DS1865_09 Datasheet, PDF (1/67 Pages) Maxim Integrated Products – PON Triplexer Control and Monitoring Circuit

19-5044; Rev 1; 11/09
PON Triplexer Control and
Monitoring Circuit
General Description
The DS1865 controls and monitors all the burst-mode
transmitter and video receiver biasing functions for a
passive optical network (PON) triplexer. It has an APC
loop with tracking-error compensation that provides the
reference for the laser driver bias current and a temper-
ature-indexed lookup table (LUT) that controls the mod-
ulation current. It continually monitors for high output
current, high bias current, and low and high transmit
power with its internal fast comparators to ensure that
laser shutdown for eye safety requirements are met with-
out adding external components. Six ADC channels
monitor V_CC, internal temperature, and four external
monitor inputs (MON1–MON4) that can be used to meet
transmitter and video receive signal monitoring require-
ments. Two digital-to-analog converter (DAC) outputs
are available for biasing the video receiver channel, and
five digital I/O pins are present to allow additional moni-
toring and configuration.
Applications
Optical Triplexers with GEPON, BPON, or GPON
Transceiver
Pin Configuration
TOP VIEW
28 27 26 25 24 23 22
BEN 1
TX-D 2
TX-F 3
FETG 4
V_CC 5
GND 6
N.C. 7
DS1865
*EP
21 MOD
20 BIAS
19 V_CC
18 GND
17 M4DAC
16 DAC1
15 MON4
8 9 10 11 12 13 14
*EXPOSED PAD.
TQFN
(5mm x 5mm x 0.8mm)
Features
♦ Meets GEPON, BPON, and GPON Timing
Requirements for Burst-Mode Transmitters
♦ Bias Current Control Provided by APC Loop with
Tracking-Error Compensation
♦ Modulation Current is Controlled by a
Temperature-Indexed Lookup Table
♦ Laser Power Leveling from -6dB to +0dB
♦ Two 8-Bit Analog Outputs, One is Controlled by
MON4 Voltage for Video Amplifier Gain Control
♦ Internal Direct-to-Digital Temperature Sensor
♦ Six Analog Monitor Channels: Temperature, V_CC,
MON1, MON2, MON3, and MON4
♦ Five Digital I/O Pins for Additional Control and
Monitoring Functions
♦ Comprehensive Fault Management System with
Maskable Laser Shutdown Capability
♦ Two-Level Password Access to Protect
Calibration Data
♦ 120 Bytes of Password 1 Protected Nonvolatile
Memory
♦ 128 Bytes of Password 2 Protected Nonvolatile
Memory in Main Device Address
♦ 128 Bytes of Nonvolatile Memory Located at A0h
Slave Address
♦ I²C-Compatible Interface for Calibration and
Monitoring
♦ Operating Voltage: 2.85V to 3.9V
♦ Operating Temperature Range: -40°C to +95°C
♦ Packaging: 28-Pin Lead-Free TQFN (5mm x 5mm
x 0.8mm)
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
DS1865T+
-40°C to +95°C
28 TQFN-EP*
DS1865T+T&R
-40°C to +95°C
28 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
T&R = Tape and reel.
______________________________________________ Maxim Integrated Products 1
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