MAX3243ECAI+T [MAXIM]
Line Transceiver, 3 Func, 3 Driver, 5 Rcvr, BICMOS, PDSO28, ROHS COMPLIANT, SSOP-28;
| 型号： | MAX3243ECAI+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Line Transceiver, 3 Func, 3 Driver, 5 Rcvr, BICMOS, PDSO28, ROHS COMPLIANT, SSOP-28 驱动 信息通信管理 光电二极管 接口集成电路 驱动器 |
| 文件： | 总16页 (文件大小：432K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-0306; Rev 8; 10/03
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
_______________General Description
Next Generation Device Features
The MAX3221/MAX3223/MAX3243 achieve 1µA supply
current with Maxim’s revolutionary AutoShutdown™ fea-
ture. 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.
♦ For Space-Constrained Applications:
MAX3228/MAX3229: +2.5V to +5.5V RS-232
Transceivers in UCSP™
♦ For Integrated ESD Protection:
MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E: ±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps, True RS-232
Transceivers (MAX3246E Available in UCSP
Package)
♦ For Low-Voltage or Data Cable Applications:
MAX3380E/MAX3381E: +2.5V to +5.5V, 1µA,
2 Tx/2 Rx RS-232 Transceivers with ±15kV ESD-
Protected I/O and Logic Pins
The MAX3221/MAX3223/MAX3243 transceivers are 3V-
powered EIA/TIA-232 and V.28/V.24 communications
interfaces intended for notebook computer applica-
tions. 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 pro-
vides compatibility with popular software for communi-
cating with personal computers.
________________________Applications
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.
Notebook, Subnotebook, and Palmtop Computers
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
The MAX3221 is a 1-driver/1-receiver 16-pin SSOP ver-
sion 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 bias-
Printers
______________Ordering Information
PART
TEMP RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 SSOP
MAX3221CAE
MAX3221CUE†
MAX3221EAE
MAX3221EUE†
MAX3223CPP
MAX3223CAP
MAX3223CUP
MAX3223EPP
MAX3223EAP
MAX3223EUP
MAX3243CWI
MAX3243CAI
MAX3243CUI
MAX3243EWI
MAX3243EAI
MAX3243EUI
ing the protection diodes in a UART that may have V
completely removed.
CC
16 TSSOP
16 SSOP
16 TSSOP
20 Plastic DIP
20 SSOP
_____________________Selector Guide
20 TSSOP
20 Plastic DIP
20 SSOP
PART
Tx
Rx
V
RANGE (V) AutoShutdown
CC
MAX3221
MAX3223
MAX3243
1
2
3
1
2
5
3.0 to 5.5
3.0 to 5.5
3.0 to 5.5
Yes
Yes
Yes
20 TSSOP
28 Wide SO
28 SSOP
Pin Configurations appear at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
28 TSSOP
28 Wide SO
28 SSOP
†Future product—contact factory for availability.
AutoShutdown and UCSP are trademarks of Maxim Integrated
Products, Inc.
28 TSSOP
* .
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
ABSOLUTE MAXIMUM RATINGS
V
...........................................................................-0.3V to +6V
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
CC
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
Short-Circuit Duration
+ 0.3V)
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, 10s) .................................+300°C
CC
T_OUT ......................................................................Continuous
Continuous Power Dissipation (T = +70°C)
A
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 rating s only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T
A
to T
, unless otherwise noted. Typical values are at T = +25°C.)
