19-4323; Rev 17; 1/15
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
General Description
The MAX220–MAX249 family of line drivers/receivers is
intended for all EIA/TIA-232E and V.28/V.24 communica-
tions interfaces, particularly applications where ±12V is
not available.
The MAX225, MAX233, MAX235, and MAX245/MAX246/
MAX247 use no external components and are
recommended for applications where printed circuit
board space is critical.
The MAX220-MAX249 are offered in 26 different pack-
ages with temperatures from 0 to +70°C up to -55°C to
+125°C. See ordering information table at the end of the
data sheet for all package and temperature options.
Applications
•Interface Translation
•Multidrop RS-232 Networks
•Portable Diagnostics Equipment
Benefits and Features
Saves Board Space
•Integrated Charge Pump Circuitry
•Eliminates the Need for a Bipolar ±12V Supply
•Enables Single Supply Operation from +5V Supply
•Integrated Capacitors (MAX223, MAX233, MAX235,
MAX245-MAX247)
Saves Power for Reduced Power Requirements
•5µW Shutdown Mode
AutoShutdown and UCSP are trademarks of Maxim Integrated
Products, Inc.
TOP VIEW
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
VCC
GND
T1OUT
R1IN
C2+
C1-
V+
C1+ +
MAX220
MAX232
MAX232A R1OUT
T1IN
T2IN
R2OUT
R2IN
T2OUT
V-
C2-
DIP/SO
V+
V-
2+10V
C1+
C1
C2
1
3
4
5
11
10
12
9
6
14
7
13
8
T1IN
R1OUT
T2IN
R2OUT
T1OUT
R1IN
T2OUT
R2IN
+5V INPUT
C2+ -10V
C4
RS-232
OUTPUTS
RS-232
INPUTS
TTL/CMOS
INPUTS
TTL/CMOS
OUTPUTS
GND
15
5kΩ
5kΩ
400kΩ
400kΩ
+5V
+5V
+10V TO -10V
VOLTAGE INVERTER
+5V TO +10V
VOLTAGE DOUBLER
16
C3
C5
CAPACITANCE (μF)
DEVICE
MAX220
MAX232
MAX232A
C1
0.047
1.0
0.1
C2
0.33
1.0
0.1
C3
0.33
1.0
0.1
C4
0.33
1.0
0.1
C5
0.33
1.0
0.1
C2-
C1-
VCC
Ordering Information and Selection Table appears at end
of data sheet.
MAX220/MAX232/MAX232A Pin Configuration and Typical Operating Circuit
Maxim Integrated | 2www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Absolute Maximum Ratings—MAX220/222/232A/233A/242/243
Electrical Characteristics—MAX220/222/232A/233A/242/243
(VCC = +5V ±10%, C1–C4 = 0.1µF‚ MAX220, C1 = 0.047µF, C2–C4 = 0.33µF, TA= TMIN to TMAX‚ unless otherwise noted.) (Note 3)
Note 1: For the MAX220, V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.
Note 2: Input voltage measured with TOUT in high-impedance state, VSHDN or VCC = 0V.
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.
(Voltages referenced to GND.)
VCC ...........................................................................-0.3V to +6V
V+ (Note 1) ..................................................(VCC - 0.3V) to +14V
V- (Note 1) ..............................................................+0.3V to -14V
Input Voltages
TIN .............................................................-0.3V to (VCC - 0.3V)
RIN (Except MAX220)........................................................±30V
RIN (MAX220) ....................................................................±25V
TOUT (Except MAX220) (Note 2) ......................................±15V
TOUT (MAX220)..............................................................±13.2V
Output Voltages
TOUT..................................................................................±15V
ROUT........................................................-0.3V to (VCC + 0.3V)
Driver/Receiver Output Short Circuited to GND.........Continuous
Continuous Power Dissipation (TA= +70°C)
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)..842mW
18-Pin Plastic DIP (derate 11.11mW/°C above +70°C)..889mW
20-Pin Plastic DIP (derate 8.00mW/°C above +70°C) ..440mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ...696mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW
18-Pin Wide SO (derate 9.52mW/°C above +70°C)......762mW
20-Pin Wide SO (derate 10.00mW/°C above +70°C)....800mW
20-Pin SSOP (derate 8.00mW/°C above +70°C) ..........640mW
16-Pin CERDIP (derate 10.00mW/°C above +70°C).....800mW
18-Pin CERDIP (derate 10.53mW/°C above +70°C).....842mW
Operating Temperature Ranges
MAX2_ _AC_ _, MAX2_ _C_ _.............................0°C to +70°C
MAX2_ _AE_ _, MAX2_ _E_ _ ..........................-40°C to +85°C
MAX2_ _AM_ _, MAX2_ _M_ _.......................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow)
20 PDIP (P20M+1) .......................................................+225°C
All other lead(Pb)-free packages.................................+260°C
All other packages containing lead(Pb) ......................+240°C
PARAMETER CONDITIONS MIN TYP MAX UNITS
RS-232 TRANSMITTERS
Output Voltage Swing All transmitter outputs loaded with 3k to GND ±5 ±8 V
Input Logic-Low Voltage 1.4 0.8 V
All devices except MAX220 2 1.4
Input Logic-High Voltage MAX220: VCC = +5.0V 2.4 V
All except MAX220, normal operation 5 40
Logic Pullup/lnput Current VSHDN = 0V, MAX222/MAX242, shutdown,
MAX220 ±0.01 ±1 μA
VCC = +5.5V, VSHDN = 0V, VOUT = ±15V,
MAX222/MAX242 ±0.01 ±10
VOUT = ±15V ±0.01 ±10
Output Leakage Current
VCC = VSHDN = 0V MAX220, VOUT = ±12V ±25
μA
Data Rate 200 116 kbps
Transmitter Output Resistance VCC = V+ = V- = 0V, VOUT = ±2V 300 10M
VOUT = 0V ±7 ±22
Output Short-Circuit Current VOUT = 0V MAX220 ±60 mA
RS-232 RECEIVERS
±30
RS-232 Input Voltage Operating Range MAX220 ±25 V
All except MAX243 R2IN 0.8 1.3
RS-232 Input Threshold Low VCC = +5V MAX243 R2IN (Note 4) -3 V
All except MAX243 R2IN 1.8 2.4
RS-232 Input Threshold High VCC = +5V MAX243 R2IN (Note 4) -0.5 -0.1 V
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 3www.maximintegrated.com
Electrical Characteristics—MAX220/222/232A/233A/242/243 (continued)
(VCC = +5V ±10%, C1–C4 = 0.1µF‚ MAX220, C1 = 0.047µF, C2–C4 = 0.33µF, TA= TMIN to TMAX‚ unless otherwise noted.) (Note 3)
PARAMETER CONDITIONS MIN TYP MAX UNITS
All except MAX220/MAX243, VCC = +5V, no
hysteresis in shutdown 0.2 0.5 1.0
MAX220 0.3
RS-232 Input Hysteresis
MAX243 1
V
3 5 7
RS-232 Input Resistance TA = +25°C (MAX220) 3 5 7 k
IOUT = 3.2mA 0.2 0.4
TTL/CMOS Output Voltage Low IOUT = 1.6mA (MAX220) 0.4 V
TTL/CMOS Output Voltage High IOUT = -1.0mA 3.5 VCC - 0.2 V
Sourcing VOUT = VGND -2 -10
TTL/CMOS Output Short-Circuit Current Sinking VOUT = VCC 10 30 mA
