MAXIM MAX3244EEWI

19-1339; Rev 2; 8/00
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
____________________________Features
♦ ESD Protection for RS-232 I/O Pins:
±15kV—Human Body Model
±8kV—IEC 1000-4-2, Contact Discharge
±15kV—IEC 1000-4-2, Air-Gap Discharge
♦ Latchup Free
♦ 1µA Supply Current
♦ AutoShutdown Plus—EDN Innovation of the Year
♦ Guaranteed Data Rate:
250kbps (MAX3224E/3226E/3244E)
1Mbps (MAX3225E/3227E/3245E)
♦ Guaranteed Slew Rate:
6V/µs (MAX3224E/3226E/3244E)
24V/µs (MAX3225E/3227E/3245E)
♦ Meets EIA/TIA-232 Specifications Down to 3.0V
♦ Guaranteed Mouse Driveability
(MAX3244E/3245E)
♦ Ready-to-Transmit Logic-Level Output
All devices achieve a 1µA supply current using Maxim’s
revolutionary AutoShutdown Plus™ feature. These
devices automatically enter a low-power shutdown
mode when the RS-232 cable is disconnected or the
transmitters of the connected peripherals are inactive,
and the UART driving the transmitter inputs is inactive
for more than 30 seconds. They turn on again when
they sense a valid transition at any transmitter or receiver input. AutoShutdown Plus saves power without
changes to the existing BIOS or operating system.
The MAX3225E/MAX3227E/MAX3245E also feature
MegaBaud™ operation, guaranteeing 1Mbps for highspeed applications such as communicating with ISDN
modems. The MAX3224E/MAX3226E/MAX3244E guarantee 250kbps operation. The transceivers have a proprietary low-dropout transmitter output stage enabling
true RS-232 performance from a +3.0V to +5.5V supply
with a dual charge pump. The charge pump requires
only four small 0.1µF capacitors for operation from a
3.3V supply. The MAX3224E–MAX3227E feature a logiclevel output (READY) that asserts when the charge
pump is regulating and the device is ready to begin
transmitting.
All devices are available in a space-saving SSOP and
TSSOP (MAX3224E/MAX3225E) packages.
________________________Applications
Notebook, Subnotebook, and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Ordering Information
PART
PIN-PACKAGE
MAX3224ECUP
0°C to +70°C
20 TSSOP
MAX3224ECAP
0°C to +70°C
20 SSOP
MAX3224ECPP
0°C to +70°C
20 Plastic DIP
MAX3224EEUP
-40°C to +85°C
20 TSSOP
MAX3224EEAP
-40°C to +85°C
20 SSOP
MAX3224EEPP
-40°C to +85°C
20 Plastic DIP
MAX3225ECUP
0°C to +70°C
20 TSSOP
MAX3225ECAP
0°C to +70°C
20 SSOP
MAX3225ECPP
0°C to +70°C
20 Plastic DIP
MAX3225EEUP
-40°C to +85°C
20 TSSOP
MAX3225EEAP
-40°C to +85°C
20 SSOP
MAX3225EEPP
-40°C to +85°C
20 Plastic DIP
Ordering Information continued at end of data sheet.
_____________________ Selector Guide
Hand-Held Equipment
PART
Peripherals
TEMP. RANGE
NO. OF
GUARANTEED
READY
DRIVERS/
DATA RATE
OUTPUT
RECEIVERS
(bps)
AutoShutdown
Plus
Printers
AutoShutdown Plus and MegaBaud are trademarks of
Maxim Integrated Products.
†Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577;
4,797,899; 4,809,152; 4,897,774; 4,999,761; 5,649,210; and other
patents pending.
MAX3224E
2/2
250k
✔
✔
MAX3225E
MAX3226E
MAX3227E
2/2
1/1
1/1
1M
250k
1M
✔
✔
✔
✔
✔
✔
MAX3244E
MAX3245E
3/5
3/5
250k
1M
—
—
✔
✔
________________________________________________________________ Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
________________General Description
The MAX3224E/MAX3225E/MAX3226E/MAX3227E/
MAX3244E/MAX3245E are 3V-powered EIA/TIA-232
and V.28/V.24 communications interfaces with automatic shutdown/wakeup features, high data-rate capabilities, and enhanced electrostatic discharge (ESD)
protection. All transmitter outputs and receiver inputs
are protected to ±15kV using IEC 1000-4-2 Air-Gap
Discharge, ±8kV using IEC 1000-4-2 Contact Discharge,
and ±15kV using the Human Body Model.
