Burst-Mode Laser Driver
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3.0V to +3.6V, TA = -40°C to +85°C. Typical values are at VCC = +3.3V, TA = +25°C, IBIAS = 20mA, IMOD = 30mA, unless
otherwise noted.) (Note 1)
PARAMETER
SYMBOL
SAMPLE/HOLD SPECIFICATIONS
CONDITIONS
MIN TYP MAX UNITS
MDIN Voltage Range
0.05
2.56
V
MDOUT Settling
Relative to final value at 3µs, CL < 20pF
±1
mV
Sample/Hold Droop
After 100µs (Note 9)
±2.56 mV
Sampling Error
Final value measured after 10µs
(MDOUT - MDIN), burst width > 576ns
3
±14
mV
BANDGAP VOLTAGE REFERENCE SPECIFICATIONS
VREF Output
RL > 10kΩ, CL < 50pF
MODULATION/BIAS CURRENT DISABLE
Enable Time
5mA < IBIAS, 10mA < IMOD (Note 10)
Disable Time
(Notes 2, 11)
RIMAX Range
Current Limit (Tested with IBIAS =
IMOD)
IBIAS+IMOD
RIMAX = 3kΩ
RIMAX = 5kΩ
RIMAX = 10kΩ
OPTICAL EVALUATION
1.175 1.235 1.295
V
5.5
µs
375
ns
3
15
kΩ
155
100
150
mA
50
75
Eye Margin
1.25Gbps (Note 12)
33
%
Note 1: DC parameters are production tested at TA = +25°C, guaranteed by design and characterization at TA = -40°C.
AC parameters are guaranteed by design and characterization.
Note 2: For 10mA ≤ IMOD ≤ 85mA and 4mA ≤ IBIAS ≤ 70mA.
Note 3: Deterministic jitter measured with a continuous pattern of 27-1 PRBS, 80 ones, 27-1 PRBS, 80 zeros at 1.25Gbps, and both
LVPECL inputs terminated by the network shown in Figure 3.
Note 4: Random jitter, rise time, fall time measured with 0000011111 pattern at 1.25Gbps.
Note 5: Voltage difference between VMSET and MODSET or VBSET and BIASSET excluding IR drops. The maximum operating
voltage at VMSET or VBSET must be less than 1.4V for proper operation.
Note 6: Turn-on/-off time is when the BEN+/BEN- LVPECL inputs are used to control modulation and bias currents.
Note 7: Burst-enable delay is measured between the time at which the rising edge of the differential burst-enable input reaches the
midpoint, and the time at which the combined output currents (bias plus modulation) reach 90% of their final level.
Note 8: Burst-disable delay is measured between the time at which the falling edge of the differential burst-enable input reaches the
midpoint, and the time at which the combined output currents (bias plus modulation) fall below 10% of the bias-on current.
Note 9: Droop measured with sample/hold output load of 10MΩ.
Note 10: Enable delay is measured between the time at which the falling edge of the EN input reaches ≤ 0.8V, and the time at which
the combined output currents (bias plus modulation) reach 90% of their final level.
Note 11: Disable delay is measured between the time at which the rising edge of the EN input reaches ≥ 2V, and the time at which
the combined output currents (bias plus modulation) fall below 10% of the bias-on current.
Note 12: Excelight SXT5731-Q laser.
Note 13: Current gain stability = [(Gain – nominal Gain) / nominal Gain], nominal Gain at VCC = 3.3V, TA = +25°C.
Note 14: Gain linearity = (Gainmax – Gainmin), Gainavg = Gainmax - Gainmin
Gainavg/2
2
Note 15: Gain matching = Gainmod / Gainbias − Gainmodnom / Gainbiasnom nominal at VCC = 3.3V, TA = +25°C.
Gainmodnom / Gainbiasnom
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