TTL/CMOS Output Leakage Current VSHDN = VCC or VEN = VCC (VSHDN = 0V for
MAX222), 0V VOUT VCC ±0.05 ±10 μA
EN Input Threshold Low MAX242 1.4 0.8 V
EN Input Threshold High MAX242 2.0 1.4 V
Supply Voltage Range 4.5 5.5 V
MAX220 0.5 2
No load MAX222/MAX232A/MAX233A/
MAX242/MAX243 4 10
MAX220 12
VCC Supply Current (VSHDN = VCC),
Figures 5, 6, 11, 19
3k load
both inputs MAX222/MAX232A/MAX233A/
MAX242/MAX243 15
mA
TA = +25°C 0.1 10
TA = 0°C to +70°C 2 50
TA = -40°C to +85°C 2 50
Shutdown Supply Current MAX222/
MAX242
TA = -55°C to +125°C 35 100
μA
SHDN Input Leakage Current MAX222/MAX242 ±1 μA
SHDN Threshold Low MAX222/MAX242 1.4 0.8 V
SHDN Threshold High MAX222/MAX242 2.0 1.4 V
MAX222/MAX232A/
MAX233/MAX242/MAX243 6 12 30
Transition Slew Rate
CL = 50pF to 2500pF,
RL = 3k to 7k,
VCC = +5V, TA =
+25°C, measured
from +3V to -3V or
-3V to +3V
MAX220 1.5 3 30.0
V/μs
MAX222/MAX232A/
MAX233/MAX242/MAX243 1.3 3.5
tPHLT, Figure 1
MAX220 4 10
MAX222/MAX232A/
MAX233/MAX242/MAX243 1.5 3.5
Transmitter Propagation Delay TLL to
RS-232 (Normal Operation)
tPLHT, Figure 1
MAX220 5 10
μs
Maxim Integrated | 4www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Typical Operating Characteristics
MAX220/MAX222/MAX232A/MAX233A/MAX242/MAX243
10
8
-10
0 5 15 25
OUTPUT VOLTAGE vs. LOAD CURRENT
-4
-6
-8
-2
6
4
2
MAX220-01
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
10
0
20
0.1μF
EITHER V+ OR V- LOADED
VCC = +5V
NO LOAD ON
TRANSMITTER OUTPUTS
(EXCEPT MAX220, MAX233A)
V- LOADED, NO LOAD ON V+
V+ LOADED, NO LOAD ON V-
1μF
1μF
0.1μF
11
10
4
010 40 60
AVAILABLE OUTPUT CURRENT
vs. DATA RATE
6
5
7
9
8
MAX220-02
DATA RATE (kb/s)
OUTPUT CURRENT (mA)
20 30 50
OUTPUT LOAD CURRENT
FLOWS FROM V+ TO V-
VCC = +5.25V
ALL CAPS
1μF
ALL CAPS
0.1μFVCC = +4.75V
+10V
-10V
MAX222/MAX242
ON-TIME EXITING SHUTDOWN
+5V
+5V
0V
0V
MAX220-03
500μs/div
V+, V- VOLTAGE (V)
1μF CAPS V+
V+
V-
V-
SHDN
0.1μF CAPS
1μF CAPS
0.1μF CAPS
Electrical Characteristics—MAX220/222/232A/233A/242/243 (continued)
(VCC = +5V ±10%, C1–C4 = 0.1µF‚ MAX220, C1 = 0.047µF, C2–C4 = 0.33µF, TA= TMIN to TMAX‚ unless otherwise noted.) (Note 3)
PARAMETER CONDITIONS MIN TYP MAX UNITS
MAX222/MAX232A/MAX233/
MAX242/MAX243 0.5 1
tPHLR, Figure 2
MAX220 0.6 3
MAX222/MAX232A/MAX233/
MAX242/MAX243 0.6 1
Receiver Propagation Delay RS-232 to
TLL (Normal Operation)
tPLHR, Figure 2
MAX220 0.8 3
μs
tPHLS, Figure 2 MAX242 0.5 10
Receiver Propagation Delay RS-232 to
TLL (Shutdown) tPHLS, Figure 2 MAX242 2.5 10 μs
Receiver-Output Enable Time tER MAX242, Figure 3 125 500 ns
Receiver-Output Disable Time tDR MAX242, Figure 3 160 500 ns
Transmitter-Output Enable Time
(SHDN Goes High) tET
MAX222/MAX242, 0.1μF
caps (includes charge-pump
start-up), Figure 4
250 μs
Transmitter-Output Disable Time
(SHDN Goes Low) tDT MAX222/MAX242,
0.1μF caps, Figure 4 600 ns
MAX222/MAX232A/MAX233/
MAX242/MAX243 300
Transmitter + to - Propagation Delay
Difference (Normal Operation) tPHLT - tPLHT
MAX220 2000
ns
MAX222/MAX232A/MAX233/
MAX242/MAX243 100
Receiver + to - Propagation Delay
Difference (Normal Operation) tPHLR - tPLHR
MAX220 225
ns
Note 3: All units are production tested at hot. Specifications over temperature are guaranteed by design.
Note 4: MAX243 R2OUT is guaranteed to be low when R2IN ≥0V or is unconnected.
(Voltages referenced to GND.)
VCC ...........................................................................-0.3V to +6V
V+ ................................................................(VCC - 0.3V) to +14V
V- ............................................................................+0.3V to -14V
Input Voltages
TIN ............................................................-0.3V to (VCC + 0.3V)
RIN .....................................................................................±30V
Output Voltages
TOUT ..................................................(V+ + 0.3V) to (V- - 0.3V)
ROUT........................................................-0.3V to (VCC + 0.3V)
Short-Circuit Duration, TOUT to GND ........................Continuous
Continuous Power Dissipation (TA= +70°C)
14-Pin Plastic DIP (derate 10.00mW/°C above +70°C)....800mW
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)....842mW
20-Pin Plastic DIP (derate 11.11mW/°C above +70°C)....889mW
24-Pin Narrow Plastic DIP
(derate 13.33mW/°C above +70°C) ..........1.07W
24-Pin Plastic DIP (derate 9.09mW/°C above +70°C)......500mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C).........762mW
20-Pin Wide SO (derate 10.00mW/°C above +70°C).......800mW
24-Pin Wide SO (derate 11.76mW/°C above +70°C).......941mW
28-Pin Wide SO (derate 12.50mW/°C above +70°C) .............1W
44-Pin Plastic FP (derate 11.11mW/°C above +70°C) .....889mW
14-Pin CERDIP (derate 9.09mW/°C above +70°C) ..........727mW
16-Pin CERDIP (derate 10.00mW/°C above +70°C) ........800mW
20-Pin CERDIP (derate 11.11mW/°C above +70°C) ........889mW
24-Pin Narrow CERDIP
(derate 12.50mW/°C above +70°C) ..............1W
24-Pin Sidebraze (derate 20.0mW/°C above +70°C)..........1.6W
28-Pin SSOP (derate 9.52mW/°C above +70°C).............762mW
Operating Temperature Ranges
MAX2 _ _ C _ _......................................................0°C to +70°C
MAX2 _ _ E _ _ ...................................................-40°C to +85°C
MAX2 _ _ M _ _......................................................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow)
20 PDIP (P20M+1) .........................................................+225°C
24 PDIP (P24M-1) ..........................................................+225°C
All other lead(Pb)-free packages...................................+260°C
All other packages containing lead(Pb) ...........................+240°C
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 5www.maximintegrated.com
Absolute Maximum Ratings—MAX223/MAX230–MAX241
Electrical Characteristics—MAX223/MAX230–MAX241
(MAX223/230/232/234/236/237/238/240/241, VCC = +5V ±10%; MAX233/MAX235, VCC = +5V ±5%‚ C1–C4 = 1.0µF;
MAX231/MAX239, VCC = +5V ±10%; V+ = +7.5V to +13.2V; TA= TMIN to TMAX; unless otherwise noted.) (Note 5)
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.
