QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 518
SLIC POSITIVE INPUT TO NEGATIVE OUTPUT DC/DC CONVERTER
3
EXTERNAL CLOCK CONECTION
1. To use an external clock source, turn the
input power source Off and remove the Burst
Mode jumper.
2. Set the clock source pulse amplitude to 5V
and set the frequency between 220kHz and
300kHz.
3. Turn the clock source off.
4. Connect the clock source (pulse generator
with TTL output) to the middle pin of the
Burst Mode jumper.
5. Apply input power and observe the switching
frequency of 200kHz.
6. Turn the clock source ON and observe the
switching frequency go up to the switching
frequency of the external clock.
USING NO-RSENSE MODE OF OPERATION
1. No-Rsense
TM
mode of operation can be
used with an input voltage of 5V. The 5V in-
put voltage combined with the –24V main
output will result in a sense pin voltage of
29V, which is within the maximum rating of
the sense pin of the LTC3704 controller. To
use No -Rsense
TM
Mode of operation, the
current sense resistor RS1 should be
shorted out. Resistor R8 must be removed
and resistor R7 should be installed.
2. Short out current sense resistor RS1.
3. Remove resistor R8.
4.
Install 0
Ω
resistor R7.