MAX A
MIN
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS
Supply Current, AutoShutdown
Supply Current, Shutdown
All R_IN open, FORCEON = GND,
1.0
1.0
0.3
10
10
µA
µA
FORCEOFF = V
CC
V
= 3.3V
CC
or 5.0V,
T = +25°C
FORCEOFF = GND
A
Supply Current,
AutoShutdown Disabled
FORCEON = FORCEOFF = V
,
CC
1.0
mA
no load
LOGIC INPUTS AND RECEIVER OUTPUTS
Input Logic Threshold Low
0.8
V
V
T_IN, FORCEON, FORCEOFF, EN (MAX3223)
V
CC
CC
= 3.3V
= 5.0V
2.0
2.4
Input Logic Threshold High
T_IN, EN, FORCEON, FORCEOFF
V
Input Leakage Current
Output Leakage Current
Output Voltage Low
Output Voltage High
0.01
0.05
1.0
10
µA
µA
V
T_IN, EN, FORCEON, FORCEOFF
Receivers disabled
I
I
= 1.6mA
= -1.0mA
0.4
OUT
OUT
V
- 0.6
V
- 0.1
CC
V
CC
AUTOSHUTDOWN (FORCEON = GND, FORCEOFF = V
)
CC
Positive threshold
Negative threshold
1µA supply current, Figure 5
2.7
Receiver Input Thresholds to
Transmitters Enabled
Figure 5
V
V
-2.7
-0.3
Receiver Input Thresholds to
Transmitters Disabled
0.3
0.4
I
I
= 1.6mA
= -1.0mA
V
V
INVALID Output Voltage Low
OUT
V
- 0.6
INVALID Output Voltage High
OUT
CC
Receiver Threshold to
Transmitters Enabled (t
Receiver Positive or Negative
Threshold to INVALID High (t
Receiver Positive or Negative
Threshold to INVALID Low (t
Figure 5
Figure 5
Figure 5
250
1
µs
µs
µs
)
WU
)
)
INVH
30
INVL
2
_______________________________________________________________________________________
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
ELECTRICAL CHARACTERISTICS (continued)
, unless otherwise noted. Typical values are at T = +25°C.)
MAX A
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T
A
to T
MIN
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
RECEIVER INPUTS
Input Voltage Range
-25
0.6
0.8
25
V
V
V
CC
V
CC
V
CC
V
CC
= 3.3V
= 5.0V
= 3.3V
= 5.0V
1.2
1.5
1.5
1.8
0.3
5
Input Threshold Low
Input Threshold High
T
T
= +25°C
= +25°C
A
2.4
2.4
V
A
Input Hysteresis
V
Input Resistance
T
A
= +25°C
3
7
kΩ
TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
All transmitter outputs loaded with 3kΩ to ground
5.0
5.4
10M
35
V
Ω
V
= V+ = V- = 0V, transmitter output = 2V
300
CC
Output Short-Circuit Current
60
25
mA
V
=
12V, V
= 0V or 3.0V to 5.5V,
CC
OUT
Output Leakage Current
µA
V
transmitters disabled
MOUSE DRIVEABILITY (MAX3243)
T1IN = T2IN = GND, T3IN = V
,
CC
Transmitter Output Voltage
T3OUT loaded with 3kΩ to GND, T1OUT and
5
T2OUT loaded with 2.5mA each
TIMING CHARACTERISTICS
Maximum Data Rate
R = 3kΩ, C = 1000pF, one transmitter switching
120
235
0.3
kbps
µs
L
L
t
t
PHL
PLH
Receiver input to receiver output,
C = 150pF
L
Receiver Propagation Delay
0.3
Receiver Output Enable Time
Receiver Output Disable Time
Normal operation
Normal operation
200
200
200
200
100
100
ns
ns
MAX3221/MAX3223
MAX3243
Transmitter Skew
Receiver Skew
t
- t
ns
ns
PHL PLH
1000
MAX3221/MAX3223
MAX3243
t
- t
PHL PLH
500
30
V
CC
= 3.3V,
C = 200pF to 2500pF
L
4
6
8.0
R = 3kΩ to 7kΩ,
L
Transition-Region Slew Rate
T = +25°C,
V/µs
A
measured from +3V to
-3V or -3V to +3V
C = 200pF to 1000pF
L
30
Note 2: C1–C4 = 0.1µF, tested at 3.3V 10%. C1 = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V 10%.
_______________________________________________________________________________________
3
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
__________________________________________Typical Operating Characteristics
(V
CC
= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T = +25°C, unless otherwise noted.)
