MIC5238-1.1BM5 [MICREL]
Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator; 超低静态电流, 150毫安?帽LDO稳压器![MIC5238-1.1BM5](http://pdffile.icpdf.com/pdf1/p00084/img/icpdf/MIC5238_444639_icpdf.jpg)
型号: | MIC5238-1.1BM5 |
厂家: | ![]() |
描述: | Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator |
文件: | 总10页 (文件大小:123K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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MIC5238
Ultra-Low Quiescent Current, 150mA µCap LDO Regulator
General Description
Features
The MIC5238 is an ultra-low voltage output, 150mA LDO
regulator. Designed to operate in a single supply or dual
supply mode, the MIC5238 consumes only 23µA of bias
current, improving efficiency. When operating in the dual
supply mode, the efficiency greatly improves as the higher
voltage supply is only required to supply the 23µA bias
currentwhiletheoutputandbasedrivecomesoffofthemuch
lower input supply voltage.
• Ultra-low input voltage range: 1.5V to 6V
• Ultra-low output voltage: 1.1V minimum output voltage
• Low dropout voltage: 310mV at 150mA
• High output accuracy: ±2.0% over temperature
• µCap: stable with ceramic or tantalum capacitors
• Excellent line and load regulation specifications
• Zero shutdown current
• Reverse leakage protection
• Thermal shutdown and current limit protection
• IttyBitty™ SOT-23-5 package
As a µCap regulator, the MIC5238 operates with a 2.2µF
ceramic capacitor on the output, offering a smaller overall
solution. It also incorporates a logic-level enable pin that
allows the MIC5238 to be put into a zero off-current mode
when disabled.
Applications
• PDAs and pocket PCs
• Cellular phones
• Battery powered systems
• Low power microprocessor power supplies
The MIC5238 is fully protected with current limit and thermal
shutdown. It is offered in the IttyBitty™ SOT-23-5 package
with an operating junction temperature range of
–40°C to +125°C.
Ordering Information
Part Number
Marking Voltage* Junction Temp. Range
Package*
SOT-23-5
SOT-23-5
TSOT-23-5
TSOT-23-5
MIC5238-1.1BM5
MIC5238-1.3BM5
MIC5238-1.1BD5
MIC5238-1.3BD5
L411
L413
N411
N413
1.1V
1.3V
1.1V
1.3V
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
* For other voltages and package option contact the factory
Typical Application
MIC5238-1.0BM5
1
5
VIN=1.5V
1.0V
CIN
2
3
COUT=2.2µF
ceramic
4
ENOFF
ON
VBIAS=2.5V
CBIAS
Ultra-Low Voltage Application
IttyBitty is a trademark of Micrel, Inc.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
August 2003
1
MIC5238
MIC5238
Micrel
Pin Configuration
EN GND IN
EN GND IN
3
2
1
3
2
1
L4xx
N4xx
4
5
4
5
BIAS
BIAS
OUT
OUT
SOT-23-5 (M5)
TSOT-23-5 (D5)
Pin Description
SOT-23-5
Pin Name
Pin Function
Supply Input
Ground
1
2
3
IN
GND
EN
Enable (Input): Logic low = shutdown; logic high = enable. Do no leave
open.
4
5
BIAS
OUT
BiasSupply Input
Regulator Output
MIC5238
2
August 2003
MIC5238
Micrel
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Input Supply Voltage ........................................ –0.3V to 7V
BIAS Supply Voltage........................................ –0.3V to 7V
Enable Input Voltage........................................ –0.3V to 7V
Power Dissipation .................................... Internally Limited
Junction Temperature .............................. –40°C to +125°C
Storage Temperature ............................... –65°C to +150°C
ESD Rating, >1.5µA HBM, Note 3
Input Supply Voltage .......................................... 1.5V to 6V
BIAS Supply Voltage.......................................... 2.3V to 6V
Enable Input Voltage............................................. 0V to 6V
Junction Temperature (T ) ....................... –40°C to +125°C
J
Package Thermal Resistance
SOT-23-5 (θ ) ..................................................235°C/W
JA
Electrical Characteristics (Note 4)
TA = 25°C with VIN = VOUT + 1V; VBIAS = 3.3V; IOUT = 100µA; VEN = 2V, Bold values indicate –40°C < TJ < +125°C; unless otherwise specified.
Parameter
Condition
Min.
Typ.
Max.