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
ABSOLUTE MAXIMUM RATINGS
VCC to GND ..............................................................-0.3V to +6V
V+ to GND (Note 1) ..................................................-0.3V to +7V
V- to GND (Note 1) ...................................................+0.3V to -7V
V+ + V-(Note 1) ................................................................+13V
Input Voltages
T_IN, FORCEON, FORCEOFF to GND ................ -0.3V to +6V
R_IN to GND ....................................................................±25V
Output Voltages
T_OUT to GND.............................................................±13.2V
R_OUT, INVALID, READY to GND .........-0.3V to (VCC + 0.3V)
Short-Circuit Duration
T_OUT to GND .......................................................Continuous
Continuous Power Dissipation (TA = +70°C)
16-Pin SSOP (derate 7.14mW/°C above +70°C) .........571mW
20-Pin Plastic DIP (derate 11.11mW/°C above +70°C) ...889mW
20-Pin SSOP (derate 8.00mW/°C above +70°C) .........640mW
20-Pin TSSOP (derate 10.9mW/°C above +70°C) .......879mW
28-Pin Wide SO (derate 12.5mW/°C above +70°C)............1W
28-Pin SSOP (derate 9.52mW/°C above +70°C) .........762mW
Operating Temperature Ranges
MAX32_ _EC_ _ .................................................0°C to +70°C
MAX32_ _EE_ _................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
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
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; CL = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA = TMIN to TMAX,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS (VCC = 3.3V or 5.0V, TA = +25°C)
Supply Current,
AutoShutDown Plus
FORCEON = GND, FORCEOFF = VCC,
all R_IN idle, all T_IN idle
1
10
µA
Supply Current, Shutdown
FORCEOFF = GND
1
10
µA
Supply Current,
AutoShutDown Plus Disabled
FORCEON = FORCEOFF = VCC, no load
0.3
1
mA
0.8
V
LOGIC INPUTS AND RECEIVER OUTPUTS
Input Logic Threshold Low
T_IN, FORCEON, FORCEOFF
Input Logic Threshold High
T_IN, FORCEON,
FORCEOFF
VCC = 3.3V
2
VCC = 5.0V
2.4
Transmitter Input Hysteresis
V
0.5
V
Input Leakage Current
T_IN, FORCEON, FORCEOFF
±0.01
±1
µA
Output Leakage Current
R_OUT (MAX3244E/MAX3245E), receivers
disabled
±0.05
±10
µA
Output Voltage Low
IOUT = 1.6mA
0.4
V
Output Voltage High
IOUT = -1.0mA
VCC - 0.6 VCC - 0.1
V
RECEIVER INPUTS
Input Voltage Range
-25
Input Threshold Low
TA = +25°C
Input Threshold High
TA = +25°C
VCC = 3.3V
0.6
1.2
VCC = 5.0V
0.8
1.5
1.5
2.4
VCC = 5.0V
1.8
2.4
2
0.5
TA = +25°C
3
5
_______________________________________________________________________________________
V
V
VCC = 3.3V
Input Hysteresis
Input Resistance
+25
V
V
7
kΩ
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; CL = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA = TMIN to TMAX,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TRANSMITTER OUTPUTS
Output Voltage Swing
All transmitter outputs loaded with 3kΩ to
ground
±5
±5.4
Output Resistance
VCC = V+ = V- = 0, transmitter outputs = ±2V
300
10M
Output Short-Circuit Current
VCC = 0 or 3V to 5.5V, VOUT = ±12V,
Transmitters disabled
Output Leakage Current
V
Ω
±60
mA
±25
µA
MOUSE DRIVEABILITY (MAX3244E/MAX3245E)
T1IN = T2IN = GND, T3IN = VCC,
T3OUT loaded with 3kΩ to GND,
T1OUT and T2OUT loaded with
2.5mA each
Transmitter Output Voltage
±5
V
ESD PROTECTION
R_IN, T_OUT
IEC1000-4-2 Air Discharge
±15
IEC1000-4-2 Contact Discharge
±8
Human Body Model
±15
kV
AutoShutdown Plus (FORCEON = GND, FORCEOFF = VCC)
Receiver Input Threshold to
INVALID Output High
Figure 4a
Receiver Input Threshold to
INVALID Output Low
Figure 4a
INVALID, READY
Output Voltage Low
(MAX3224E–MAX3227E)
IOUT = -1.6mA
INVALID, READY
Output Voltage High
(MAX3224E–MAX3227E)
IOUT = -1.0mA
Positive threshold
Negative threshold
2.7
-2.7
-0.3
V
0.3
V
0.4
V
VCC - 0.6
V
Receiver Positive or Negative
Threshold to INVALID High
tINVH
VCC = 5V, Figure 4b
1
µs
Receiver Positive or Negative
Threshold to INVALID Low
tINVL
VCC = 5V, Figure 4b
30
µs
Receiver or Transmitter Edge to
Transmitters Enabled
tWU
VCC = 5V, Figure 5b (Note 2)
100
µs
Receiver or Transmitter Edge to
tAUTOSHDN VCC = 5V, Figure 5b (Note 2)
Transmitters Shutdown
15
30
60
sec
_______________________________________________________________________________________
3
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
ELECTRICAL CHARACTERISTICS (continued)
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
TIMING CHARACTERISTICS—MAX3224E/MAX3226E/MAX3244E
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; CL = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA = TMIN to TMAX,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Maximum Data Rate
Receiver Propagation Delay
CONDITIONS
MIN
RL = 3kΩ, CL = 1000pF,
one transmitter switching
tPHL
tPLH
TYP
MAX
250
kbps
0.15
R_IN to R_OUT, CL = 150pF
UNITS
µs
0.15
Receiver Output Enable Time
Normal operation (MAX3244E only)
200
ns
Receiver Output Disable Time
Normal operation (MAX3244E only)
200
ns
(Note 3)
100
ns
50
ns
Transmitter Skew
Receiver Skew
 tPHL - tPLH 
 tPHL - tPLH 
VCC = 3.3V, TA = +25°C,
RL = 3kΩ to 7kΩ,
measured from +3V to -3V
or -3V to +3V, one transmitter switching
Transition-Region Slew Rate
CL = 150pF
to 1000pF
6
30
CL = 150pF
to 2500pF
4
30
V/µs
TIMING CHARACTERISTICS—MAX3225E/MAX3227E/MAX3245E
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; CL = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA = TMIN to TMAX,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Maximum Data Rate
Receiver Propagation Delay
tPHL
tPLH
CONDITIONS
MIN
RL = 3kΩ, CL = 1000pF,
one transmitter switching
250
VCC = 3.0V to 4.5V, RL = 3kΩ,
CL = 250pF, one transmitter switching
1000
VCC = 4.5V to 5.5V, RL = 3kΩ,
CL = 1000pF, one transmitter switching
1000
R_IN to R_OUT, CL = 150pF
TYP
MAX
UNITS
kbps
0.15
0.15
µs
Receiver Output Enable Time
Normal operation (MAX3245E only)
200
ns
Receiver Output Disable Time
Normal operation (MAX3245E only)
200
ns
(Note 3)
25
ns
Transmitter Skew
 tPHL - tPLH 
Receiver Skew
 tPHL - tPLH 
50
VCC = 3.3V, TA = +25°C,
RL = 3kΩ to 7kΩ, CL = 150pF to 1000pF,
Transition-Region Slew Rate
24
150
measured from +3V to -3V or -3V to +3V,
one transmitter switching
Note 2: A transmitter/receiver edge is defined as a transition through the transmitter/receiver input logic thresholds.
