Datasheet
4 ______________________________________________________________________________________
MAX3945
1.0625Gbps to 11.3Gbps,
SFP+ Dual-Path Limiting Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 2.85V to 3.63V, CML receiver output is AC-coupled to differential 100I load, C
CAZ
= 0.1FF, T
A
= -40NC to +85NC. Registers
are set to default values, unless otherwise noted. Typical values are at V
CC
= 3.3V, T
A
= +25NC, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Random Jitter
(Note 1)
RJ
Input = 60mV
P-P
at 10.32Gbps
,
RATE_SEL = 1, RXDE_EN = 0, input transi-
tion time 28ps, pattern 11110000,
V
DIFF_ROUT
= 800mV
P-P
0.28 0.51 ps
RMS
Low-Frequency Cutoff
(Simulated Value)
RATE_SEL = 0, C
CAZ
= 0.1FF
2
kHz
RATE_SEL = 1, C
CAZ
= 0.1FF
0.7
Small-Signal Bandwidth
(Simulated Value)
f
3dB
RATE_SEL = 0, BW1 = 0, BW0 = 0 1.0
GHz
RATE_SEL = 0, BW1 = 0, BW0 = 1 2.1
RATE_SEL = 0, BW1 = 1, BW0 = 0 2.5
RATE_SEL = 0, BW1 = 1, BW0 = 1 3.0
RATE_SEL = 1 9
Rx INPUT-BASED LOS SPECIFICATIONS (LOS1_EN = 1 and LOS2_EN = 0) (Note 1)
LOS Assert Sensitivity Range (Note 3) 14 77 mV
P-P
SET_LOS DAC Range 7 63 Decimal
LOS Hysteresis 10log(V
DEASSERT
/V
ASSERT
) 1.25 2.1 dB
LOS Assert/Deassert Time (Note 4) 2.3 20 80
Fs
Low Assert Level
SET_LOS[5:0] = 7d (Note 3)
8 11 14
mV
P-P
Low Deassert Level 14 18 22
Medium Assert Level
SET_LOS[5:0] = 32d (Note 3)
39 49 58
mV
P-P
Medium Deassert Level 65 82 95
High Assert Level
SET_LOS[5:0] = 63d (Note 3)
77 96 112
mV
P-P
High Deassert Level 127 158 182
LOS Output Masking Time
Range
SET_LOSTIMER[6:0] = 0d for minimum and
SET_LOSTIMER[6:0] = 127d for maximum
0 2920
Fs
LOS Output Masking DAC
Resolution
SET_LOSTIMER[6:0] = 1d to 127d 23 35 50
Fs
RSSI MONITOR-BASED LOS SPECIFICATIONS (LOS1_EN = 0 and LOS2_EN = 1) (Note 1)
LOS Assert Sensitivity Range (Note 5) 8.3 90 mV
SET_LOS DAC Range 4 63 Decimal
LOS Hysteresis 10log(V
DEASSERT
/V
ASSERT
) 1.25 2.1 dB
LOS Assert/Deassert Time (Note 4) 2.3 20 80
Fs
Low Assert Level
SET_LOS[5:0] = 4d (Note 5)
5.1 6.7 8.3
mV
Low Deassert Level 9.0 10.8 12.7
Medium Assert Level
SET_LOS[5:0] = 32d (Note 5)
45 50 55
mV
Medium Deassert Level 77 85 92
High Assert Level
SET_LOS[5:0] = 63d (Note 5)
90 98 106
mV
High Deassert Level 153 167 180
LOS Output Masking Time
Range
SET_LOSTIMER[6:0] = 0d for minimum and
SET_LOSTIMER[6:0] = 127d for maximum
0 2920
Fs
LOS Output Masking DAC
Resolution
SET_LOSTIMER[6:0] = 1d to 127d 23 35 50
Fs