19-0323; Rev 5; 5/01
Single +5V, Fully Integrated,
1.25Gbps Laser Diode Driver
The MAX3261 is a complete, easy-to-program, single
+5V-powered, 1.25Gbps laser diode driver with complementary enable inputs and automatic power control
(APC). The MAX3261 accepts differential PECL inputs
and provides complementary output currents. A temperature-stabilized reference voltage is provided to
simplify laser current programming. This allows modulation current to be programmed up to 30mA and bias
current to be programmed up to 60mA with two external 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 programmable 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
____________________________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
__________Typical Operating Circuit
+5V
+5V
VCCA
VCCA
VCCA
GNDA
OUT+
GNDA
OUTGNDA
PECL
INPUTS
VINGND A
GND B
32
31
30
29
28
27
26
25
TO OPEN
FIBER
CONTROL
IBIASOUT
IMODSET
IBIASSET
IBIASFB
OSADJ
VREF1
VCCB
ENB+
PHOTODIODE
MAX3261
LASER
IPIN
IBIASOUT
ENBSLWSTRT
+5V
OUT-
ZO = 25Ω
MICROSTRIP
VREF1
FAILOUT
VREF2
2.7k
IBIASFB
IBIASSET
IMODSET
OSADJ
IPINSET
GNDB
VIN+
GNDB
VINGNDB
VCCB
VCCB
ENB-
9
10
11
12
13
14
15
16
MAX3261
24
23
22
21
20
19
18
17
OUT+
VIN+
ENB+
1
2
3
4
5
6
7
8
+5V
VCCA VCCB
__________________Pin Configuration
GNDA
GNDA
IPIN
SLWSTRT
GNDB
VREF2
IPINSET
FAILOUT
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.
622Mbps SDH/SONET
Gigabit Ethernet
TOP VIEW
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
TQFP
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX3261
_______________General Description