Note 3: Transmitter skew is measured at the transmitter zero cross points.
4
_______________________________________________________________________________________
ns
V/µs
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
-SLEW
10
+SLEW
8
6
4
2000
3000
4000
1000
2000
3000
4000
5000
0
1000
2000
MAX3225E/MAX3227E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
60
-SLEW
50
+SLEW
40
30
1 TRANSMITTER AT FULL DATA RATE
1 TRANSMITTER AT 1/16 DATA RATE
(MAX3225E)
LOAD = 3kΩ + CL
90
80
70
2Mbps
60
50
1.5Mbps
40
30
1Mbps
20
1 TRANSMITTER AT 1Mbps
1 TRANSMITTER AT 62.5kbps (MAX3225E)
10
10
0
1000
1500
2000
0
0
2500
500
35
30
25
20
AVERAGE; 10 PARTS
15
32
30
28
26
22
0
20
1000
1500
2000
LOAD CAPACITANCE (pF)
2500
3000
500
1000
1500
2000
MAX3224E–MAX3227E
READY TURN-OFF TIME
vs. TEMPERATURE
34
5
0
MAX3224E–MAX3227E
READY TURN-ON TIME
vs. TEMPERATURE
36
10
500
2500
LOAD CAPACITANCE (pF)
38
24
0
2000
MAX3224-7/44/45E-08
1 TRANSMITTER AT 512kbps
1 TRANSMITTER AT 30kbps
(MAX3225E)
LOAD = 3kΩ + CL
READY TURN-ON TIME (µs)
MAX3224-7/44/45E-07
50
1500
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3225E/MAX3227E
TRANSMITTER SKEW vs.
LOAD CAPACITANCE
1000
200
2500
MAX3224-7/44/45E-09
500
180
READY TURN-OFF TIME (ns)
-7.5
5000
100
SUPPLY CURRENT (mA)
MAX3224-7/44/45E-05
70
SLEW RATE (V/µs)
MAX3224-7/44/45E-04
80
-5.0
40
4000
MAX3225E/MAX3227E
SLEW RATE vs. LOAD CAPACITANCE
20
45
3000
MAX3225E/MAX3227E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
1Mbps
1 TRANSMITTER AT FULL DATA RATE
1 TRANSMITTER AT 1/16 DATA RATE
(MAX3225E)
LOAD = 3kΩ + CL
1.5Mbps 1Mbps
2Mbps
0
MAX3224-7/44/45E-03
T1 TRANSMITTING AT 250kbps
T2 (MAX3224E) TRANSMITTING AT 15.6kbps
LOAD CAPACITANCE (pF)
1.5Mbps
-2.5
20kbps
15
LOAD CAPACITANCE (pF)
2Mbps
0
20
LOAD CAPACITANCE (pF)
5.0
2.5
120kbps
25
0
0
5000
30
5
0
1000
250kbps
35
10
FOR DATA RATES UP TO 250kbps
7.5
TRANSMITTER SKEW (ns)
40
2
VOUT0
TRANSMITTER OUTPUT VOLTAGE (V)
12
MAX3224-7/44/45E-06
1
0
-1
-2
-3
-4
-5
-6
14
45
SUPPLY CURRENT (mA)
T1 TRANSMITTING AT 250kbps
T2 (MAX3224E) TRANSMITTING AT 15.6kbps
MAX3224-7/44/45E-02
VOUT+
4
3
2
16
SLEW RATE (V/µs)
6
5
MAX3224E/MAX3226E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3224E/MAX3226E
SLEW RATE vs. LOAD CAPACITANCE
MAX3224-7/44/45E-01
TRANSMITTER OUTPUT VOLTAGE (V)
MAX3224E/MAX3226E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
160
140
120
100
80
60
40
20
0
-40
-20
0
20
40
60
TEMPERATURE (°C)
80
100
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
_______________________________________________________________________________________
5
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
__________________________________________Typical Operating Characteristics
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and CL, TA = +25°C, unless otherwise noted.)
_____________________________Typical Operating Characteristics (continued)
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and CL, TA = +25°C, unless otherwise noted.)
10
8
6
4
1000
2000
3000
4000
0
1000
2000
3000
4000
1.5Mbps
1Mbps
1 TRANSMITTER AT FULL DATA RATE
2 TRANSMITTERS AT 1/16 DATA RATE
2Mbps
3000
1.5Mbps 1Mbps
MAX3224-7/44/45E-14
2Mbps
-2.5
70
60
SLEW RATE (V/µs)
5.0
2.5
2000
50
40
30
20
-5.0
10
-7.5
1 TRANSMITTER AT 1Mbps
2 TRANSMITTERS AT 62.5kbps
0
400
800
1200
1600
2000
800
1200
1600
MAX3245E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3245E
TRANSMITTER SKEW vs.
