MIC2039
Evaluation Board
High-Accuracy, High-Side, Adjustable
Current Limit Power Switch
General Description
Getting Started
The MIC2039 is a high-side MOSFET power distribution
switch providing increased system reliability by using 5%
current limit accuracy.
The MIC2039 has an operating input voltage range from
2.5V to 5.5V, is internally current limited, and has thermal
shutdown to protect the device and system. The MIC2039
is offered with either active-high or active-low logic level
enable input controls. It has an open drain fault status
output flag with a built-in 32ms delay that asserts low
during overcurrent or thermal shutdown conditions.
The MIC2039 switch features an adjustable output current
limit that is resistor programmable from 0.2A to 2.5A. The
MIC2039 switch also offers a unique Kickstart feature,
which allows momentary high-current surges up to the
secondary current limit (ILIMIT_2nd) during startup or while
operating in steady state. This is useful for charging loads
with high inrush currents, such as capacitors. After an
overcurrent condition is established, these switches enter
into a constant current limit mode unless the die
temperature exceeds the thermal shutdown specification.
The MIC2039 is offered in both 6-pin SOT-23 and 6-pin
2mm x 2mm thin DFN packages. It has an operating
junction temperature range of −40°C to +125°C.
Requirements
The MIC2039 evaluation board requires a single power
supply to provide VIN. The VIN power supply must be able
to deliver a minimum of 2.5V and more than 1.5A
capability. The output load can either be active or passive.
Precautions
The evaluation board does not have reverse polarity
protection. Applying a negative voltage to the VIN terminal
can damage the device. In addition, the maximum VIN
operating voltage of the MIC2039 evaluation board is 5.5V.
Exceeding 5.5V on VIN can permanently damage the
device.
1. Connect an external supply to VIN terminal.
Apply the desired input voltage to the VIN and ground
terminals of the evaluation board, paying careful
attention to polarity and supply voltage. The user can
place an ammeter between the input supply and the
VIN terminal to the evaluation board. Make sure 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). The user can place an ammeter
between the load and the VOUT terminal. Make sure
that the output voltage is monitored at the VOUT
terminal.
3. Enable the switch.
The MIC2039 evaluation boards are configured for
default enable using a 10kΩ pull-up resistor from the
ENABLE pin to VIN. To disable the switch, place a
jumper short across the jumper pins at TP2.
4. Fault detection
The MIC2039 is equipped with an error flag pin,
FAULT/. TP3 is provided to monitor the FAULT/ pin.
Ordering Information
Part Number
Description
MIC2039-05AYM6 EV
Evaluation board featuring the
MIC2039AYM6 Power Switch
Current limit is set for 500mA
MIC2039-1AYM6 EV
Evaluation board featuring the
MIC2039AYM6 Power Switch
Current limit is set for 1A
MIC2039-05AYMT EV
Evaluation board featuring the
MIC2039AYMT Power Switch
Current limit is set for 500mA
MIC2039-1AYMT EV
Evaluation board featuring the
MIC2039AYMT Power Switch
Current limit is set for 1A
Ramp Control is a trademark of Micrel, 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 2012
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Micrel, Inc.
MIC2039 Evaluation Board
Application Information
where ILIMIT is the typical current limit from the electrical
table. If the output current exceeds the set current limit,
the MIC2039 switch enters constant current limit mode.
The maximum allowable current limit may be less than
the full specified and/or expected current if the MIC2039
is not mounted on a circuit board with sufficiently low
thermal resistance. Resistor values (1%) for select
current limit settings are shown in Table 1.
Adjustable Current Limit
The factory sets the MIC2039-xYMx evaluation boards
for either a 500mA or 1A current limit. However,
connecting a resistor (R3) from the ILIMIT pin to GND
allows the current limit to be adjusted from 0.2A to 2.5A.
For the MIC2039-xYMT evaluation board, jumper TP4
must be shorted for R3 to connect to the ILIMIT pin of
the IC. The following equation determines the value of
R3:
R3 ≅ 289/ILIMIT
Eq. 1
ILIMIT
0.2A
0.5A
1.0A
2A
2.5A
R3
1.43kΩ
576Ω
287Ω
143Ω
115Ω
Table 1. Resistor Selection for Adjustable Current Limit
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MIC2039 Evaluation Board
Evaluation Board Schematics
MIC2039xYMT Evaluation Board
MIC2039xYM6 Evaluation Board
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MIC2039 Evaluation Board
Bill of Materials
Item
C1, C2
R1, R2
R3
U1
Part Number
Manufacturer
C1608X5R0J105K
TDK
06036D105KAT2A
AVX(2)
CRCW060310K0FKEA
CRCW06032870FKEA
CRCW06031430FKEA
MIC2039xYMT
MIC2039xYM6
Description
Qty.
(1)
Vishay/Dale(3)
Vishay/Dale
Micrel(4)
1µF/6.3V ceramic capacitor, X5R, 0603
2
10kΩ, film resistor, 0603, 1%
2
287Ω film resistor, 0603, 1% or
1
143Ω film resistor, 0603, 1%
High-accuracy, high-side, adjustable current limit power switch
1
Notes:
1. TDK: www.tdk.com.
2. AVX: www.avx.com.
3. Vishay: www.vishay.com.
4. Micrel, Inc.: www.micrel.com.
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MIC2039 Evaluation Board
Evaluation Board PCB Layout
MIC2039xYMT Evaluation Board – Top Layer
MIC2039xYMT Evaluation Board – Bottom Layer
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MIC2039 Evaluation Board
Evaluation Board PCB Layout (Continued)
MIC2039xYM6 Evaluation Board – Top Layer
MIC2039xYM6 Evaluation Board – Bottom Layer
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MIC2039 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
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.
© 2012 Micrel, Incorporated.
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