Linear Technology DC1185B-A Demo Manual page 6

DEMO MANUAL
DC1185B-A/-B
SYNCHRONIZATION TO AN EXTERNAL CLOCK
The LTC3850 uses a phase-lock-loop which forces its
internal clock to be synchronized to an external clock.
Once synchronized, the rising edge of the top FET gate is
aligned to the rising edge of the external clock. The external
clock signal needs to be applied to the LTC3850's MODE
pin which is tied to the turret labeled SYNC. The internal
phase lock loop is stabilized by a network on the FREQ pin
of the LTC3850. To set up the DC1185 for synchronization
to an external clock, follow the steps below.
6
1. Remove R7.
2. Stuff 10kΩ at R8.
3. Stuff 10nF at R10.
4. Leave 1nF at C12.
5. Float the MODE pin by placing the MODE jumper in the
BM position.
6. Apply the external clock from the turret la-beled SYNC
to GND.
dc1185b-a/-bf