Rainbow Electronics MAX3798 User Manual
Page 12
MAX3798
1.0625Gbps to 10.32Gbps, Integrated, Low-
Power SFP+ Limiting Amplifier and VCSEL Driver
12
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Typical Operating Characteristics—VCSEL Driver (continued)
(V
CC
= 3.3V, T
A
= +25°C, unless otherwise specified. Figure 1 shows the typical setup used for measurements. Registers are set to
default values unless otherwise noted, and the 3-wire interface is static during measurements. For testing, the MODE_SEL bit was
used and the MSEL pin was left open.)
MODULATION CURRENT
vs. DAC SETTING
MAX3798 toc26
SET_IMOD[8:0]
MODULATION CURRENT (mA)
250
200
150
100
50
2
4
6
8
10
12
14
0
0
300
R
LOAD
= 50
Ω
R
LOAD
= 75
Ω
R
LOAD
= 100
Ω
BIAS CURRENT
vs. DAC SETTING
MAX3798 toc27
SET_IBIAS[8:0]
BIAS CURRENT (mA)
250
200
150
100
50
2
4
6
8
10
12
14
0
0
300
TRANSMITTER DISABLE
MAX3798 toc28
100ns/div
V
CC
FAULT
DISABLE
OUTPUT
LOW
LOW
HIGH
3.3V
TRANSMITTER ENABLE
MAX3798 toc29
1
μs/div
V
CC
FAULT
DISABLE
OUTPUT
LOW
LOW
HIGH
3.3V
t
ON
= 420ns
RESPONSE TO FAULT
MAX3798 toc30
1
μs/div
V
BIAS
FAULT
DISABLE
OUTPUT
LOW
LOW
HIGH
EXTERNALLY
FORCED FAULT
FAULT RECOVERY
MAX3798 toc31
4
μs/div
V
BIAS
FAULT
DISABLE
OUTPUT
LOW
LOW
HIGH
EXTERNAL
FAULT
HIGH
FREQUENCY ASSERTION OF DISABLE
MAX3798 toc32
4
μs/div
V
BIAS
FAULT
DISABLE
OUTPUT
LOW
LOW
HIGH
HIGH
EXTERNALLY
FORCED FAULT
Tx INPUT RETURN LOSS
MAX3798 toc33
FREQUENCY (Hz)
SDD11 (dB)
10G
1G
-50
-40
-30
-20
-10
0
-60
100M
100G
Tx OUTPUT RETURN LOSS
MAX3798 toc34
FREQUENCY (Hz)
SDD22 (dB)
10G
1G
-40
-35
-30
-25
-20
-15
-10
-5
0
-45
100M
100G