LOAD CAPACITANCE
80
2Mbps
1.5Mbps
50
40
30
1Mbps
50
2000
MAX3224-7/44/45E-16
MAX3224-7/44/45E-15
90
60
400
LOAD CAPACITANCE (pF)
100
70
0
LOAD CAPACITANCE (pF)
45
40
TRANSMITTER SKEW (ns)
0
35
30
25
20
15
10
20
1 TRANSMITTER AT FULL DATA RATE
2 TRANSMITTERS AT 1/16 DATA RATE
10
5
0
0
0
400
800
1200
1600
LOAD CAPACITANCE (pF)
2000
4000
LOAD CAPACITANCE (pF)
MAX3245E
SLEW RATE vs. LOAD CAPACITANCE
MAX3224-7/44/45E-13
TRANSMITTER OUTPUT VOLTAGE (V)
1000
LOAD CAPACITANCE (pF)
7.5
SUPPLY CURRENT (mA)
0
5000
MAX3245E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
6
20kbps
20
0
5000
LOAD CAPACITANCE (pF)
0
120kbps
30
0
0
250kbps
40
10
2
VOUT-
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
50
SUPPLY CURRENT (mA)
-1
-2
-3
-4
-5
-6
12
SLEW RATE (V/µs)
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
60
MAX3224-7/44/45E-11
VOUT+
2
1
0
14
MAX3224-7/44/45E-10
6
5
4
3
MAX3244E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3244E
SLEW RATE vs. LOAD CAPACITANCE
MAX3224-7/44/45E-12
MAX3244E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
TRANSMITTER OUTPUT VOLTAGE (V)
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
0
1000
2000
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________
3000
5000
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
PIN
MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E
NAME
FUNCTION
1
1
—
READY
2
2
28
C1+
3
3
27
V+
+5.5V generated by the charge pump
4
4
24
C1-
Negative Terminal of Voltage-Doubler Charge-Pump Capacitor
5
5
1
C2+
Positive Terminal of Inverting Charge-Pump Capacitor
6
6
2
C2-
Negative Terminal of Inverting Charge-Pump Capacitor
7
7
3
V-
8, 17
13
9–11
T_OUT
9, 16
8
4–8
R_IN
10, 15
9
15–19
R_OUT
11
10
21
INVALID
12, 13
11
12–14
T_IN
14
12
23
FORCEON
18
14
25
GND
Ground
19
15
26
VCC
+3.0V to +5.5V Single Supply Voltage
20
16
22
FORCEOFF
—
—
20
R2OUTB
Ready to Transmit Output, active-high. READY is enabled high when
V- goes below -4V and the device is ready to transmit.
Positive Terminal of Voltage-Doubler Charge-Pump Capacitor
-5.5V generated by the charge pump
RS-232 Transmitter Outputs
RS-232 Receiver Inputs
TTL/CMOS Receiver Outputs
Valid Signal Detector Output, active low. A logic high indicates that a valid
RS-232 level is present on a receiver input.
TTL/CMOS Transmitter Inputs
Force-On Input, active high. Drive high to override AutoShutdown Plus,
keeping transmitters and receivers on (FORCEOFF must be high) (Table 1).
Force-Off Input, active low. Drive low to shut down transmitters, receivers
(except R2OUTB), and charge pump. This overrides AutoShutdown Plus
and FORCEON (Table 1).
TTL/CMOS Noninverting Complementary Receiver Outputs. Always active.
_______________Detailed Description
Dual Charge-Pump Voltage Converter
The MAX3224E–MAX3227E/MAX3244E/MAX3245E’s
internal power supply consists of a regulated dual
charge pump that provides output voltages of +5.5V
(doubling charge pump) and -5.5V (inverting charge
pump), over the +3.0V to +5.5V range. The charge
pump operates in discontinuous mode: if the output
voltages are less than 5.5V, the charge pump is
enabled; if the output voltages exceed 5.5V, the
charge-pump is disabled. Each charge pump requires
a flying capacitor (C1, C2) and a reservoir capacitor
(C3, C4) to generate the V+ and V- supplies.
The READY output (MAX3224E–MAX3227E) is low
when the charge pumps are disabled in shutdown
mode. The READY signal asserts high when V- goes
below -4V.
RS-232 Transmitters
The transmitters are inverting level translators that
convert CMOS-logic levels to 5.0V EIA/TIA-232 levels.
The MAX3224E/MAX3226E/MAX3244E guarantee a
250kbps data rate (1Mbps, for the MAX3225E/MAX3227E/
MAX3245E) with worst-case loads of 3kΩ in parallel with
1000pF, providing compatibility with PC-to-PC communication software (such as LapLink™). Transmitters
LapLink is a trademark of Traveling Software.
_______________________________________________________________________________________
7
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
______________________________________________________________ Pin Description
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
POWERMANAGEMENT
UNIT OR
KEYBOARD
CONTROLLER
VCC
FORCEOFF
FORCEON
INVALID
PROTECTION
DIODE
MAX3244E
MAX3245E
PREVIOUS
RS-232
VCC
I
Rx
5k
UART
Tx
GND
CPU
I/O
CHIP
WITH
UART
SHDN = GND
RS-232
a)
OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE
RECEIVER OUTPUT IN SHUTDOWN.
VCC
TO
µP
LOGIC
TRANSITION
DETECTOR
I
Figure 1. Interface Under Control of PMU
PROTECTION
DIODE
can be paralleled to drive multiple receivers. Figure 1
shows a complete system connection.
When FORCEOFF is driven to ground or when the AutoShutdown Plus circuitry senses that all receiver and
transmitter inputs are inactive for more than 30sec, the
transmitters are disabled and the outputs go into a highimpedance state. When powered off or shut down, the
outputs can be driven to ±12V. The transmitter inputs
do not have pull-up resistors. Connect unused inputs to
GND or VCC.
MAX3244E
MAX3245E
R2OUTB
VCC
Rx
THREE-STATED
UART
5k
Tx
GND
R2IN
R2OUT
T1IN
T1OUT
FORCEOFF = GND
RS-232 Receivers
The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3224E–MAX3227E feature
inverting outputs that always remain active (Table 1).
The MAX3244E/MAX3245E have inverting three-state
b)
NEW MAX3244E/MAX3245E: IN SHUTDOWN, R2OUTB IS USED TO MONITOR
EXTERNAL DEVICES AND R2OUT IS THREE STATED, ELIMINATING A CURRENT
PATH THROUGH THE UART'S PROTECTION DIODE.
Figure 2. The MAX3244E/MAX3245E detect RS-232 activity
when the UART and interface are shut down.
