MAX3901 Maxim, MAX3901 Datasheet - Page 8

• Manufacturer Part Number: MAX3901
• Description: 150Mbps Automotive Fiber Optic Receivers
• Manufacturer: Maxim

150Mbps Automotive Fiber Optic Receiver
The MAX3901/MAX3902 receivers are optimized for
automotive fiber optic applications. The MAX3901 is a
single-ended TTL output receiver. The MAX3902 is a
differential CML output receiver. The MAX3901/
MAX3902 are both comprised of a transimpedance
amplifier, a voltage-gain amplifier, an output buffer, a
DC cancellation circuit, and a power detector with sta-
tus monitor, as shown in Figure 2.
The signal path consists of a transimpedance amplifier, a
voltage-gain amplifier, and a DC cancellation circuit. The
transimpedance amplifier converts input current to volt-
age. The voltage-gain amplifier converts single-ended to
differential voltage. The DC cancellation circuit uses low-
frequency feedback to remove the DC component of the
input signal. This feature centers the input signal within
the transimpedance amplifier’s linear range, thereby
reducing pulse-width distortion. The highpass response
of the DC cancellation circuit limits the number of con-
secutive identical digits that can be tolerated.
The output buffer for the MAX3901 is a single-ended
TTL output designed to drive a high-impedance load.
Output capacitance should be less than 15pF to ensure
stable operation. The TTL output is not compatible with
50Ω test equipment. Use a high-impedance probe to
monitor the output.
During standby mode, the TTL output is actively pulled
to a low state.
8
13, 14, 15
8, 16, 17
BOND
5, 6, 7
_______________________________________________________________________________________
PAD
3, 4,
10
11
12
1
2
9
MAX3901
OUT_TTL
STATUS
NAME
GND
N.C.
N.C.
N.C.
FILT
V
IN
CC
Detailed Description
MAX3902
STATUS
NAME
OUT+
OUT-
GND
FILT
N.C.
N.C.
V
IN
CC
TTL Output Buffer
Filter Pin. Must be connected to photodiode cathode for the IC to operate. This pin provides
connection to an integrated photodiode filter.
Data Input. Connect photodiode anode to this pin.
No Connection
Supply Voltage
Circuit Ground
Noninverting Data Output. Current flowing into IN causes the voltage at OUT+ to increase.
Inverting Data Output. Current flowing into IN causes the voltage at OUT- to decrease.
Status Monitor. STATUS is TTL low when the receiver is in operating mode. STATUS is TTL
high when the receiver is in standby mode.
TTL Data Output. Current flowing into IN causes the voltage at OUT_TTL to increase.
Signal Path
The output buffer for the MAX3902 is a differential CML
output designed to drive a 100Ω differential load between
OUT+ and OUT- (Figure 3). For optimum supply noise
rejection, the MAX3902 should be terminated with a dif-
ferential load. If a single-ended output is required, both
the used and the unused outputs should be terminated in
a similar manner.
Figure 2. Functional Diagram
FILT
IN
FUNCTION
DETECTOR
POWER
TIA
CANCELLATION
V
CC
DC
MAX3901
MAX3902
AMPLIFIER
VOLTAGE
Pad Description
CML Output Buffer
V
CML
TTL
CC
INTERNAL
STATUS
OUT+
(MAX3902)
OUT_TTL
(MAX3901)
OUT-
(MAX3902)