19-1402; Rev 0; 11/98
3V to 5.5V, IrDA Infrared Transceiver with
Integrated RS-232 Interface
General Description
The MAX3130/MAX3131 combine an IrDA 1.2 compati-
ble infrared transceiver with an RS-232 interface—all in
a single 3V-powered hybrid microcircuit. The infrared
transceiver supports IrDA data rates of 2.4kbps to
115kbps. The infrared receive channel provides a high-
gain/low-noise PIN-diode amplifier with 100µA of ambi-
ent photodiode current rejection at a +3V supply. A
high-power LED driver capable of sinking 200mA is
included in the infrared transmit path. The on-board
encoder/decoder (ENDEC) compresses/stretches sig-
nals to and from the external UART, allowing IrDA com-
munication even with non-IrDA UARTs.
A 2-driver/2-receiver RS-232 transceiver supports data
rates up to 120kbps. A proprietary, high-efficiency, dual
charge-pump power supply and a low-dropout trans-
mitter combine to deliver true RS-232 performance from
a single +3.0V to +5.5V supply. Selectable shutdown
for IR and RS-232 circuitry reduces supply current to
1µA.
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’s IrDA transceiver and RS-232 transceivers
are separate and have their own data inputs and outputs.
Both these devices require a minimum of external com-
ponents: four small 0.1µF capacitors, a photodiode, an
infrared LED, and a current-setting resistor.
Features
o
Integrated RS-232 and IrDA in Single 28-Pin SSOP
Package
o
370µA Supply Current
o
IrDA 1.2 Compatible: 2.4kbps to 115kbps
Data Rate
o
On-Board IR Encoder/Decoder Allows Use of
Non-IrDA UARTs
o
+3.0V to +5.5V Single-Supply Operation
o
Meet EIA/TIA-232 Specifications Down to +3V
o
200mA, High-Current Infrared LED Drive
o
1µA Low-Power Shutdown with RS-232
Receivers Active
MAX3130/MAX3131
Ordering Information
PART
MAX3130CAI
MAX3130EAI
MAX3131CAI
MAX3131EAI
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
28 SSOP
28 SSOP
28 SSOP
28 SSOP
Pin Configuration
TOP VIEW
EDGEDET (RXD) 1
28 R2OUT
27 R2IN
26 T2OUT
25 RSSD
24 V-
Applications
Personal Digital Assistants (PDAs)
Palmtop Computers
Battery-Powered Systems
Hand-Held Equipment
Peripherals
IrDA Applications
Cellular Phones
T1IN 2
T2IN 3
IRMODE (TXD) 4
R1OUT 5
R1IN 6
T1OUT 7
BAUD16 8
GND 9
V
CC
10
N.C. 11
AV
CC
12
AGND 13
PINC 14
MAX3130
MAX3131
23 C2-
22 C2+
21 C1-
20 C1+
19 V+
18 N.C.
17 LEDC
16 PGND
15 IRSD
( ) ARE FOR MAX3131
SSOP
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
3V to 5.5V, IrDA Infrared Transceiver with
Integrated RS-232 Interface
MAX3130/MAX3131
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ..............................................................-0.3V to +6V
AV
CC
to AGND .........................................................-0.3V to +6V
V
CC
to AV
CC
.......................................................................±0.3V
AGND, PGND to GND ........................................................±0.1V
V+ to GND ................................................................-0.3V to +7V
V- to GND .................................................................+0.3V to -7V
V+ to V- ................................................................................+13V
Inputs (referenced to GND)
T1IN, T2IN, TXD,
RSSD, IRMODE,
BAUD16,
IRSD....................................................................-0.3V
to +6V
R1IN, R2IN .....................................................................±25V
Outputs (referenced to GND)
T1OUT, T2OUT............................................................±13.2V
R1OUT, R2OUT,
EDGEDET,
RXD.........-0.3V to (V
CC
+ 0.3V)
LEDC...................................................................-0.3V to +6V
Output Short-Circuit Duration (to V
CC
or GND)
T1OUT, T2OUT .....................................................Continuous
Output Currents
LEDC Continuous ........................................................200mA
LEDC 20% Duty Cycle t
ON
< 90µs..............................500mA
Input Current
PINC ..............................................................................10mA
Continuous Power Dissipation (T
A
= +70°C)
SSOP (derate 9.52mW/°C above +70°C) ...................762mW
Operating Temperature Ranges
MAX3130/MAX3131CAI ....................................0°C to +70°C
MAX3130/MAX3131EAI..................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= AV
CC
= 3.0V to 5.5V, GND = AGND = PGND, C1–C4 = 0.1µF (Note 1), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +25°C and V
CC
= AV
CC
= 3.3V.)
