGND
Ground Current, Note 7
IOUT = 2.5A, VIN = VOUT + 1V
IOUT = 5A, VIN = VOUT + 1V
70
IGND(do)
IOUT(lim)
Dropout Ground Pin Current
Current Limit
VIN ≤ VOUT(nominal) – 0.5V, IOUT = 10mA
VOUT = 0V, VIN = VOUT + 1V
2.1
7.5
260
en
Output Noise Voltage
COUT = 47µF, IOUT = 100mA, 10Hz to 100kHz
µV(rms)
Enable Input (MIC39501)
VEN Enable Input Voltage
logic low (off)
logic high (on)
VEN = VIN
0.8
V
V
2.25
IIN
Enable Input Current
30
10
35
75
µA
µA
VEN = 0.8V
2
4
µA
µA
IOUT(shdn)
Shutdown Output Current
Note 8
20
µA
Flag Output (MIC39501)
IFLG(leak) Output Leakage Current
VOH = 16V
0.01
180
1
2
µA
µA
VFLG(do)
Output Low Voltage
VIN = 2.250V, IOL, = 250µA, Note 9
300
400
mV
mV
Low Threshold
High Threshold
Hysteresis
1% of VOUT
1% of VOUT
93
%
%
%
VFLG
99.2
1
Note 1. Exceeding the absolute maximum ratings 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. PD(max) = (TJ(max) – TA) θJA, where θdepends upon the printed circuit layout. See “Applications Information.”
Note 5. Output voltage temperature coefficient is ∆VOUT(worst case) (TJ(max) – TJ(min)) where TJ(max) is +125°C and TJ(min) is –40°C.
Note 6. VDO = VIN – VOUT when VOUT decreases to 98% of its nominal output voltage with VIN = VOUT + 1V. For voltages below 2.25V, Dropout volt-
age is the input-to-output voltage differential with the minimum input voltage being 2.25V. Minimum input operating voltage is 2.25V.
Note 7. IGND is the quiescent current. IIN = IGND + IOUT
Note 8. VEN ≤ 0.8V, VIN ≤ 8V, and VOUT = 0V
Note 9. For a 2.5V device, VIN = 2.250V (device is in dropout).
August 2005
3
M9999-082605-B
MIC39500/39501
Micrel
Typical Characteristics
Dropout Voltage vs .
Output C urrent
P ower S upply
P ower S upply
R ejection R atio
R ejection R atio
450
400
350
300
250
200
150
100
50
35
35
30
25
20
15
10
5
VOUT = 1.8V
VIN = 3.3V
VOUT = 2.5V
ILOAD = 5A
30
25
20
15
10
5
VIN = 3.3V
VOUT = 2.5V
ILOAD = 5A
VOUT = 2.5V
C IN = 0
C IN = 0
C OUT = 100µF C eramic
C OUT = 47µF Tant
0
0
0
1E+1 1E+2 1E+3 1E+4 1E+5 1E+6
1E+1 1E+2 1E+3 1E+4 1E+5 1E+6
1k 10k
1M
1k 10k
1M
10M
100k
10 100
100k
10M
10 100
FREQUENCY (Hz)
FREQUENCY (Hz)
OUTPUT CURRENT (mA)
Dropout Voltage
vs . Temperature
Dropout C haracteris tics
G round C urrent vs .
Output C urrent
80
70
60
50
40
30
20
10
0
600
500
400
300
200
100
0
2.8
2.6
2.4
2.2
2
VIN = VOUT +1V
VOUT = 1.8V
ILOAD = 100mA
ILOAD = 2.5A
VOUT = 2.5V
ILOAD = 5A
VOUT = 2.5V
1.8
1.6
1.4
VOUT = 1.8V
ILOAD = 5A
INPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
TEMPERATURE (°C)
G round C urrent vs .
S upply Voltage
G round C urrent
vs . Temperature
G round C urrent vs .