Units
Output Voltage Accuracy
Variation from nominal VOUT
–1.5
–2
+1.5
+2
%
%
Line Regulation
VBIAS = 2.3V to 6V, Note 5
VIN = (VOUT + 1V) to 6V
Load = 100µA to 150mA
0.25
0.04
0.7
0.5
1
%
%
%
Input Line Regulation
Load Regulation
Dropout Voltage
I
OUT = 100µA
50
230
mV
mV
mV
mV
mV
mV
mV
IOUT = 50mA
IOUT = 100mA
IOUT = 150mA
300
400
270
310
450
500
BIAS Current, Note 6
Input Current, Pin 1
IOUT = 100µA
23
µA
I
OUT = 100µA
IOUT = 50mA, Note 7
OUT = 100mA
IOUT = 150mA
7
0.35
1
20
µA
mA
mA
mA
I
2
2.5
Ground Current in Shutdown
V
EN ≤ 0.2V; VIN = 6V; VBIAS = 6V
1.5
0.5
350
5
5
µA
µA
mA
µA
VEN = 0V; VIN = 6V; VBIAS = 6V
VOUT = 0V
Short Circuit Current
Reverse Leakage
Enable Input
500
0.2
VIN = 0V; VEN = 0V; VOUT = nom VOUT
Input Low Voltage
Input High Voltage
Enable Input Current
Regulator OFF
Regulator ON
V
V
2.0
VEN = 0.2V; Regulator OFF
–1.0
0.01
0.1
1.0
1.0
µA
µA
VEN = 2.0V; Regulator ON
Note 1. 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. Human body model, 1.5k in series with 100pF.
Note 4. Specification for packaged product only.
Note 5. Line regulation measures a change in output voltage due to a change in the bias voltage.
Note 6. Current measured from bias input to ground.
Note 7. Current differential between output current and main input current at rated load current.
August 2003
3
MIC5238
MIC5238
Micrel
Typical Characteristics
Output Voltage
PSRR
Output Voltage
vs. V
150mA Load
vs. V
BIAS
IN
1.15
1.1
80
1.2
1.1
1
100µA
150mA
100µA
150mA
70
60
50
40
30
1.05
1
0.9
0.8
0.7
0.6
0.5
0.4
0.95
0.9
COUT = 2.2µF ceramic
20
VIN = 2.1V
0.85
0.8
10
V
OUT = 1.1V
0
1.11.21.31.41.51.61.71.81.9 2 2.1
1.2 1.7 2.2 2.7 3.2 3.7 4.2 4.7 5.2
INPUT BIAS (V)
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
INPUT V (V)
IN
Ground Current (V
)
IN
Dropout Voltage
vs. Load
Ground Current (V
)
IN
vs. V Supply
IN
vs. Output Current
VIN = VOUT + 1
400
1800
1600
1400
1200
1000
800
600
400
200
0
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
VIN = VOUT + 1
1.1V
150mA
350
300
250
200
150
100
50
0
0
25 50 75 100 125 150
OUTPUT CURRENT (A)
0
25 50 75 100 125 150
OUTPUT CURRENT (mA)
0
0.5
V
1.0
SUPPLY (V)
1.5
2.0
IN
Ground Current (V
)
BIAS
Ground Current (V
)
BIAS
Shutdown Current of
vs. Output Current
VIN = VOUT + 1
30
25
20
15
10
5
vs. Input Voltage
V
IN
30
25
20
15
10
5
7
6
5
4
3
2
1
0
ILOAD = 150mA
No Load
0
0
25 50 75 100 125 150
OUTPUT CURRENT (mA)
0
0
0.5
1
1.5
2
2.5
3
0
0.5
1
1.5
2
INPUT VOLTAGE (V)
ENABLE (V)
Ground Current (V
vs Temperature
)
Shutdown Current
IN
Shutdown Current of V
V
+ V Tied
BIAS
BIAS
IN
10
9
8
7
6
5
4
3
2
1
0
20
30
25
20
15
10
5
1.1V
100µA
No Load
No Load
18
16
14
12
10
8
6
4
2
-40 -20
0
20 40 60 80 100 120
0
0
0
0.5
1
1.5
2
0
0.5
1
1.5
2
TEMPERATURE (°C)
ENABLE (V)
ENABLE (V)
MIC5238
4
August 2003
MIC5238
Micrel
V
Ground Current
V
Ground Current
IN
IN
V
Ground Current
BIAS
vs. Temperature
vs. Temperature
2
2.4
2.2
2
vs. Temperature
1.1V
75mA
1.1V
150mA
40
35
30
25
20
15
10
5
1.8
1.6
1.4
1.2
1
1.1V
100µA
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
0.8
0.6
0.4
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
0
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
V
Ground Current
V
Ground Current
BIAS
BIAS
Output Voltage
vs. Temperature
vs. Temperature
vs. Temperature
40
40
35
30
25
20
15
10
5
1.1025
1.1020
1.1015
1.1010
1.1005
1.1000
1.0995
1.0990
1.0985
1.0980
1.0975
1.1V
1.1V
1.1V
100µA
150mA
35
30
25
20
15
10
5
75mA
0
0
-40 -20
0
20 40 60 80 100 120
-40 -20
0
20 40 60 80 100 120
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
Short Circuit Current
vs. Temperature
Dropout Voltage
vs. Temperature
500
450
400
350
300
250
200
150
100
50
500
Load = 150mA
450
400
350
300
250
200
150
100
50
0
0
-40 -20
0
20 40 60 80 100 120
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
TEMPERATURE (°C)
August 2003
5
MIC5238
MIC5238
Micrel
Line Transient Response
Load Transient Response
3.1V
2.1V
1.1V output
COUT = 4.7µF ceramic
1.1V Output
COUT = 4.7 F ceramic
150mA
1mA
TIME (200 s/div.)
