MAX5943AEVKIT Maxim Integrated, MAX5943AEVKIT Datasheet - Page 4

• Manufacturer Part Number: MAX5943AEVKIT
• Description: Power Management IC Development Tools Evaluation Kit for the MAX5943A/B/C/D/E
• Manufacturer: Maxim Integrated
• Series: MAX5943r

175ms by removing resistor R6, the shunt on jumper
JU1, and leaving resistor R10 pads open, which lets the
TIM pin float. Note: Long timeout periods may pro-
duce excessive heating and electrical stresses in
R1, N1-A, N1-B, and other components in the power
path. Verify that the components on the board can
handle the electrical and thermal stresses with the
new timeout period.
The MAX5943A EV kit circuit ORing function can be
enabled or disabled by configuring jumper JU3. See
Table 3 for jumper JU3 configuration.
When the ORing function is disabled, the MAX5943A
controller will fully enhance MOSFET N1-A, during nor-
mal operation, regardless of the load-current condition.
In this mode, current can flow from the output OUT to
the input IN if the voltage present at the OUT terminal is
higher than the voltage at the IN terminal, without cur-
rent limiting.
When the ORing function is enabled, the MAX5943A
controller turns MOSFET N1-A on or off depending on
the load-current conditions. Initially during startup,
MOSFET N1-A is turned off and the load current con-
ducts through the body diode of MOSFET N1-A. The
MAX5943A controller turns on MOSFET N1-A when the
voltage across current-sense resistor R1 exceeds the
programmed threshold V
monitor the voltage across resistor R1 and turns off
MOSFET N1-A when that voltage drops below the V
threshold. When MOSFET N1-A is turned off, current
cannot back drive the input source IN if the voltage at
OUT is higher than the IN voltage. The V
can be programmed to 5mV, 7.5mV, or 10mV by con-
figuring jumper JU4. See Table 4 to reconfigure jumper
JU4 and program the V
MAX5943A Evaluation Kit
Table 2. Current-Limit Timer
Configuration
4
JUMPER JU1
Not installed
POSITION
_______________________________________________________________________________________
Installed
SHUNT
Connected to GND
through a 4.03kΩ
equivalent resistor
Connected to GND
through a 8.06kΩ
resistor
CONNECTION
TIM PIN
OR
OR
threshold.
. The controller continues to
Power-Supply ORing
TIMEOUT PERIOD
OVERCURRENT
LIMIT (ms)
OR
1.1
2
threshold
OR
The MAX5943A EV kit FAULT output is a high-voltage
output signal that is asserted low to GND when a
current-limit fault condition has occurred. The FAULT
output is pulled up to IN by resistor R2 during normal
operating conditions. During a fault occurrence, the
MAX5943A turns off MOSFETs N1-A and N1-B and
asserts a logic-low signal on the FAULT output.
The fault mode can be programmed for latched or
autoretry mode. In latched fault mode, the MAX5943A
turns off MOSFET N1-A and N1-B indefinitely. The
MAX5943A EV kit circuit can be reset to normal opera-
tion by removing the fault condition and cycling the ON
pin low and then high. Cycling the ON pin can be
achieved by momentarily pressing pushbutton switch
SW1 or by applying a high-low-high transition at the ON
PC board pad with a microcontroller. The MAX5943A will
not enter a startup cycle until timer t
t
turning the input power supply off and on. This method
allows the circuit to restart without a wait period of t
In autoretry mode, after a fault condition has occurred,
the MAX5943A controller automatically attempts to
restart after the t
on every restart cycle.
Table 3. ONQ1 Configuration
Table 4. ORing Threshold Voltage
Configuration*
*Remove the shunt across jumper JU3 to enable the ORing
function.
ILIM
SHUNT POSITION
JUMPER JU4
Not installed
POSITION
JUMPER JU3
Not installed
SHUNT
) has expired. The latched fault can also be reset by
Installed
2-3
1-2
OFF
Connected to
GND
Floating
Connected to IN
CONNECTION
OR_ADJ PIN
Connected to GND
through resistor R7
Connected to IN
period. The FAULT output deasserts
CONNECTION
ONQ1 PIN
VOLTAGE (V
ORing THRESHOLD
OFF
EV KIT ORing
(t
FUNCTION
7.5
10
OFF
Disabled
5
Enabled
OR
FAULT
= 128 x
, mV)
OFF
.