MIC5201-3.3BM TR Micrel Inc, MIC5201-3.3BM TR Datasheet - Page 8

• Manufacturer Part Number: MIC5201-3.3BM TR
• Description: IC REG LDO 200MA 3.3V 1% 8SOIC
• Manufacturer: Micrel Inc

Specifications of MIC5201-3.3BM TR

• Regulator Topology: Positive Fixed
• Voltage - Output: 3.3V
• Voltage - Input: Up to 26V
• Voltage - Dropout (typical): 0.27V @ 200mA
• Number Of Regulators: 1
• Current - Output: 200mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Limit (min): -
• Other names: MIC5201-3.3BMTR

MIC5201
MIC5201
Applications Information
Figure 1 shows a basic fixed-voltage application with the
unused enable input connected to V
Adjustable regulators require two resistors to set the output
voltage. See Figure 2.
Resistors values are not critical because ADJ (adjust) has a
high impedance, but for best results use resistors of 470kΩ
or less.
Output Capacitors
A 1µF capacitor is recommended between the MIC5201
output and ground to prevent oscillations due to instability.
Larger values serve to improve the regulator’s transient
response. Most types of tantalum or aluminum electrolytics
will be adequate; film types will work, but are costly and
therefore not recommended. Many aluminum electrolytics
have electrolytes that freeze at about –30°C, so solid tanta-
lums are recommended for operation below –25°C. The
important parameters of the capacitor are an effective series
resistance of about 5Ω or less and a resonant frequency
above 500kHz. The value of this capacitor may be increased
without limit.
At lower values of output current, less output capacitance is
required for output stability. The capacitor can be reduced to
0.47µF for current below 10mA or 0.33µF for currents below
1mA.
Input Capacitors
A 1µF capacitor should be placed from the MIC5201 input to
ground if there is more than 10 inches of wire between the
input and the ac filter capacitor or if a battery is used as the
input.
Noise Reduction Capacitors
On adjustable devices, a capacitor from ADJ to GND will
decrease high-frequency noise on the output. See Figure 3.
Figure 2. Adjustable Application
V
Figure 1. Fixed Application
V
IN
OUT
V
IN
=
IN
EN
1.242V 1
MIC5201BM
MIC5201-x.xBM
MIC5201-x.xBS
GND
IN
EN
OUT
GND



ADJ
+
OUT
R2
R1



R1
R2
IN
1µF
.
V
OUT
3.3µF
V
OUT
8
Minimum Load
The MIC5201 will remain stable and in regulation with no
load unlike many other voltage regulators. This is
especially important in CMOS RAM keep-alive
applications.
Dual-Supply Systems
When used in dual supply systems where the regulator
load is returned to a negative supply, the output voltage
must be diode clamped to ground.
Thermal Considerations Layout
The MIC5201-x.xBM (8-pin surface mount package) has the
following thermal characteristics when mounted on a single
layer copper-clad printed circuit board.
Multilayer boards having a ground plane, wide traces near the
pads, and large supply bus lines provide better thermal
conductivity.
The “worst case” value of 160°C/W assumes no ground
plane, minimum trace widths, and a FR4 material board.
Nominal Power Dissipation and Die Temperature
The MIC5201-x.xBM at a 25°C ambient temperature will
operate reliably at up to 625mW power dissipation when
mounted in the “worst case” manner described above. At an
ambient temperature of 55°C, the device may safely dissi-
pate 440mW. These power levels are equivalent to a die
temperature of 125°C, the recommended maximum tem-
perature for non-military grade silicon integrated circuits.
For MIC5201-x.xBS (SOT-223 package) heat sink character-
istics, please refer to Micrel Application Hint 17, P.C. Board
Heat Sinking.
Figure 4. Min. Recommended SO-8 PCB Pads Size
Figure 3. Decreasing Ouput Noise
V
245 mil
IN
30 mil
PC Board
Dielectric
Ceramic
IN
EN
MIC5201BM
FR4
GND
OUT
ADJ
50 mil
R1
R2
160ºC/W
120ºC/W
θ θ θ θ θ
JA
C
ADJ
3.3µF
V
150 mil
50 mil
OUT
Micrel, Inc.
June 2005