MAX3222CWNT [MAXIM]
LINE TRANSCEIVER, PDSO18, 0.300 INCH, SOIC-18;型号: | MAX3222CWNT |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | LINE TRANSCEIVER, PDSO18, 0.300 INCH, SOIC-18 |
文件: | 总16页 (文件大小:269K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
19-0273; Rev 5; 3/99
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241*
_______________Ge n e ra l De s c rip t io n
____________________________Fe a t u re s
♦ Low Supply Current:
The MAX3222/MAX3232/MAX3237/MAX3241 tra ns -
ceivers have a proprietary low-dropout transmitter out-
put stage enabling true RS-232 performance from a
3.0V to 5.5V supply with a dual charge pump. The
devices require only four small 0.1µF external charge-
p ump c a p a c itors . The MAX3222, MAX3232, a nd
MAX3241 a re g ua ra nte e d to run a t d a ta ra te s of
120kbps while maintaining RS-232 output levels. The
MAX3237 is guaranteed to run at data rates of 250kbps
in the norma l op e ra ting mod e a nd 1Mb p s in the
MegaBaud™ operating mode, while maintaining RS-232
output levels.
300µA (MAX3222/MAX3232/MAX3241)
500µA (MAX3237)
♦ Guaranteed Data Rate:
120kbps (MAX3222/MAX3232/MAX3241)
250kbps (MAX3237—Normal Operation)
1Mbps (MAX3237—MegaBaud Operation)
♦ 1µA Low-Power Shutdown with Receivers Active
(MAX3222/MAX3237/MAX3241)
♦ Flow-Through Pinout (MAX3237)
♦ Meets EIA/TIA-232 Specifications Down to 3.0V
♦ Guaranteed Mouse Driveability (MAX3241)
The MAX3222/MAX3232 ha ve 2 re c e ive rs a nd 2
drivers. The MAX3222 features a 1µA shutdown mode
that reduces power consumption and extends battery
life in portable systems. Its receivers remain active in
shutdown mode, allowing external devices such as
modems to be monitored using only 1µA supply cur-
rent. The MAX3222 and MAX3232 are pin, package,
and functionally compatible with the industry-standard
MAX242 and MAX232, respectively.
♦ Pin Compatible with Industry-Standard MAX232
(MAX3232)
Pin Compatible with Industry-Standard MAX242
(MAX3222)
♦ Guaranteed Slew Rate:
6V/µs (MAX3222/MAX3232/MAX3237/MAX3241)
24V/µs (MAX3237—MegaBaud Operation)
The MAX3241 is a c omp le te s e ria l p ort (3 d rive rs /
5 receivers) designed for notebook and subnotebook
computers. The MAX3237 (5 drivers/3 receivers) is ideal
for fast modem applications. Both these devices feature
a shutdown mode in which all receivers can remain
active while using only 1µA supply current. Receivers R1
(MAX3237/MAX3241) and R2 (MAX3241) have extra out-
puts in addition to their standard outputs. These extra
outputs are always active, allowing external devices
such as a modem to be monitored without forward bias-
______________Ord e rin g In fo rm a t io n
PART
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
20 TSSOP
20 SSOP
MAX3222CUP
MAX3222CAP
MAX3222CWN
MAX3222CPN
18 SO
18 Plastic DIP
Ordering Information continued at end of data sheet.
ing the protection diodes in circuitry that may have V
CC
completely removed.
_________________P in Co n fig u ra t io n s
The MAX3222, MAX3237, and MAX3241 are available
in space-saving TSSOP and SSOP packages.
TOP VIEW
EN
C1+
V+
1
2
3
4
5
6
7
8
9
SHDN
18
17
16
15
14
13
12
11
V
CC
________________________Ap p lic a t io n s
Notebook, Subnotebook, and Palmtop Computers
High-Speed Modems
GND
T1OUT
R1IN
C1-
MAX3222
C2+
C2-
Battery-Powered Equipment
Hand-Held Equipment
R1OUT
T1IN
V-
Peripherals
T2IN
T2OUT
R2IN
10 R2OUT
Printers
DIP/SO
Typical Operating Circuits appear at end of data sheet.