PARAMETER
DC CHARACTERISTICS
Power-Supply Current
Analog Power-Supply Current
Shutdown Supply Current
Shutdown Analog Supply Current
V
CC
= 3.3V or 5V, T
A
= +25°C (Note 2)
T
A
= +25°C (Note 2)
RSSD
= low or
IRMODE
= low,
T
A
= +25°C (Note 2)
IRSD
= low, T
A
= +25°C (Note 2)
0.25
120
1.0
0.01
1.0
200
10
1.0
mA
µA
µA
µA
CONDITIONS
MIN
TYP
MAX
UNITS
LOGIC INPUTS (T1IN, T2IN, TXD,
IRMODE,
BAUD16,
IRSD, RSSD)
Input Logic Threshold Low
Input Logic Threshold High
Input Leakage Current
V
CC
= AV
CC
= 3.3V
V
CC
= AV
CC
= 5V
V
IN
= 0 to V
CC
I
SINK
= 1.6mA
I
SOURCE
= 1.0mA
V
CC
-
0.6
2.4
10
(Note 3)
AV
CC
= 3.3V
AV
CC
= 5V
0.0002
100
375
6
2.0
2.4
±0.01
±1.0
0.8
V
V
µA
LOGIC OUTPUTS (R1OUT, R2OUT, RXD,
EDGEDET)
Output Voltage Low
Output Voltage High
IR RECEIVER
Data Rate
Equivalent Input Noise Current
Input Current Sensitivity
Ambient Photodiode Current
Rejection
(Note 3)
115.2
kbps
nA
RMS
mA
µA
µA
0.1
V
CC
-
0.05
0.4
V
V
2
_______________________________________________________________________________________
3V to 5.5V, IrDA Infrared Transceiver with
Integrated RS-232 Interface
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= AV
CC
= 3.0V to 5.5V, GND = AGND = PGND, C1–C4 = 0.1µF (Note 1), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +25°C and V
CC
= AV
CC
= 3.3V.)
PARAMETER
IR Receiver Disable Time
IR Receiver Enable Time
IR Receiver Output Pulse Width
IR TRANSMITTER
Transmitter Rise Time
Transmitter Fall Time
Transmitter Output Resistance
Off-Leakage Current
IrDA ENCODER/DECODER (ENDEC)
Maximum Operating Frequency
IR Output Pulse Width
BAUD16 Operating Frequency Range
RS-232 RECEIVER
Input Voltage Range
Input Threshold Low
Input Threshold High
Input Hysteresis
Input Resistance
Receiver Propagation Delay
Receiver Skew
RS-232 TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
Maximum Data Rate
Transmitter Skew
T1OUT, T2OUT, loaded with 3kΩ to GND
V
CC
= V+ = V- = 0, T_OUT = ±2V
V
T_OUT
= 0
V
T_OUT
= ±12V, V
CC
= 0 to 5.5V,
RS-232 transceiver shutdown
R
L
= 3kΩ, C
L
= 1000pF, one transmitter switching
t
PHL
- t
PLH
120
235
300
±5
300
±5.4
10M
±35
±60
±25
V
Ω
mA
µA
kbps
ns
T
A
= +25°C
R_IN to R_OUT,
C
L
= 150pF
t
PHL
- t
PLH
, C
L
= 150pF
t
PHL
t
PLH
3
V
CC
= 3.3V
V
CC
= 5V
V
CC
= 3.3V
V
CC
= 5V
-25
0.6
0.8
1.2
1.5
1.5
1.8
0.3
5
300
300
300
7
2.4
2.4
25
V
V
V
V
kΩ
ns
ns
Maximum frequency at BAUD16
f
BAUD16
= 1.8432MHz, measured at V
LEDC
f
BAUD16
required to enable ENDEC
1.43
34.6
2
2.23
2000
MHz
µs
kHz
10% to 90% of 200mA drive current
90% to 10% of 200mA drive current
I
OUT
= 200mA
V
LEDC
= 5.5V
AV
CC
= 3.3V
AV
CC
= 5V
20
20
1.15
0.9
0.01
600
600
2
1.6
10.0
ns
ns
Ω
µA
CONDITIONS
Delay until I
AVCC
< 1µA
Delay until maximum IR receive data rate is valid
BAUD16 = static
(Note 3)
Data rate = 2.4kbps
Data rate = 115kbps
1
1
1.6
MIN
TYP
10
300
90
8
MAX
UNITS
µs
µs
µs
MAX3130/MAX3131
_______________________________________________________________________________________
3
3V to 5.5V, IrDA Infrared Transceiver with
Integrated RS-232 Interface
MAX3130/MAX3131
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= AV
CC
= 3.0V to 5.5V, GND = AGND = PGND, C1–C4 = 0.1µF (Note 1), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +25°C and V
CC
= AV
CC
= 3.3V.)
PARAMETER
CONDITIONS
V
CC
= 3.3V, R
L
= 3kΩ to
7kΩ, measured from
+3V to -3V or -3V to +3V,
T
A
= +25°C
C
L
= 150pF to 1000pF
C
L
= 150pF to 2500pF
MIN
6
4
100
TYP
MAX
30
V/µs
30
µs
UNITS
Transition-Region Slew Rate
Transmitter Enable Time
Delay until transmitter outputs are valid
Note 1:
C1–C4 = 0.1µF, tested at +3.3V ±10%. C1 = 0.047µF, C2–C4 = 0.33µF, tested at +5.0V ±10%.
