Maxim MAX3243EAI, MAX3243CAI, MAX3223EAP, MAX3223CUP, MAX3243EWI Datasheet
...
_______________General Description
The MAX3221/MAX3223/MAX3243 achieve 1µA supply
current with Maxim’s revolutionary AutoShutdown™ feature. When the MAX3221/MAX3223/MAX3243 do not
sense a valid signal level on their receiver inputs, the
on-board power supply and drivers shut down. This
occurs if the RS-232 cable is disconnected or if the
transmitters of the connected peripheral are turned off.
The system turns on again when a valid level is applied
to any RS-232 receiver input. As a result, the system
saves power without changes to the existing BIOS or
operating system.
The MAX3221/MAX3223/MAX3243 transceivers are 3Vpowered EIA/TIA-232 and V.28/V.24 communications
interfaces intended for notebook computer applications. A proprietary, high-efficiency, dual charge-pump
power supply and a low-dropout transmitter combine to
deliver true RS-232 performance from a single +3.0V to
+5.5V supply. A guaranteed data rate of 120kbps provides compatibility with popular software for communicating with personal computers.
The MAX3221/MAX3223/MAX3243 require only 0.1µF
capacitors in 3.3V operation, and can operate from input
voltages ranging from +3.0V to +5.5V. They are ideal for
3.3V-only systems, mixed 3.3V and 5.0V systems, or
5.0V-only systems that require true RS-232 performance.
The MAX3221 is a 1-driver/1-receiver 16-pin SSOP version of the 20-pin MAX3223 (2-driver/2-receiver). The
MAX3243 3-driver/5-receiver, complete serial port is
ideal for notebook or subnotebook computers. The
MAX3243 includes one complementary always-active
receiver. This receiver can monitor an external device
(such as a modem) in shutdown, without forward biasing the protection diodes in a UART that may have V
CC
completely removed.
____________________________Features
♦ 1µA Supply Current Achieved with AutoShutdown
♦ Small 0.1µF Capacitors
♦ True RS-232 Operation from V
CC
= +3.0V to +5.5V
♦ Meets EIA/TIA-562 Specifications Down to 2.7V
♦ Guaranteed 120kbps Data Rate
♦ 6V/µs Min Guaranteed Slew Rate
♦ Smallest Single-Supply RS-232 Transceiver
(MAX3221)
♦ Guaranteed Mouse Driveability (MAX3243)
♦ Small TSSOP Package (MAX3223/MAX3243)
________________________Applications
Notebook, Subnotebook, and Palmtop Computers
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
MAX3221/MAX3223/MAX3243*
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
________________________________________________________________ Maxim Integrated Products 1
19-0306; Rev 6; 3/99
PART
MAX3221CAE
MAX3221EUE†
-40°C to +85°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
16 SSOP
16 TSSOP
* 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; and other patents pending.
†Future product—contact factory for availability.
AutoShutdown is a trademark of Maxim Integrated Products.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
MAX3223EPP -40°C to +85°C 20 Plastic DIP
MAX3223EAP -40°C to +85°C 20 SSOP
MAX3243CWI
0°C to +70°C 28 Wide SO
MAX3243CAI 0°C to +70°C 28 SSOP
MAX3243EWI -40°C to +85°C 28 Wide SO
MAX3243EAI -40°C to +85°C 28 SSOP
MAX3223CPP
MAX3223CAP 0°C to +70°C
0°C to +70°C 20 Plastic DIP
20 SSOP
______________Ordering Information
_____________________Selector Guide
MAX3221
MAX3223
MAX3243
1
2
3
1
2
3.0 to 5.5
3.0 to 5.5
3.0 to 5.55
Yes
Yes
Yes
PART Tx Rx VCCRANGE (V) AutoShutdown
MAX3221CUE†
0°C to +70°C 16 TSSOP
MAX3221EAE -40°C to +85°C 16 SSOP
MAX3223CUP 0°C to +70°C 20 TSSOP
MAX3223EUP -40°C to +85°C 20 TSSOP
MAX3243CUI 0°C to +70°C 28 TSSOP
MAX3243EUI -40°C to +85°C 28 TSSOP
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.
MAX3221/MAX3223/MAX3243
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA= +25°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.