A
MAX3221/MAX3223
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3221/MAX3223
SUPPLY CURRENT vs. LOAD CAPACITANCE
MAX3221/MAX3223
SLEW RATE
vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA
MAX3221/3223-03
6
5
22
20
18
16
40
35
35
30
V
OUT+
4
235kbps
3
30
25
20
15
25
20
15
10
2
14
12
10
8
1
-SLEW
+SLEW
0
120kbps
20kbps
-1
-2
-3
-4
-5
-6
6
4
2
0
FOR DATA RATES UP TO 235kbps
V
OUT-
10
5
5
0
0
1000
2000
3000
4000
5000
0
1000
2000
3000 4000
5000
150 500 1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3243
SUPPLY CURRENT vs. LOAD
CAPACITANCE WHEN TRANSMITTING DATA
MAX3243
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3243
SLEW RATE
vs. LOAD CAPACITANCE
7.5
5.0
2.5
0
45
40
35
30
24
22
235kbps
V
+
OUT
20
18
16
120kbps
20kbps
-SLEW
+SLEW
1 TRANSMITTER AT 235kbps
2 TRANSMITTERS AT 30kbps
25
20
15
10
5
14
12
10
-2.5
-5.0
-7.5
V
OUT
-
8
1000 2000 3000 4000
LOAD CAPACITANCE (pF)
6
4
0
0
1000
2000
3000 4000
5000
0
1000
2000
3000 4000
5000
0
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
4
_______________________________________________________________________________________
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
______________________________________________________________Pin Description
PIN
NAME
FUNCTION
MAX3221
MAX3223
MAX3243
Receiver Enable Control. Drive low for normal operation. Drive high to force
the receiver outputs into a high-Z state.
1
1
—
EN
5
6
5
6
1
2
C2+
C2-
Positive terminal of inverting charge-pump capacitor
Negative terminal of inverting charge-pump capacitor
-5.5V generated by the charge pump
RS-232 Receiver Inputs
7
7
3
V-
8
9, 16
8, 17
12, 13
10, 15
—
4–8
R_IN
13
11
9
9, 10, 11
12, 13, 14
15–19
20
T_OUT
T_IN
RS-232 Transmitter Outputs
TTL/CMOS Transmitter Inputs
R_OUT
R2OUTB
TTL/CMOS Receiver Outputs
—
Noninverting Receiver Output—active in shutdown
Output of the valid signal detector. Indicates if a valid RS-232 level is pres-
ent on receiver inputs logic “1”.
10
16
12
11
20
14
21
22
23
INVALID
FORCEOFF
FORCEON
Drive low to shut down transmitters and on-board power supply. This over-
rides all automatic circuitry and FORCEON (Table 1).
Drive high to override automatic circuitry keeping transmitters on
(FORCEOFF must be high) (Table 1).
4
14
15
3
4
18
19
3
24
25
26
27
28
C1-
Negative terminal of the voltage doubler charge-pump capacitor
Ground
GND
V
+3.0V to +5.5V Supply Voltage
CC
V+
+5.5V generated by the charge pump
Positive terminal of the voltage doubler charge-pump capacitor
2
2
C1+
RS-232 Transmitters
_______________Detailed Description
The transmitters are inverting level translators that con-
vert 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 oper-
ate at data rates of 235kbps. Transmitters can be paral-
leled to drive multiple receivers or mice (MAX3243).
Figure 1 shows a complete system connection.
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 (V ) over the +3.0V to +5.5V
CC
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.
When FORCEOFF is driven to ground, or the Auto-
Shutdown circuitry senses invalid voltage levels at all
receiver inputs, the transmitters are disabled and the
outputs are forced into a high-impedance state.
LapLink is a trademark of Traveling Software.
_______________________________________________________________________________________
5
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
POWER
MANAGEMENT
UNIT OR
KEYBOARD
CONTROLLER
V
CC
FORCEOFF
FORCEON
INVALID
PROTECTION
DIODE
PREVIOUS
RS-232
MAX3243
V
CC
I
Rx
Tx
5kΩ
UART
I/O
GND
SHDN = GND
CHIP
WITH
UART
CPU
RS-232
(a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE
RECEIVER OUTPUT IN SHUTDOWN.
V
CC
TO
µP
LOGIC
TRANSITION
DETECTOR
Figure 1. Interface Under Control of PMU
I
MAX3243
PROTECTION
DIODE
R2OUTB
RS-232 Receivers
The MAX3221/MAX3223/MAX3243’s receivers convert
RS-232 signals to CMOS-logic output levels. All
receivers have one inverting three-state output. In shut-
down (FORCEOFF = low) or in AutoShutdown, the
MAX3221/MAX3223’s receivers are active (Table 1).
