M02066 Datasheet, PDF (13/20 Pages) M/A-COM Technology Solutions, Inc. – 3.3 Volt Laser Driver IC for Applications to 3 Gbps Data Sheet

Functional Description
There are two safety features integrated into the MPC loop; an Over-Current Alarm and an MPC loop failure alarm.
The Over-Current Alarm (OCA) circuit limits the maximum bias current generated by the M02060. The bias current
limit is set by an external resistor to ground, R_OCA. When this limit is exceeded the OCA pin is asserted LOW.
Figure 3-4 shows the maximum bias current limit vs R_OCA.
Figure 3-4. Typical limiting current vs R_OCA (at 25 °C)
100
90
80
70
60
50
40
30
20
10
0
0
10000
20000
30000
R_OCA (Ω)
40000
3.5
Safety Logic
Safety logic is provided in order to limit the maximum bias current. The bias current at which the safety logic trips
is set by an external resistor to ground (R_OCA) from the OCA_SET pin. When the bias current limit is reached alarm
flag OCA is asserted LOW. A loop failure alarm is also provided to detect when the bias current can no longer be
adjusted to achieve the desired average optical power.
3.6
Data Input Latch
To minimize input data pattern-dependent jitter, a differential clock signal can be connected to the data input latch.
If CEN is HIGH, the input data is retimed by the rising edge of CLK+. If CEN is LOW, the input data is directly
connected to the output stage. If CEN is left floating it will be pulled HIGH by the internal circuitry. When this latch
function is not used, connect CLK+ to V_CC and leave CLK- unconnected.
3.7
Enable Control
The M02066 incorporates a dual laser driver enable function. When ENA is LOW or DIS is HIGH, both the bias
and modulation currents are off. DIS and ENA are available on the M02066 die only, DIS is available on the BCC
package only, ENA is available on the TQPF package.
02066-DSH-001-D
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Preliminary Information / Mindspeed Proprietary and Confidential