8
_______________________________________________________________________________________
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
RECEIVER OR
TRANSMITTER
EDGE WITHIN
30sec
T_OUT
R_OUT
(MAX3224E/
MAX3225E/
MAX3226E/
MAX3227E)
R_OUT
(MAX3244E/
MAX3245E)
R2OUTB
(MAX3244E/
MAX3245E)
FORCEON
FORCEOFF
VALID
RECEIVER
LEVEL
Shutdown
(Forced Off)
X
0
X
X
High-Z
Active
High-Z
Active
Normal
Operation
(Forced On)
1
1
X
X
Active
Active
Active
Active
Normal
Operation
(AutoShutdown
Plus)
0
1
X
Yes
Active
Active
Active
Active
Shutdown (AutoShutdown Plus)
0
1
X
No
High-Z
Active
Active
Active
Normal
Operation
INVALID*
1
Yes
X
Active
Active
Active
Active
Normal
Operation
INVALID*
1
X
Yes
Active
Active
Active
Active
Shutdown
INVALID*
1
No
No
High-Z
Active
Active
Active
Normal
Operation
(AutoShutdown)
INVALID*
INVALID**
Yes
X
Active
Active
Active
Active
Shutdown
(AutoShutdown)
INVALID*
INVALID**
No
X
High-Z
Active
High-Z
Active
OPERATION
STATUS
X = Don’t care
* INVALID connected to FORCEON
** INVALID connected to FORCEON and FORCEOFF
outputs that are high impedance when shut down
(FORCEOFF = GND) (Table 1).
The MAX3244E/MAX3245E feature an extra, always
active, noninverting output, R2OUTB. R2OUTB output
monitors receiver activity while the other receivers are
high impedance, allowing Ring Indicator applications to
be monitored without forward biasing other devices
connected to the receiver outputs. This is ideal for systems where V CC is set to ground in shutdown to
accommodate peripherals such as UARTs (Figure 2).
The MAX3224E–MAX3227E/MAX3244E/MAX3245E feature an INVALID output that is enabled low when no
valid RS-232 voltage levels have been detected on all
receiver inputs. Because INVALID indicates the receiv-
er input’s condition, it is independent of FORCEON and
FORCEOFF states (Figures 3 and 4).
AutoShutdown Plus Mode
The MAX3224E–MAX3227E/MAX3244E/MAX3245E
achieve a1µA supply current with Maxim’s AutoShutdown
Plus feature, which operates when FORCEOFF is high
and a FORCEON is low. When these devices do not
sense a valid signal transition on any receiver and transmitter input for 30sec, the on-board charge pumps are
shut down, reducing supply current to 1µA. This occurs
if the RS-232 cable is disconnected or if the connected
peripheral transmitters are turned off, and the UART driving the transmitter inputs is inactive. The system turns
on again when a valid transition is applied to any
RS-232 receiver or transmitter input. As a result, the sys-
_______________________________________________________________________________________
9
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
Table 1. Output Control Truth Table
+0.3V
T_IN
R_IN
30µs
TIMER
R
-0.3V
INVALID
R_IN
EDGE
DETECT
Figure 3a. INVALID Functional Diagram, INVALID Low
FORCEOFF
S
30sec
TIMER
EDGE
DETECT
INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR
AT LEAST 30µs.
AUTOSHDN
R
FORCEON
Figure 3c. AutoShutdown Plus Logic
+2.7V
FORCEOFF
POWERDOWN*
FORCEON
R_IN
30µs
TIMER
R
-2.7V
AUTOSHDN
INVALID
INVALID DEASSERTED IF ANY RECEIVER INPUT HAS BEEN BETWEEN +2.7V AND -2.7V
FOR LESS THAN 30µs.
Figure 3b. INVALID Functional Diagram, INVALID High
Table 2. INVALID Truth Table
RS-232 SIGNAL
PRESENT AT ANY
RECEIVER INPUT
INVALID OUTPUT
Yes
High
No
Low
tem saves power without changes to the existing BIOS
or operating system.
Figures 3a and 3b depict valid and invalid RS-232
receiver voltage levels. INVALID indicates the receiver
input’s condition, and is independent of FORCEON and
FORCEOFF states. Figure 3 and Tables 1 and 2 summarize the operating modes of the MAX3224E–
MAX3227E/MAX3244E/MAX3245E. FORCEON and
FORCEOFF override AutoShutdown Plus circuitry.
When neither control is asserted, the IC selects
between these states automatically based on the last
receiver or transmitter input edge received.
When shut down, the device’s charge pumps turn off,
V+ is pulled to VCC, V- is pulled to ground, the transmitter outputs are high impedance, and READY
* POWERDOWN IS ONLY AN INTERNAL SIGNAL.
IT CONTROLS THE OPERATIONAL STATUS OF
THE TRANSMITTERS AND THE POWER SUPPLIES.
Figure 3d. Power-Down Logic
(MAX3224E–MAX3227E) is driven low. The time
required to exit shutdown is typically 100µs (Figure 8).
By connecting FORCEON to INVALID, the MAX3224E–
MAX3227E/MAX3244E/MAX3245E shut down when no
valid receiver level and no receiver or transmitter edge is
detected for 30sec, and wake up when a valid receiver
level or receiver or transmitter edge is detected.
By connecting FORCEON and FORCEOFF to INVALID,
the MAX3224E–MAX3227E/MAX3244E/MAX3245E shut
down when no valid receiver level is detected and
INVALID HIGH
+2.7V
RECEIVER INPUT LEVELS
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
INDETERMINATE
+0.3V
0
INVALID LOW
-0.3V
INDETERMINATE
-2.7V
INVALID HIGH
Figure 4a. Receiver Positive/Negative Thresholds for INVALID
10
______________________________________________________________________________________
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
INVALID
} REGION
TRANSMITTER
INPUTS
TRANSMITTER
OUTPUTS
INVALID
OUTPUT
VCC
tINVL
0
tINVH
tAUTOSHDN
tAUTOSHDN
tWU
tWU
*VCC
OUTPUT
0
V+
VCC
0
V-
*MAX3224E–MAX3227E
Figure 4b. AutoShutdown Plus, INVALID, and READY Timing Diagram
wake up when a valid receiver level is detected (same
functionality as AutoShutdown feature on MAX3221E/
MAX3223E/MAX3243E).
