Datasheet
______________________________________________________________________________________ 15
MAX3946
1Gbps to 11.3Gbps, SFP+ Laser Driver
with Laser Impedance Mismatch Tolerance
Table 2. Circuit Response to Single-Point Faults
Note 1: Normal—Does not affect laser power.
Note 2: Supply-shorted current is assumed to be primarily on the circuit board (outside this device), and the main supply is col-
lapsed by the short.
Note 3: Normal in functionality, but performance could be affected.
Warning: Shorted to V
CC
or shorted to ground on some pins can violate the Absolute Maximum Ratings.
PIN NAME SHORT TO V
CC
SHORT TO GROUND OPEN
1 V
CCD
Normal Disabled—HARD FAULT Normal (Note 3)—Redundant path
2 DISABLE Disabled
Normal (Note 1). Can only be dis-
abled by other means.
Disabled
3 FAULT Normal (Note 1) Normal (Note 1) Normal (Note 1)
4 BMAX Disabled—HARD FAULT Normal (Note 1) Disabled—HARD FAULT
5 BMON Disabled—HARD FAULT Normal (Note 1) Disabled—HARD FAULT
6 V
CCT
Normal
Disabled—Fault (external supply
shorted) (Note 2)
Normal (Note 3)—Redundant path
7 V
CCT
Normal
Disabled—Fault (external supply
shorted) (Note 2)
Normal (Note 3)—Redundant path
8 TOUT- I
MOD
is reduced Disabled—HARD FAULT I
MOD
is reduced
9 TOUT- I
MOD
is reduced Disabled—HARD FAULT I
MOD
is reduced
10 TOUT+ I
MOD
is reduced Disabled—HARD FAULT I
MOD
is reduced
11 TOUT+ I
MOD
is reduced Disabled—HARD FAULT I
MOD
is reduced
12 V
CCT
Normal
Disabled—Fault (external supply
shorted) (Note 2)
Normal (Note 3)—Redundant path
13 V
CCT
Normal
Disabled—Fault (external supply
shorted) (Note 2)
Normal (Note 3)—Redundant path
14 BIAS I
BIAS
is on—No fault Disabled—HARD FAULT Disabled—HARD FAULT
15 V
CCD
Normal
Disabled—Fault (external supply
shorted) (Note 2)
Normal (Note 3)—Redundant path
16 CSEL Normal (Note 1) Normal (Note 1) Normal (Note 1)
17 SDA Normal (Note 1) Normal (Note 1) Normal (Note 1)
18 SCL Normal (Note 1) Normal (Note 1) Normal (Note 1)
19 V
EET
Disabled—Fault (external
supply shorted) (Note 2)
Normal Normal (Note 3)—Redundant path
20 V
CC
Normal
Disabled—HARD FAULT (external
supply shorted) (Note 2)
Normal (Note 3)—Redundant path
21 TIN+ SOFT FAULT SOFT FAULT Normal (Note 1)
22 TIN- SOFT FAULT SOFT FAULT Normal (Note 1)
23 V
CC
Normal
Disabled—HARD FAULT (external
supply shorted) (Note 2)
Normal (Note 3)—Redundant path
24 V
EET
Disabled—Fault (external
supply shorted) (Note 2)
Normal Normal (Note 3)—Redundant path