CONDITIONS MIN TYP MAX UNITS
Output Voltage Swing All transmitter outputs loaded with 3kΩto ground ±5.0 ±7.3 V
VCC Supply Current No load,
TA= +25°C
510
mA
715
0.4 1
V+ Supply Current 1.8 5 mA
515
Shutdown Supply Current TA= +25°C 15 50
VInput Logic-High Voltage
TIN 2.0
EN, SHDN (MAX223);
EN, SHDN (MAX230/235/236/240/241) 2.4
Logic Pullup Current VTIN =0V 1.5 200
Receiver Input Voltage
Operating Range -30 +30 V
µA
µA
110
VInput Logic-Low Voltage TIN, EN, SHDN (MAX233); EN, SHDN (MAX230/235–241) 0.8
MAX231/239
MAX223/230/234–238/240/241
MAX232/233
PARAMETER
MAX239
MAX230/235/236/240/241
MAX231
MAX223
Maxim Integrated | 6www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
mA
V
0.8 1.2
PARAMETER MIN TYP MAX UNITSCONDITIONS
Normal operation
VSHDN = 5V (MAX223)
VSHDN = 0V (MAX235/236/240/241)
1.7 2.4
RS-232 Input Logic-Low Voltage TA= +25°C,
VCC = +5V
0.6 1.5
VRS-232 Input Logic-High Voltage TA= +25°C,
VCC = +5V Shutdown (MAX223)
VSHDN = 0V,
VEN = +5V (R4IN‚ R5IN)
1.5 2.4
Electrical Characteristics—MAX223/MAX230–MAX241 (continued)
(MAX223/230/232/234/236/237/238/240/241, VCC = +5V ±10%; MAX233/MAX235, VCC = +5V ±5%‚ C1–C4 = 1.0µF;
MAX231/MAX239, VCC = +5V ±10%; V+ = +7.5V to +13.2V; TA= TMIN to TMAX; unless otherwise noted.) (Note 5)
Shutdown (MAX223)
VSHDN = 0V,
VEN = +5V (R4IN, R5IN)
Normal operation
VSHDN = +5V (MAX223)
VSHDN = 0V (MAX235/236/240/241)
RS-232 Input Hysteresis VCC = +5V, no hysteresis in shutdown 0.2 0.5 1.0 V
RS-232 Input Resistance TA= +25°C, VCC = +5V 357kΩ
TTL/CMOS Output Voltage Low IOUT = 1.6mA (MAX231/232/233, IOUT = 3.2mA) 0.4 V
TTL/CMOS Output Voltage High IOUT = -1mA 3.5 VCC - 0.4 V
TTL/CMOS Output Leakage Current 0V ≤ROUT ≤VCC; VEN = 0V (MAX223);
VEN = VCC (MAX235–241) ±0.05 ±10 µA
MAX223 600 nsReceiver Output Enable Time Normal
operation MAX235/236/239/240/241 400
MAX223 900 nsReceiver Output Disable Time Normal
operation MAX235/236/239/240/241 250
Normal operation 0.5 10
µs
VSHDN = 0V
(MAX223)
440
Propagation Delay
RS-232 IN to
TTL/CMOS OUT,
CL= 150pF 640
3 5.1 30
V/µs
MAX231/MAX232/MAX233, TA= +25°C, VCC = +5V,
RL= 3kΩto 7kΩ, CL= 50pF to 2500pF, measured from
+3V to -3V or -3V to +3V
430
Transmitter Output Resistance VCC = V+ = V- = 0V, VOUT = ±2V 300 Ω
Transmitter Output Short-Circuit
Current ±10 mA
tPHLS
tPLHS
Transition Region Slew Rate
MAX223/MAX230/MAX234–241, TA= +25°C, VCC = +5V,
RL= 3kΩto 7kΩ‚ CL= 50pF to 2500pF, measured from
+3V to -3V or -3V to +3V
Note 5: All units are production tested at hot except for the MAX240, which is production tested at TA= +25°C. Specifications over
temperature are guaranteed by design.
