IC-HT_15 Datasheet, PDF (10/45 Pages) IC-Haus GmbH – DUAL CW LASER DIODE DRIVER

iC-HT
DUAL CW LASER DIODE DRIVER
OPERATING AND STANDBY MODES
preliminary
Rev B1, Page 10/45
iC-HT operating modes are selected by the pins EMC
and INS. These pins are intended to be static and
should not be changed during operation to avoid mis-
configuration or unintended operation. It is recom-
mended to tie the pins EMC and INS to VDD or GND.
Floating pins EMC and INS/WKR are detected as
faulty configuration and signaled at NCHK.
iC-WK mode
In iC-WK mode the iC-HT operates as an Automatic
Power Control (APC) laser controller, similar to iC-
Haus iC-WK/iC-WKL , iC-WKM and iC-WKN. iC-WK
mode is set by pin configuration and the external mon-
itor resistor. Pin EMC is set to lo and pin INS/WKR
selects the reference voltage:
• INS/WKR = hi for 0.5 V reference voltage, similar to
iC-WK, iC-WKL, iC-WKN.
• INS/WKR = lo for 0.25 V reference voltage, similar to
iC-WM.
Floating pins EMC and INS/WKR are detected as
faulty configuration and signaled at NCHK.
• INS/WKR = hi for I2C.
• INS/WKR = lo for SPI.
Floating pins EMC and INS/WKR are detected as
faulty configuration and signaled at pin NCHK. Any in-
put interface could be enabled if EMC or INS pins are
open. Comunication with the chip might be possible
but laser cannot be switched on. This situation is only
signaled at pin NCHK, which would remain low as long
as any of the EMC or INS pins are unconnected. MCU
must monitor the status of the pin NCHK to get all the
status information of the chip.
Standby Mode
iC-HT in standby mode has a very low current con-
sumption (< 10 µA) and does retain its configuration.
Standby mode will not reset the internal RAM.
In order to exit standby mode, pin NSTBY must be set
to hi (e.g. VB). VDD is switched off in standby mode
and can not be used to exit standby mode.
MCU mode
In microcontroller unit (MCU) mode, iC-HT features
two control modes: automatic power control (APC) and
automatic current control (ACC). Pin EMC is set to hi
and pin INS/WKR selects the serial communication in-
terface protocol. Selection of the communication pro-
tocol is achieved through pin INS/WKR:
VB, NSTBY and LDKx withstand voltages up to 11 V,
whereas the remaining input pins operate up to 5.5 V
and do have high impedance at standby mode.
Information on timing after waking up from standby
mode can be found on page 36.