MIC5209 [MICREL]
500mA Low-Noise LDO Regulator; 500毫安低噪声LDO稳压器
| 型号： | MIC5209 |
| 厂家： | 
MICREL SEMICONDUCTOR |
| 描述： | 500mA Low-Noise LDO Regulator |
| 文件： | 总13页 (文件大小：93K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MIC5209
500mA Low-Noise LDO Regulator
General Description
Features
The MIC5209 is an efficient linear voltage regulator with very
low dropout voltage, typically 10mV at light loads and less
than 500mV at full load, with better than 1% output voltage
accuracy.
• Meets Intel® Slot 1 and Slot 2 requirements
• Guaranteed 500mA output over the full operating
temperature range
• Low 500mV maximum dropout voltage at full load
• Extremely tight load and line regulation
• Thermally-efficient surface-mount package
• Low temperature coefficient
• Current and thermal limiting
• Reversed-battery protection
• No-load stability
• 1% output accuracy
• Ultra-low-noise capability in SO-8 and TO-263-5
Designedespeciallyforhand-held,battery-powereddevices,
the MIC5209 features low ground current to help prolong
battery life. An enable/shutdown pin on SO-8 and TO-263-5
versions can further improve battery life with near-zero shut-
down current.
Key features include reversed-battery protection, current
limiting, overtemperature shutdown, ultra-low-noise capabil-
ity (SO-8 and TO-263-5 versions), and availability in ther-
mallyefficientpackaging. TheMIC5209isavailableinadjust-
able or fixed output voltages.
Applications
• Pentium II Slot 1 and Slot 2 support circuits
• Laptop, notebook, and palmtop computers
• Cellular telephones
• Consumer and personal electronics
• SMPS post-regulator/dc-to-dc modules
• High-efficiency linear power supplies
For space-critical applications where peak currents do not
exceed 500mA, see the MIC5219.
Typical Applications
Ordering Information
Part Number
Voltage
2.5V
3.0V
3.3V
3.6V
4.2V
5.0V
1.8V
2.5V
3.0V
3.3V
3.6V
5.0V
Adj.
Junct. Temp. Range
–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
0°C to +125°C
Package
SOT-223
SOT-223
SOT-223
SOT-223
SOT-223
SOT-223
SO-8
MIC5209-2.5BS
MIC5209-2.5BS
MIC5209-3.0BS
MIC5209-3.3BS
MIC5209-3.6BS
MIC5209-4.2BS
MIC5209-5.0BS
MIC5209-1.8BM
MIC5209-2.5BM
MIC5209-3.0BM
MIC5209-3.3BM
MIC5209-3.6BM
MIC5209-5.0BM
MIC5209BM
1
2
3
VIN
≥ 3.0V
VOUT
2.5V ±1%
0.1µF
22µF
tantalum
3.3V Nominal-Input Slot-1
Power Supply
–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
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
SO-8
SO-8
SO-8
SO-8
MIC5209-5.0BM
ENABLE
SHUTDOWN
1
2
3
4
8
7
6
5
SO-8
VIN
6V
SO-8
VOUT
5V
MIC5209-2.5BU
MIC5209-3.0BU
MIC5209-3.3BU
MIC5209-3.6BU
MIC5209-5.0BU
MIC5209BU
2.5V
3.0V
3.3V
3.6V
5.0V
Adj.
TO-263-5
TO-263-5
TO-263-5
TO-263-5
TO-263-5
TO-263-5
2.2µF
tantalum
470pF
(OPTIONAL)
Ultra-Low-Noise 5V Regulator
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 2, 2000
1
MIC5209
MIC5209
Micrel
Pin Configuration
GND
TAB
1
2
3
IN GND OUT
MIC5209-x.xBS
SOT-223
Fixed Voltages
EN
IN
GND
GND
GND
GND
1
2
3
4
8
7
6
5
5 BYP
4 OUT
3 GND
2 IN
OUT
BYP
1 EN
MIC5209-x.xBU
TO-263-5
Fixed Voltages
MIC5209-x.xBM
SO-8
Fixed Voltages
EN
IN
GND
GND
GND
GND
1
2
3
4
8
7
6
5
5 ADJ
4 OUT
3 GND
2 IN
OUT
ADJ
1 EN
MIC5209BU
TO-263-5
Adjustable Voltage
MIC5209BM
SO-8
Adjustable Voltage
Pin Description
Pin No.
