MAX3261 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Single +5V, Fully Integrated, 1.25Gbps Laser Diode Driver

19-0323; Rev 4; 8/97
Single +5V, Fully Integrated,
1.25Gbps Laser Diode Driver
_______________General Description
The MAX3261 is a complete, easy-to-program, single
+5V-powered, 1.25Gbps laser diode driver with com-
plementary enable inputs and automatic power control
(APC). The MAX3261 accepts differential PECL inputs
and provides complementary output currents. A tem-
perature-stabilized reference voltage is provided to
simplify laser current programming. This allows modu-
lation current to be programmed up to 30mA and bias
current to be programmed up to 60mA with two exter-
nal resistors.
Complementary enable inputs allow the MAX3261 to
interface with open-fiber-control architecture—a feature
not found in other 1.25Gbps laser diode drivers.
An APC circuit is provided to maintain constant laser power
in transmitters that use a monitor photodiode. Only two
external components are required to implement the APC
function.
The MAX3261’s fully integrated feature set includes a
TTL-compatible laser failure indicator and a program-
mable slow-start circuit to prevent laser damage. The
slow-start is preset to 50ns and can be extended by
adding an external capacitor.
________________________Applications
Laser Diode Transmitters
531Mbps and 1062Mbps Fibre Channel
622Mbps SDH/SONET
Gigabit Ethernet
__________________Pin Configuration
TOP VIEW
GNDA
1
GNDA
2
IPIN
3
SLWSTRT
4
GNDB
5
VREF2
6
IPINSET
7
FAILOUT
8
MAX3261
24
IBIASOUT
23
IMODSET
22
IBIASSET
21
IBIASFB
20
OSADJ
19
VREF1
18
V_CCB
17
ENB+
____________________________Features
o Rise Times Less than 250ps
o Differential PECL Inputs
o Single +5V Supply
o Automatic Power Control
o Temperature-Compensated Reference Voltage
o Complementary Enable Inputs
______________Ordering Information
PART
MAX3261CCJ
MAX3261ECJ
MAX3261E/D
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
32 TQFP
32 TQFP
Dice*
*Dice are designed to operate over a -40°C to +140°C junction
temperature (Tj) range. Tested and guaranteed at Tj = +25°C.
__________Typical Operating Circuit
+5V
+5V
V_CCA V_CCB
VIN+
PECL
INPUTS
VIN-
GND A
GND B
OUT+
ENB+
TO OPEN
FIBER
CONTROL
ENB-
MAX3261 IPIN
IBIASOUT
SLWSTRT
OUT-
VREF1
FAILOUT
VREF2
IBIASFB
IMODSET IBIASSET
OSADJ
IPINSET
+5V
PHOTO-
DIODE
LASER
Z_O = 25Ω
MICROSTRIP
+5V
2.7k
TQFP
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