Pin Configurations continued at end of data sheet.
MegaBaud is a trademark 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; and other patents pending.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
ABSOLUTE MAXIMUM RATINGS
V
CC
...........................................................................-0.3V to +6V
Continuous Power Dissipation (T = +70°C)
A
V+ (Note 1)...............................................................-0.3V to +7V
V- (Note 1) ................................................................+0.3V to -7V
V+ + V- (Note 1)...................................................................+13V
Input Voltages
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ....696mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)........762mW
16-Pin TSSOP (derate 6.7mW/°C above +70°C).............533mW
18-Pin Plastic DIP (derate 11.11mW/°C above +70°C) ..889mW
18-Pin SO (derate 9.52mW/°C above +70°C)..............762mW
20-Pin SSOP (derate 8.00mW/°C above +70°C) .........640mW
20-Pin TSSOP (derate 7.0mW/°C above +70°C).............559mW
28-Pin SO (derate 12.50mW/°C above +70°C) .....................1W
28-Pin SSOP (derate 9.52mW/°C above +70°C) .........762mW
28-Pin TSSOP (derate 8.7mW/°C above +70°C).............696mW
Operating Temperature Ranges
T_IN, SHDN, EN ...................................................-0.3V to +6V
MBAUD...................................................-0.3V to (V + 0.3V)
CC
R_IN .................................................................................±25V
Output Voltages
T_OUT...........................................................................±13.2V
R_OUT....................................................-0.3V to (V + 0.3V)
CC
Short-Circuit Duration
T_OUT ....................................................................Continuous
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 a maximum magnitude 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
(V = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T
to T , unless otherwise noted. Typical values are at T = +25°C.)
MAX A
CC
A
MIN
PARAMETER
DC CHARACTERISTICS
CONDITIONS
MIN
TYP
MAX
UNITS
MAX3222/MAX3232/
MAX3241
0.3
1.0
No load, V = 3.3V or 5.0V,
CC
V
Power-Supply Current
mA
µA
CC
T
A
= +25°C
MAX3237
0.5
1.0
2.0
10
Shutdown Supply Current
SHDN = GND, T = +25°C
A
LOGIC INPUTS AND RECEIVER OUTPUTS
Input Logic Threshold Low
(Note 3)
0.8
V
V
T_IN, EN, SHDN, MBAUD
7/MAX3241
V
= 3.3V
= 5.0V
2.0
2.4
CC
Input Logic Threshold High
(Note 3)
V
CC
Input Leakage Current
Output Leakage Current
Output Voltage Low
Output Voltage High
RECEIVER INPUTS
Input Voltage Range
±0.01
±0.05
±1.0
±10
0.4
µA
µA
V
T_IN, EN, SHDN, MBAUD
Receivers disabled
I
= 1.6mA
= -1.0mA
OUT
I
V
CC
- 0.6
V
CC
- 0.1
V
OUT
-25
0.6
0.8
25
V
V
V
= 3.3V
= 5.0V
= 3.3V
= 5.0V
1.2
1.5
1.5
1.8
CC
Input Threshold Low
Input Threshold High
T
= +25°C
= +25°C
A
V
CC
V
CC
2.4
2.4
T
V
A
V
CC
2
_______________________________________________________________________________________
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241
ELECTRICAL CHARACTERISTICS (continued)
(V = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T
to T , unless otherwise noted. Typical values are at T = +25°C.)
MAX A
CC
A
MIN
PARAMETER
CONDITIONS
MIN
TYP
0.3
5
MAX
UNITS
V
Input Hysteresis
Input Resistance
T
A
= +25°C
3
7
kΩ
TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
All transmitter outputs loaded with 3kΩ to ground
= V+ = V- = 0V, T = ±2V
±5.0
300
±5.4
V
Ω
V
CC
10M
±35
OUT
Output Short-Circuit Current
±60
±25
mA
V
OUT
= ±12V, V = 0V or 3V to 5.5V, transmitters
CC
Output Leakage Current
µA
disabled
MOUSE DRIVEABILITY (MAX3241)
T1IN = T2IN = GND, T3IN = V
,
CC
Transmitter Output Voltage
T3OUT loaded with 3kΩ to GND,
T1OUT and T2OUT loaded with 2.5mA each
±5.0
V
TIMING CHARACTERISTICS—MAX3222/MAX3232/MAX3241
(V = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T
to T , unless otherwise noted. Typical values are at T = +25°C.)
