Owner's manual

DS1874
SFP+ Controller with Digital LDD Interface
10 ______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1 RSELOUT Rate-Select Output
2 SCL I
2
C Serial-Clock Input
3 SDA I
2
C Serial-Data Input/Output
4 TXF Transmit-Fault Input and Output. The output is open drain.
5 LOS Loss-of-Signal Input
6 IN1 Digital Input. General-purpose input with AS1 in SFF-8079 or RS1 in SFF-8431.
7 TXD Transmit-Disable Input
8, 17, 21 GND Ground Connection
9 RSEL Rate-Select Input
10 TXDOUT Transmit-Disable Output
11 MON4 External Monitor Input 4
12, 13
MON3P,
MON3N
Differential External Monitor Input 3 and LOS Quick Trip
14 MON1 External Monitor Input 1 and HBATH Quick Trip
15, 23 V
CC
Power-Supply Input
16 MON2 External Monitor Input 2. Feedback voltage for APC loop and HTXP/LTXP quick trip.
18 REFIN Reference Input for DAC1 and DAC2
19, 20 DAC1, DAC2 Delta-Sigma Output 1/2
22 N.C. No Connection
24 CSELOUT
Chip-Select Output. Part of the 3-wire interface to the MAX3798/MAX3799 laser driver/limiting
amplifier.
25 SCLOUT
Serial-Clock Output. Part of the 3-wire interface to the MAX3798/MAX3799 laser driver/limiting
amplifier.
26 SDAOUT
Serial-Data Input/Output. Part of the 3-wire interface to the MAX3798/MAX3799 laser driver/limiting
amplifier.
27 LOSOUT Open-Drain Receive Loss-of-Signal Output
28 OUT1 Digital Output. General-purpose output with AS1 output in SFF-8079 or RS1 output in SFF-8431.
— EP Exposed Pad