SOT-223
Pin No.
SO-8
Pin No.
TO-263-5
Pin Name
Pin Function
1
2
2
3
IN
Supply Input
2, TAB
5–8
GND
Ground: SOT-223 pin 2 and TAB are internally connected. SO-8 pins 5
through 8 are internally connected.
3
3
1
4
1
OUT
EN
Regulator Output
Enable (Input): CMOS compatible control input. Logic high = enable; logic
low or open = shutdown.
4 (fixed)
4 (adj.)
5 (fixed)
5 (adj.)
BYP
ADJ
Reference Bypass: Connect external 470pF capacitor to GND to reduce
output noise. May be left open. For 1.8V or 2.5V operation, see “Applica-
tions Information.”
Adjust (Input): Feedback input. Connect to resistive voltage-divider network.
MIC5209
2
August 2, 2000
MIC5209
Micrel
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Supply Input Voltage (V ) ............................ –20V to +20V
Supply Input Voltage (V ) ........................... +2.5V to +16V
IN
IN
Power Dissipation (P ) ............... Internally Limited, Note 3
Enable Input Voltage (V ) .................................. 0V to V
D
EN
IN
Junction Temperature (T )
Junction Temperature (T )
J
J
all except 1.8V...................................... –40°C to +125°C
1.8V only .................................................. 0°C to +125°C
all except 1.8V...................................... –40°C to +125°C
1.8V only .................................................. 0°C to +125°C
Lead Temperature (soldering, 5 sec.) ....................... 260°C
Package Thermal Resistance .................................. Note 3
Storage Temperature (T ) ....................... –65°C to +150°C
S
Electrical Characteristics
VIN = VOUT + 1.0V; COUT = 4.7µF, IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C except
0°C ≤ TJ ≤ +125°C for 1.8V version; unless noted.
Symbol
Parameter
Conditions
Min Typical Max
Units
VOUT
Output Voltage Accuracy
variation from nominal VOUT
–1
–2
1
2
%
%
∆VOUT/∆T
Output Voltage
Temperature Coefficient
Note 4
40
0.009
0.05
10
ppm/°C
∆VOUT/VOUT Line Regulation
VIN = VOUT + 1V to 16V
IOUT = 100µA to 500mA, Note 5
IOUT = 100µA
0.05
0.1
%/V
%/V
∆VOUT/VOUT Load Regulation
0.5
0.7
%
%
VIN – VOUT
Dropout Voltage, Note 6
60
80
mV
mV
I
I
I
OUT = 50mA
OUT = 150mA
OUT = 500mA
115
165
350
80
175
250
mV
mV
300
400
mV
mV
500
600
mV
mV
IGND
Ground Pin Current, Notes 7, 8
V
V
V
V
EN ≥ 3.0V, IOUT = 100µA
EN ≥ 3.0V, IOUT = 50mA
EN ≥ 3.0V, IOUT = 150mA
EN ≥ 3.0V, IOUT = 500mA
130
170
µA
µA
350
1.8
650
900
µA
µA
2.5
3.0
mA
mA
8
20
25
mA
mA
IGND
Ground Pin Quiescent Current,
Note 8
V
EN ≤ 0.4V (shutdown)
EN ≤ 0.18V (shutdown)
0.05
0.10
75
3
8
µA
µA
dB
V
PSRR
ILIMIT
Ripple Rejection
Current Limit
f = 120Hz
VOUT = 0V
700
900
1000
mA
mA
∆VOUT/∆PD
Thermal Regulation
Note 9
0.05
500
%/W
eno
Output Noise
VOUT = 2.5V, IOUT = 50mA,
nV/ Hz
Note 10
COUT = 2.2µF, CBYP = 0
IOUT = 50mA, COUT = 2.2µF, CBYP = 470pF
300
nV/ Hz
August 2, 2000
3
MIC5209
MIC5209
Micrel
ENABLE Input
VENL
Enable Input Logic-Low Voltage
VEN = logic low (regulator shutdown)
VEN = logic high (regulator enabled)
0.4
0.18
V
V
2.0
V
IENL
Enable Input Current
VENL ≤ 0.4V
VENL ≤ 0.18V
VENH ≥ 2.0V
0.01
0.01
5
–1
µA
µA
–2
IENH
20
25
µA
µA
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: The maximum allowable power dissipation at any T (ambient temperature) is calculated using: P
= (T
– T ) ÷ θ . Exceeding the
A
D(max)
J(max) A JA
maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. See Table 1
and the “Thermal Considerations” section for details.