MAX A
CC
A
MIN
PARAMETER
CONDITIONS
= 3kΩ, C = 1000pF, one transmitter switching
MIN
TYP
235
0.3
MAX
UNITS
Maximum Data Rate
R
120
kbps
L
L
t
t
PHL
PLH
Receiver Propagation Delay
R_IN to R_OUT, C = 150pF
µs
L
0.3
Receiver Output Enable Time Normal operation
Receiver Output Disable Time Normal operation
200
200
300
300
ns
ns
ns
ns
Transmitter Skew
Receiver Skew
| t
| t
- t
|
|
PHL PLH
- t
PHL PLH
C
= 150pF to
L
6
4
30
30
V
= 3.3V, R = 3Ω to 7kΩ,
L
CC
1000pF
Transition-Region Slew Rate
+3V to -3V or -3V to +3V,
= +25°C
V/µs
C
= 150pF to
L
T
A
2500pF
_______________________________________________________________________________________
3
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
TIMING CHARACTERISTICS—MAX3237
(V = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T
to T , unless otherwise noted. Typical values are at T = +25°C.)
MAX A
CC
A
MIN
PARAMETER
CONDITIONS
= 3kΩ, C = 1000pF, one transmitter switching,
MIN
TYP
MAX
UNITS
R
L
L
250
MBAUD = GND
V
= 3.0V to 4.5V, R = 3kΩ, C = 250pF,
CC
L
L
Maximum Data Rate
1000
1000
kbps
one transmitter switching, MBAUD = V
CC
V
= 4.5V to 5.5V, R = 3kΩ, C = 1000pF,
L L
CC
one transmitter switching, MBAUD = V
CC
t
t
0.15
0.15
200
200
100
25
PHL
Receiver Propagation Delay
R_IN to R_OUT, C = 150pF
µs
L
PLH
Receiver Output Enable Time Normal operation
Receiver Output Disable Time Normal operation
ns
ns
ns
ns
ns
| t
| t
| t
- tPLH |, MBAUD = GND
PHL
PHL
Transmitter Skew
Receiver Skew
- tPLH |, MBAUD = V
CC
50
- t
|
PHL PLH
MBAUD =
GND
6
24
4
30
150
30
C
= 150pF
L
V
CC
= 3.3V, R = 3Ω to 7kΩ,
L
to 1000pF
MBAUD =
V
CC
Transition-Region Slew Rate
+3V to -3V or -3V to +3V,
= +25°C
V/µs
T
A
C
= 150pF to 2500pF,
MBAUD = GND
L
Note 2: MAX3222/MAX3232/MAX3241: C1–C4 = 0.1µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested at 5.0V ±10%.
MAX3237: C1–C4 = 0.1µF tested at 3.3V ±5%; C1–C4 = 0.22µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested
at 5.0V ±10%.
Note 3: Transmitter input hysteresis is typically 250mV.
__________________________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s
(V = +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T = +25°C, unless otherwise noted.)
CC
A
MAX3222/MAX3232
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA
MAX3222/MAX3232
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3222/MAX3232
SLEW RATE
vs. LOAD CAPACITANCE
7/MAX3241
6
22
20
18
16
40
35
5
4
V
+
FOR DATA RATES UP TO 235kbps
OUT
235kbps
3
30
25
2
14
12
10
8
-SLEW
+SLEW
1
120kbps
20kbps
0
20
15
-1
-2
-3
-4
-5
-6
6
4
2
0
10
5
V
OUT
-
0
0
1000
2000
3000 4000
5000
0
1000
2000
3000 4000
5000
150 1000
2000
3000 4000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
4
_______________________________________________________________________________________
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241
_____________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s (c o n t in u e d )
(V = +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T = +25°C, unless otherwise noted.)