TIME (400 s/div.)
EN Turn-On Characteristic
Load Transient Response
150mA
0mA
VIN = 4V
VOUT = 3V
COUT = 4.7µF ceramic
TIME (40 s/div.)
TIME (400µs/div.)
MIC5238
6
August 2003
MIC5238
Micrel
Functional Diagram
OUT
IN
BIAS
EN
ENABLE
VREF
GND
Block Diagram – Fixed Output Voltage
August 2003
7
MIC5238
MIC5238
Micrel
Recommended
Applications Information
Package
θ
JA
Minimum Footprint
Enable/Shutdown
SOT-23-5
235°C/W
The MIC5238 comes with an active-high enable pin that
allowstheregulatortobedisabled.Forcingtheenablepinlow
disables the regulator and sends it into a “zero” off-mode-
current state. In this state, current consumed by the regulator
goes nearly to zero. Forcing the enable pin high enables the
output voltage.
Table 1. SOT-23-5 Thermal Resistance
The actual power dissipation of the regulator circuit can be
determined using the equation:
P = (V – V
)I
+ V I
D
IN
OUT OUT IN GND
Substituting P
for P and solving for the operating
D
Input Bias Capacitor
D(MAX)
conditions that are critical to the application will give the
maximum operating conditions for the regulator circuit. For
example, when operating the MIC5238-1.0BM5 at 50°C with
a minimum footprint layout, the maximum input voltage for a
set output current can be determined as follows:
The input capacitor must be rated to sustain voltages that
may be used on the input. An input capacitor may be required
when the device is not near the source power supply or when
supplied by a battery. Small, surface mount, ceramic capaci-
tors can be used for bypassing. Larger values may be
required if the source supply has high ripple.
125°C − 50°C
P
=
D(MAX)
Output Capacitor
235°C/W
The MIC5238 requires an output capacitor for stability. The
design requires 2.2µF or greater on the output to maintain
stability. The design is optimized for use with low-ESR
ceramic chip capacitors. High ESR capacitors may cause
high frequency oscillation. The maximum recommended
ESR is 3Ω. The output capacitor can be increased without
limit. Larger valued capacitors help to improve transient
response.
P
= 319mW
D(MAX)
The junction-to-ambient (θ ) thermal resistance for the
JA
minimum footprint is 235°C/W, from Table 1. It is important
that the maximum power dissipation not be exceeded to
ensure proper operation. With very high input-to-output volt-
age differentials, the output current is limited by the total
powerdissipation. Totalpowerdissipationiscalculatedusing
the following equation:
X7R/X5R dielectric-type ceramic capacitors are recom-
mended because of their temperature performance. X7R-
type capacitors change capacitance by 15% over their oper-
ating temperature range and are the most stable type of
ceramiccapacitors.Z5UandY5Vdielectriccapacitorschange
value by as much as 50% and 60% respectively over their
operatingtemperatureranges. Touseaceramicchipcapaci-
tor with Y5V dielectric, the value must be much higher than a
X7R ceramic capacitor to ensure the same minimum capaci-
tance over the equivalent operating temperature range.
P = (V – V
)I
+ V x I
+ V
x I
D
IN
OUT OUT
IN
GND
BIAS BIAS
Since the bias supply draws only 18µA, that contribution can
be ignored for this calculation.
