MAX3243EETJ+T Maxim Integrated, MAX3243EETJ+T Datasheet - Page 9

• Manufacturer Part Number: MAX3243EETJ+T
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX3221E, MAX3223E, MAX3243Er

Specifications of MAX3243EETJ+T

• Data Rate: 120 Kbps
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 1 mA
• Operating Temperature Range: 0 C to + 70 C
• Function: Transceiver
• Number Of Drivers: 3
• Number Of I/os: 16
• Number Of Receivers: 5
• Propagation Delay Time Ns: 0.3 us
• Shutdown: Yes

Figure 2a. Simplified Laser Driver Functional Diagram
Figure 2b. Laser Driver Functional Diagram
PORDLY
FLTDLY
MON
POL
POL
MD
IN+
IN-
EN
EN
LV
PORDLY
FLTDLY
FAULT
FAULT
POR
POL
POL
IN+
IN-
EN
EN
_______________________________________________________________________________________
TC
BIAS GENERATOR
MODULATOR
POR CIRCUIT
SAFETY
LASER
MODULATOR
MODSET
INPUT BUFFER
LASER
SMOOTH-
START
POR CIRCUIT
LV
R
TC
TC
MODULATION CURRENT
OUT-
OUT+
POR
FAULT
FAULT
SHDNDRV
MD
BIASDRV
REF
3.0V to 5.5V, 1.25Gbps/2.5Gbps
GENERATOR
MAX3286
MAX3296
CIRCUITRY
SAFETY
MODSET
R
MOD
the anode or cathode of a monitor photodiode or to a
resistor-divider, depending on the specific application
circuit. Three application circuits are supported:
common-cathode laser with photodiode, common-
cathode laser without photodiode, and common-anode
laser with photodiode (as shown in the Design Procedure
section). The POL and POL inputs determine the laser
pinning (common cathode, common anode) (Table 4).
The smooth-start circuitry prevents current spikes to the
laser during power-up or enable; this ensures compliance
with safety requirements and extends the life of the laser.
The power-control amplifier drives an external transistor
to control the laser bias current. In a fault condition, the
power-control amplifier’s output is disabled (high
+1.7V
1.7V
REF
LAN Laser Drivers
CONTROLLED
V
50
GENERATOR
REFERENCE
CC
- 0.54V
BIAS GENERATOR
V
1.97V
CC
1.53V
50
OUT+
REF
MD
OUT-
MON
SHDNDRV
BIASDRV
9