2
dc2161af
DEMO MANUAL DC2161A
DC2161A contains 3 jumpers. A description of each
jumper follows.
JP1, UV/OV.
This jumper selects whether or not undervolt-
age or overvoltage lockout is enabled. When the jumper
is in the disable position, a UV or OV condition will not
block operation of the Hot Swap Controller. The default
is ENABLE.
JP2, IQ.
The LTC4231 is a low power device, meaning it
draws very little current to perform its function. Any board
leakage on the GATE pin caused by board contamination or
a defective MOSFET will cause this current to increase. JP2,
when in the MEASURE IQ position, facilitates measurement
of the quiescent current of the LTC4231 exclusive of the
current of other components on the board, such as LED
OPERATING PRINCIPLES
D2, output coupling capacitor C3, TVS diode D1, capacitor
C1, voltage divider R6, R7, R8 and R9, or any leakage on
the board. This current is measured via a microammeter
connected between turret E7 and GND. If the MEASURE IQ
position is selected, verify a microammeter is connected
to prevent damage to the board via leakage between V
IN
and the gate of the MOSFETs. The default position for JP2
is NORMAL.
JP3, ENABLE.
This jumper either enables or disables the
output or provides external control of the output. This is
provided by the ON pin of the LTC4231. When in the ON
position, the 12V V
OUT
is enabled. When in the OFF posi-
tion, the 12V V
OUT
is disabled. When in the EXT position,
the ON pin is connected via a 100kΩ resistor from turret
E9 to the ON pin of the LTC4231. A logic 1 on this pin will
enable the 12V V
OUT
. The default position for JP3 is ON.
The LTC4231 is a Micropower Hot Swap Controller that
has a 2.7V to 36V operating range and a
–
40V to 40V ab-
solute maximum voltage for the IN pin. This demo circuit
is populated for +12V operation, but it can easily be re-
adjusted for any voltage between 2.7V and 36V by replac-
ing R6, R7, R8, and R9 in the UVL, UVH, and OV divider
string. These values should be selected using guidelines
suggested in the LTC4231 data sheet to minimize current
drain. The DC2161A is populated with a Si7960DP dual
MOSFET with one section used as a pass MOSFET and the
other section used for reverse voltage protection. It also
has a 15mΩ sense resistor. This combination provides
an output current of 3A. Pads are provided on the PCB
for external MOSFET and sense resistor connections for
other voltages and currents.
JUMPERS
