MIC49300 Evaluation Board

MIC49300 Evaluation Board
3.0A Low Voltage LDO Regulator
with Dual Input Voltages
General Description
Features
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The MIC49300 voltage regulator provides highbandwidth, low-dropout, and high current drive for
powering
core
voltages
of
low-power
microprocessors. The MIC49300 uses separate
supplies for VIN and VBIAS allowing for very low output
impedance and very fast transient response.
The main input supply of the MIC49300 is separate
from the bias input supply, thus allowing for ultra-low
input voltages on the main supply rail. The main input
supply operates between 1.4V to 6.5V and the bias
supply requires between 3V to 6.5V for proper
operation.
Main Input voltage range: 1.4V to 6.5V
Bias Input voltage range: 3V to 6.5V
Maximum load current: 3.0A
Adjustable output voltage down to 0.9V
Stable with 1µF ceramic capacitor
Power S-Pak package
MIC49300BR
+VIN
VOUT
+VIN
C1
10µF
VBIAS
VOUT
R1
BIAS
ADJ
C3
10µF
C2
1µF
GND
R2
GND
GND
Pin Description
Pin Number
Part Name Pin Function
1
Adj
Adjustable regulator feedback input. Connect to resistor voltage divider
2
Vbias
Input Bias Voltage for powering all circuitry on the regulator with the exception of the output
power device
3
GND
Ground (TAB is connected to ground on S-Pak)
4
VIN
Input voltage which supplies current to the output power device
5
VOUT
Regulator Output
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax 1 (408) 474-1000 • http://www.micrel.com
M9999-030405
(408) 955-1690
March 2005
Micrel, Inc.
MIC49300 Evaluation Board
GND
TAB is also used for ground
Adjustable Regulator Design
The MIC49300 adjustable version allows the output
voltage to be set between 0.9V and 5V. The ADJ pin
voltage is 0.9V on the adjustable versions. Once a
suitable VOUT voltage is determined values for R1 and
R2 can be calculated. The only requirement is that R1
should not exceed 1kΩ.
VIN
VIN provides the high current to the collector of the
pass transistor of the regulator. The minimum input
voltage for the MIC49300 is 1.4V. The suggested
bypass capacitor value for VIN on the demo board is a
100µF ceramic capacitor.
R1 = R2 x (Vout/0.9 – 1)
VBIAS
The VBIAS input voltage must be 1.6V above the
output voltage with a minimum VBIAS input voltage of
3V. Small ceramic capacitors from VBIAS to group help
reduce high frequency noise from being injected into
the control circuitry from the bias rail and are good
design practice. A 4.7µF capacitor should be
sufficient.
VOUT
The MIC49300 does not require a minimum load to
maintain output voltage regulation. The suggested
bypass capacitor value for VOUT on the demo board is
a 10µF ceramic capacitor. An output capacitance is
required on the MIC49300 to maintain stability.
Bill of Material
MIC49300 Evaluation Board
Ref Des
C1
C2
C3
C4
J1-J5
R1,R2
U1
Part Number
C3225X5R0J107K
C2012Y5V1A475M
C3225Y5V0J106K
Description
100µF, 6.3V X5R Ceramic Capacitor
4.7µF, 10V Y5V Ceramic Capacitor
10µF, 6.3V Y5V Ceramic Capacitor
2551-2-00-01-00-00-07-0 Turret pins
CRCW08051001FRT1
1k, 1%, 1/10W, 0805
MIC49300BR
SPAK – 5 Pins
Manufacturer Qty
TDK
1
TDK
1
TDK
1
1
MillMax
5
Vishay
2
Micrel
1
Notes:
1.
Mill Max: www.millmax.com
2.
TDK: www.tdk.com
3.
Vishay: www.vishay.com
4.
Micrel Semiconductor: www.micrel.com
March 2005
2
M9999-030405
(408) 955-1690
Micrel, Inc.
MIC49300 Evaluation Board
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
March 2005
3
M9999-030405
(408) 955-1690