Note 4: Output voltage temperature coefficient is the worst case voltage change divided by the total temperature range.
Note 5: Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load
range from 100µA to 500mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
Note 6: 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.
Note 7: Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of
the load current plus the ground pin current.
Note 8:
V
is the voltage externally applied to devices with the EN (enable) input pin. [SO-8 (M) and TO-263-5 (U) packages only.]
EN
Note 9: Thermal regulation is the change in output voltage at a time “t” after a change in power dissipation is applied, excluding load or line regulation
effects. Specifications are for a 500mA load pulse at V = 16V for t = 10ms.
IN
Note 10: C
is an optional, external bypass capacitor connected to devices with a BYP (bypass) or ADJ (adjust) pin. [SO-8 (M) and TO-263-5 (U)
BYP
packages only].
MIC5209
4
August 2, 2000
MIC5209
Micrel
Block Diagrams
OUT
IN
VOUT
COUT
VIN
Bandgap
Ref.
Current Limit
Thermal Shutdown
MIC5209-x.xBS
GND
Low-Noise Fixed Regulator (SOT-223 version only)
OUT
IN
VOUT
COUT
VIN
BYP
CBYP
(optional)
Bandgap
Ref.
EN
Current Limit
Thermal Shutdown
MIC5209-x.xBM/U
GND
Ultra-Low-Noise Fixed Regulator
OUT
IN
VOUT
COUT
VIN
R1
R2
ADJ
CBYP
(optional)
Bandgap
Ref.
EN
Current Limit
Thermal Shutdown
MIC5209BM/U [adj.]
GND
Ultra-Low-Noise Adjustable Regulator
August 2, 2000
5
MIC5209
MIC5209
Micrel
Typical Characteristics
Power Supply
Rejection Ratio
Power Supply
Rejection Ratio
Power Supply
Rejection Ratio
0
0
-20
0
-20
VIN = 6V
VIN = 6V
VOUT = 5V
VIN = 6V
OUT = 5V
V
OUT = 5V
V
-20
-40
-40
-40
-60
-60
-60
IOUT = 100mA
OUT = 1µF
-80
-80
-80
IOUT = 100µA
OUT = 1µF
IOUT = 1mA
OUT = 1µF
C
C
C
-100
-100
-100
1E+11E+21E1+k311E0+k41E+51E1M+6 E+7
1E+11E+21E1+k311E0+k41E+51E1M+6 E+7
1E+11E+21E1+k311E0+k41E+51E1M+6 E+7
10 100 100k
10M
10 100
100k
10M
10 100
100k
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
Power Supply
Rejection Ratio
Power Supply
Rejection Ratio
Power Supply
Rejection Ratio
0
0
0
VIN = 6V
OUT = 5V
VIN = 6V
OUT = 5V
VIN = 6V
VOUT = 5V
V
V
-20
-40
-20
-40
-20
-40
-60
-60
-60
IOUT = 1mA
IOUT = 100µA
IOUT = 100mA
COUT = 2.2µF
BYP = 0.01µF
-80
-80
-80
COUT = 2.2µF
BYP = 0.01µF
COUT = 2.2µF
BYP = 0.01µF
C
C
C
-100
-100
-100
1E+11E+21E1+k311E0+k41E+51E1M+6 E+7
1E+11E+21E1+k311E0+k41E+51E1M+6 E+7
1E+11E+21E1+k311E0+k41E+51E1M+6 E+7
10 100 100k
10M
10 100
