iC-NZ
FAIL-SAFE LASER DIODE DRIVER
Rev B2, Page 7/20
ELECTRICAL CHARACTERISTICS: DIAGRAMS
V
VDD−0.45V
Vt()hi
Input/Output
Vt()lo
0.45V
t
LENL
LENM
LENH
1
0
Figure 1: Reference levels
I(LDKL)
I(LED)
t
r
I
pk
90% I
pk
t
f
I(LDKM)
I(LDKH)
t plh
t plh
t phl
t phl
t plh
t phl
10% I
pk
V(MDL)
t
Zeit
Figure 2: Laser current pulse
Figure 3: Turn on/turn off behavior of the laser current
ENCAL
LENL
LENM
LENH
P(Laser)
Ph
Pm
Pl
Zeit
Zeit
V(MDL)
0.5V
V(SMD)
VSH
VSL
Zeit
SMD(0)
SMD(1)
t
S0
t
S1
t
d
NERR
NSEN
NTREN
t
off
Figure 4: Safety shutdown times with failure of the control unit, for example