DS1864 Datasheet, PDF (1/72 Pages) Dallas Semiconductor – SFP Laser Controller and Diagnostic IC

Rev 0; 4/06
SFP Laser Controller and
Diagnostic IC
General Description
The DS1864 is an SFF-8472 multisource agreement
(MSA)-compliant laser controller/monitor that is ideal for
SFP optical-transceiver module designs. It controls laser
driver bias and modulation currents through a pair of tem-
perature-controlled current-sink DACs. System diagnos-
tics are provided by monitoring three analog inputs, V_CC,
and temperature through the internal temperature sensor.
The device also contains all EEPROM required by the
SFF-8472 MSA, including all A0h and A2h EEPROM. The
DS1864’s memory map can be configured to be compati-
ble with both the DS1852/DS1856 and the DS1859 mem-
ory maps. Additionally, memory is secured with customer-
configurable two-level password protection.
Eye-safety features are integrated by three fast-trip
comparators that monitor transmit-power high, transmit-
power low, and bias current. The fast-trip comparators
drive a FET driver output to disable the laser in the case
of eye safety violation.
With its integrated laser driver control, system diagnos-
tics, eye-safety features, and internal temperature sen-
sor, the DS1864 provides an ideal solution for SFP
optical transceiver modules by improving system perfor-
mance, reducing board space, and simplifying design.
Applications
SFP Optical Transceiver Modules
Laser Control and Monitoring
Features
♦ SFF-8472 MSA Compatible
♦ Five Monitored Channels (Temperature, V_CC,
MON1, MON2, MON3)
Three External Analog Inputs (MON1, MON2,
MON3) Support Internal and External
Calibration
Enhanced RSSI Monitoring (26dB Range, 0.5dB
Accuracy)
Scalable Dynamic Range for External Analog
Inputs
Internal Direct-to-Digital Temperature Sensor
Alarm and Warning Flags for All Monitored
Channels
♦ Two Linear 8-Bit Current-Sink DACs
Two User-Selectable Full-Scale Ranges (0.5mA
or 1.5mA)
Values Changeable Every 2°C
♦ Three Fast-Trip Comparators (Tx Power High,
Tx Power Low, and Bias Current) for Eye Safety
♦ Flexible, Two Level Password Scheme Provides
Three Levels of Security
♦ Provides All Optional and Required SFF-8472
MSA EEPROM (Both A0h and A2h Memory)
♦ I²C-Compatible Serial Interface
♦ Operates from a 3.3V or 5V Supply
♦ -40°C to +95°C Operating Temperature Range
♦ 28-Pin TQFN Package (5mm x 5mm)
Pin Configuration
TOP VIEW
28 27 26 25 24 23 22
RSELOUT 1
SDA 2
SCL 3
INTX-F 4
INLOS 5
IN1 6
N.C. 7
DS1864
21 V_CC
20 DAC0
19 GND
18 DAC1
17 MON1P
16 MON1N
15 N.C.
8 9 10 11 12 13 14
Ordering Information
PART
DS1864T
DS1864T+
TEMP RANGE
-40°C to +95°C
-40°C to +95°C
+Denotes lead-free only package.
PIN-PACKAGE
28 TQFN (5mm x 5mm)
28 TQFN (5mm x 5mm)
*Purchase of I²C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys
a license under the Philips I²C Patent Rights to use these com-
ponents in an I²C system, provided that the system conforms to
the I²C Standard Specification as defined by Philips.
Typical Operating Circuit appears at end of data sheet.
TQFN
5mm x 5mm
______________________________________________ Maxim Integrated Products 1
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.