Driving EN high places the receiver(s) in a high-imped-
ance state. The MAX3243’s receivers are high imped-
ance when the part is shut down.
V
CC
R2IN
Rx
R2OUT
THREE-STATED
UART
5kΩ
T1OUT
T1IN
Tx
GND
FORCEOFF = GND
The MAX3243 has an always-active complementary
output (R2OUTB). R2OUTB is an extra output that mon-
itors receiver activity while the other receivers are high
impedance. This allows Ring Indicator to be monitored
without forward biasing other devices connected to the
(b) NEW MAX3243: IN SHUTDOWN, R2OUTB IS USED TO MONITOR EXTERNAL
DEVICES AND R2OUT IS THREE STATED, ELIMINATING A CURRENT PATH
THROUGH THE UART'S PROTECTION DIODE.
receiver outputs. This is ideal for systems where V
is
CC
set to 0V in shutdown to accommodate peripherals,
such as UARTs (Figure 2).
Figure 2. The MAX3243 detects RS-232 activity when the
UART and interface are shut down.
6
_______________________________________________________________________________________
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
Table 1a. MAX3221/MAX3223 FORCEOFF and
Enable Control Truth Table
+0.3V
TO MAX32_ _
POWER SUPPLY
AND TRANSMITTERS
R_IN
-0.3V
FORCEOFF
EN
T_OUT
R_OUT
30µs
COUNTER
R
INVALID
0
0
1
1
0
1
0
1
High-Z
High-Z
Active*
Active*
Active
High-Z
Active
High-Z
* TRANSMITTERS ARE DISABLED, REDUCING SUPPLY CURRENT TO 1µA IF
ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30µs.
Figure 3a. MAX32_ _ Entering 1µA Supply Mode via
AutoShutdown
Table 1b. MAX3243 FORCEOFF Control
+2.7V
Truth Table
TO MAX32_ _
POWER SUPPLY
FORCEOFF
T_OUT
R_OUT
R2OUTB
R_IN
30µs
COUNTER
R
INVALID
0
1
High-Z
Active*
High-Z
Active*
Active
Active
-2.7V
*Note: If the part is in AutoShutdown mode (FORCEOFF = V
FORCEON = GND), it is shut down if no valid RS-232
levels are present on all receiver inputs.
,
CC
* TRANSMITTERS ARE ENABLED IF:
ANY RECEIVER INPUT IS GREATER THAN +2.7V OR LESS THAN -2.7V.
ANY RECEIVER INPUT HAS BEEN BETWEEN +0.3V AND -0.3V FOR LESS THAN 30µs.
Figure 3b. MAX32_ _ with Transmitters Enabled Using
AutoShutdown
AutoShutdown
A 1µA supply current is achieved with Maxim’s new
AutoShutdown feature, which operates when
FORCEON is low and FORCEOFF is high. When the
MAX3221/MAX3223/MAX3243 sense no valid signal
levels on all receiver inputs for 30µs, the on-board
power supply and drivers are shut off, reducing supply
current to 1µA. This occurs if the RS-232 cable is dis-
connected or the connected peripheral transmitters 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. When using AutoShutdown,
the INVALID output is high when the device is on and
low when the device is shut down. Because INVALID
indicates the receiver inputs’ condition, it can be used
in any mode (Figure 3).
FORCEOFF
POWER DOWN
FORCEON
INVALID
INVALID IS AN INTERNALLY GENERATED SIGNAL
THAT IS USED BY THE AUTOSHUTDOWN LOGIC
AND APPEARS AS AN OUTPUT OF THE DEVICE.
POWER DOWN IS ONLY AN INTERNAL SIGNAL.
IT CONTROLS THE OPERATIONAL STATUS OF
THE TRANSMITTERS AND THE POWER SUPPLIES.