Maxim Integrated | 7www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
8.5
6.5
4.5 5.5
TRANSMITTER OUTPUT
VOLTAGE (VOH) vs. VCC
7.0
8.0
MAX220-04
VCC (V)
VOH (V)
5.0
7.5
1 TRANSMITTER
LOADED 3 TRANS-
MITTERS
LOADED
4 TRANSMITTERS
LOADED
2 TRANSMITTERS
LOADED
TA = +25°C
C1–C4 = 1μF
TRANSMITTER
LOADS =
3kΩ || 2500pF
7.4
6.0
02500
TRANSMITTER OUTPUT VOLTAGE (VOH)
vs. LOAD CAPACITANCE AT
DIFFERENT DATA RATES
6.4
6.2
7.2
7.0
MAX220-05
LOAD CAPACITANCE (pF)
VOH (V)
15001000500 2000
6.8
6.6
160kb/s
80kb/s
20kb/s
TA = +25°C
VCC = +5V
3 TRANSMITTERS LOADED
RL = 3kΩ
C1–C4 = 1μF
12.0
4.0
0 2500
TRANSMITTER SLEW RATE
vs. LOAD CAPACITANCE
6.0
5.0
11.0
9.0
10.0
MAX220-06
LOAD CAPACITANCE (pF)
SLEW RATE (V/μs)
15001000500 2000
8.0
7.0
TA = +25°C
VCC = +5V
LOADED, RL = 3kΩ
C1–C4 = 1μF
1 TRANSMITTER LOADED
2 TRANSMITTERS
LOADED
3 TRANSMITTERS
LOADED
4 TRANSMITTERS
LOADED
-6.0
-9.0
4.5 5.5
TRANSMITTER OUTPUT
VOLTAGE (VOL) vs. VCC
-8.0
-8.5
-6.5
-7.0
MAX220-07
VCC (V)
VOL (V)
5.0
-7.5
4 TRANS-
MITTERS
LOADED
TA = +25°C
C1–C4 = 1μF
TRANSMITTER
LOADS =
3kΩ || 2500pF
1 TRANS-
MITTER
LOADED
2 TRANS-
MITTERS
LOADED
3 TRANS-
MITTERS
LOADED
-6.0
-7.6
0 2500
TRANSMITTER OUTPUT VOLTAGE (VOL)
vs. LOAD CAPACITANCE AT
DIFFERENT DATA RATES
-7.0
-7.2
-7.4
-6.2
-6.4
MAX220-08
LOAD CAPACITANCE (pF)
VOL (V)
15001000500 2000
-6.6
-6.8 160kb/s
80kb/s
20kb/s
TA = +25°C
VCC = +5V
3 TRANSMITTERS LOADED
RL = 3kΩ
C1–C4 = 1μF
10
-10
05 10 15 20 25 30 35 40 45 50
TRANSMITTER OUTPUT VOLTAGE (V+, V-)
vs. LOAD CURRENT
-2
-6
-4
-8
8
6
MAX220-09
CURRENT (mA)
V+, V- (V)
4
2
0
V+ AND V-
EQUALLY
LOADED
V- LOADED,
NO LOAD
ON V+
TA = +25°C
VCC = +5V
C1–C4 = 1μF
ALL TRANSMITTERS UNLOADED
V+ LOADED,
NO LOAD
ON V-
Typical Operating Characteristics
MAX223/MAX230–MAX241
*SHUTDOWN POLARITY IS REVERSED
FOR NON MAX241 PARTS
V+, V- WHEN EXITING SHUTDOWN
(1μF CAPACITORS)
MAX220-13
VSHDN*
V-
O
V+
500ms/div
Maxim Integrated | 8www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Input Logic-Low Voltage
Absolute Maximum Ratings—MAX225/MAX244–MAX249
Electrical Characteristics—MAX225/MAX244–MAX249
(MAX225, VCC = +5.0V ±5%; MAX244–MAX249, VCC = +5.0V ±10%, external capacitors C1–C4 = 1µF; TA= TMIN to TMAX; unless
otherwise noted.) (Note 7)
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.
(Voltages referenced to GND.)
Supply Voltage (VCC) ...............................................-0.3V to +6V
Input Voltages
TIN‚ ENA, ENB, ENR, ENT, ENRA,
ENRB, ENTA, ENTB..................................-0.3V to (VCC + 0.3V)
RIN .....................................................................................±25V
TOUT (Note 6)....................................................................±15V
ROUT........................................................-0.3V to (VCC + 0.3V)
Short Circuit Duration (one output at a time)
TOUT to GND ...........................................................Continuous
ROUT to GND...........................................................Continuous
Continuous Power Dissipation (TA= +70°C)
28-Pin Wide SO (derate 12.50mW/°C above +70°C) .............1W
40-Pin Plastic DIP (derate 11.11mW/°C above +70°C) ...611mW
44-Pin PLCC (derate 13.33mW/°C above +70°C) ...........1.07W
Operating Temperature Ranges
MAX225C_ _, MAX24_C_ _ ..................................0°C to +70°C
MAX225E_ _, MAX24_E_ _ ...............................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering,10s)) .................................+300°C
Soldering Temperature (reflow)
40 PDIP (P40M-2) ..........................................................+225°C
All other lead(Pb)-free packages...................................+260°C
All other packages containing lead(Pb) ........................+240°C
VCC = 0V,
VOUT = ±15V
µATables 1a–1d
±0.01 ±25
Normal operation
Shutdown
Tables 1a–1d, normal operation
All transmitter outputs loaded with 3kΩto GND
VENA, VENB, VENT, VENTA,
VENTB = VCC, VOUT = ±15V
VRS-232 Input Hysteresis
RS-232 Input Logic-Low Voltage V
V±5 ±7.5Output Voltage Swing
Output Leakage Current (Shutdown)
±0.01 ±25
Ω300 10MVCC = V+ = V- = 0V, VOUT = ±2V (Note 8)Transmitter Output Resistance
µA
PARAMETER
±0.05 ±0.10
MIN TYP MAX UNITS
Normal operation, outputs disabled,
Tables 1a–1d, 0V ≤VOUT ≤VCC, VENR_ = VCC
TTL/CMOS Output Leakage Current
10 30Sinking VOUT = VCC
mA
-2 -10Sourcing VOUT = VGND
V3.5 VCC - 0.2IOUT = -1.0mATTL/CMOS Output Voltage High
V0.2 0.4IOUT = 3.2mATTL/CMOS Output Voltage Low
kΩ357
0.2 0.5 1.0VCC = +5V
1.4 0.8 V
TTL/CMOS Output Short-Circuit Current
V1.8 2.4
0.8 1.3VCC = +5V
RS-232 Input Resistance
V±25RS-232 Input Voltage Operating Range
mA±7 ±30VOUT = 0VOutput Short-Circuit Current
kbps120 64Data Rate
CONDITIONS
VCC = +5V
µA
±0.01 ±1
Logic Pullup/lnput Current 10 50
Tables 1a–1d
RS-232 Input Logic-High Voltage
V2 1.4Input Logic-High Voltage
RS-232 TRANSMITTERS
RS-232 RECEIVERS
Note 6: Input voltage measured with transmitter output in a high-impedance state, shutdown, or VCC = 0V.
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 9www.maximintegrated.com
Supply Voltage Range 4.75 5.25 V
Transmitter Enable Time
MAX225 10 20
tET
No load MAX244–MAX249 11 30
51030
MAX225 40
VCC Supply Current
(Normal Operation) 3kΩloads on
all outputs MAX244–MAX249 57
mA
Transition Slew Rate
825
CL= 50pF to 2500pF, RL= 3kΩto 7kΩ, VCC = +5V,
TA= +25°C, measured from +3V to -3V or -3V to +3V
TA= TMIN to TMAX
CONDITIONS
50
V/µs
MAX246–MAX249
(excludes charge-pump startup)
Shutdown Supply Current µA
5
tPHLT, Figure 1 1.3 3.5
µs
tPLHT, Figure 1 1.5 3.5
Transmitter Disable Time
Transmitter Propagation Delay
TLL to RS-232 (Normal Operation) µs
tDT, Figure 4 100 ns
Transmitter + to - Propagation
Delay Difference (Normal Operation) tPHLT - tPLHT
UNITSMIN TYP MAX
350
PARAMETER
ns
Receiver + to - Propagation
Delay Difference (Normal Operation) tPHLR - tPLHR 350 ns
4.5 5.5MAX244–MAX249
MAX225
Leakage current ±1
Logic-low voltage 1.4 0.8
Control Input
Logic-high voltage 2.4 1.4 V
µA
TA= +25°C
tPHLR, Figure 2 0.6 1.5
tPLHR, Figure 2 0.6 1.5
Receiver Propagation Delay
TLL to RS-232 (Normal Operation) µs
tPHLS, Figure 2 0.6 10
tPLHS, Figure 2 3.0 10
Receiver Propagation Delay
TLL to RS-232 (Low-Power Mode) µs
Receiver-Output Enable Time tER, Figure 3 100 500 ns
Receiver-Output Disable Time tDR, Figure 3 100 500 ns
MAX225/MAX245–MAX249
(includes charge-pump startup) 10 ms
POWER SUPPLY AND CONTROL LOGIC
AC CHARACTERISTICS
Note 7: All units production tested at hot. Specifications over temperature are guaranteed by design.
