QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 868
LOW QUIESCENT CURRENT DUAL SYNCHRONOUS BUCK CONVERTER
2
NOTE:
The maximum load at 3.3V is 5A, and the
maximum at 8.5V is 3.5A.
3.
Connect the input power supply to the VIN
and GND
terminals on the right, center of the board.
NOTE:
Do not increase V
IN
over 32V.
4.
Switch on the desired channel(s) by moving the
RUN1 and/or RUN2 jumper to “on” position.
5.
Measure the output voltages. They should be 3.3V
±
0.066V and 8.5V
±
0.17V respectively, within each
specified maximum load current.
6.
For better efficiency at high input voltage, tie EXTVCC
to external source of 5V-9V or mount the optional re-
sistor R1(0 ohm).
7.
If external synchronization is desired, remove JP2 and
tie PLLIN/MODE to external clock signal. Please refer
to datasheet for more details.
The following table shows the different output tracking options for Vout1 and Vout2
JP5 Set
Function
R25
R26
R27
SS1*
SS w/o tracking
DNP
DNP
DNP
TRACK
Track Track1
35.7k
11.5k DNP
TRACK
Track Vout2
35.7k
11.5k zero
Table 3. Tracking Jumper Settings
*With default JP5 and JP6 setting, Vout1 and Vout2 will start independently. Please refer to datasheet for TBD
value calculation.
JP6 Set
Function
R28
R29
SS2*
SS w/o tracking
DNP
DNP
TRACK
Track Track2
TBD*
TBD*
