MAX3131EAI Maxim Integrated Products, MAX3131EAI Datasheet - Page 8

• Manufacturer Part Number: MAX3131EAI
• Description: IC TXRX RS2332 IRDA IR 28-SSOP
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of MAX3131EAI

• Number Of Drivers/receivers: 2/2
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5 V
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

3V to 5.5V, IrDA Infrared Transceiver with
Integrated RS-232 Interface
X = Don’t care
The MAX3130/MAX3131 are IrDA 1.2 compatible,
infrared transceivers with an integrated RS-232 inter-
face. By selecting appropriate external optical compo-
nents, these devices support IrDA 1.2 data rates from
2.4kbps to 115kbps at distances from 1cm to 1m. A
low-noise design allows them to achieve a bit-error rate
below 10
rejects out-of-band ambient light signals that interfere
with infrared communication. Both devices include a
high-power LED driver capable of sinking 200mA.
The MAX3130 and MAX3131 contain two RS-232 drivers
and two RS-232 receivers that support data rates up to
120kbps. The RS-232 transceiver is powered by a high-
efficiency, dual charge-pump power supply that oper-
ates with input supply voltages from +3.0V to +5.5V.
The MAX3130 is optimized for applications using a sin-
gle UART for both infrared and RS-232 communication.
The infrared transmitter input and infrared receiver out-
put are multiplexed with one RS-232 transmitter input
and one RS-232 receiver output, respectively. The
MAX3131 IrDA and RS-232 transceivers are indepen-
dent of each other for use in simultaneous multiprotocol
transceiver applications.
8
RSSD
X
X
0
0
1
1
CONTROL INPUTS
_______________________________________________________________________________________
RSSD
0
0
1
1
MAX3130
IRMODE
-8
0
0
1
1
1
1
at maximum data rates. On-chip filtering
IRSD
IRSD
0
1
0
1
0
1
0
1
0
1
Detailed Description
RS-232
RS-232
RS-232
RS-232
RS-232
RS-232
LOGIC INPUTS
Input
Input
Input
Input
Input
Input
T1IN
RS-232
RS-232
RS-232
RS-232
Enabled
Enabled
Input
Input
Input
Input
Input
Input
T_OUT
T2IN
High-Z
High-Z
IrDA
IrDA
T1OUT
RS-232
RS-232
High-Z
High-Z
High-Z
High-Z
Output
Output
T2OUT
RS-232
RS-232
High-Z
High-Z
High-Z
High-Z
Output
Output
RS-232 I/O
Enabled
Enabled
Enabled
Enabled
R_IN
RS-232
RS-232
RS-232
RS-232
RS-232
RS-232
R1IN
Input
Input
Input
Input
Input
Input
MAX3131 Operational Modes Table
The receiver amplifier reverse biases the PIN diode
with approximately 1.2V, and the PIN diode converts
pulses of IR light into pulses of current. The input trans-
impedance (current-to-voltage) amplifier converts and
amplifies these current pulses into voltage pulses. The
MAX3130/MAX3131 incorporate filters that remove low-
frequency ambient light interference and high-frequency
circuit noise from these voltage pulses. A high-speed
comparator then translates these voltage pulses into
CMOS output levels. Figures 1 and 2 show system
functional diagrams.
The RXD pin is the output of the infrared receiver for
the MAX3131. The R2OUT pin is the output of the
infrared receiver for the MAX3130 (IRMODE = low).
With the ENDEC disabled, the infrared receiver output
pulses low upon each incoming infrared pulse. The
pulse width of the receiver output depends on many
factors, including transmitter distance and power, PIN
photodiode efficiency and area, and incoming data
rate. Under all circumstances the output pulse is less
than one baud period. To communicate with UARTs
that are not IrDA compatible, enable the ENDEC (see
the IrDA Encoder/Decoder (ENDEC) section).
RS-232
RS-232
RS-232
RS-232
RS-232
RS-232
R2IN
Input
Input
Input
Input
Input
Input
Enabled
Enabled
Enabled
Enabled
LEDC
MAX3130 Function Table
R1OUT
LOGIC OUTPUTS
RS-232
RS-232
RS-232
RS-232
RS-232
RS-232
Output
Output
Output
Output
Output
Output
R2OUT
RS-232
RS-232
RS-232
RS-232
Output
Output
Output
Output
Output
Output
IrDA
IrDA
OUTPUT
Disabled
Disabled
Disabled
Disabled
Enabled
Enabled
IrDA Output
IrDA Output
LEDC
Logic High
Logic High
IrDA
IR Receivers
RXD
Disabled
Disabled
Disabled
Enabled
Enabled
Enabled
INPUT
PINC
IrDA