QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 536
HOT SWAP CONTROLLER WITH MULTIFUNCTION CURRENT CONTROL
2
QUICK START PROCEDURE
Demonstration circuit 536 is easy to set up to evaluate the performance of the LTC4211. Refer to Figure 1 for proper
measurement equipment setup and follow the procedure below:
1.
The DC536 is factory setup to operate in a 5 volt
system at current levels up to 5 amps. If the
LTC4211 is to be evaluated at a different operating
condition, follow 2-6 below, otherwise skip to 7.
2.
If evaluating at a voltage other than 5V, R3 must be
adjusted for proper RESET PIN response. Select
R3=V
MIN
•15K/1.223-15K, where V
MIN
is the mini-
mum output voltage expected for normal operation.
3.
The ON pin operates as a precision comparator and
can accurately provide an adjustable under voltage
lockout. The DC536 is initially configured to turn on
at 4.15V
MIN
. If 3.3V logic will drive this pin, R1 can
be replaced with a short. If the ON pin will be used
to provide under voltage lockout, then select R1
such that R1=V
UVLO
•10K/1.39-10K, where V
UVLO
is
the minimum turn on voltage. Refer to the data
sheet figure 3 for common configurations
4.
If the DC536 will operate at other than 7Amps max,
increase the value of R
SENSE
=0.99•I
LOAD
/40mV for a
1% tolerance current sense resistor.
5.
If the DC536 will be operating above 7Amps, re-
place Q1 with a suitable DD package MOSFET such
as the FDB8030L suitable for up to 20Amps. There
is a DD package footprint on the back of the board.
6.
The soft start and power good (RESET release) de-
lay is factory set to 6.2ms. This delay can be ad-
justed by changing C
TIMER
refer to the data sheet
Table 1 for common values and the SYSTEM
TIMING section for more detailed information.
7.
After any necessary component changes have been
made, connect a suitable load between VOUT and
GND. This may be a passive resistive load or an ac-
tive electronic load box.
8.
Connect a power supply capable of supplying
1.5•I
LOAD
between the VIN and GND turrets. The
minimum current capability of the supply must ac-
commodate the tolerance of the circuit breaker
threshold of ±20%. With the 7m
Ω
factory installed
sense resistor, the overload circuit breaker will trip
at between 5.7A to 8.5Amp (7Amp nominal).
Connect the ON/OFF turret to the VIN turret to
enable power to the load. A function generator can
be used to generate a single event and trigger a
scope. The DC536 provides convenient turrets for
observing the FAULT, RESET and VOUT signals.
9.
The following experiments can be run. Turn on
into a nominal load. Turn on into an overload.
Turn on into a short circuit. Turn on into a nomi-
nal load and increase the load until the LTC4211
trips off. A digital storage scope provides a con-
venient means of observing the turn on and over-
load events. Observe the input or output current
using a current probe. A current transformer can
be used to observe turn on current transients if a
current probe is not available.
