Datasheet

MAX3996
3.0V to 5.5V, 2.5Gbps VCSEL
and Laser Driver
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.0V to 5.5V, T
A
= 0°C to +70°C, unless otherwise noted. Typical values are at V
CC
= 3.3V, TC pin not connected, T
A
=
+25°C.) (Figure 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Minimum Modulation Current i
MOD
2
mA
P-P
Maximum Modulation Current i
MOD
R
L
≤ 25Ω 30 40
mA
P-P
Accuracy of Modulation Current
(Part-to-Part Variation)
R
MODSET
= 2.37kΩ
(i
MOD
≈ 30mA
P-P
into 25Ω)
-10
+10
%
i
MOD
= 5mA into 25Ω, 20% to 80% (Note 3) 54
100
i
MOD
= 10mA into 25Ω, 20% to 80% (Note 3)
55
125
Edge Transition Time t
r
, t
f
i
MOD
= 30mA into 25Ω, 20% to 80% (Note 3)
65
130
ps
i
MOD
= 5mA into 25Ω (Notes 2, 3) 17 35
i
MOD
= 10mA into 25Ω (Notes 2, 3) 14 22Deterministic Jitter
i
MOD
= 30mA into 25Ω (Notes 2, 3) 9 20
ps
P-P
Random Jitter (Note 3) 2 8
ps
RMS
Modulation Current During Fault
i
MOD_OFF
15
200
µA
P-P
Tempco = MAX, R
MOD
= open
4000
Modulation Current Tempco
Tempco = MIN, R
TC
= open 50
ppm/°C
Input Resistance R
IN
Differential 85
115
Ω
Output Resistance R
OUT
Single ended; outputs to V
CC
42 50 58 Ω
Input Common-Mode Voltage
V
CC
- 0.3
V
SAFETY FEATURES (See Typical Operating Characteristics)
MODSET and TC Pin
Fault Threshold
200
mV
BIAS Pin Fault Threshold
A fault will be triggered if V
BIAS
is less than
this voltage
300 400
mV
Excessive Bias Current Fault
A fault will be triggered if V
MON2
exceeds
this voltage
400 440
mV
TX Disable Time t_off
Time from rising edge of TX_DISABLE to
I
BIAS
= I
BIAS _OFF
and i
M OD
= i
M OD_OFF
( Note 3)
0.06
5µs
TX Disable Negate Time t_on
Time from falling edge of TX_DISABLE to
I
BIA S
and i
M OD
at 95% of stead y state ( N ote 3)
37
500
µs
Reset Initialization Time t_init
Fr om p ow er ON or neg ation of FAU LT usi ng
TX _D IS ABLE . Ti me to set FAULT = l ow, i
M OD
=
95% of stead y state and I
BIAS
= 95% of steady
state ( N ote 3)
23
200
ms
Fault Assert Time t_fault
Time from fault to FAULT = high, C
FAULT
< 20pF, R
FAULT
= 4.7kΩ (Note 3)
14 50 µs
TX_DISABLE Reset
t_reset
Time TX_DISABLE must be held high to
reset FAULT (Note 3)
0.01
1µs
Note 1: Supply current excludes bias and modulation currents.
Note 2: Deterministic jitter is the peak-to-peak deviation from the ideal time crossings measured with a K28.5 bit pattern
00111110101100000101.
Note 3: AC characteristics guaranteed by design and characterization.