If we know the maximum load current, we can solve for the
maximum input voltage using the maximum power dissipa-
tion calculated for a 50°C ambient, 319mV.
P
= (V – V
)I
+ V x I
DMAX
IN
OUT OUT IN GND
319mW = (V – 1V)150mA + V x 2.8mA
IN
IN
Ground pin current is estimated using the typical character-
istics of the device.
No-Load Stability
TheMIC5238willremainstableandinregulationwithnoload
unlike many other voltage regulators. This is especially
important in CMOS RAM keep-alive applications.
469mW = V (152.8mA)
IN
V
= 3.07V
IN
Thermal Considerations
For higher current outputs only a lower input voltage will work
for higher ambient temperatures.
The MIC5238 is designed to provide 150mA of continuous
current in a very small package. Maximum power dissipation
canbecalculatedbasedontheoutputcurrentandthevoltage
drop across the part. To determine the maximum power
dissipation of the package, use the junction-to-ambient ther-
malresistanceofthedeviceandthefollowingbasicequation:
Assumingaloweroutputcurrentof20mA,themaximuminput
voltage can be recalculated:
319mW = (V – 1V)20mA + V x 0.2mA
IN
IN
339mW = V x 20.2mA
IN
V
= 16.8V
IN
T
− T
A
J(MAX)
Maximum input voltage for a 20mA load current at 50°C
ambient temperature is 16.8V. Since the device has a 6V
rating, it will operate over the whole input range.
P
=
D(MAX)
θ
JA
T
is the maximum junction temperature of the die,
J(MAX)
Dual Suppy Mode Efficiency
125°C, and T is the ambient operating temperature. θ is
A
JA
By utilizing a bias supply the conversion efficiency can be
greatly enhanced. This can be realized as the higher bias
supplywillonlyconsumeafewµA’swhiletheinputsupplywill
require a few mA’s! This equates to higher efficiency saving
valuable power in the system. As an example, consider an
output voltage of 1V with an input supply of 2.5V at a load
layout dependent; Table 1 shows the junction-to-ambient
thermal resistance for the MIC5238.
MIC5238
8
August 2003
MIC5238
Micrel
current of 150mA. The input ground current under these
conditions is 2mA, while the bias current is only 20µA. If we
calculate the conversion efficiency using the single supply
approach, it is as follows:
Input power = V × output current + V × V ground current
IN
IN
IN
+ V
x V
ground current
BIAS
BIAS
Input power = 1.5 × 150mA + 1.5 × 0.002 + 2.5 × 0.0002 =
225mW
Input power = V × output current + V × (V
ground
Output power = 1V × 150mA = 150mW
Efficiency = 150/225 × 100 = 66.6 %
IN
IN
BIAS
current + V ground current)
IN
Input power = 2.5V × 150mA + 2.5 × (0.0002+0.002) =
380.5mW
Therefore, by using the dual supply MIC5238 LDO the
efficiency is nearly doubled over the single supply version.
Output power = 1V × 0.15 = 150mW
Efficiency = 150/380.5 × 100 = 39.4%
This is a valuable asset in portable power management
applications equating to longer battery life and less heat
being generated in the application.
Now, using a lower input supply of 1.5V, and powering the
bias voltage only from the 2.5V input, the efficiency is as
follows:
This in turn will allow a smaller footprint design and an
extended operating life.
August 2003
9
MIC5238
MIC5238
Micrel
Package Information
1.90 (0.075) REF
0.95 (0.037) REF
1.75 (0.069) 3.00 (0.118)
1.50 (0.059) 2.60 (0.102)
DIMENSIONS:
MM (INCH)
1.30 (0.051)
0.90 (0.035)
3.02 (0.119)
2.80 (0.110)
0.20 (0.008)
0.09 (0.004)
10°
0°
0.15 (0.006)
0.00 (0.000)
0.50 (0.020)
0.35 (0.014)
0.60 (0.024)
0.10 (0.004)
SOT-23-5 (M5)
1.90BSC
2.90BSC
1.90BSC
0.30
0.45
DIMENSIONS:
Millimeter
0.90
0.80
1.00
0.90
2.9BSC
1.60BSC
1.60BSC
0.20
0.12
0.30
0.50
0.10
0.01
1.90BSC
TSOT-23-5 (D5)
MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com
The information furnished by Micrel in this datasheet 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.
© 2003 Micrel, Incorporated.
MIC5238
10
August 2003
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