MIC61300 Evaluation Board

MIC61300 Evaluation Board
Low Input Voltage, Single-Supply
High-Current LDO
General Description
Getting Started
Micrel’s MIC61300 is a 3A output, low input voltage,
single-supply regulator. This regulator operates over an
input voltage range of 1.1V to 3.6V and offers an ultra-low
dropout less than 350mV over the entire operating
temperature range.
The MIC61300 is designed to drive digital circuits requiring
low voltages at high currents such as DSPs, FPGAs, and
microcontrollers. The regulator is available as a 1.0V fixedoutput voltage option or as an adjustable-output voltage
option.
The MIC61300 is stable with a 47µF, low-ESR ceramic
output capacitor, and includes protection features such as
thermal shutdown, current limiting and logic enable.
The MIC61300 is offered in two different packages: a lowprofile, leadless 10-pin 3mm x 3mm MLF® and a 10-pin
ePad MSOP. The MIC61300 has an operating junction
temperature range of −40°C to +125°C.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
1. Connect an external supply to VIN terminal. Apply
desired input voltage to the VIN and ground terminals
of the evaluation board, paying careful attention to
polarity and supply voltage. An ammeter may be
placed between the input supply and the VIN terminal
to the evaluation board. Ensure that the supply voltage
is monitored at the VIN terminal. The ammeter and/or
power lead resistance can reduce the voltage supplied
to the input.
2. Connect the load to the VOUT and ground terminals.
The load can be either passive (resistive) or active (as
in an electronic load). An ammeter can be placed
between the load and the VOUT terminal. Ensure that
the output voltage is monitored at the VOUT terminal.
The VOUT can be adjusted by changing the feedback
resistors. See Adjustable Regulator Design section.
3. Enable the MIC61300. The EN pin is provided on the
evaluation board with a 10k pull-up resistor. The
output of the MIC61300 may be turned off by shorting
the EN pin to ground. An external connection on the
board provides easy access to the enable pin.
Removing the pull-up resistor and leaving the EN pin
floating will cause the regulator to operate in an
indeterminate state.
4. Soft-Start. The CP pin is the output of the internal
charge pump. The soft-start rise time is controlled by
the external capacitor connected from the CP pin to
GND (J5). During soft-start, the charge pump feeds a
current to CCP. The output voltage rise time is
dependent upon the value of CCP, the input voltage,
output voltage and the current limit. The value of the
charge pump external capacitor selected is
recommended in the range of 0.1µF to 1µF.
Requirements
The MIC61300 evaluation board requires a single power
supply to provide VIN. The VIN power supply must be able
to deliver greater than 1.1V with more than 3A capability.
The output load can either be an active or passive load.
Precautions
The evaluation board does not have reverse polarity
protection. Applying a negative voltage to the VIN terminal
may damage the device. In addition, the maximum VIN
operating voltage of the MIC61300 evaluation board is
3.6V, exceeding 3.6V on VIN could damage the device.
Ordering Information
Part Number
Description
MIC61300YML EV
Evaluation Board
MIC61300YMME EV
Evaluation Board
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
October 2010
M9999-102910-A
Micrel, Inc.
MIC61300
Adjustable Regulator Design
The MIC61300 adjustable version allows programming the
output voltage from 0.5V to 3.0V by placing a resistor
divider network (R1, R2) from VOUT to GND (see
Application Circuit). The high side of R1 should be
connected at the point-of-load for high-accuracy Kelvin
sensing. VOUT is determined by the following equation:
⎛ R1 ⎞
VOUT = 0.5 × ⎜
+ 1⎟
⎝ R2 ⎠
Eq. 1
where VOUT is the desired output voltage.
The resistor (R2) value between the FB pin and GND is
selected to maintain a minimum 10mA load on the output.
The resistor values are calculated from the previous
equation, resulting in the following:
Output Capacitor
As part of the frequency compensation, the MIC61300
requires a 47µF ceramic output capacitor. However, any
other type of capacitor can be placed in parallel as long as
the 47µF ceramic output capacitor is placed next to the
MIC61300.
Output voltages below 0.8V require either a 100µF or
2x 47µF output capacitance for large output transients.
The increased output capacitance reduces the output
voltage drop caused by load transients, which increases
as a percentage of the output voltage as the output voltage
is lowered.
The output capacitor type and placement criteria are the
same as the input capacitor. See the Input Capacitor
section in the MIC61300 datasheet for a detailed
description.
Minimum Load Current
⎛V
⎞
R1 = R2 × ⎜⎜ OUT − 1⎟⎟
⎝ 0.5
⎠
Eq. 2
The MIC61300 requires a minimum load of 10mA to
maintain output voltage regulation.
Table 1 is a list of resistor combinations to set the output
voltage. A 1% tolerance is recommended for both R1 and
R2. For a unity gain, 0.5V output voltage, connect the FB
pin directly to the output.
