MAX3643ETG+T Maxim Integrated Products, MAX3643ETG+T Datasheet - Page 11

• Manufacturer Part Number: MAX3643ETG+T
• Description: IC LASR DRVR 2.5GBPS 3.6V 24TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Driver (Fiber Optic)r

Specifications of MAX3643ETG+T

• Data Rate: 2.5Gbps
• Number Of Channels: 1
• Voltage - Supply: 3 V ~ 3.6 V
• Current - Supply: 32mA
• Current - Modulation: 85mA
• Current - Bias: 70mA
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 24-TQFN Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

An LVCMOS input, EN, is provided to disable both bias
and modulation currents under external control. The
maximum time to disable laser current with the EN con-
trol is 375ns.
A current limiter is provided to protect the laser diode
by shutting down both bias and modulation currents
when total current exceeds a value set by the resistor
connected from IMAX to ground. Do not use less than
3kΩ R
R
To program the laser modulation current using a cur-
rent DAC, connect VMSET to VREF, attach the DAC to
the MODSET pin and set the current according to:
Figure 2. Sample-and-Hold Timing Diagram
IMAX
IMAX
155Mbps to 2.5Gbps Burst-Mode Laser Driver
graph in the Typical Operating Characteristics.
1.2V
. See the I
Programming the MODSET and
______________________________________________________________________________________
BIAS
Setting the Current Limit
+ I
MOD
3μs
Current Threshold vs.
BIASSET Inputs
Enable Input
INTERNAL MDIN VOLTAGE SAMPLER
BENOUT OUTPUT
≤ 125μs FOR BPON/GPON
BURST-ENABLE (BEN±) IN
100μs
MDOUT
To program the laser modulation current using a resis-
tor or digital potentiometer, connect VMSET to VREF,
attach a resistor from the MODSET pin to ground, and
set the current according to:
To program the laser modulation current using a PWM
voltage DAC (requiring a high-impedance load), attach
a DAC output to the VMSET pin, connect a resistor from
the MODSET pin to ground as shown in the Typical
Applications Circuit , and set the current according to:
I
I
MOD
MOD
I
MOD
=
=
R
R
MODSET
MODSET
= I
< 2.56mV
MODSET
V
1 2
DAC
.
V
+
+
R
R
MOD
MOD
x 88
× 88
×
88
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