Figure 3c. AutoShutdown Logic
POWER
MASTER SHDN LINE
MANAGEMENT
Table 2 and Figure 3c summarize the MAX3221/
MAX3223/MAX3243 operating modes. FORCEON and
FORCEOFF override the automatic circuitry and force
the transceiver into its normal operating state or into its
low-power standby state. When neither control is assert-
ed, the IC selects between these states automatically
based on receiver input levels. Figures 3a, 3b, and 5a
depict valid and invalid RS-232 receiver levels.
0.1µF
1MΩ
UNIT
FORCEOFF FORCEON
MAX3221
MAX3223
MAX3243
A mouse or other system with AutoShutdown may need
time to wake up. Figure 4 shows a circuit that forces the
transmitters on for 100ms, allowing enough time for the
Figure 4. AutoShutdown with Initial Turn-On to Wake Up a
Mouse or Another System
_______________________________________________________________________________________
7
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
Table 2. AutoShutdown Logic
RS-232 SIGNAL
FORCEON
PRESENT AT
FORCEOFF INPUT
INVALID OUTPUT
TRANSCEIVER STATUS
Normal Operation
INPUT
RECEIVER INPUT
Yes
No
H
H
H
L
X
H
L
H
L
Normal Operation (Forced On)
Shutdown (AutoShutdown)
Shutdown (Forced Off)
No
L
Yes
No
X
X
H
L
L
Shutdown (Forced Off)
other system to realize that the MAX3221/MAX3223/
MAX3243 is awake. If the other system outputs valid
RS-232 signals within that time, the RS-232 ports on
both systems remain enabled.
TRANSMITTERS ENABLED, INVALID HIGH
+2.7V
INDETERMINATE
When shut down, the device’s charge pumps are turned
off, V+ decays to V , V- decays to ground, and the
CC
+0.3V
0V
transmitter outputs are disabled (high impedance). The
time required to exit shutdown is typically 100µs (Figure
5b).
AUTOSHUTDOWN, TRANSMITTERS DISABLED,
1µA SUPPLY CURRENT, INVALID LOW
-0.3V
INDETERMINATE
Software-Controlled Shutdown
If direct software control is desired, INVALID can be
used to indicate DTR or Ring Indicator signal. Tie
FORCEOFF and FORCEON together to bypass Auto-
Shutdown so the line acts like a SHDN input.
-2.7V
TRANSMITTERS ENABLED, INVALID HIGH
(a)
___________Applications Information
Capacitor Selection
The capacitor type used for C1–C4 is not critical for
proper operation; either polarized or nonpolarized
capacitors may be used. The charge pump requires
0.1µF capacitors for 3.3V operation. For other supply
voltages, refer to 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, and C4 to maintain the proper ratios (C1
to the other capacitors).
RECEIVER
INPUT
VOLTAGE
(V)
INVALID
REGION
V
CC
0
INVALID
OUTPUT
(V)
t
t
INVH
INVL
t
WU
V+
V
CC
0
When using the minimum required capacitor values,
make sure the capacitor value does not degrade
excessively with temperature. If in doubt, use capaci-
tors with a larger nominal value. The capacitor’s equiva-
lent series resistance (ESR) usually rises at
low temperatures and influences the amount of ripple
on V+ and V-.
V-
(b)
Figure 5. AutoShutdown Trip Levels
8
_______________________________________________________________________________________
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
6
5
5V/div
2V/div
T2
V +
OUT
4
3
V
CC
= 3.0V
2
T
T
T
1
2
3
1
V
+
-
OUT
0
-1
-2
-3
-4
-5
-6
V
V
CC
1
OUT
T1
V
OUT
-
50µs/div
0
2
3
4
5
6
7
V
= +3.3V
CC
LOAD CURRENT PER TRANSMITTER (mA)
C1–C4 = 0.1µF
Figure 7a. MAX3243 Transmitter Output Voltage vs. Load
Current per Transmitter
Figure 6. Transmitter Outputs when Exiting Shutdown or
Powering Up
Microsoft. The MAX3243 successfully drove all serial
mice and met their respective current and voltage
requirements. Figure 7a shows the transmitter outputs
under increasing load current. The MAX3243’s switching
regulator ensures the transmitters will supply at least 5V
during worst-case conditions. The AutoShutdown feature
does not work with a mouse, so FORCEOFF and
Power-Supply Decoupling
In most circumstances a 0.1µF bypass capacitor is
adequate. In applications that are sensitive to power-
supply noise, decouple V
to ground with a capacitor
CC
of the same value as the charge-pump capacitor C1.
