Datasheet
8 ______________________________________________________________________________________
MAX3945
1.0625Gbps to 11.3Gbps,
SFP+ Dual-Path Limiting Amplifier
Typical Operating Characteristics (continued)
(V
CC
= 3.3V, T
A
= +25NC, unless otherwise noted. Registers are set to default values, unless otherwise noted, and the 3-wire interface
is static during measurements.)
DIFFERENTIAL OUTPUT SIGNAL LEVEL
vs. SET_CML DAC SETTING
MAX3945 toc10
SET_CML DAC SETTING
DIFFERENTIAL OUTPUT AMPLITUDE (mV
P-P
)
250200100 150
500
600
700
800
1000
900
1100
1200
400
50 300
RXDE_EN = 0
RXDE1 = 0, RXDE0 = 0
RXDE1 = 0, RXDE0 = 1
RXDE1 = 1,
RXDE0 = 0
RXDE1 = 1,
RXDE0 = 1
DEEMPHASIS VALUE
vs. SET_CML DAC SETTING
(RATE_SEL = 1)
MAX3945 toc11
SET_CML DAC SETTING
DEEMPHASIS LEVEL (dB)
200150100
2
4
6
0
50 250
RXDE1 = 1, RXDE0 = 1
RXDE1 = 1, RXDE0 = 0
RXDE1 = 0, RXDE0 = 1
RXDE1 = 0,
RXDE0 = 0
RXDE_EN = 0
Rx INPUT-BASED LOS THRESHOLD vs. DAC
CODE (LOS1_EN = 1 AND LOS2_EN = 0)
MAX3945 toc12
SET_LOS[5:0] DAC CODE
LOS THRESHOLD (mV
P-P
)
605010 20 30 40
20
40
60
80
100
120
140
160
0
0 70
DEASSERT
ASSERT
RSSI MONITOR-BASED LOS THRESHOLDS
(LOS1_EN = 0 AND LOS2_EN = 1)
MAX3945 toc13
SET_LOS[5:0] DAC CODE
LOS THRESHOLD (mV)
605030 402010
20
40
60
80
100
120
140
160
180
0
0 70
DEASSERT
ASSERT
LOS MASKING TIME vs. DAC SETTING
MAX3945 toc14
SET_LOSTIMER[6:0] DAC CODE
MASKING TIME (µs)
12010080604020
1000
2000
3000
4000
5000
0
0
DETERMINISTIC JITTER vs. INPUT AMPLITUDE AT 1.25Gbps
(K28.5 PATTERN, 933MHz INPUT FILTER)
MAX3945 toc15
SIGNAL AMPLITUDE (mV
P-P
)
DJ (ps)
1000800600400200
10
15
20
25
5
0 1200
RATE_SEL = 0, BW1 = 0, BW2 = 0
DETERMINISTIC JITTER AT 10.32Gbps
(PRBS7 PATTERN WITH 100 CIDs, RATE_SEL = 1)
MAX3945 toc16
INPUT SIGNAL AMPLITUDE (mV
P-P
)
DJ (ps)
1000800200 400 600
1
2
3
4
5
6
7
8
9
10
0
0 1200
DETERMINISTIC JITTER vs. DATA RATE
(INPUT = 100mV
P-P
)
MAX3945 toc17
DATA RATE (Gbps)
DJ (ps)
963
5
10
15
20
25
0
0 12
K28.5 PATTERN, RATE_SEL = 1
DJ WITH 100mV
P-P
NOISE
ON POWER SUPPLY
DJ WITH NO NOISE ON POWER SUPPLY
POWER-SUPPLY CURRENT vs. TEMPERATURE
(SET_CML[7:0] = 91d)
MAX3945 toc18
TEMPERATURE (°C)
POWER-SUPPLY CURRENT (mA)
806040200-20
30
40
50
60
70
80
20
-40 100
LOS2_EN = 0 AND LOS1_EN = 1
LOS2_EN = 1 AND LOS1_EN = 0