Note 8: The 300Ωminimum specification complies with EIA/TIA-232E, but the actual resistance when in shutdown mode or VCC =
0V is 10MΩas is implied by the leakage specification.
Electrical Characteristics—MAX225/MAX244–MAX249 (continued)
(MAX225, VCC = +5.0V ±5%; MAX244–MAX249, VCC = +5.0V ±10%, external capacitors C1–C4 = 1µF; TA= TMIN to TMAX; unless
otherwise noted.) (Note 7)
Typical Operating Characteristics
MAX225/MAX244–MAX249
18
2
012345
TRANSMITTER SLEW RATE
vs. LOAD CAPACITANCE
8
6
4
16
MAX220-10
LOAD CAPACITANCE (nF)
TRANSMITTER SLEW RATE (V/μs)
14
12
10
VCC = +5V
EXTERNAL POWER SUPPLY
1μF CAPACITORS
40kb/s DATA RATE
8 TRANSMITTERS
LOADED WITH 3kΩ
10
-10
05 10 15 20 25 30 35
OUTPUT VOLTAGE
vs. LOAD CURRENT FOR V+ AND V-
-2
-4
-6
-8
8
MAX220-11
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
6
4
2
0
V+ AND V- LOADED
EITHER V+ OR
V- LOADED
V+ AND V- LOADED
VCC = +5V
EXTERNAL CHARGE PUMP
1μF CAPACITORS
8 TRANSMITTERS
DRIVING 5kΩ AND
2000pF AT 20kb/s
V- LOADED
V+ LOADED
9.0
5.0
012345
TRANSMITTER OUTPUT VOLTAGE (V+, V-)
vs. LOAD CAPACITANCE AT
DIFFERENT DATA RATES
6.0
5.5
8.5
MAX220-12
LOAD CAPACITANCE (nF)
V+, V- (V)
8.0
7.5
7.0
6.5
VCC = +5V WITH ALL TRANSMITTERS DRIVEN
LOADED WITH 5kΩ
40kb/s
60kb/s
100kb/s
200kb/s
ALL CAPACITIORS 1μF
10kb/s
20kb/s
Maxim Integrated | 10www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 11www.maximintegrated.com
INPUT
OUTPUT
+3V
V+
0V
V-
0V
tPLHT tPHLT
tPHLR
tPHLS
tPLHR
tPLHS
50%
VCC
50%
+3V
50%
INPUT
OUTPUT
*EXCEPT FOR R2 ON THE MAX243
WHERE -3V IS USED.
0V*
50%
GND
Figure 1. Transmitter Propagation-Delay Timing Figure 2. Receiver Propagation-Delay Timing
EN
RX IN
a) TEST CIRCUIT
b) ENABLE TIMING
c) DISABLE TIMING
EN INPUT
RECEIVER
OUTPUTS
RX OUT
RX
1kΩ
0V
+3V
EN
EN
+0.8V
+3.5V
OUTPUT ENABLE TIME (tER)
VCC - 2V
VOL + 0.5V
VOH - 0.5V
OUTPUT DISABLE TIME (tDR)
VCC - 2V
+3V
0V
150pF
EN INPUT
VOH
RECEIVER
OUTPUTS
VOL
1 OR 0 TX
3kΩ50pF
-5V
+5V
OUTPUT DISABLE TIME (tDT)
V+
SHDN +3V
0V
V-
0V
a) TIMING DIAGRAM
b) TEST CIRCUIT
Figure 3. Receiver-Output Enable and Disable Timing Figure 4. Transmitter-Output Disable Timing
Test Circuits/Timing Diagrams
Maxim Integrated | 12www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
ENT ENR OPERATION STATUS TRANSMITTERS RECEIVERS
0 0 Normal Operation All Active All Active
0 1 Normal Operation All Active All High-Z
1 0 Shutdown All High-Z All Low-Power Receive Mode
1 1 Shutdown All High-Z All High-Z
Table 1a. MAX245 Control Pin Configurations
ENT ENR OPERATION
STATUS
TRANSMITTERS RECEIVERS
TA1–TA4 TB1–TB4 RA1–RA5 RB1–RB5
0 0 Normal Operation All Active All Active All Active All Active
0 1 Normal Operation All Active All Active RA1–RA4 High-Z,
RA5 Active
RB1–RB4 High-Z,
RB5 Active
1 0 Shutdown All High-Z All High-Z All Low-Power
Receive Mode
All Low-Power
Receive Mode
1 1 Shutdown All High-Z All High-Z
RA1–RA4 High-Z,
RA5 Low-Power
Receive Mode
RB1–RB4 High-Z,
RB5 Low-Power
Receive Mode
Table 1b. MAX245 Control Pin Configurations
Table 1c. MAX246 Control Pin Configurations
ENA ENB OPERATION
STATUS
TRANSMITTERS RECEIVERS
TA1–TA4 TB1–TB4 RA1–RA5 RB1–RB5
0 0 Normal Operation All Active All Active All Active All Active
0 1 Normal Operation All Active All High-Z All Active RB1–RB4 High-Z,
RB5 Active
1 0 Shutdown All High-Z All Active RA1–RA4 High-Z,
RA5 Active All Active
1 1 Shutdown All High-Z All High-Z
RA1–RA4 High-Z,
RA5 Low-Power
Receive Mode
RB1–RB4 High-Z,
RA5 Low-Power
Receive Mode
Control Pin Configuration Tables
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 13www.maximintegrated.com
TA1–TA4 TB1–TB4 RA1–RA4 RB1–RB4
0 0 0 0 Normal Operation All Active All Active All Active All Active
0 0 0 1 Normal Operation All Active All Active All Active
All High-Z, except
RB5 stays active on
MAX247
0 0 1 0 Normal Operation All Active All Active All High-Z All Active
0 0 1 1 Normal Operation All Active All Active All High-Z
All High-Z, except
RB5 stays active on
MAX247
0 1 0 0 Normal Operation All Active All High-Z All Active All Active
0 1 0 1 Normal Operation All Active All High-Z All Active
All High-Z, except
RB5 stays active on
MAX247
0 1 1 0 Normal Operation All Active All High-Z All High-Z All Active
0 1 1 1 Normal Operation All Active All High-Z All High-Z
All High-Z, except
RB5 stays active on
MAX247
1 0 0 0 Normal Operation All High-Z All Active All Active All Active
1 0 0 1 Normal Operation All High-Z All Active All Active
All High-Z, except
RB5 stays active on
MAX247
1 0 1 0 Normal Operation All High-Z All Active All High-Z All Active
1 0 1 1 Normal Operation All High-Z All Active All High-Z
All High-Z, except
RB5 stays active on
MAX247
1 1 0 0 Shutdown All High-Z All High-Z Low-Power
Receive Mode
Low-Power
Receive Mode
1 1 0 1 Shutdown All High-Z All High-Z Low-Power
Receive Mode
All High-Z, except
RB5 stays active on
MAX247
1 1 1 0 Shutdown All High-Z All High-Z All High-Z Low-Power
Receive Mode
1 1 1 1 Shutdown All High-Z All High-Z All High-Z
All High-Z, except
RB5 stays active on
MAX247
Table 1d. MAX247/MAX248/MAX249 Control Pin Configurations
MAX248
OPERATION
STATUS
ENRB MAX247 TA1–TA4 TB1–TB4 RA1–RA4 RB1–RB5
TRANSMITTERS
ENRAENTBENTA
MAX249 TA1–TA3 TB1–TB3 RA1–RA5 RB1–RB5
RECEIVERS
Maxim Integrated | 14www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Detailed Description
The MAX220–MAX249 contain four sections: dual
charge-pump DC-DC voltage converters, RS-232 dri-
vers, RS-232 receivers, and receiver and transmitter
enable control inputs.