CC
A
MAX3241
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3241
SLEW RATE
vs. LOAD CAPACITANCE
MAX3241
SUPPLY CURRENT vs. LOAD
CAPACITANCE WHEN TRANSMITTING DATA
7.5
24
22
45
40
35
30
235kbps
V
+
OUT
5.0
2.5
0
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
6
4
0
0
1000
2000
3000 4000
5000
0
1000
2000
3000 4000
5000
0
1000
2000
3000 4000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3237
MAX3237
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = GND)
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = GND)
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = V
)
CC
7.5
5.0
2.5
0
12
7.5
1Mbps
10
8
-SLEW
+SLEW
5.0
2.5
0
2Mbps
1.5Mbps
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
6
4
3kΩ + C LOADS
L
3kΩ + C LOAD, EACH OUTPUT
L
V
CC
= 3.3V
V
CC
= 3.3V
-2.5
-5.0
-7.5
-2.5
-5.0
-7.5
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
3kΩ + C LOADS
1.5Mbps
1Mbps
2Mbps
2
0
L
V
CC
= 3.3V
0
1000
2000
3000 4000
5000
0
1000
2000
3000 4000
5000
0
500
1000
1500
2000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3237
SUPPLY CURRENT vs.
LOAD CAPACITANCE (MBAUD = GND)
MAX3237
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = V
SKEW vs. LOAD CAPACITANCE
(t - t
)
CC
)
PLH PHL
60
50
40
30
70
60
50
40
30
20
70
1 TRANSMITTER AT 512kbps
4 TRANSMITTERS AT 32kbps
60
50
3kΩ + C LOADS
240kbps
120kbps
L
-SLEW, 1Mbps
+SLEW, 1Mbps
-SLEW, 2Mbps
+SLEW, 2Mbps
V
CC
= 3.3V
MBAUD = V
CC
MAX
40
30
AVERAGE; 10 PARTS
20kbps
20
20
10
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C LOAD EACH OUTPUT
10
0
10
0
3kΩ + C LOADS
L
MIN
L
V
CC
= 3.3V
V
CC
= 3.3V
0
0
1000
2000
3000 4000
5000
0
500
1000
1500
2000
0
500
1000
1500 2000
2500
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________
5
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
______________________________________________________________P in De s c rip t io n
PIN
MAX3222
NAME
FUNCTION
MAX3232
MAX3237
MAX3241
DIP/SO
SSOP
1
2
3
4
1
—
1
13
28
27
25
23
28
27
24
Receiver Enable. Active low.
EN
C1+
V+
Positive Terminal of Voltage-Doubler Charge-Pump
Capacitor
2
3
4
2
+5.5V Generated by the Charge Pump
Negative Terminal of Voltage-Doubler Charge-Pump
Capacitor
3
C1-
Positive Terminal of Inverting Charge-Pump
Capacitor
5
5
4
1
1
C2+
Negative Terminal of Inverting Charge-Pump
Capacitor
6
7
6
7
5
6
3
4
2
3
C2-
V-
-5.5V Generated by the Charge Pump
RS-232 Transmitter Outputs
5, 6, 7,
10, 12
8, 15
8, 17
7, 14
9, 10, 11
T_OUT
9, 14
9, 16
8, 13
9, 12
8, 9, 11
4–8
R_IN
RS-232 Receiver Inputs
10, 13
10, 15
18, 20, 21
15–19
R_OUT
TTL/CMOS Receiver Outputs
17, 19, 22,
23, 24
11, 12
12, 13
10, 11
12, 13, 14
T_IN
GND
TTL/CMOS Transmitter Inputs
16
17
18
—
18
19
15
16
—
—
2
25
26
22
—
Ground
26
14
—
V
CC
+3.0V to +5.5V Supply Voltage
Shutdown Control. Active low.
No Connection
20
SHDN
11, 14
N.C.
MegaBaud Control Input. Connect to GND for normal
operation; connect to V for 1Mbps transmission rates.
CC
—
—
—
—
—
—
15
16
—
MBAUD
R_OUTB
7/MAX3241
Noninverting Complementary Receiver Outputs.