VOUT
R1
R2
0.5V
−
49.9Ω
0.6V
10.0Ω
49.9Ω
0.7V
20.0Ω
49.9Ω
0.8V
30.1Ω
49.9Ω
0.9V
40.2Ω
49.9Ω
1.0
49.9Ω
49.9Ω
1.1V
60.4Ω
49.9Ω
1.2V
69.8Ω
49.9Ω
1.5V
100Ω
49.9Ω
1.8V
130Ω
49.9Ω
2.2V
169Ω
49.9Ω
Table 1. Resistor Selection for Specific VOUT
October 2010
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M9999-102910-A
Micrel, Inc.
MIC61300
MIC61300YML Evaluation Board Schematic (3mm × 3mm 10-Pin ePad MLF®)
MIC61300YML Evaluation Board
(J1, J2, J5, and R4 are for testing purposes)
Bill of Materials
Item
C1
Part Number
C0805C106K8PACTU
C3216X5ROJ476M
C2
GRM31Cr60J476ME19L
12066D476MAT2A
Manufacturer
Kemet
(1)
Description
Qty.
10µF/10V Ceramic Capacitor, X5R,Size 0805
TDK(2)
47µF/6.3V Ceramic Capacitor, X5R, Size 1206 or
Murata(3)
47µF/6.3V Ceramic Capacitor, X5R, Size 1206 or
(4)
AVX
(1)
1
1
47µF/6.3V Ceramic Capacitor, X5R, Size 1206
C3
C0603C104K8RACTU
Kemet
0.1µF/10V Ceramic Capacitor, X7R, Size 0603
1
R1
CRCW080569R8F
Vishay(5)
69.8Ω Film Resistor, Size 0805, 1%
1
CRCW080549R9F
(5)
49.9Ω Film Resistor, Size 0805, 1%
1
(5)
R2
Vishay
R3
CRCW08051002F
Vishay
10kΩ Film Resistor, Size 0805, 1%
1
R4
CRCW080500R0F
Vishay(5)
0Ω Film Resistor, Size 0805, 1%
1
U1
MIC61300YML
3A Low-Voltage, Single-Supply LDO
1
Micrel, Inc.(6)
Notes:
1. Kemet: www.kemet.com.
2. TDK: www.tdk.com.
3. Murata: www.murata.com.
4. AVX: www.avx.com.
5. Vishay: www.vishay.com.
6. Micrel, Inc.: www.micrel.com.
October 2010
3
M9999-102910-A
Micrel, Inc.
MIC61300
MIC61300YML PCB Layout Recommendations
MIC61300YML Evaluation Board – Top Layer
MIC61300YML Evaluation Board – Bottom Layer
October 2010
4
M9999-102910-A
Micrel, Inc.
MIC61300
MIC61300YMME Evaluation Board Schematic (10-Pin ePad MSOP)
MIC61300YMME Evaluation Board
(J1, J2, J5, and R4 are for testing purposes)
Bill of Materials
Item
C1
Part Number
C0805C106K8PACTU
C3216X5ROJ476M
C2
GRM31Cr60J476ME19L
12066D476MAT2A
C3
C0603C104K8RACTU
Manufacturer
Kemet
(1)
(2)
TDK
Murata(3)
(4)
AVX
Kemet
Description
Qty.
10µF/10V Ceramic Capacitor, X5R,Size 0805
1
47µF/6.3V Ceramic Capacitor, X5R, Size 1206 or
47µF/6.3V Ceramic Capacitor, X5R, Size 1206 or
1
47µF/6.3V Ceramic Capacitor, X5R, Size 1206
(1)
0.1µF/10V Ceramic Capacitor, X7R, Size 0603
1
(5)
R1
CRCW080569R8F
Vishay
69.8Ω Film Resistor, Size 0805, 1%
1
R2
CRCW080549R9F
Vishay(5)
49.9Ω Film Resistor, Size 0805, 1%
1
CRCW08051002F
(5)
10kΩ Film Resistor, Size 0805, 1%
1
R3
R4
CRCW080500R0F
U1
MIC61300YMME
Vishay
(5)
Vishay
Micrel, Inc.(6)
0Ω Film Resistor, Size 0805, 1%
1
3A Low-Voltage, Single-Supply LDO
1
Notes:
1. Kemet: www.kemet.com.
2. TDK: www.tdk.com.
3. Murata: www.murata.com.
4. AVX: www.avx.com.
5. Vishay: www.vishay.com.
6. Micrel, Inc.: www.micrel.com.
October 2010
5
M9999-102910-A
Micrel, Inc.
MIC61300
MIC61300YMME PCB Layout Recommendations
MIC61300YMME Evaluation Board – Top Layer
MIC61300YMME Evaluation Board – Bottom Layer
October 2010
6
M9999-102910-A
Micrel, Inc.
MIC61300
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
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right
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.
© 2010 Micrel, Incorporated.
October 2010
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M9999-102910-A