Dual Charge-Pump Voltage Converter
The MAX220–MAX249 have two internal charge-pumps
that convert +5V to ±10V (unloaded) for RS-232 driver
operation. The first converter uses capacitor C1 to dou-
ble the +5V input to +10V on C3 at the V+ output. The
second converter uses capacitor C2 to invert +10V to
-10V on C4 at the V- output.
A small amount of power may be drawn from the +10V
(V+) and -10V (V-) outputs to power external circuitry
(see the
Typical Operating Characteristics
section),
except on the MAX225 and MAX245–MAX247, where
these pins are not available. V+ and V- are not regulated,
so the output voltage drops with increasing load current.
Do not load V+ and V- to a point that violates the mini-
mum ±5V EIA/TIA-232E driver output voltage when
sourcing current from V+ and V- to external circuitry.
When using the shutdown feature in the MAX222,
MAX225, MAX230, MAX235, MAX236, MAX240,
MAX241, and MAX245–MAX249, avoid using V+ and V-
to power external circuitry. When these parts are shut
down, V- falls to 0V, and V+ falls to +5V. For applica-
tions where a +10V external supply is applied to the V+
pin (instead of using the internal charge pump to gen-
erate +10V), the C1 capacitor must not be installed and
the SHDN pin must be connected to VCC. This is
because V+ is internally connected to VCC in shutdown
mode.
RS-232 Drivers
The typical driver output voltage swing is ±8V when
loaded with a nominal 5kΩRS-232 receiver and VCC =
+5V. Output swing is guaranteed to meet the EIA/TIA-
232E and V.28 specification, which calls for ±5V mini-
mum driver output levels under worst-case conditions.
These include a minimum 3kΩload, VCC = +4.5V, and
maximum operating temperature. Unloaded driver out-
put voltage ranges from (V+ -1.3V) to (V- +0.5V).
Input thresholds are both TTL and CMOS compatible.
The inputs of unused drivers can be left unconnected
since 400kΩinput pullup resistors to VCC are built in
(except for the MAX220). The pullup resistors force the
outputs of unused drivers low because all drivers invert.
The internal input pullup resistors typically source 12µA,
except in shutdown mode where the pullups are dis-
abled. Driver outputs turn off and enter a high-imped-
ance state—where leakage current is typically
microamperes (maximum 25µA)—when in shutdown
mode, in three-state mode, or when device power is
removed. Outputs can be driven to ±15V. The power-
supply current typically drops to 8µA in shutdown mode.
The MAX220 does not have pullup resistors to force the
outputs of the unused drivers low. Connect unused
inputs to GND or VCC.
The MAX239 has a receiver three-state control line, and
the MAX223, MAX225, MAX235, MAX236, MAX240,
and MAX241 have both a receiver three-state control
line and a low-power shutdown control. Table 2 shows
the effects of the shutdown control and receiver three-
state control on the receiver outputs.
The receiver TTL/CMOS outputs are in a high-imped-
ance, three-state mode whenever the three-state enable
line is high (for the MAX225/MAX235/MAX236/MAX239–
MAX241), and are also high-impedance whenever the
shutdown control line is high.
When in low-power shutdown mode, the driver outputs
are turned off and their leakage current is less than 1µA
with the driver output pulled to ground. The driver output
leakage remains less than 1µA, even if the transmitter
output is backdriven between 0V and (VCC + 6V). Below
-0.5V, the transmitter is diode clamped to ground with
1kΩseries impedance. The transmitter is also zener
clamped to approximately VCC + 6V, with a series
impedance of 1kΩ.
The driver output slew rate is limited to less than 30V/µs
as required by the EIA/TIA-232E and V.28 specifica-
tions. Typical slew rates are 24V/µs unloaded and
10V/µs loaded with 3Ωand 2500pF.
RS-232 Receivers
EIA/TIA-232E and V.28 specifications define a voltage
level greater than 3V as a logic 0, so all receivers invert.
Input thresholds are set at 0.8V and 2.4V, so receivers
respond to TTL level inputs as well as EIA/TIA-232E and
V.28 levels.
PART SHDN EN EN(R) RECEIVERS
MAX223 __
Low
High
High
X
Low
High
High Impedance
Active
High Impedance
MAX225 __ __ High Impedance
Active
__
MAX235
MAX236
MAX240
Low
Low
High
__ __
Low
High
X
High Impedance
Active
High Impedance
Table 2. Three-State Control of
Receivers
Low
High
SHDN
__
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 15www.maximintegrated.com
The receiver inputs withstand an input overvoltage up
to ±25V and provide input terminating resistors with
nominal 5kΩvalues. The receivers implement Type 1
interpretation of the fault conditions of V.28 and
EIA/TIA-232E.
The receiver input hysteresis is typically 0.5V with a
guaranteed minimum of 0.2V. This produces clear out-
put transitions with slow-moving input signals, even
with moderate amounts of noise and ringing. The
receiver propagation delay is typically 600ns and is
independent of input swing direction.
Low-Power Receive Mode
The low-power receive mode feature of the MAX223,
MAX242, and MAX245–MAX249 puts the IC into shut-
down mode but still allows it to receive information. This
is important for applications where systems are periodi-
cally awakened to look for activity. Using low-power
receive mode, the system can still receive a signal that
will activate it on command and prepare it for communi-
cation at faster data rates. This operation conserves
system power.
Negative Threshold—MAX243
The MAX243 is pin compatible with the MAX232A, differ-
ing only in that RS-232 cable fault protection is removed
on one of the two receiver inputs. This means that control
lines such as CTS and RTS can either be driven or left
unconnected without interrupting communication.
Different cables are not needed to interface with different
pieces of equipment.