VCC...........................................................................-0.3V to +6V
V+ (Note 1) ...............................................................-0.3V to +7V
V- (Note 1) ...............................................................+0.3V to -7V
V+ +
|V-
| (Note 1).................................................................+13V
Input Voltages
T_IN, FORCEOFF, FORCEON, EN (MAX3223) ......-0.3V to +6V
R_IN ...................................................................................±25V
Output Voltages
T_OUT.............................................................................±13.2V
R_OUT, INVALID ......................................-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
T_OUT ......................................................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
16-Pin SSOP (derate 7.14mW/°C above +70°C) ...........571mW
16-Pin TSSOP (derate 6.70mW/°C above +70°C) .........533mW
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 DIP (derate 7.00mW/°C above +70°C).....559mW
28-Pin Wide SO (derate 12.50mW/°C above +70°C) ............1W
28-Pin SSOP (derate 9.52mW/°C above +70°C) ...........762mW
28-Pin TSSOP (derate 8.70mW/°C above +70°C) .........696mW
Operating Temperature Ranges
MAX32_ _C_ _.......................................................0°C to +70°C
MAX32_ _E_ _....................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
I
OUT
= 1.6mA
Receivers disabled
T_IN, EN, FORCEON, FORCEOFF
T_IN, EN, FORCEON, FORCEOFF
T_IN, FORCEON, FORCEOFF, EN (MAX3223)
I
OUT
= -1.0mA
CONDITIONS
VVCC- 0.6 VCC- 0.1Output Voltage High
V0.4Output Voltage Low
µA±0.05 ±10Output Leakage Current
µA±0.01 ±1.0Input Leakage Current
V
2.4
Input Logic Threshold High
µA1.0 10
V0.8Input Logic Threshold Low
UNITSMIN TYP MAXPARAMETER
VCC= 3.3V
VCC= 5.0V
2.0
Supply Current, AutoShutdown
Supply Current, Shutdown µA1.0 10
Supply Current,
AutoShutdown Disabled
VCC= 3.3V
or 5.0V,
T
A
= +25°C
mA0.3 1.0
2.7
Receiver Positive or Negative
Threshold to INVALID High (t
INVH
)
Figure 5 µs1
Receiver Threshold to
Transmitters Enabled (t
WU
)
Figure 5 µs250
Receiver Positive or Negative
Threshold to INVALID Low (t
INVL
)
Figure 5 µs30
Receiver Input Thresholds to
Transmitters Enabled
Figure 5 V
-2.7
INVALID Output Voltage Low
I
OUT
= 1.6mA V0.4
Receiver Input Thresholds to
Transmitters Disabled
1µA supply current, Figure 5 V-0.3 0.3
Positive threshold
Negative threshold
INVALID Output Voltage High
I
OUT
= -1.0mA VVCC- 0.6
DC CHARACTERISTICS
LOGIC INPUTS AND RECEIVER OUTPUTS
AUTOSHUTDOWN (FORCEON = GND, FORCEOFF = VCC)
All R_IN open, FORCEON = GND,
FORCEOFF = V
CC
FORCEOFF = GND
FORCEON = FORCEOFF = VCC,
no load
MAX3221/MAX3223/MAX3243
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VCC= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA= +25°C.)
Note 2: C1–C4 = 0.1µF, tested at 3.3V ±10%. C1 = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%.
200
Normal operation 200
Receiver Output Enable Time Normal operation ns
t
PLH
Receiver input to receiver output,
CL= 150pF
4 8.0 30
Transition-Region Slew Rate V/µs
VCC= 3.3V,
RL= 3kΩ to 7kΩ,
TA= +25°C,
measured from +3V to
-3V or -3V to +3V
Transmitter Skew
200
ns
t
PHL
- t
PLH
PARAMETER MIN TYP MAX UNITS
±25
Output Short-Circuit Current ±35 ±60 mA
Output Resistance 300 10M Ω
Output Leakage Current µA
Input Threshold Low
0.6 1.2
V
±5.0 ±5.4Output Voltage Swing V
Maximum Data Rate 120 235 kbps
Receiver Propagation Delay
0.3
µs
CONDITIONS
VCC= V+ = V- = 0V, transmitter output = ±2V
V
OUT
= ±12V, VCC= 0V or 3.0V to 5.5V,
transmitters disabled
RL= 3kΩ, CL= 1000pF, one transmitter switching
All transmitter outputs loaded with 3kΩ to ground
nsReceiver Output Disable Time
t
PHL
0.3
Input Voltage Range -25 25 V
Input Hysteresis 0.3 V
Input Threshold High V
Input Resistance 35 7kΩTA= +25°C
0.8 1.5
1.8 2.4
1.5 2.4
TA= +25°C
TA= +25°C
VCC= 3.3V
VCC= 3.3V
VCC= 5.0V
VCC= 5.0V
CL= 200pF to 2500pF
CL= 200pF to 1000pF 630
±5Transmitter Output Voltage V
T1IN = T2IN = GND, T3IN = VCC,
T3OUT loaded with 3kΩ to GND, T1OUT and
T2OUT loaded with 2.5mA each
MAX3221/MAX3223
MAX3243
200 1000
Receiver Skew
100
ns
t
PHL
- t
PLH
MAX3221/MAX3223
MAX3243
100 500
RECEIVER INPUTS
TIMING CHARACTERISTICS
TRANSMITTER OUTPUTS
MOUSE DRIVEABILITY (MAX3243)
MAX3221/MAX3223/MAX3243
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
4 _______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(VCC= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, TA= +25°C, unless otherwise noted.)