A mouse or other system with AutoShutdown Plus may
need time to wake up. Figure 5 shows a circuit that
forces the transmitters on for 100ms, allowing enough
time for the other system to realize that the MAX3244E/
MAX3245E is awake. If the other system outputs valid
RS-232 signal transitions within that time, the RS-232
ports on both systems remain enabled.
have developed state-of-the-art structures to protect
these pins against ESD of ±15kV without damage. The
ESD structures withstand high ESD in all states: normal
operation, shutdown, and powered down. After an ESD
event, Maxim’s E versions keep working without
latchup, whereas competing RS-232 products can
latch and must be powered down to remove latchup.
POWERMANAGEMENT
UNIT
MASTER SHDN LINE
0.1µF
1M
Software-Controlled Shutdown
If direct software control is desired, use INVALID to
indicate DTR or Ring Indicator signal. Tie FORCEOFF
and FORCEON together to bypass the AutoShutdown
Plus so the line acts like a SHDN input.
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The driver outputs and receiver inputs of the
MAX3224E–MAX3227E/MAX3244E/MAX3245E have extra
protection against static electricity. Maxim’s engineers
FORCEOFF FORCEON
MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E
Figure 5. AutoShutdown Plus Initial Turn-On to Wake Up a
Mouse or Another System
______________________________________________________________________________________
11
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
RECEIVER
INPUTS
RC 1M
CHARGE-CURRENT
LIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
Cs
100pF
RC 50M to 100M
RD 1500Ω
DISCHARGE
RESISTANCE
CHARGE CURRENT
LIMIT RESISTOR
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
Figure 6a. Human Body ESD Test Model
HIGHVOLTAGE
DC
SOURCE
Cs
150pF
RD 330Ω
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 7a. IEC1000-4-2 ESD Test Model
I
IP 100%
90%
Ir
100%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
90%
AMPERES
I PEAK
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
36.8%
10%
0
0
tRL
TIME
tDL
CURRENT WAVEFORM
10%
Figure 6b. Human Body Current Waveform
t r = 0.7ns to 1ns
ESD protection can be tested in various ways; the
transmitter outputs and receiver inputs of this product
family are characterized for protection to the following
limits:
t
30ns
60ns
Figure 7b. IEC1000-4-2 ESD Generator Current Waveform
1) ±15kV using the Human Body Model
2) ±8kV using the contact-discharge method specified
in IEC1000-4-2
a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the test device
through a 1.5kΩ resistor.
3) ±15kV using IEC1000-4-2’s air-gap method.
IEC1000-4-2
The IEC1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifically
refer to integrated circuits. The MAX3224E–MAX3227E,
MAX3244E/MAX3245E help you design equipment that
meets Level 4 (the highest level) of IEC1000-4-2, without the need for additional ESD-protection components.
The major difference between tests done using the
Human Body Model and IEC1000-4-2 is higher peak
current in IEC1000-4-2, because series resistance is
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 6a shows the Human Body Model and Figure 6b
shows the current waveform it generates when discharged into a low impedance. This model consists of
12
______________________________________________________________________________________
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
The air-gap test involves approaching the device with a
charged probe. The contact-discharge method connects
the probe to the device before the probe is energized.
Machine Model
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resistance. Its objective is to emulate the stress caused by
contact that occurs with handling and assembly during
manufacturing. Of course, all pins require this protection during manufacturing, not just RS-232 inputs and
outputs. Therefore, after PC board assembly, the
Machine Model is less relevant to I/O ports.
__________Applications Information
Capacitor Selection
The capacitor type used for C1–C4 is not critical for
proper operation; polarized or nonpolarized capacitors
can be used. The charge pump requires 0.1µF capacitors for 3.3V operation. For other supply voltages, see
Table 3 for required capacitor values. Do not use values smaller than those listed in Table 3. Increasing the
capacitor values (e.g., by a factor of 2) reduces ripple
on the transmitter outputs and slightly reduces power
consumption. C2, C3, and C4 can be increased without
changing C1’s value. However, do not increase C1
without also increasing the values of C2, C3, C4,
and CBYPASS, to maintain the proper ratios (C1 to
the other capacitors).
Table 3. Required Minimum Capacitance
Values
VCC
(V)
C1, CBYPASS
(µF)
C2, C3, C4
(µF)
3.0 to 3.6
0.22
0.22
3.15 to 3.6
0.1
0.1
4.5 to 5.5
0.047
0.33
3.0 to 5.5
0.22
1
5V/div
0
FORCEON = FORCEOFF
T1OUT
2V/div
0
5V/div
0
T2OUT
VCC = 3.3V
C1–C4 = 0.1µF
READY
5µs/div
Figure 8. Transmitter Outputs when Exiting Shutdown or
Powering Up
When using the minimum required capacitor values,
make sure the capacitor value does not degrade
excessively with temperature. If in doubt, use capacitors with a larger nominal value. The capacitor’s equivalent series resistance (ESR), which usually rises at low
temperatures, influences the amount of ripple on V+
and V-.
Power-Supply Decoupling
In most circumstances, a 0.1µF VCC bypass capacitor
is adequate. In applications that are sensitive to powersupply noise, use a capacitor of the same value as
charge-pump capacitor C1. Connect bypass capacitors as close to the IC as possible.
Transmitter Outputs
when Exiting Shutdown
Figure 8 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two transmitter outputs are shown going to opposite RS-232 levels (one transmitter input is high, the other is low). Each
transmitter is loaded with 3kΩ in parallel with 1000pF.
The transmitter outputs display no ringing or undesirable transients as they come out of shutdown. Note that
the transmitters are enabled only when the magnitude
of V- exceeds approximately -3V.