Connect bypass capacitors as close to the IC as possible.
Transmitter Outputs
when Exiting Shutdown
FORCEON should be connected to V
.
CC
High Data Rates
The MAX3221/MAX3223/MAX3243 maintain the RS-232
5.0V minimum transmitter output voltage even at high
data rates. Figure 8 shows a transmitter loopback test
circuit. Figure 9 shows a loopback test result at
120kbps, and Figure 10 shows the same test at
235kbps. For Figure 9, all three transmitters were driv-
en simultaneously at 120kbps into RS-232 loads in par-
allel with 1000pF. For Figure 10, a single transmitter
was driven at 235kbps, but all three transmitters were
loaded with an RS-232 receiver in parallel with 1000pF.
Figure 6 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232
levels. Each transmitter is loaded with 3kΩ in parallel
with 2500pF. The transmitter outputs display no ringing
or undesirable transients as they come out of shut-
down. Note that the transmitters are enabled only when
the magnitude of V- exceeds approximately 3V. Figure
7a shows the MAX3243’s transmitter output voltage
vs. current per transmitter. Figure 7b is a mouse driver
test circuit.
Interconnection with 3V and 5V Logic
The MAX3221/MAX3223/MAX3243 can directly inter-
face with various 5V logic families, including ACT and
HCT CMOS. See Table 4 for more information on possi-
ble combinations of interconnections.
Mouse Driveability (MAX3243)
The MAX3243 has been specifically designed to power
serial mice while operating from low-voltage power sup-
plies. It has been tested with samples of ten major mouse
models from six manufacturers including the leading
three: Logitech (5 models), Mouse Systems, and
_______________________________________________________________________________________
9
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
+3.3V
26
0.1µF
V
CC
27
3
28
C1+
V+
C1
0.1µF
C3
0.1µF
24
1
C1-
C2+
COMPUTER SERIAL PORT
MAX3243
V-
C4
C2
0.1µF
0.1µF
2
C2-
+V
+V
-V
T1IN
T1OUT
9
14
T2IN
T3IN
LOGIC
INPUTS
T2OUT 10
13
12
11
T3OUT
GND
Tx
R2OUTB
20
R1OUT
R2OUT
R1IN
4
5
19
18
5kΩ
R2IN
R3IN
R4IN
R5IN
LOGIC
OUTPUTS
5kΩ
5kΩ
R3OUT
R4OUT
R5OUT
6
7
8
17
16
RS-232
INPUTS
5kΩ
5kΩ
SERIAL
MOUSE
15
23
FORCEON
FORCEOFF
INVALID
22
21
V
CC
TO POWER
MANAGEMENT
UNIT
GND
25
Figure 7b. Mouse Driver Test Circuit
10 ______________________________________________________________________________________
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
Table 3. Required Capacitor Values
V
CC
V
C1
C2, C3, C4
(µF)
CC
0.1µF
(V)
(µF)
3.0 to 3.6
4.5 to 5.5
3.0 to 5.5
0.1
0.047
0.1
0.1
V
CC
0.33
0.47
C1+
V+
V-
C3
C4
C1
C1-
C2+
Table 4. Logic Family Compatibility with
Various Supply Voltages
MAX3221
MAX3223
MAX3243
C2
C2-
SYSTEM
POWER-
SUPPLY
VOLTAGE
(V)
V
SUPPLY
CC
T_ OUT
T_ IN
VOLTAGE
(V)
COMPATIBILITY
R_ IN
R_ OUT
Compatible with all CMOS
families.
3.3
5
3.3
5
EN (MAX3221/3)
FORCEOFF
5kΩ
0V
1000pF
Compatible with all TTL and
CMOS-logic families.
V
CC
GND
Compatible with ACT and
HCT CMOS, and with TTL.
Incompatible with AC, HC,
or CD4000 CMOS.
