MIC2033
Evaluation Board
High-Accuracy, High-Side, Fixed
Current Limit Power Switch
General Description
The MIC2033 is a high-side MOSFET power distribution
switch providing increased system reliability using 5%
current limit accuracy.
The MIC2033 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 MIC2033
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 MIC2033 is available with several different fixed
current limit options: 0.5A, 0.8A, 1A, and 1.2A. A
capacitor-adjustable soft-start circuit minimizes inrush
current in applications using high capacitive loads.
The MIC2033 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 MIC2033 evaluation board requires a single power
supply to provide V
IN
. The V
IN
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 V
IN
terminal
can damage the device. In addition, the maximum V
IN
operating voltage of the MIC2033 evaluation board is 5.5V.
Exceeding 5.5V on V
IN
can permanently damage the
device.
Getting Started
1.
Connect an external supply to the V
IN
terminal.
Apply the desired input voltage to the V
IN
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
V
IN
terminal to the evaluation board. Make sure that
the supply voltage is monitored at the V
IN
terminal. The
ammeter and/or power lead resistance can reduce the
voltage supplied to the input.
2.
Connect the load to the V
OUT
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 V
OUT
terminal. Make sure
that the output voltage is monitored at the V
OUT
terminal.
3.
Enable the switch
The MIC2033-12AYxx 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. The MIC2033-05BYxx evaluation boards are
configured for default disable. To enable the switch,
place a jumper short across the jumper pins at TP2.
4.
Fault detection
The MIC2033 is equipped with an error flag, FAULT/.
TP3 is provided to monitor the FAULT/ pin.
Ordering Information
Part Number
MIC2033-05BYM6 EV
MIC2033-12AYM6 EV
MIC2033-05BYMT EV
MIC2033-12AYMT EV
Description
Evaluation board featuring the
MIC2033-05BYM6 500mA Switch
Evaluation board featuring the
MIC2033-12AYM6 1.2A Switch
Evaluation board featuring the
MIC2033-05BYMT 500mA Switch
Evaluation board featuring the
MIC2033-12AYMT 1.2A Switch
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
September 2012
M9999-092812-A
Micrel, Inc.
MIC2033 Evaluation Board
Application Information
Soft-Start
Soft-start reduces the power supply input surge current
at startup by controlling the output voltage rise time. The
input surge appears while the output capacitor is
charged up. A slower output rise time draws a lower
input surge current.
During soft-start, an internal current sink discharges the
external capacitor at CSLEW to ground to control the
ramp of the output voltage. The output voltage rise time
depends on the value of C
CSLEW
, the input voltage,
output voltage, and the current limit. Micrel recommends
that the value of the CSLEW external capacitor be in the
range of 0.1µF to 1µF. For the MIC2033 evaluation
board, CSLEW = C3 = 0.1µF.
Output Voltage
The MIC2033 evaluation board is available with either a
0.5A or 1.2A fixed current limit. If the output current
exceeds the current limit, the MIC2033 switch enters
constant current limit mode. The maximum allowable
current limit can be less than the full specified and/or
expected current if the MIC2033 is not mounted on a
circuit board with sufficiently low thermal resistance. The
MIC2033 responds to short circuits within 10µs to limit
the output current. It also provides an output fault flag
that asserts (low) for an overcurrent condition that lasts
longer than the overcurrent fault response delay time
(t
FAULT/
), which is typically 32ms.
September 2012
2
M9999-092812-A
Embedded System
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