______________________________________________________________________________________
13
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
lower in the IEC1000-4-2 model. Hence, the ESD withstand voltage measured to IEC1000-4-2 is generally
lower than that measured using the Human Body
Model. Figure 7a shows the IEC1000-4-2 model and
Figure 7b shows the current waveform for the 8kV,
IEC1000-4-2, Level 4, ESD contact-discharge test.
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
High Data Rates
The MAX3224E/MAX3226E/MAX3244E maintain the
RS-232 ±5.0V minimum transmitter output voltage even
at high data rates. Figure 9 shows a transmitter loopback test circuit. Figure 10 shows a loopback test result
at 120kbps, and Figure 11 shows the same test at
250kbps. For Figure 10, all transmitters were driven
simultaneously at 120kbps into RS-232 loads in parallel
with 1000pF. For Figure 11, a single transmitter was driven at 250kbps, and all transmitters were loaded with
an RS-232 receiver in parallel with 250pF.
The MAX3225E/MAX3227E/MAX3245E maintain the
RS-232 ±5.0V minimum transmitter output voltage at
data rates up to 1Mbps (MegaBaud). Figure 12 shows
a loopback test result with a single transmitter driven at
1Mbps and all transmitters loaded with an RS-232
receiver in parallel with 250pF.
5V/div
T1IN
5V/div
T1OUT
5V/div
R1OUT
VCC = 3.3V
2µs/div
Figure 10. MAX3224E/MAX3226E/MAX3244E Loopback Test
Result at 120kbps
Mouse Driveability
The MAX3244E/MAX3245E are specifically designed to
power serial mice while operating from low-voltage
power supplies. They have been tested with leading
mouse brands from manufacturers such as Microsoft
and Logitech. The MAX3244E/MAX3245E successfully
drove all serial mice tested and met their respective
current and voltage requirements. The MAX3244E/
T1IN
5V/div
T1OUT
5V/div
VCC
CBYPASS
5V/div
R1OUT
VCC = 3.3V
VCC
C1+
C1
C1C2+
C2
C2-
C4
R_ IN
5k
FORCEON
GND
Figure 11. MAX3224E/MAX3226E/MAX3244E Loopback Test
Result at 250kbps
V-
T_ OUT
R_ OUT
FORCEOFF
C3*
MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E
T_ IN
VCC
2µs/div
V+
T1IN
5V/div
T1OUT
5V/div
1000pF
5V/div
R1OUT
VCC = 3.3V
*C3 CAN BE RETURNED TO VCC OR GND.
Figure 9. Loopback Test Circuit
14
200ns/div
Figure 12. MAX3225E/MAX3227E/MAX3245E Loopback Test
Result at 1Mbps
______________________________________________________________________________________
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
+3.3V
26
0.1µF
28
C1
0.1µF
24
1
C2
0.1µF
2
LOGIC
INPUTS
VCC
27
C1+
V+
C3
0.1µF
C1C2+
MAX3244E
MAX3245E
COMPUTER SERIAL PORT
3
V-
C4
0.1µF
C2-
14
T1IN
T1OUT
9
+V
13
T2IN
T2OUT
10
+V
12
T3IN
T3OUT
11
-V
20
R2OUTB
19
R1OUT
GND
R1IN
4
R2IN
5
R3IN
6
R4IN
7
R5IN
8
Tx
5k
18
R2OUT
LOGIC
OUTPUTS
5k
17
R3OUT
RS-232
INPUTS
5k
16
R4OUT
5k
15
23
VCC
TO POWERMANAGEMENT
UNIT
22
21
R5OUT
SERIAL
MOUSE
5k
FORCEON
FORCEOFF
INVALID
GND
25
Figure 13a. Mouse Driver Test Circuit
______________________________________________________________________________________
15
5
4
VOUT+
VCC = 3.0V
3
2
MAX3245E dual charge pump ensures the transmitters
will supply at least ±5V during worst-case conditions.
Figure 13b shows the transmitter output voltages under
increasing load current. Figure 13a shows a typical
mouse connection.
MAX2343E-FIG15
6
TRANSMITTER OUTPUT VOLTAGE (V)
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Interconnection with 3V and 5V Logic
VOUT+
1
The MAX3224E–MAX3227E/MAX3244E/MAX3245E can
directly interface with various 5V logic families, including ACT and HCT CMOS. See Table 4 for more information on possible combinations of interconnections.
Table 5 lists other Maxim ESD-powered transceivers.
0
-1
-2
VCC
-3
-4
VOUTVOUT-
-5
-6
0
1
2
3
4
5
6
7
8
9
10
LOAD CURRENT PER TRANSMITTER (mA)
Figure 13b. MAX324_E Transmitter Output Voltage vs. Load
Current per Transmitter
Table 4. Logic Family Compatibility with Various Supply Voltages
SYSTEM
POWER-SUPPLY
VOLTAGE (V)
VCC SUPPLY
VOLTAGE
(V)
3.3
3.3
5
5
5
3.3
COMPATIBILITY
Compatible with all CMOS families
Compatible with all TTL and CMOS families
Compatible with ACT and HCT CMOS, and with AC, HC, or CD4000 CMOS
Table 5. ±15kV ESD-Protected, 3.0V to 5.5V Powered RS-232 Transceivers from Maxim
Part
Supply
Voltage
Range
(V)
No.