100k
10M
10 100
100k
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
Power Supply Ripple Rejection
vs. Voltage Drop
Power Supply Ripple Rejection
vs. Voltage Drop
Noise Performance
60
100
10
1
500mA pending
500mA pending
1mA
90
80
70
60
50
40
30
20
10
0
10mA, COUT = 1µF
50
40
30
20
10
0
1mA
0.1
IOUT = 100mA
10mA
IOUT = 100mA
500mA Pending
0.01
0.001
0.0001
10mA
COUT = 2.2µF
C
BYP = 0.01µF
COUT = 1µF
VOUT = 5V
0
0.1
0.2
0.3
0.4
10
1E+11E+21E1+k31E+41E+51E+61E+7
0
0.1
0.2
0.3
0.4
100 10k 100k 1M 10M
VOLTAGE DROP (V)
VOLTAGE DROP (V)
FREQUENCY (Hz)
Dropout Voltage
vs. Output Current
Noise Performance
Noise Performance
10
1
10
1
400
300
200
100
0
500mA Pending
100mA
100mA
10mA
0.1
0.1
500mA Pending
VOUT = 5V
0.01
0.001
0.0001
0.01
0.001
0.0001
1mA
VOUT = 5V
OUT = 10µF
electrolytic
BYP = 100pF
1mA
C
C
OUT = 10µF
electrolytic
10mA
C
0
100 200 300 400 500
OUTPUT CURRENT (mA)
10
1k 10k 100k 1M 10M
1E+111E0+021E+31E+41E+51E+61E+7
FREQUENCY (Hz)
10
1k 10k 100k 1M 10M
1E+111E0+021E+31E+41E+51E+61E+7
FREQUENCY (Hz)
MIC5209
6
August 2, 2000
MIC5209
Micrel
Dropout Characteristics
Ground Current
vs. Output Current
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
12
10
8
I
=100µA
L
6
I =100mA
L
4
I =500mA
L
2
0
0
1
2
3
4
5
6
7
8
9
0
100 200 300 400 500
OUTPUT CURRENT (mA)
INPUT VOLTAGE (V)
Ground Current
vs. Supply Voltage
Ground Current
vs. Supply Voltage
25
20
15
10
5
3.0
2.5
2.0
1.5
1.0
0.5
0
I =100 mA
L
I =500mA
L
0
I =100µA
0
1
2
3
4
5
6
7
8
9
L
INPUT VOLTAGE (V)
0
2
4
6
8
INPUT VOLTAGE (V)
August 2, 2000
7
MIC5209
MIC5209
Micrel
Thermal Considerations
Applications Information
The SOT-223 has a ground tab which allows it to dissipate
morepowerthantheSO-8. Referto“Slot-1PowerSupply”for
details. At 25°C ambient, it will operate reliably at 2W dissipa-
tion with “worst-case” mounting (no ground plane, minimum
trace widths, and FR4 printed circuit board).
Enable/Shutdown
Enable is available only on devices in the SO-8 (M) and
TO-263-5 (U) packages.
Forcing EN (enable/shutdown) high (> 2V) enables the regu-
lator. EN is compatible with CMOS logic. If the enable/
shutdown feature is not required, connect EN to IN (supply
input).
Thermal resistance values for the SO-8 represent typical
mounting on a 1"-square, copper-clad, FR4 circuit board. For
greater power dissipation, SO-8 versions of the MIC5209
feature a fused internal lead frame and die bonding arrange-
ment that reduces thermal resistance when compared to
standard SO-8 packages.