5
3.3
Figure 8. Loopback Test Circuit
5V/div
T1IN
5V/div
T1IN
5V/div
5V/div
T1OUT
R1OUT
5V/div
5V/div
T1OUT
R1OUT
5µs/div
2µs/div
V
= +3.3V, 120kbps
V
= +3.3V, 235kbps
CC
CC
C1–C4 = 0.1µF
C1–C4 = 0.1µF
Figure 9. Loopback Test Result at 120kbps
Figure 10. Loopback Test Result at 235kbps
______________________________________________________________________________________ 11
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
__________________________________________________Typical Operating Circuits
+3.3V
15
0.1µF
C5
V
CC
3
7
2
C1+
V+
V-
C1
C3
0.1µF
4
5
6
+3.3V
0.1µF
0.1µF
C1-
C2+
MAX3221
26
C4
0.1µF
V
CC
C2
0.1µF
27
3
28
C1+
V+
C1
0.1µF
C2-
C3
0.1µF
24
1
C1-
C2+
11
9
T1IN
T1OUT 13
MAX3243
V-
C4
C2
0.1µF
0.1µF
2
R1OUT
R1IN
5kΩ
8
C2-
T1IN
T1OUT
9
14
RS-232
OUTPUTS
T2IN
T3IN
LOGIC
INPUTS
T2OUT 10
13
12
TO POWER
MANAGEMENT
UNIT
EN
INVALID 10
1
11
T3OUT
FORCEOFF
FORCEON
16
12
V
CC
GND
14
R2OUTB
R1OUT
20
19
R1IN
4
5
5kΩ
+3.3V
19
R2OUT
R3OUT
R4OUT
R2IN
18
17
16
0.1µF
C5
V
CC
3
2
5kΩ
C1+
V+
V-
LOGIC
OUTPUTS
C1
0.1µF
C3
0.1µF
4
5
6
R3IN
6
7
8
RS-232
INPUTS
C1-
C2+
MAX3223
7
5kΩ
C4
0.1µF
C2
0.1µF
R4IN
C2-
13
T1IN
T1OUT 17
5kΩ
TTL/CMOS
INPUTS
RS-232
OUTPUTS
R5OUT
15
23
R5IN
8
T2IN
T2OUT
12
5kΩ
FORCEON
FORCEOFF
INVALID
16
15 R1OUT
R1IN
22
21
V
CC
TTL/CMOS
OUTPUTS
RS-232
INPUTS
5kΩ
TO POWER
MANAGEMENT UNIT
GND
25
R2IN
10 R2OUT
9
5kΩ
TO POWER
MANAGEMENT
UNIT
EN
INVALID 11
1
FORCEOFF
FORCEON
20
14
V
CC
GND
18
12 ______________________________________________________________________________________
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
______3V-Powered EIA/TIA-232 and EIA/TIA-562 Transceivers from Maxim
GUAR-
POWER-
SUPPLY
VOLTAGE
(V)
No. OF
No. OF
ANTEED
DATA
EIA/TIA-
232
RECEIVERS
ACTIVE IN
SHUTDOWN
PART
TRANSMITTERS/
RECEIVERS
FEATURES
RATE
OR 562
(kbps)
MAX212
MAX218
3.0 to 3.6
3/5
2/2
5
2
120
232
232
Drives mice
Operates directly from batteries
without a voltage regulator
1.8 to 4.25
120
MAX562
MAX563
2.7 to 5.25
3.0 to 3.6
3/5
2/2
5
2
230
120
562
562
230kbps guaranteed data rate
0.1µF capacitors
AutoShutdown, complementary
receiver, drives mice, transient
detection
MAX3212
2.7 to 3.6
3/5
5
235
232
MAX3221
MAX3222
MAX3223
MAX3232
3.0 to 5.5
3.0 to 5.5
3.0 to 5.5
3.0 to 5.5
1/1
2/2
2/2
2/2
1
2
120
120
120
120
232
232
232
232
0.1µF capacitors, 16-pin SSOP
0.1µF capacitors, MAX242 pinout
0.1µF capacitors, AutoShutdown
0.1µF capacitors, MAX232 pinout
2
N/A
0.1µF capacitors, 2 complemen-
tary receivers, drives mice
MAX3241
3.0 to 5.5
3/5
5
1
120
232
0.1µF capacitors, AutoShutdown
complementary receiver,
drives mice
MAX3243
3.0 to 5.5
3/5
120
232
______________________________________________________________________________________ 13
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