S upply Voltage
12.0
10.0
8.0
180
160
140
120
100
80
10
9
8
7
6
5
4
3
2
1
0
VOUT = 2.5V
ILOAD = 10mA
6.0
VOUT = 1.8V
ILOAD = 100mA
ILOAD = 5.0A
4.0
60
2.0
ILOAD = 2.5A
ILOAD = 2.0A
40
ILOAD = 10mA
VIN = VOUT + 1V
20
0.0
0
1 2 3 4 5 6 7 8 9 10
SUPPLY VOLTAGE (V)
0
0
2
4
6
8
10
-40 -20 0 20 40 60 80 100 120140
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
G round C urrent
vs . Temperature
S hort C ircuit C urrent
vs . Temperature
G round C urrent
vs . Temperature
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
10.0
30
25
20
15
10
5
VOUT = 2.5V
9.0 Typical 2.5V Device
VOUT = 2.5V
8.0
7.0
VOUT = 1.8V
6.0 Typical 1.8V Device
VOUT = 1.8V
5.0
4.0
3.0
2.0
ILOAD = 5A
VIN = VOUT = 1V
ILOAD = 2.5A
VIN = VOUT + 1V
1.0
VIN = VOUT + 1V
0
0
0
-40 -20
0
20 40 60 80 100 120140
-40 -20
0 20 40 60 80 100 120140
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120 140
TEMPERATURE (°C)
TEMPERATURE (°C)
M9999-082605-B
4
August 2005
MIC39500/39501
Micrel
E nable C urrent
vs . Temperature
Flag L ow Voltage
vs . Temperature
E rror Flag P ull-up R es is tor
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
350
300
250
200
150
100
50
F lag_HIG H (OK)
F lag_LOW
(FAULT)
VE N = 2.25V
VIN = VOUT + 1V
VIN = 2.8V
R P ULL-UP = 22kΩ
0
-40 -20
0
20 40 60 80 100120 140
-40 -20
0
20 40 60 80 100120 140
TEMPERATURE (°C)
TEMPERATURE (°C)
RESISTANCE (kΩ)
August 2005
5
M9999-082605-B
MIC39500/39501
Micrel
Functional Diagram
IN
OUT
O.V.
ILIMIT
18V
1.180V
1.240V
Ref.
FLAG*
EN*
Thermal
Shut-
down
GND
* MIC39501 only
M9999-082605-B
6
August 2005
MIC39500/39501
Micrel
pared 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
MicrelSuperβetaPNPregulatorsallowsignificantreductions
in regulator power dissipation and the associated heat sink
without compromising performance. When this technique
is employed, a capacitor of at least 1µF is needed directly
between the input and regulator ground.
Applications Information
The MIC39500/1 is a high-performance low-dropout voltage
regulatorsuitableformoderatetohigh-currentvoltageregula-
tor applications. Its 400mV dropout voltage at full load makes
it especially valuable in battery-powered systems and as a
high-efficiency noise filter in post-regulator applications. Un-
like older NPN-pass transistor designs, where the minimum
dropout voltage is limited by the base-to-emitter voltage drop
and collector-to-emitter saturation voltage, dropout perfor-
mance of the PNP output of these devices is limited only by
Refer to Application Note 9 for further details and examples
on thermal design and heat sink specification.
the low V saturation voltage.
Output capacitor
CE
Atrade-off for the low dropout voltage is a varying base drive
requirement.Micrel’sSuperβetaPNP™processreducesthis
drive requirement to only 2% to 5% of the load current.
The MIC39500/1 requires an output capacitor to maintain
stability and improve transient response. Proper capaci-
tor selection is important to ensure proper operation. The
MIC39500/1outputcapacitorselectionisdependentuponthe
ESR (equivalent series resistance) of the output capacitor to
maintainstability.Whentheoutputcapacitoris47µForgreater,
the output capacitor should have less than 1Ω of ESR. This
will improve transient response as well as promote stability.
Ultra-low-ESR capacitors, such as ceramic chip capacitors
may promote instability. These very low ESR levels may
causeanoscillationand/orunderdampedtransientresponse.
When larger capacitors are used, the ESR requirement ap-
proaches zero. A 100µF ceramic capacitor can be used on
the output while maintaining stability. A low-ESR 47µF solid
tantalum capacitor works extremely well and provides good
transient response and stability over temperature.Aluminum
electrolytics can also be used, as long as the ESR of the
capacitor is < 1Ω.
TheMIC39500/1regulatorisfullyprotectedfromdamagedue
to fault conditions. Current limiting is provided. This limiting is
linear; output current during overload conditions is constant.