Input Capacitor
A 1µF capacitor should be placed from IN to GND if there is
morethan10inchesofwirebetweentheinputandtheacfilter
capacitor or if a battery is used as the input.
Package
θJA
50°C/W
50°C/W
—
θJC
Output Capacitor
SOT-223 (S)
SO-8 (M)
8°C/W
25°C/W
2°C/W
An output capacitor is required between OUT and GND to
prevent oscillation. The minimum size of the output capacitor
is dependent upon whether a reference bypass capacitor is
TO-263-5 (U)
used. 1µF minimum is recommended when C
(see Figure 1). 2.2µF minimum is recommended when C
is not used
BYP
Table 1. MIC5209 Thermal Resistance
BYP
Multilayer boards with a ground plane, wide traces near the
pads, and large supply-bus lines will have better thermal
conductivity and will also allow additional power dissipation.
is470pF(seeFigure2).Largervaluesimprovetheregulator’s
transient response.
The output capacitor should have an ESR (equivalent series
resistance) of about 5Ω and a resonant frequency above
1MHz. Ultra-low-ESR capacitors can cause a low amplitude
oscillation on the output and/or underdamped transient re-
sponse. Most tantalum or aluminum electrolytic capacitors
are adequate; film types will work, but are more expensive.
Since many aluminum electrolytics have electrolytes that
freeze at about –30°C, solid tantalums are recommended for
operation below –25°C.
For additional heat sink characteristics, please refer to Micrel
Application Hint 17, “Designing P.C. Board Heat Sinks”,
included in Micrel’s Databook. For a full discussion of heat
sinking and thermal effects on voltage regulators, refer to
Regulator Thermals section of Micrel’s Designing with Low-
Dropout Voltage Regulators handbook.
Low-Voltage Operation
The MIC5209-1.8 and MIC5209-2.5 require special consid-
eration when used in voltage-sensitive systems. They may
momentarily overshoot their nominal output voltages unless
appropriate output and bypass capacitor values are chosen.
At lower values of output current, less output capacitance is
needed for output stability. The capacitor can be reduced to
0.47µF for current below 10mA or 0.33µF for currents below
1mA.
During regulator power up, the pass transistor is fully satu-
rated for a short time, while the error amplifier and voltage
reference are being powered up more slowly from the output
(see “Block Diagram”). Selecting larger output and bypass
capacitors allows additional time for the error amplifier and
reference to turn on and prevent overshoot.
No-Load Stability
TheMIC5209willremainstableandinregulationwithnoload
(other than the internal voltage divider) unlike many other
voltage regulators. This is especially important in CMOS
RAM keep-alive applications.
To ensure that no overshoot is present when starting up into
a light load (100µA), use a 4.7µF output capacitance and
470pF bypass capacitance. This slows the turn-on enough to
allow the regulator to react and keep the output voltage from
exceeding its nominal value. At heavier loads, use a 10µF
output capacitance and 470pF bypass capacitance. Lower
values of output and bypass capacitance can be used,
depending on the sensitivity of the system.
Reference Bypass Capacitor
BYP (reference bypass) is available only on devices in SO-8
and TO-263-5 packages.
BYP is connected to the internal voltage reference. A 470pF
capacitor (C
) connected from BYP to GND quiets this
BYP
reference, providing a significant reduction in output noise
(ultra-low-noise performance). Because C reduces the
phase margin, the output capacitor should be increased to at
BYP
Applications that can withstand some overshoot on the
output of the regulator can reduce the output capacitor and/
orreduceoreliminatethebypasscapacitor. Applicationsthat
are not sensitive to overshoot due to power-on reset delays
can use normal output and bypass capacitor configurations.
least 2.2µF to maintain stability.
The start-up speed of the MIC5209 is inversely proportional
to the size of the reference bypass capacitor. Applications
requiring a slow ramp-up of output voltage should consider
larger values of C
consider omitting C
. Likewise, if rapid turn-on is necessary,
.
BYP
Please note the junction temperature range of the regulator
at 1.8V output (fixed and adjustable) is 0˚C to +125˚C.
