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DS1886_V1 Datasheet - Page 19

Download or read online Maxim Integrated DS1886_V1 SFP and PON ONU Controller with Digital LDD Interface pdf datasheet.



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Detailed Description
The DS1886 integrates the control and monitoring func-
tionality required to implement an SFP or PON ONU
system using the Maxim MAX3710 or other compatible
laser driver and limiting amplifier. Key components of the
DS1886 are shown in the
Block Diagram
in subsequent sections.
Table 1. Acronyms
ACRONYM
DESCRIPTION
ADC
Analog-to-Digital Converter
APC
Automatic Power Control
APD
Avalanche Photodiode
DAC
Digital-to-Analog Converter
LOS
Loss of Signal
LUT
LUT
NV
Nonvolatile
QT
Quick Trip
ROSA
Receiver Optical Subassembly
SEE
Shadowed EEPROM
(A)
65,536
(MD0REGH[7:0] + 8
x
TXP =
x MD1REGH[7:0])
TXP SCALE
*USER HAS TO CALIBRATE THE GAIN USING THE SCALE REGISTERS
IN CASE RIGHT-SHIFTING IS DESIRED IN ORDER TO MAINTAIN CORRECT BIT WEIGHTING.
Figure 1a. ADC Channel Only for TXP when BURST_MODE = 1 in Table 02h, Register 89h
(B)
SCALE
REGISTERS
ANALOG INPUT
*USER HAS TO CALIBRATE THE GAIN USING THE SCALE REGISTERS
IN CASE RIGHT-SHIFTING IS DESIRED IN ORDER TO MAINTAIN CORRECT BIT WEIGHTING.
Figure 1b. ADC Channel
SFP and PON ONU Controller
with Digital LDD Interface
The DS1886 monitors five ADC channels. This monitoring
combined with the alarm enables (A2h Table 01h/05h)
determines when/if the DS1886 turns off the MAX3710
DACs and triggers the TXFOUT and TXDOUT outputs.
and described
All the monitoring levels and interrupt masks are user-
programmable. See
ACRONYM
SFF-8472
RIGHT-SHIFT1
RIGHT-SHIFT2
OFFSET
DETERMINED
DETERMINED
REGISTERS
BY KIMD
BY KRMD
16
16
SHIFT
SHIFT
COUPLED*
ALARM AND WARNING
OFFSET
RIGHT-SHIFT
REGISTERS
SETTINGS
13
13
13
ADC
SHIFT
*
COUPLED
ALARM AND WARNING
THRESHOLDS
Monitors and Fault Detection
Figure
1a.
DESCRIPTION
SFF
Small Form Factor
Document Defining Register Map of SFPs
and SFFs
SFP
Small Form-Factor Pluggable
SFP+
Enhanced SFP
Tracking Error. Deviation from linear of the
TE
relationship between transmitted power and
monitor diode current.
TIA
Transimpedance Amplifier
TOSA
Transmit Optical Subassembly
TXP
Transmit Power
16
RESULTS
REGISTERS
16
ALARM/
COMPARE
WARNING
FLAGS
ALARM/
WARNING
THRESHOLDS
ENABLES
13
RESULTS
REGISTERS
ALARM/
WARNING
COMPARE
FLAGS
ALARM/
WARNING
ENABLES
DS1886
Monitors
TXFINT
TXFINT
19

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