
9
Functional Description
T e PL-TEC operating principle is based on t e LDP-CW 2050. LDP-CW operates wit four parallel
buck converters (S1, S2, D1, D2, L1; S3, S4, D3, D4, L2; S5, S6, D5, D6, L3; S7, S8, D7, D8, L4). Every
single converter as an independent control loop wit a current sensor (Imeas1, Imeas2, Imeas3 and
Imeas4). T e set point current t at is pretended by t e user is evenly spread over all four converters.
Several security features protect t e laser diode and LDP-CW from damage. D8 protects t e laser
diode from reverse currents w ile D7 protects t e driver in case of a load failure. In case of a failure,
t e control unit disables t e LDP-CW. A soft-start mec anism slowly raises t e current after enabling
t e LDP-CW.
In contrary to t e LDP-CW 2050 all 4 c annels are linked to separate screw terminals. Furt ermore
t ey are terminated wit an RC-Filter to reduce t e EMI noise on t e TEC.
Operation Principle of LDP-CW 20 50 driver
Elemen Func ion
S1, S2, S3, S4, S5, S6, S7, S8,
D1, D2, D3, D4, D5, D6, D7,
D8, L1, L2, L3, L4
Buck Converter
C0 Input Buffer Capacitor
D7, D8 Free w eeling and driver protection diodes