The input threshold of the receiver without cable fault
protection is -0.8V rather than +1.4V. Its output goes
positive only if the input is connected to a control line
that is actively driven negative. If not driven, it defaults
to the 0 or “OK to send” state. Normally‚ the MAX243’s
other receiver (+1.4V threshold) is used for the data line
(TD or RD)‚ while the negative threshold receiver is con-
nected to the control line (DTR‚ DTS‚ CTS‚ RTS, etc.).
Other members of the RS-232 family implement the
optional cable fault protection as specified by EIA/TIA-
232E specifications. This means a receiver output goes
high whenever its input is driven negative‚ left uncon-
nected‚ or shorted to ground. The high output tells the
serial communications IC to stop sending data. To
avoid this‚ the control lines must either be driven or
connected with jumpers to an appropriate positive volt-
age level.
Shutdown—MAX222–MAX242
On the MAX222‚ MAX235‚ MAX236‚ MAX240‚ and
MAX241‚ all receivers are disabled during shutdown.
On the MAX223 and MAX242‚ two receivers continue to
operate in a reduced power mode when the chip is in
shutdown. Under these conditions‚ the propagation
delay increases to about 2.5µs for a high-to-low input
transition. When in shutdown, the receiver acts as a
CMOS inverter with no hysteresis. The MAX223 and
MAX242 also have a receiver output enable input (EN
for the MAX242 and EN for the MAX223) that allows
receiver output control independent of SHDN (SHDN
for MAX241). With all other devices‚ SHDN (SHDN for
MAX241) also disables the receiver outputs.
The MAX225 provides five transmitters and five
receivers‚ while the MAX245 provides ten receivers and
eight transmitters. Both devices have separate receiver
and transmitter-enable controls. The charge pumps
turn off and the devices shut down when a logic high is
applied to the ENT input. In this state, the supply cur-
rent drops to less than 25µA and the receivers continue
to operate in a low-power receive mode. Driver outputs
enter a high-impedance state (three-state mode). On
the MAX225‚ all five receivers are controlled by the
ENR input. On the MAX245‚ eight of the receiver out-
puts are controlled by the ENR input‚ while the remain-
ing two receivers (RA5 and RB5) are always active.
RA1–RA4 and RB1–RB4 are put in a three-state mode
when ENR is a logic high.
Receiver and Transmitter Enable
Control Inputs
The MAX225 and MAX245–MAX249 feature transmitter
and receiver enable controls.
The receivers have three modes of operation: full-speed
receive (normal active)‚ three-state (disabled)‚ and low-
power receive (enabled receivers continue to function
at lower data rates). The receiver enable inputs control
the full-speed receive and three-state modes. The
transmitters have two modes of operation: full-speed
transmit (normal active) and three-state (disabled). The
transmitter enable inputs also control the shutdown
mode. The device enters shutdown mode when all
transmitters are disabled. Enabled receivers function in
the low-power receive mode when in shutdown.
Maxim Integrated | 16www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Tables 1a–1d define the control states. The MAX244
has no control pins and is not included in these tables.
The MAX246 has ten receivers and eight drivers with
two control pins, each controlling one side of the
device. A logic high at the A-side control input (ENA)
causes the four A-side receivers and drivers to go into
a three-state mode. Similarly, the B-side control input
(ENB) causes the four B-side drivers and receivers to
go into a three-state mode. As in the MAX245, one A-
side and one B-side receiver (RA5 and RB5) remain
active at all times. The entire device is put into shut-
down mode when both the A and B sides are disabled
(ENA = ENB = +5V).
The MAX247 provides nine receivers and eight drivers
with four control pins. The ENRA and ENRB receiver
enable inputs each control four receiver outputs. The
ENTA and ENTB transmitter enable inputs each control
four drivers. The ninth receiver (RB5) is always active.
The device enters shutdown mode with a logic high on
both ENTA and ENTB.
The MAX248 provides eight receivers and eight drivers
with four control pins. The ENRA and ENRB receiver
enable inputs each control four receiver outputs. The
ENTA and ENTB transmitter enable inputs control four
drivers each. This part does not have an always-active
receiver. The device enters shutdown mode and trans-
mitters go into a three-state mode with a logic high on
both ENTA and ENTB.
The MAX249 provides ten receivers and six drivers with
four control pins. The ENRA and ENRB receiver enable
inputs each control five receiver outputs. The ENTA
and ENTB transmitter enable inputs control three dri-
vers each. There is no always-active receiver. The
device enters shutdown mode and transmitters go into
a three-state mode with a logic high on both ENTA and
ENTB. In shutdown mode, active receivers operate in a
low-power receive mode at data rates up to 20kb/s.
Applications Information
Figures 5 through 25 show pin configurations and typi-
cal operating circuits. In applications that are sensitive
to power-supply noise, VCC should be decoupled to
ground with a capacitor of the same value as C1 and
C2 connected as close as possible to the device.
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 17www.maximintegrated.com
TOP VIEW
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
VCC
GND
T1OUT
R1IN
C2+
C1-
V+
C1+ +
MAX220
MAX232
MAX232A R1OUT
T1IN
T2IN
R2OUT
R2IN
T2OUT
V-
C2-
DIP/SO
V+
V-
2+10V
C1+
C1
C2
1
3
4
5
11
10
12
9
6
14
7
13
8
T1IN
R1OUT
T2IN
R2OUT
T1OUT
R1IN
T2OUT
R2IN
+5V INPUT
C2+ -10V
C4
RS-232
OUTPUTS
RS-232
INPUTS
TTL/CMOS
INPUTS
TTL/CMOS
OUTPUTS
GND
15
5kΩ
5kΩ
400kΩ
400kΩ
+5V
+5V
+10V TO -10V
VOLTAGE INVERTER
+5V TO +10V
VOLTAGE DOUBLER
16
C3
C5
CAPACITANCE (μF)
DEVICE
MAX220
MAX232
MAX232A
C1
0.047
1.0
0.1
C2
0.33
1.0
0.1
C3
0.33
1.0
0.1
C4
0.33
1.0
0.1
C5
0.33
1.0
0.1
C2-
C1-
VCC
5kΩ
DIP/SO
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
SHDN
VCC
GND
T1OUT
C1-
V+
C1+
(N.C.) EN
R1IN
R1OUT
T1IN
T2IN
T2OUT
V-
C2-
C2+
10
9R2OUT
R2IN
MAX222
MAX242
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
SHDN
VCC
GND
T1OUT
C1-
V+
C1+
(N.C.) EN
N.C.
R1IN
R1OUT
N.C.
T2OUT
V-
C2-
C2+
12
11
9
10
T1IN
T2IN
R2OUT
R2IN
MAX222
MAX242
SSOP
( ) ARE FOR MAX222 ONLY.
PIN NUMBERS IN TYPICAL OPERATING CIRCUIT ARE FOR DIP/SO PACKAGES ONLY.
