Datasheet

MAX3740A
3.2Gbps SFP VCSEL Driver with Diagnostic
Monitors
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.97V to +3.63V, T
A
= -40°C to +85°C. Typical values are at V
CC
= +3.3V, TC1 and TC2 are shorted, PEAKSET open, T
A
=
+25°C, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SAFETY FEATURES (see the Typical Operating Characteristics section)
High-Current Fault Threshold V
BMTH
V
BIASMON
> V
BMTH
causes a fault 0.7 0.8 0.9 V
V
BIAS
Fault Threshold V
BTH
V
BIAS
referenced to V
CC
-0.250 -0.2 -0.150 V
Power-Monitor Fault Threshold V
PMTH
V
PWRMON
> V
PMTH
causes a fault 0.7 0.8 0.9 V
TX Disable Time t_
OFF
Time from rising edge of TX_DISABLE to
I
BIAS
= I
BIAS_OFF
and I
MOD
= I
MOD_OFF
(Note 6)
1.8 5 µs
TX Disable Negate Time t_
ON
Time from rising edge of TX_DISABLE to
I
BIAS
and I
MOD
at 99% of steady state
(Note 6)
55 500 µs
Fault Reset Time t_
INIT
1
Time to set V
FAULT
= low after power-on or
after rising edge of TX_DISABLE (Note 6)
60 200 ms
Power-On Time t_
INIT
2
Time after power-on to transmitter-on with
TX_DISABLE low (Note 6)
60 200 ms
Fault Assert Time t_
FAULT
Time from fault occurrence to V
FAULT
=
high; C
FAULT
< 20pF, R
FAULT
= 4.7kΩ
(Note 6)
1.4 50 µs
Fault Delay Time t_
FLTDLY
Time from fault to I
BIAS
= I
BIAS_OFF
and
I
MOD
= I
MOD_OFF
(Note 6)
15µs
TX_DISABLE Reset t_
RESET
Time TX_DISABLE must be held high to
reset FAULT (Note 6)
1µs
Note 1: Supply current measurements exclude I
BIAS
from the total current.
Note 2: Tested with R
PEAK
= 1.18kΩ.
Note 3: Measured by applying a pattern that contains 20µs of K28.5, followed by 5µs of zeros, then 20µs of K28.5, followed by 5µs
of ones. Data rate is equal to 2.5Gbps, with inputs filtered using 1.8GHz Bessel filters.
Note 4: V
BIAS
< V
CC
- 0.7V.
Note 5: Variation of bias monitor gain for any single part over the range of V
CC
, temperature, 3mA < I
BIAS
< 15mA.
Note 6: Guaranteed by design and characterization.
Note 7: Measured electrically with a 50Ω load AC-coupled to OUT+.
Note 8: Deterministic jitter is the peak-to-peak deviation from the ideal time crossings measured with a K28.5 bit pattern at 3.2Gbps
(00111110101100000101).