GN2014A Datasheet, PDF (10/18 Pages) Gennum Corporation – XFP Tx Signal Conditioner with VCSEL Driver

Iref
POLInv or
1.5k
LBEn or
RTEn
Vcc
C P A P ol
1 .5 k
Vref
V cc
V re f
Figure 3-2: GN2014A Control Input Equivalent Circuits
When left unconnected, the POLInv, LBEn and RTEn input level defaults to logic HIGH
and the CPAPol input defaults to logic LOW (see Figure 7-1).
Note: Since the GN2014A device is specified to operate at VCC values down to 2.8V,
special care must be taken when driving control inputs from a controller that uses
separate supply line. Under no condition should the controller's V_OH exceed GN2014A's
VCC + 0.3V.
Table 3-1: Operational Modes
Pin#
1
2
10
24
Pin Symbol
POLInv
RTEn
CPAPol
LBEn
Description
Serial Data Output Polarity Inversion Control Input
0 → Inverted Polarity (SDOP/LBSDOP = EQInN and
SDON/LBSDON = EQInP)
1 → Normal Polarity (SDOP/LBSDOP = EQInP and
SDON/LBSDON = EQInN)
Retimer Enable Control Input
0 → CDR Bypassed
1 → CDR In Path
Cross Point Adjust Polarity Control Input
0 → Negative Cross Point Adjust
1 → Positive Cross Point Adjust
Loop Back Enable Control Input
0 → Loop Back Disabled (Data available only on
SDOP/SDON)
1 → Loop Back Enabled (Data available on SDOP/SDON
and LBSDOP/LBSDON)
GN2014A XFP Tx Signal Conditioner with VCSEL Driver
Data Sheet
39260 - 8
May 2010
10 of 18
Proprietary & Confidential