of
Tx/Rx
MAX3241E
+3.0 to +5.5
3/5
300
MAX3243E
+3.0 to +5.5
3/5
MAX3244E
+3.0 to +5.5
3/5
MAX3245E
+3.0 to +5.5
MAX3232E
MAX3222E
Supply
AutoAutoCurrent Shutdown Shutdown
(µA)
Plus
Human
Body
Model
(kV)
IEC 1000-4-2
Contact
Discharge
(kV)
IEC 1000-4-2
Air-Gap
Discharge
(kV)
Guaranteed
Data Rate
(kbps)
—
—
±15
±8
±15
250
1
—
Yes
±15
±8
±15
250
1
Yes
—
±15
±8
±15
250
3/5
1
Yes
—
±15
±8
±15
1Mbps
+3.0 to +5.5
2/2
300
—
—
±15
±8
±15
250
+3.0 to +5.5
2/2
300
—
—
±15
±8
±15
250
MAX3223E
+3.0 to +5.5
2/2
1
—
Yes
±15
±8
±15
250
MAX3224E
+3.0 to +5.5
2/2
1
Yes
—
±15
±8
±15
250
MAX3225E
+3.0 to +5.5
2/2
1
Yes
—
±15
±8
±15
1Mbps
MAX3221E
+3.0 to +5.5
1/1
1
—
Yes
±15
±8
±15
250
MAX3226E
+3.0 to +5.5
1/1
1
Yes
—
±15
±8
±15
250
MAX3227E
+3.0 to +5.5
1/1
1
Yes
—
±15
±8
±15
1Mbps
16
______________________________________________________________________________________
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
+3.3V
+3.3V
15
0.1µF
CBYPASS
2 C1+
C1
0.1µF
4 C15
C2
0.1µF
6
C2+
3
V+
MAX3226E
MAX3227E
V-
9 R1OUT
C3
0.1µF
C1
0.1µF
C4
0.1µF
C2
0.1µF
7
C2-
11 T1IN
12
READY
AutoShutdown
Plus
24
1
2
27
V+
C3
0.1µF
C1C2+
MAX3244E
MAX3245E
V-
3
C4
0.1µF
C2-
14 T1IN
T1OUT 9
R1IN 8
13 T2IN
T2OUT 10
12 T3IN
T3OUT 11
INVALID 10
FORCEOFF 16
FORCEON
28 C1+
VCC
T1OUT 13
5k
1
26
CBYPASS
0.1µF
VCC
GND
TO POWERMANAGEMENT
UNIT
VCC
22 FORCEOFF
23 FORCEON
AutoShutdown
Plus
INVALID 21
20 R2OUTB
14
19 R1OUT
R1IN 4
18 R2OUT
R2IN
17 R3OUT
R3IN 6
16 R4OUT
R4IN 7
15 R5OUT
R5IN 8
+3.3V
CBYPASS
C1
0.1µF
2 C1+
4 C15
C2
0.1µF
TTL/CMOS
INPUTS
19
0.1µF
6
C2+
VCC
3
V+
MAX3224E
MAX3225E
V-
C3
0.1µF
7
C4
0.1µF
C2-
13 T1IN
T1OUT 17
12 T2IN
T2OUT 8
RS-232
OUTPUTS
GND
R1IN 16
15 R1OUT
TTL/CMOS
OUTPUTS
RS-232
INPUTS
5k
R2IN
10 R2OUT
5
25
9
5k
1
14
READY
AutoShutdown
Plus
INVALID 11
FORCEOFF 20
FORCEON
GND
TO POWERMANAGEMENT
UNIT
VCC
18
______________________________________________________________________________________
17
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
___________________________________________________Typical Operating Circuits
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
___________________________________________________________ Pin Configurations
READY 1
16 FORCEOFF
C1+ 2
15 VCC
V+ 3
14 GND
C1- 4
C2+ 5
MAX3226E
MAX3227E
C2- 6
28 C1+
C2- 2
27 V+
V+ 3
18 GND
13 T1OUT
12 FORCEON
C2+ 5
9 R1OUT
MAX3224E
MAX3225E
C2- 6
26 VCC
R1IN 4
25 GND
16 R1IN
R2IN 5
MAX3244E
MAX3245E
24 C1-
15 R1OUT
R3IN 6
R4IN 7
22 FORCEOFF
8
13 T1IN
R5IN 8
21 INVALID
R2IN 9
12 T2IN
T1OUT 9
20 R2OUTB
11 INVALID
T2OUT 10
19 R1OUT
T3OUT 11
18 R2OUT
T3IN 12
17 R3OUT
T2IN 13
16 R4OUT
T1IN 14
15 R5OUT
T2OUT
SSOP
V- 3
17 T1OUT
14 FORCEON
V- 7
10 INVALID
R1IN 8
C2+ 1
19 VCC
C1- 4
11 T1IN
V- 7
20 FORCEOFF
C1+ 2
READY 1
R2OUT 10
DIP/SSOP/TSSOP
23 FORCEON
SO/SSOP
__Ordering Information (continued)
___________________ Chip Information
PART
TEMP. RANGE
PIN-PACKAGE
MAX3224E
MAX3226ECAE
0°C to +70°C
16 SSOP
TRANSISTOR COUNT: 1129
MAX3226EEAE
-40°C to +85°C
16 SSOP
MAX3225E
MAX3227ECAE
0°C to +70°C
16 SSOP
TRANSISTOR COUNT: 1129
MAX3227EEAE
MAX3244ECWI
-40°C to +85°C
0°C to +70°C
0°C to +70°C
16 SSOP
28 Wide SO
28 SSOP
MAX3245ECAI
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
28 Wide SO
28 SSOP
28 Wide SO
28 SSOP
MAX3245EEWI
MAX3245EEAI
-40°C to +85°C
-40°C to +85°C
28 Wide SO
28 SSOP
MAX3244ECAI
MAX3244EEWI
MAX3244EEAI
MAX3245ECWI
18
MAX3226E
TRANSISTOR COUNT: 1129
MAX3227E
TRANSISTOR COUNT: 1129
MAX3244E/MAX3245E
TRANSISTOR COUNT: 1335
______________________________________________________________________________________
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
SSOP.EPS
SOICW.EPS
______________________________________________________________________________________
19
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
________________________________________________________Package Information
___________________________________________Package Information (continued)
TSSOP,NO PADS.EPS
PDIPN.EPS
MAX3224E–MAX3227E/MAX3244E/MAX3245E †
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
20 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2000 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.