Datasheet

MAX3747A/MAX3747B
155Mbps to 3.2Gbps, Low-Power SFP
Limiting Amplifiers
8
Maxim Integrated
CML Output Buffer
The CML outputs of the MAX3747A/MAX3747B limiting
amplifiers provide high tolerance to impedance mis-
matches and inductive connectors. The output current
is approximately 16mA for the MAX3747A/MAX3747B.
Connecting the DISABLE pin to V
CC
disables the out-
put. If the LOS pin is connected to the DISABLE pin,
the outputs OUT+ and OUT- are at a static voltage
(squelch) whenever the input signal level drops below
the LOS threshold. The output buffer can be AC- or DC-
coupled to the load (Figure 4).
The MAX3747A/MAX3747B output is 800mV
P-P
.
MAX3747A
MAX3747B
50Ω
50Ω
DIGITAL
OFFSET
CORRECTION
V
REF
SIGNAL DETECT
50Ω
50Ω
IN+
IN-
V
REF
V
REF
TH LOS
V
CC
V
CC
OUT+
DISABLE
OUT-
R
TH1
R
TH1
+ R
TH2
≥ 5kΩ
R
TH2
Functional Diagram
50Ω
50Ω
V
CC
OUT+
OUT-
DISABLEDISABLE
Q4 Q2Q1Q3
DISABLE
DATA
ESD
STRUCTURES
Figure 4. CML Output Buffer