V+
V-
3+10V
C1
C2
2
4
5
6
12
11
13
7
15
8
14
9
T1IN
R1OUT
T2IN
R2OUT
T1OUT
(EXCEPT MAX220)
(EXCEPT MAX220)
R1IN
T2OUT
R2IN
+5V INPUT
C2+ -10V
C4
RS-232
OUTPUTS
RS-232
INPUTS
TTL/CMOS
INPUTS
TTL/CMOS
OUTPUTS
GND
16
5kΩ
400kΩ
400kΩ
+5V
+5V
+10V TO -10V
VOLTAGE INVERTER
VCC
+5V TO +10V
VOLTAGE DOUBLER
17
C3
C5
1
10
18
SHDN
EN
(N.C.)
ALL CAPACITORS = 0.1μF
C2-
C1+
C1-
+
+
TOP VIEW
Figure 5. MAX220/MAX232/MAX232A Pin Configuration and Typical Operating Circuit
Figure 6. MAX222/MAX242 Pin Configurations and Typical Operating Circuit
Maxim Integrated | 18www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
13
14
28
27
26
25
24
23
22
21
1
2
3
4
5
6
7
8
VCC
VCC VCC
400kΩ
400kΩ
400kΩ
400kΩ
400kΩ
T1OUT
+5V
+5V
0.1μF
+5V
3
28 27
4
25
24
23
26
5
6
7
22
GND
ENR
ENR
GND
21
+5V
+5V
+5V
T2OUT
T3OUT
T4OUT
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
14
13
2
1
T5OUT
T5OUT
R1IN
R2IN
R3IN
R4IN
R5IN
T1IN 11
12
18
17
16
15
10
9
8
19
20
T2IN
T3IN
T4IN
T5IN
ENT
R2OUT
R3OUT
R4OUT
PINS (ENR, GND, VCC, T5OUT) ARE INTERNALLY CONNECTED.
CONNECT EITHER OR BOTH EXTERNALLY. T5OUT IS A SINGLE DRIVER.
R5OUT
R1OUT
VCC
ENT
T3IN
T2IN
T1IN
ENR
ENR
T4IN
T5IN
R4OUT
R5OUT
R3IN
R3OUT
R2OUT
R1OUT
20
19
18
17
9
10
11
12
R5IN
R4IN
T3OUT
T4OUT
T2OUT
T1OUT
R1IN
R2IN
SO
MAX225
16
15
T5OUT
MAX225 FUNCTIONAL DESCRIPTION
5 RECEIVERS
5 TRANSMITTERS
2 CONTROL PINS
1 RECEIVER ENABLE (ENR)
1 TRANSMITTER ENABLE (ENT)
T5OUT
GND
GND
TOP VIEW
+
Figure 7. MAX225 Pin Configuration and Typical Operating Circuit
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
Maxim Integrated | 19www.maximintegrated.com
GND
10
27R3OUT
23
R4OUT
R3IN
R4IN
5kΩ
5kΩ
54
R2OUT R2IN
5kΩ
RS-232
INPUTS
LOGIC
OUTPUTS
RS-232
OUTPUTS
TTL/CMOS
INPUTS
R2
89
R1OUT R1IN
5kΩ
R1
R3
R4
19 18
R5OUT R5IN
5kΩ
R5
2
7T1IN T1OUT
+5V
400kΩ
+5V
63
T2IN T2OUT
T2
400kΩ
20 T3OUT 1
T3IN
+5V
T3
400kΩ
C1+
C1-
1.0μF
12 VCC
+5V INPUT
11
17
1.0μF
13
1.0μF
+5V TO +10V
VOLTAGE DOUBLER
26
1.0μF
T1
28
21 T4IN T4OUT
+5V
400kΩ
T4
14
C2+
C2-
15
1.0μF16
+10V TO -10V
VOLTAGE INVERTER
V+
22
EN (EN)
24 25
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
T4OUT
R3IN
R3OUT
SHDN (SHDN)
R4IN*
C2+
R4OUT*
T4IN
T3IN
R5OUT*
R5IN*
V-
C2-
C1-
V+
C1+
VCC
GND
R1IN
R1OUT
T1IN
T2IN
R2OUT
R2IN
T2OUT
T1OUT
T3OUT
Wide SO/
SSOP
MAX223
MAX241
EN (EN)
SHDN
(SHDN)
*R4 AND R5 IN MAX223 REMAIN ACTIVE IN SHUTDOWN.
NOTE: PIN LABELS IN ( ) ARE FOR MAX241.
V-
+
TOP VIEW
Figure 8. MAX223/MAX241 Pin Configuration and Typical Operating Circuit
Maxim Integrated | 20www.maximintegrated.com
MAX220–MAX249 +5V-Powered, Multichannel
RS-232 Drivers/Receivers
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
T5IN
N.C.
SHDN
T2IN
T2OUT
T1OUT
T5OUT
T4IN
T3IN
V-
C1+
VCC
GND
T1IN
12
11
9
10
C2-
C2+
C1-
V+
DIP/SO
MAX230
V+
V-
9
C1+
C1-
8
10
11
12
5
4
14
13
2
3
1
20
T3IN
T4IN
T2IN
T5IN
T1OUT
T2OUT
+5V INPUT
C2+
C2-
RS-232
OUTPUTS
TTL/CMOS
INPUTS
GND
6
400kΩ
+5V
400kΩ
+5V
400kΩ
+5V
400kΩ
+5V
400kΩ
+5V
+10V TO -10V
VOLTAGE INVERTER
VCC
+5V TO +10V
VOLTAGE DOUBLER
7
1.0μF
1.0μF
1.0μF
1.0μF
19
15
16
T3OUT T4OUT
18
x
T1IN
T3OUT
T4OUT
T5OUT
17
1.0μF
T2
T3
T4
T5
N.C. SHDN
T1
+
TOP VIEW
Figure 9. MAX230 Pin Configuration and Typical Operating Circuit
V+
V-
14
C1+
C1-
1
2
8
7
3
11
4
T2IN
T1IN T1OUT
T2OUT
+5V INPUT
RS-232
INPUTS
TTL/CMOS
OUTPUTS
GND
12 (14)
5kΩ
5kΩ
+12V TO -12V
VOLTAGE CONVERTER
13 (15)
1.0μF
1.0μF
C2
1.0μF
400kΩ
+5V
400kΩ
+5V
6
910
R1IN
R2IN
R2OUT
R1OUT
5
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
V+
VCC
GND
T1OUT
T2OUT
V-
C-
C+
MAX231
R1IN
R1OUT
T1IN
N.C.
N.C.
T2IN
R2OUT
R2IN
SO
(12)
RS-232
OUTPUTS
TTL/CMOS
INPUTS
(11)
(13)(10)
VCC
PIN NUMBERS IN ( ) ARE FOR SO PACKAGE.
14
13
12
11
10
9
8
1
2
3
4
5
6
7
V+
VCC
GND
T1OUTT2OUT
V-
C-
C+
MAX231
R1IN
R1OUT
T1INT2IN
R2OUT
R2IN
DIP
+7.5V TO +12V
(16)
T1
T2
R1
R2
++
TOP VIEW
Figure 10. MAX231 Pin Configurations and Typical Operating Circuit