Note 2:
All supply current measurements are made under no-load condition on all outputs, and all input voltages are at V
CC
or GND.
Note 3:
For a compliant IrDA input signal where the data rate is within the supported data rate for the IR receive mode: rise/fall
times are less than 600ns and pulse widths are between 1.41µs and 3/16 of the baud rate.
Typical Operating Characteristics
(V
CC
= AV
CC
= 3.3V, GND = AGND = PGND, C1–C4 = 0.1µF, R
L
= 3kΩ, T
A
= +25°C, unless otherwise noted.)
ANALOG SUPPLY CURRENT
vs. TEMPERATURE
MAX3130 toc02
MAX3130 toc01
SUPPLY CURRENT vs. TEMPERATURE
380
360
340
320
I
AVCC
(µA)
I
CC
(µA)
300
280
260
240
220
200
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
90
-40
V
CC
= 3.3V or 5V
150
140
130
120
110
100
AMBIENT PHOTODIODE CURRENT
REJECTION vs. SUPPLY VOLTAGE
MAX3130 toc03
500
AV
CC
= 5V
CURRENT REJECTION (µA)
80
100
400
300
AV
CC
= 3.3V
200
100
0
-20
0
20
40
60
3.0
3.5
4.0
4.5
5.0
5.5
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
LED DRIVER ON-RESISTANCE
vs. TEMPERATURE
MAX3130 toc04
LEDC VOLTAGE vs. LEDC CURRENT
MAX3130 toc05
RXD OUTPUT PULSE WIDTH
vs. DISTANCE (2400bps)
TRANSMITTER POWER = 200mW/sr
INPUT PULSE WIDTH = 78µs
TEMIC BPV22NF
V
CC
= 3.3V
MAX3130 toc06
1.6
1.4
1.2
R
LED
(Ω)
1.0
0.8
0.6
0.4
0.2
I
LEDC
= 200mA
0
-40
-20
0
20
40
80
V
CC
= 5V
V
CC
= 3.3V
600
500
LEDC VOLTAGE (mV)
400
300
200
100
0
V
CC
= 3.3V
100
80
RXD PULSE WIDTH (µs)
60
40
V
CC
= 5V
PULSED AT
20% DUTY CYCLE
20
0
100
150
200
250
300
350
400
0
20
40
60
80
100
LEDC CURRENT (mA)
DISTANCE (cm)
100
TEMPERATURE (°C)
4
_______________________________________________________________________________________
3V to 5.5V, IrDA Infrared Transceiver with
Integrated RS-232 Interface
Typical Operating Characteristics (continued)
(V
CC
= AV
CC
= 3.3V, GND = AGND = PGND, C1–C4 = 0.1µF, R
L
= 3kΩ, T
A
= +25°C, unless otherwise noted.)
RXD OUTPUT PULSE WIDTH vs. DISTANCE
(115.2 kbps)
MAX3130 toc07
MAX3130/MAX3131
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
TRANSMITTER OUTPUT VOLTAGE (V)
V
OUT
+
1 TRANSMITTER AT 235kbps
1 TRANSMITTER AT 15kbps
MAX3130 toc08
4.0
3.5
RXD PULSE WIDTH (µs)
3.0
2.5
2.0
1.5
1.0
0
20
TRANSMITTER POWER = 200mW/sr
INPUT PULSE WIDTH = 1.63µs
TEMIC BPV22NF
V
CC
= 3.3V
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
0
1000
2000
3000
V
OUT
-
40
60
80
100
4000
5000
DISTANCE (cm)
LOAD CAPACITANCE (pF)
RS-232 TRANSMITTER SLEW RATE
vs. LOAD CAPACITANCE
MAX3130 toc09
SUPPLY CURRENT vs. LOAD CAPACITANCE
(RS-232 TRANSMITTING)
1 TRANSMITTER DRIVEN ONLY
35
235kbps
30
I
CC
(mA)
25
120kbps
20
15
20kbps
10
5
0
MAX3130-toc10
18
16
14
SLEW RATE (V/µs)
12
10
8
6
4
2
0
0
1000
2000
3000
4000
+SLEW
-SLEW
40
5000
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
RXD OUTPUT
vs. INFRARED INPUT
RXD OUTPUT
vs. INFRARED INPUT
MAX3130 toc11
MAX3130 toc12
2V/div
RXD
OUTPUT
2V/div
RXD
OUTPUT
2V/div
INFRARED
INPUT
2V/div
INFRARED
INPUT
2µs/div
V
CC
= 3.3V, 115.2kbps AT 1cm DISTANCE
TEMIC BPV22NF
TRANSMIT POWER 200mW/sr
100µs/div
V
CC
= 3.3V, 2400bps AT 1cm DISTANCE
TEMIC BPV22NF
TRANSMIT POWER 200mW/sr
_______________________________________________________________________________________
5
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