Thermalshutdowndisablesthedevicewhenthedietempera-
tureexceedsthemaximumsafeoperatingtemperature.Tran-
sient protection allows device (and load) survival even when
theinputvoltagespikesaboveandbelownominal.Theoutput
structureoftheseregulatorsallowsvoltagesinexcessofthede-
siredoutputvoltagetobeappliedwithoutreversecurrentflow.
MIC39500-x.x
VIN
VOUT
IN
OUT
GND
CIN
COUT
The value of the output capacitor can be increased without
limit. Higher capacitance values help to improve transient
response and ripple rejection and reduce output noise.
Figure 1. Capacitor Requirements
Thermal Design
Input capacitor
An input capacitor of 1µF or greater is recommended when
thedeviceismorethan4inchesawayfromthebulkacsupply
capacitance, or when the supply is a battery. Small surface-
mount ceramic chip capacitors can be used for bypassing.
Larger values will help to improve ripple rejection by bypass-
ing the input to the regulator, further improving the integrity
of the output voltage.
Linear regulators are simple to use. The most complicated
design parameters to consider are thermal characteristics.
Thermal design requires four application-specific param-
eters:
• Maximum ambient temperature (T )
A
• Output Current (I
)
OUT
Transient Response and 3.3V to 2.5V or 2.5V to 1.8V
Conversion
• Output Voltage (V
)
)
OUT
• Input Voltage (V )
IN
The MIC39500/1 has excellent transient response to varia-
tions in input voltage and load current. The device has been
designed to respond quickly to load current variations and
input voltage variations. Large output capacitors are not re-
quired to obtain this performance. A standard 47µF output
capacitor, preferably tantalum, is all that is required. Larger
values improve performance even further.
• Ground Current (I
GND
Calculate the power dissipation of the regulator from these
numbers and the device parameters from this datasheet,
where the ground current is taken from data sheet.
P = (V – V
) × I
+ V × I
D
IN
OUT
OUT IN GND
The heat sink thermal resistance is determined by:
By virtue of its low-dropout voltage, this device does not
saturate into dropout as readily as similar NPN-based de-
signs. When converting from 3.3V to 2.5V, or 2.5V to 1.8V,
the NPN-based regulators are already operating in dropout,
with typical dropout requirements of 1.2V or greater. To con-
vert down to 2.5V without operating in dropout, NPN-based
regulators require an input voltage of 3.7V at the very least.
The MIC39500/1 regulator provides excellent performance
where:
T
≤ 125°C and θ is between 0° and 2°C/W.
CS
J (max)
The heat sink may be significantly reduced in applications
where the minimum input voltage is known and is large com-
August 2005
7
M9999-082605-B
MIC39500/39501
Micrel
with an input as low as 3.0V or 2.5V respectively. This gives
PNP-based regulators a distinct advantage over older, NPN-
based linear regulators.
Error Flag
The MIC39501 version features an error flag circuit which
monitors the output voltage and signals an error condition
when the voltage 5% below the nominal output voltage. The
error flag is an open-collector output that can sink 10mA
during a fault condition.
A typical NPN regulator does not have the headroom to do
this conversion.
Minimum Load Current
Low output voltage can be caused by a number of problems,
including an overcurrent fault (device in current limit) or low
input voltage. The flag is inoperative during overtemperature
shutdown.
The MIC39500/1 regulator is specified between finite loads.
If the output current is too small, leakage currents dominate
and the output voltage rises. A 10mA minimum load current
is necessary for proper regulation.
When the error flag is not used, it is best to leave it open.
The flag pin can be tied directly to pin 4, the output pin.
Enable Input
The MIC39501 version features an enable input for on/off
control of the device. Its shutdown state draws “zero” cur-
rent (only microamperes of leakage). The enable input is
TTL/CMOS compatible for simple logic interface, but can be
connected to up to 20V.
M9999-082605-B
8
August 2005
MIC39500/39501
Micrel
Package Information
3-Lead TO-263 (U)
3-Lead TO-220 (T)
August 2005
9
M9999-082605-B
MIC39500/39501
Micrel
θ4
θ1
θ2
θ1
θ3
5-Lead TO-263-5 (U)
5-Lead TO-220 (T)
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
This 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 a Purchaser's own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2005 Micrel Incorporated
M9999-082605-B
10
August 2005
相关型号：
©2020 ICPDF网 联系我们和版权申明