__________________________________________________________Pin Configurations
TOP VIEW
EN
C1+
V+
FORCEOFF
1
2
20
19
18
17
16
15
14
13
12
11
EN
16 FORCEOFF
1
2
3
4
5
6
7
8
V
CC
15
14
C1+
V+
V
CC
GND
3
GND
C1-
T1OUT
R1IN
4
C1-
C2+
C2-
V-
13 T1OUT
MAX3221
MAX3223
C2+
C2-
5
FORCEON
12
R1OUT
FORCEON
T1IN
6
11 T1IN
10 INVALID
V-
7
T2OUT
8
9
R1IN
R1OUT
R2IN
T2IN
9
R2OUT
INVALID
10
SSOP/TSSOP
DIP/SSOP/TSSOP
C2+
C2-
C1+
V+
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
V-
V
CC
3
R1IN
R2IN
R3IN
R4IN
R5IN
T1OUT
T2OUT
T3OUT
T3IN
T2IN
T1IN
GND
4
C1-
5
MAX3243
FORCEON
6
FORCEOFF
INVALID
R2OUTB
R1OUT
7
8
9
10
11
12
13
14
R2OUT
R3OUT
R4OUT
R5OUT
SO/SSOP/TSSOP
___________________Chip Information
MAX3221 TRANSISTOR COUNT: 269
MAX3223 TRANSISTOR COUNT: 339
MAX3243 TRANSISTOR COUNT: 476
14 ______________________________________________________________________________________
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
2
1
INCHES
MILLIMETERS
DIM
A
MIN
0.068
MAX
MIN
1.73
0.05
0.25
0.09
MAX
1.99
0.21
0.38
0.20
INCHES
MIN
MAX
MILLIMETERS
MIN
6.07
6.07
7.07
8.07
MAX
6.33
N
0.078
A1
B
D
D
D
D
D
0.239 0.249
0.239 0.249
0.278 0.289
0.317 0.328
14L
0.002 0.008
0.010 0.015
0.004 0.008
6.33 16L
7.33
8.33 24L
20L
C
E
H
D
SEE VARIATIONS
0.205 0.212 5.20
0.0256 BSC
0.397 0.407 10.07 10.33 28L
E
5.38
e
0.65 BSC
H
0.301 0.311 7.65
0.025 0.037 0.63
7.90
0.95
8∞
L
0∞
8∞
0∞
N
A
C
B
L
e
A1
D
NOTES:
1. D&E DO NOT INCLUDE MOLD FLASH.
2. MOLD FLASH OR PROTRUSIONS NOT TO EXCEED .15 MM (.006").
3. CONTROLLING DIMENSION: MILLIMETERS.
4. MEETS JEDEC MO150.
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, SSOP, 5.3 MM
APPROVAL
DOCUMENT CONTROL NO.
REV.
5. LEADS TO BE COPLANAR WITHIN 0.10 MM.
1
21-0056
C
1
______________________________________________________________________________________ 15
1µA Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
INCHES
MILLIMETERS
N
DIM
A
MIN
MAX
0.104
0.012
0.019
0.013
MIN
2.35
0.10
0.35
0.23
MAX
2.65
0.30
0.49
0.32
0.093
0.004
0.014
0.009
A1
B
C
e
0.050
1.27
E
H
E
0.291
0.394
0.016
0.299
0.419
0.050
7.40
10.00
0.40
7.60
10.65
1.27
H
L
VARIATIONS:
INCHES
1
MILLIMETERS
TOP VIEW
MAX
0.413
0.463
0.512
0.614
0.713
MAX
DIM
D
MIN
MIN
10.10
11.35
12.60
15.20
17.70
N MS013
0.398
0.447
0.496
0.598
0.697
10.50 16 AA
11.75 18 AB
13.00 20 AC
15.60 24 AD
18.10 28 AE
D
D
D
D
D
C
A
B
e
0∞-8∞
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .300" SOIC
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0042
B
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circu
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
it patent licenses are
16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
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