DS1878T+T&R Maxim Integrated Products, DS1878T+T&R Datasheet - Page 22

• Manufacturer Part Number: DS1878T+T&R
• Description: IC CTLR SFP W/DGTL LDD RX 28TQFN
• Manufacturer: Maxim Integrated Products
• Type: SFP+ Controllerr

Specifications of DS1878T+T&R

• Input Type: *
• Output Type: *
• Interface: *
• Current - Supply: *
• Mounting Type: Surface Mount
• Package / Case: 28-WFQFN exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SFP+ Controller with Digital LDD Interface
Figure 14. Logic Diagram 1
Figure 15. Logic Diagram 2
22
BIAS MAX ENABLE
TXP LO ENABLE
LOS LO
TXP HI ENABLE
TXDC
HBAL ENABLE
RSEL
TXD
TXP LO FLAG
LOS
TXP HI FLAG
______________________________________________________________________________________
PINS
IN1
HBAL FLAG
BIAS MAX
R
PU
V
CC
LOSC
MUX
RSELC
RSELS
INV LOS
TXDS
t
INITR1
INVRSOUT
IN1S
RXL
OUT
FAULT RESET TIMER
OUT
IN
(130ms)
SETLOSCTL
IN
LOSOUT
C
C
D
R
S
Q
Q
RSELOUT
POWER-ON
RESET
FETG. See the Transmit Fault (TXFOUT) Output section
for a detailed explanation of TXFOUT. Figure 14 shows
that the same signals and faults can also be used to
generate the internal signal FETG (Table 01h/05h,
Registers FAh–FBh). FETG is used to send a fast “turn-
off” command to the laser driver. The status of FTEG
can be read (Lower Memory, Register 71h). The intend-
ed use is a direct connection to the Maxim laser dri-
ver’s TXD input if this is desired. When V
TXDOUT is high impedance.
TXFOUT can be triggered by TXF input and all alarms,
warnings, and quick trips (Figure 15). The six ADC
alarms, warnings, and the LOS quick trips require
enabling (Table 01h/05h, Registers F8h, FCh–FDh).
See Figures 16a and 16b for nonlatched and latched
operation. Latching of the alarms is controlled by the
CNFGB and CNFGC registers (Table 02h, Registers
8Ah–8Bh).
SET BIAS REGISTER
AND MODULATION
REGISTER TO 0
FETG
INVTXF
TXF
TXFINT
TXDFLT
PINS
TXDFG
TXDIO
TXD
Transmit Fault (TXFOUT) Output
TXFS
TXDOUT
CC
< POA,
TXFOUTS
TXFOUT