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
0
MAX3221/MAX3223
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3221/3223-01
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
2000 30001000 4000 5000
V
OUT+
V
OUT-
0
2
4
6
8
10
12
14
16
18
20
22
150 500
MAX3221/MAX3223
SLEW RATE
vs. LOAD CAPACITANCE
MAX3221/3223-02
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
2000 30001000 4000 5000
FOR DATA RATES UP TO 235kbps
+SLEW
-SLEW
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
0
MAX3221/MAX3223
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA
MAX3221/3223-03
LOAD CAPACITANCE (pF)
MAX3223 SUPPLY CURRENT (mA)
MAX3221 SUPPLY CURRENT (mA)
2000 30001000 4000 5000
235kbps
120kbps
20kbps
-7.5
-5.0
-2.5
0
2.5
5.0
7.5
0
MAX3243
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3221/3223-04
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
2000 30001000 4000 5000
V
OUT
+
1 TRANSMITTER AT 235kbps
2 TRANSMITTERS AT 30kbps
V
OUT
-
ALL OUTPUTS LOADED WITH 3kΩ +CL
0.1µF CHARGE-PUMP CAPACITORS
FOR ALL DATA RATES UP TO 235kbps
4
6
8
10
12
14
16
18
20
22
24
0
MAX3243
SLEW RATE
vs. LOAD CAPACITANCE
MAX3221/3223-05
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
2000 30001000 4000 5000
+SLEW
-SLEW
0
5
10
15
20
25
30
35
45
40
0
MAX3243
SUPPLY CURRENT vs. LOAD
CAPACITANCE WHEN TRANSMITTING DATA
MAX3221/3223-06
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
2000 30001000 4000 5000
235kbps
120kbps
20kbps
MAX3221/MAX3223/MAX3243
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
_______________________________________________________________________________________ 5
______________________________________________________________Pin Description
Noninverting Receiver Output—active in shutdownR2OUTB
Output of the valid signal detector. Indicates if a valid RS-232 level is present on receiver inputs logic “1”.
INVALID
Drive low to shut down transmitters and on-board power supply. This overrides all automatic circuitry and FORCEON (Table 1).
FORCEOFF
Drive high to override automatic circuitry keeping transmitters on
(FORCEOFF must be high) (Table 1).
FORCEON
Negative terminal of the voltage doubler charge-pump capacitorC1-
RS-232 Receiver InputsR_IN
RS-232 Transmitter OutputsT_OUT
TTL/CMOS Transmitter InputsT_IN
TTL/CMOS Receiver OutputsR_OUT
-5.5V generated by the charge pumpV-
Negative terminal of inverting charge-pump capacitorC2-
Positive terminal of inverting charge-pump capacitorC2+
Receiver Enable Control. Drive low for normal operation. Drive high to force
the receiver outputs into a high-Z state.
EN
FUNCTION
GroundGND
+3.0V to +5.5V Supply VoltageV
CC
LapLink is a trademark of Traveling Software.
_______________Detailed Description
Dual Charge-Pump Voltage Converter
The MAX3221/MAX3223/MAX3243’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), regardless
of the input voltage (VCC) over the +3.0V to +5.5V
range. The charge pumps operate in a discontinuous
mode: if the output voltages are less than 5.5V, the
charge pumps are enabled; if the output voltages
exceed 5.5V, the charge pumps are disabled. Each
charge pump requires a flying capacitor (C1, C2) and
a reservoir capacitor (C3, C4) to generate the V+ and
V- supplies.
RS-232 Transmitters
The transmitters are inverting level translators that convert CMOS-logic levels to 5.0V EIA/TIA-232 levels. They
guarantee a 120kbps data rate with worst-case loads of
3kΩ in parallel with 1000pF, providing compatibility with
PC-to-PC communication software (such as Laplink™).
Typically, the MAX3221/MAX3223/MAX3243 can operate at data rates of 235kbps. Transmitters can be paralleled to drive multiple receivers or mice (MAX3243).
Figure 1 shows a complete system connection.
When FORCEOFF is driven to ground, or the AutoShutdown circuitry senses invalid voltage levels at all
receiver inputs, the transmitters are disabled and the
outputs are forced into a high-impedance state.
—
10
16
12
4
8
13
11
9
7
6
5
1
14
15
NAME
MAX3221
+5.5V generated by the charge pumpV+3
Positive terminal of the voltage doubler charge-pump capacitorC1+2
—
11
20
14
4
9, 16
8, 17
12, 13
10, 15
7
6
5
1
18
19
20
21
22
23
24
4–8
9, 10, 11
12, 13, 14
15–19
3
2
1
—
25
26
MAX32233MAX3243
27
2 28
PIN
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