BYP
If output noise is not critical, omit C
and leave BYP open.
BYP
MIC5209
8
August 2, 2000
MIC5209
Micrel
Fixed Regulator Circuits
Although ADJ is a high-impedance input, for best perfor-
mance, R2 should not exceed 470kΩ.
MIC5209-x.xBM
VIN
VOUT
1µF
2
3
MIC5209BM
IN
OUT
BYP
GND
VIN
VOUT
2
1
3
4
1
4
IN
OUT
ADJ
EN
R1
R2
EN
5–8
GND
2.2µF
5–8
470pF
Figure 1. Low-Noise Fixed Voltage Regulator
Figure1showsabasicMIC5209-x.xBM(SO-8)fixed-voltage
regulator circuit. See Figure 5 for a similar configuration
usingthemorethermally-efficientMIC5209-x.xBS(SOT-223).
A 1µF minimum output capacitor is required for basic fixed-
voltage applications.
Figure 4. Ultra-Low-Noise Adjustable Application.
Figure 4 includes the optional 470pF bypass capacitor from
ADJ to GND to reduce output noise.
Slot-1 Power Supply
MIC5209-x.xBM
Intel’s Pentium II processors have a requirement for a 2.5V
±5% power supply for a clock synthesizer and its associated
loads. The current requirement for the 2.5V supply is depen-
dant upon the clock synthesizer used, the number of clock
outputs, and the type of level shifter (from core logic levels to
2.5V levels). Intel estimates a worst-case load of 320mA.
VIN
VOUT
2
3
IN
OUT
BYP
GND
1
4
EN
2.2µF
5–8
470pF
The MIC5209 was designed to provide the 2.5V power
requirement for Slot-1 applications. Its guaranteed perfor-
mance of 2.5V ±3% at 500mA allows adequate margin for all
systems, and its dropout voltage of 500mV means that it
operates from a worst-case 3.3V supply where the voltage
can be as low as 3.0V.
Figure 2. Ultra-Low-Noise Fixed Voltage Regulator
Figure 2 includes the optional 470pF noise bypass capacitor
between BYP and GND to reduce output noise. Note that the
minimum value of C
capacitor is used.
must be increased when the bypass
OUT
MIC5209-x.xBS
Adjustable Regulator Circuits
VIN
VOUT
1
3
IN
OUT
MIC5209BM
VIN
VOUT
1µF
2
1
3
IN
OUT
ADJ
GND
GND
CIN
0.1µF
COUT
22µF
4
R1
R2
EN
2,TAB
5–8
Figure 5. Slot-1 Power Supply
A Slot-1 power supply (Figure 5) is easy to implement. Only
twocapacitorsarenecessary,andtheirvaluesarenotcritical.
Figure 3. Low-Noise Adjustable Voltage Regulator
C
bypasses the internal circuitry and should be at least
IN
The MIC5209BM/U can be adjusted to a specific output
voltage by using two external resistors (Figure 3). The resis-
tors set the output voltage based on the equation:
0.1µF. C
provides output filtering, improves transient
OUT
response, and compensates the internal regulator control
loop. Its value should be at least 22µF. C and C
may be
IN
OUT
increased as much as desired.
R2
VOUT = 1.242V 1 +
R1
Slot-1 Power Supply Power Dissipation
Powered from a 3.3V supply, the Slot-1 power supply of
Figure 5 has a nominal efficiency of 75%. At the maximum
anticipated Slot 1 load (320mA), the nominal power dissipa-
tion is only 256mW.
This equation is correct due to the configuration of the
bandgap reference. The bandgap voltage is relative to the
output, as seen in the block diagram. Traditional regulators
normally have the reference voltage relative to ground;
therefore, their equations are different from the equation for
the MIC5209BM/U.
The SOT-223 package has sufficient thermal characteristics
for wide design margins when mounted on a single layer
copper-clad printed circuit board. The power dissipation of
August 2, 2000
9
MIC5209
MIC5209
Micrel
the MIC5209 is calculated using the voltage drop across the
device × output current plus supply voltage × ground current.
