MIC5206_06 Datasheet, PDF (9/11 Pages) Micrel Semiconductor – 150mA Low-Noise LDO Regulator

Micrel, Inc.
Ultra-Low-Noise Application
Figure 2. Ultra-Low-Noise Fixed Voltage Application
Figure 2 includes a 470pF capacitor for low-noise
operation and shows EN (pin 7) connected to IN (pin 8)
for an application where enable/shutdown is not
required. The error flag is shown with a 47kΩ pull-up
resistor.
Adjustable Regulator Applications
Figure 3 shows the MIC5206BMM adjustable output
voltage configuration. Two resistors set the output
voltage. The formula for output voltage is:
V_OUT
= 1.242V × ⎜⎛ ^R2 + 1⎟⎞
⎝ ^R1 ⎠
Resistor values are not critical because ADJ (adjust) has
a high input impedance, but for best results use resistors
of 470kΩ or less. A capacitor from ADJ to ground
provides greatly improved noise performance.
Figure 3. Ultra-Low-Noise Adjustable Voltage Application
Figure 3 also includes a 470pF capacitor for lowest-
noise operation and shows EN (pin 7) connected to IN
(pin 8) for an application where enable/shutdown is not
required. C_OUT = 2.2µF minimum. The error flag is shown
with a 47kΩ pull-up resistor.
MIC5206
Thermal Considerations
Layout
The MIC5206-x.xBM5 (5-pin SOT-23 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.
PC Board
θ_JA
Dielectric
FR4
220°C/W
Ceramic
200°C/W
SOT-23-5 Thermal Characteristics
The “worst case” value of 220°C/W assumes no ground
plane, minimum trace widths, and a FR4 material board.
The MIC5206-xxBMM (8-pin MSOP) has a thermal
resistance of 200°C/W when mounted on a FR4 board
with minimum trace widths and no ground plane.
PC Board
θ_JA
Dielectric
FR4
200°C
MSOP Thermal Characteristics
Nominal Power Dissipation and Die Temperature
The MIC5206-x.xBM5 at a 25°C ambient temperature
will operate reliably at over 450mW power dissipation
when mounted in the “worst case” manner described
above. At an ambient temperature of 40°C, the device
may safely dissipate over 380mW. These power levels
are equivalent to a die temperature of 125°C, the
maximum operating junction temperature for the
MIC5206.
For additional heat sink characteristics, please refer to
Micrel Application Hint 17, “Calculating P.C. Board Heat
Sink Area For Surface Mount Packages”.
May 2006
9
M9999-051506
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