iC-HG
3 A LASER SWITCH
Rev A2, Page 8/21
CONFIGURATION INPUT ELVDS
Pin ELVDS selects between 6 channel TTL mode or 3 connected to 70% VDD selects the three channel slow
channel LVDS mode and chooses slow or fast switch- LVDS mode. Pin ELVDS connected to VDD selects the
ing speed. The unconnected pin ELVDS is an error three channel fast LVDS mode.
condition signaled at pin NER with the laser current
disabled.
An easy way to set the slow operation mode for TTL
and LVDS mode is to connect a voltage divider at pin
Pin ELVDS connected to GND selects the six channel ELVDS. Figure 1 shows the recommended voltage di-
fast TTL mode. Pin ELVDS connected to 30% VDD vider for slow TTL mode and Figure 2 shows the rec-
selects the six channel slow TTL mode. Pin ELVDS ommended voltage divider for slow LVDS mode.
Figure 1: TTL Slow
Figure 2: LVDS Slow
DIGITAL INPUTS EN1. . . 6
EN1. . . 6 are the digital switching inputs. With pin and EN6 control LDK5 and LDK6. For correct LVDS
ELVDS set to 6 channel TTL mode, each pin ENx en- operation 100 Ω terminating resistors between the re-
ables the current sink at the respective LDKx. With pin spective EPx and ENx pins, very close to the inputs,
ELVDS set to 3 channel LVDS mode, the odd ENx pins are strongly recommended. Input pins from unused
are the positive and the even ENx pins are the neg- channels have to be connected to GND (TTL opera-
ative LVDS inputs. EN1 and EN2 control LDK1 and tion) resp. EPx to GND and ENx to VDD (LVDS opera-
LDK2, EN3 and EN4 control LDK3 and LDK4 and EN5 tion).
ANALOG CURRENT CONTROL VOLTAGE INPUTS CI1. . . 6
The Voltage at pins CI1. . . 6 set the current value at Voltage at CI. The figures 5 and 6 shows the min., typ.
pins LDK1. . . 6. The figures 3 and 4 shows the tem- and max. variations between devices.
perature dependency of the current at LDK versus the
ICHAUS [ IC-HAUS GMBH ]
