MAX5943AEVKIT Maxim Integrated, MAX5943AEVKIT Datasheet - Page 5

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

Table 5. LATCH Configuration
The MAX5943A EV kit can also be used to evaluate ver-
sions B, C, D, or E of the MAX5943 controller. Refer to
the MAX5943 data sheet to review the functional and
electrical differences between these versions. Verify
that the EV kit circuit components will function properly
when evaluating the other MAX5943 controllers. The
MAX5943A must be removed and replaced with the
desired IC (see the Selector Guide).
Multiple MAX5943A EV kits can be connected together
to simulate the implementation of power-supply ORing
in FireWire power systems. Connect the OUT outputs of
two or more EV kits as well as their respective ground
(GND) connections to simulate a FireWire system with
multiple power sources. Connect different power sup-
plies to the IN input of each EV kit. Start up each power
supply independently and observe the undervoltage
lockout, ORing, and current-limit feature in each EV kit.
Once all the power supplies are turned on, induce fault
conditions on the power bus. Note: Each EV kit can be
configured for different limits and thresholds for a better
evaluation of the MAX5943A functions.
The MAX5943A EV kit provides an unpopulated series
RC circuit (R13 and C5) at the GATE2 pin that can be
used to increase the turn-on time of MOSFET N1-B.
This reduces the output voltage ramp rate and load
capacitor charging current.
MAX5943A
MAX5943B
MAX5943C
MAX5943D
MAX5943E
SHUNT POSITION
JUMPER JU2
Not installed
Installed
PART
Evaluating the MAX5943B/C/D/E
_______________________________________________________________________________________
Connected to GND
through resistor R8
Connected to IN
DEFAULT TIMEOUT,
CONNECTION
LATCH PIN
TIM = IN
(ms)
GATE2 Turn-On Time
0.5
2
1
2
4
Multiple Kits
EV KIT FAULT
Autoretry
Latched
MODE
PROGRAMMABLE
(4kΩ < R6 < 50kΩ)
1.04ms to 11.05ms
TIMEOUT RANGE
130µs to 1.38ms
260µs to 2.76ms
32.5µs to 345µs
65µs to 690µs
MAX5943A Evaluation Kit
Installing resistor R13 and capacitor C5 will be neces-
sary when the combination of current-limit setting, cur-
rent-limit timeout, load capacitance value, and operat-
ing voltage could cause the IC to time out before a con-
nected load capacitance is fully charged. The RC cir-
cuit may be needed when:
• Current limit < 2A,
• Current-limit timer setting < 2ms,
• Load capacitance > 20µF, and
• V
The time required to charge the load capacitance can
be determined by using the following equation:
Example: If V
the current-limit timer is set at 2ms, then add probable
or known tolerances to obtain:
Allowing ±12% tolerance on the timer setting, the timer
should be set for 3.03ms typ. See the Current-Limit
Timer section to reconfigure the timeout period. Refer
to the Startup Consideration section in the MAX5943 IC
data sheet to select C5.
R13 should be 3kΩ to minimize the effect of C5 slowing
the gate discharge rate at current trip.
IN
I
sense resistor tolerance = 1.488A to 1.712A,
t
MAX5943 data sheet),
C
V
LIM
LIM
IN
LOAD
> 20V
= 32V ±5% = 32.4V to 33.6V.
= 1.6A ±6% trip-threshold tolerance plus 1%
t
= 2.02ms ±12% = 1.78ms to 2.26ms (from
CHARGE
MAXIMUM TIMEOUT,
= 100µF ±20% = 80µF to 120µF, and
TIM = FLOATING
IN
t
CHARGE
= 32V, current limit is set at 1.6A, and
=
(ms)
10.9
21.9
175
5.5
44
33 6
.
1 488
=
.
V x
V
IN
120
A
×
I
LIM
C
μ
Selector Guide
F
LOAD
=
ACTIVE CURRENT-
2 709
LIMIT FUNCTION
.
ms
Yes
No
No
No
No
5