IC-HV Datasheet, PDF (6/8 Pages) IC-Haus GmbH – VCSEL ARRAY DRIVER

iC-HV
VCSEL ARRAY DRIVER
CONFIGURATION INPUT ELVDS
preliminary
Rev A1, Page 6/8
Pin ELVDS selects between TTL or LVDS mode. The
unconnected pin ELVDS is an error condition signaled
at pin NER with the VCSEL current disabled.
Pin ELVDS connected to GND selects the TTL mode.
Pin ELVDS connected to VDD selects the LVDS mode.
DIGITAL INPUTS EP1...3 EN1...3
EP1...3 and EN1..3 are the digital switching inputs. With
pin ELVDS set to TTL mode, each pin EPx enables the
current sink at the respective switch. The ENx pins are
unused. With pin ELVDS set to LVDS mode, the EPx
pins are the positive and the ENx pins are the negative
LVDS inputs. EP1 and EN1 control switch 1, EP2 and
EN2 control switch 2 and EP3 and EN3 control switch 3.
For correct LVDS operation 100 Ω terminating resistors
between the respective EPx and ENx pins, very close
to the inputs, are required. Input pins from unused
switches have to be connected to GND (TTL operation)
resp. EPx to GND and ENx to VDD (LVDS operation).
ANALOG CURRENT CONTROL VOLTAGE INPUTS CI1...3
The voltage at pins CI1...3 sets the current.
PULSED OPERATION
The current for pulsed operation may be higher than for
CW operation. Therefore the RMS current of the pulse
train has to be considered.
With I_CWmax from Electrical Characteristics No. 101 and
pulses < 10 µs. So for a single switch operated with a
50% duty cycle, the max. VCSEL current becomes
repetition time(T)
I_pulsemax = I_CWmax ·
pulse time(t)
(1)
ERROR OUTPUT NER
The open drain pin NER is a low-active error output.
Signalled errors are ELVDS open or at 50% VDD, VDD
undervoltage and thermal shutdown.
√
I_pulsemax = 1000 mA · 2 = 1414 mA
TEMPERATURE MEASUREMENT VTEMP
Pin VTEMP shows the voltage of three stacked diodes
and can be used to measure the chip temperature.