Considering worst case tolerances, the power dissipation
could be as high as:
Table 2 and Figure 6 show that the Slot-1 power supply
application can be implemented with a minimum footprint
layout. Figure 6 shows the necessary copper pad area to
obtainspecificheatsinkthermalresistance(θ )values. The
SA
2
θ
values in Table 2 require much less than 500mm of
(V
– V
) × I
+ V
× I
IN(max) GND
SA
IN(max)
OUT(max)
OUT
copper, according to Figure 6, and can easily be accom-
plished with the minimum footprint.
[(3.6V – 2.375V) × 320mA] + (3.6V × 4mA)
P = 407mW
D
70
60
50
40
30
20
10
0
Using the maximum junction temperature of 125°C and a θ
JC
of 8°C/W for the SOT-223, 25°C/W for the SO-8, or 2°C/W for
the TO-263 package, the following worst-case heat-sink
thermal resistance (θ ) requirements are:
SA
T
− T
A
J(max)
θ
=
JA
P
D
θSA = θJA − θJC
0
2000
4000
6000
2
COPPER HEAT SINK AREA (mm )
TA
θJA (limit)
θSA SOT-223 201°C/W
θSA SO-8 184°C/W
θSA TO-263-5 207°C/W
40°C
50°C
60°C
75°C
Figure 6. PCB Heat Sink Thermal Resistance
209°C/W
184°C/W 160°C/W 123°C/W
176°C/W 152°C/W 115°C/W
159°C/W 135°C/W 98°C/W
182°C/W 158°C/W 121°C/W
Table 2. Maximum Allowable Thermal Resistance
MIC5209
10
August 2, 2000
MIC5209
Micrel
Package Information
3.15 (0.124)
2.90 (0.114)
C
L
7.49 (0.295)
6.71 (0.264)
3.71 (0.146)
3.30 (0.130)
C
L
2.41 (0.095)
2.21 (0.087)
1.04 (0.041)
0.85 (0.033)
4.7 (0.185)
4.5 (0.177)
DIMENSIONS:
MM (INCH)
1.70 (0.067)
1.52 (0.060)
16°
10°
6.70 (0.264)
6.30 (0.248)
0.10 (0.004)
0.038 (0.015)
10°
MAX
0.02 (0.0008)
0.25 (0.010)
0.84 (0.033)
0.64 (0.025)
0.91 (0.036) MIN
SOT-223 (S)
0.026 (0.65)
MAX)
PIN 1
0.157 (3.99)
0.150 (3.81)
DIMENSIONS:
INCHES (MM)
0.020 (0.51)
0.013 (0.33)
0.050 (1.27)
TYP
45°
0.0098 (0.249)
0.0040 (0.102)
0.010 (0.25)
0.007 (0.18)
0°–8°
0.197 (5.0)
0.189 (4.8)
0.050 (1.27)
0.016 (0.40)
SEATING
PLANE
0.064 (1.63)
0.045 (1.14)
0.244 (6.20)
0.228 (5.79)
8-Pin SOP (M)
August 2, 2000
11
MIC5209
MIC5209
Micrel
0.405±0.005
0.176 ±0.005
0.060 ±0.005
0.050±0.005
0.360±0.005
0.065 ±0.010
20°±2°
0.600±0.025
SEATING PLANE
+0.004
0.004
–0.008
0.100±0.01
8° MAX
0.067±0.005
DIM. = INCH
0.032 ±0.003
0.015 ±0.002
TO-263-5 (U)
MIC5209
12
August 2, 2000
MIC5209
Micrel
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
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or
other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.
© 2000 Micrel Incorporated
August 2, 2000
13
MIC5209
相关型号：
MIC5209-1.8YUTR
2.5V FIXED POSITIVE LDO REGULATOR, 0.6V DROPOUT, PSSO5, LEAD FREE, TO-263, 5 PIN
MICROCHIP
©2020 ICPDF网 联系我们和版权申明