Always active.
20, 21
6
_______________________________________________________________________________________
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241
The MAX3222/MAX3237/MAX3241’s output stage is
turned off (high impedance) when the device is in shut-
_______________De t a ile d De s c rip t io n
Du a l Ch a rg e -P u m p Vo lt a g e Co n ve rt e r
The MAX3222/MAX3232/MAX3237/MAX3241’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
d own mod e . Whe n the p owe r is off, the MAX3222/
MAX3232/MAX3237/MAX3241 permit the outputs to be
driven up to ±12V.
The transmitter inputs do not have pull-up resistors.
Connect unused inputs to GND or V
.
CC
the input voltage (V ) over the 3.0V to 5.5V range. The
CC
charge pumps operate in a discontinuous mode; if the
output voltages are less than 5.5V, the charge pumps
are enabled, and if the output voltages exceed 5.5V, the
c ha rg e p ump s a re d is a b le d . Ea c h c ha rg e p ump
requires a flying capacitor (C1, C2) and a reservoir
capacitor (C3, C4) to generate the V+ and V- supplies.
MAX3 2 3 7 Me g a Ba u d Op e ra t io n
In norma l op e ra ting mod e (MBAUD = GND), the
MAX3237 transmitters guarantee a 250kbps data rate
with worst-case loads of 3kΩ in parallel with 1000pF.
This provides compatibility with PC-to-PC communica-
tion software, such as Laplink™.
For higher speed serial communications, the MAX3237
features MegaBaud operation. In MegaBaud operating
RS -2 3 2 Tra n s m it t e rs
The transmitters are inverting level translators that con-
vert CMOS-logic levels to 5.0V EIA/TIA-232 levels.
mode (MBAUD = V ), the MAX3237 transmitters guar-
CC
antee a 1Mbps data rate with worst-case loads of 3kΩ in
The MAX3222/MAX3232/MAX3241 transmitters guaran-
tee a 120kbps data rate with worst-case loads of 3kΩ in
parallel with 1000pF, providing compatibility with PC-to-
PC c ommunic a tion s oftwa re (s uc h a s La p Link™).
Typically, these three devices can operate at data rates
of 235kbps. Transmitters can be paralleled to drive multi-
ple receivers or mice.
parallel with 250pF for 3.0V < V < 4.5V. For 5V ±10%
CC
operation, the MAX3237 transmitters guarantee a 1Mbps
data rate into worst-case loads of 3kΩ in parallel with
1000pF.
LapLink is a trademark of Traveling Software.
V
CC
V
CC
0.1µF
0.1µF
V
V
CC
CC
C1+
C1+
V+
V-
V+
V-
C1
C1
C3
C4
C3
C4
C1-
C1-
MAX3222
MAX3232
MAX3237
MAX3241
MAX3222
MAX3232
MAX3237
MAX3241
C2+
C2+
C2
C2
C2-
C2-
T_ OUT
R_ IN
T_ OUT
R_ IN
T_ IN
T_ IN
R_ OUT
EN*
R_ OUT
EN*
0V
0V
5k
5k
V
CC
V
CC
SHDN*
SHDN*
2500pF
150pF
3k
7k
GND
GND
* MAX3222/MAX3241 ONLY
MINIMUM SLEW-RATE TEST CIRCUIT
Figure 1. Slew-Rate Test Circuits
_______________________________________________________________________________________
MAXIMUM SLEW-RATE TEST CIRCUIT
7
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
RS -2 3 2 Re c e ive rs
The receivers convert RS-232 signals to CMOS-logic out-
V
CC
put levels. The MAX3222/MAX3237/MAX3241 receivers
have inverting three-state outputs. In shutdown, the
receivers can be active or inactive (Table 1).
The complementary outputs on the MAX3237 (R1OUTB)
and the MAX3241 (R1OUTB, R2OUTB) are always active,
regardless of the state of EN or SHDN. This allows for
Ring Indicator applications without forward biasing other
devices connected to the receiver outputs. This is ideal
PREVIOUS
RS-232
V
CC
Rx
for s ys te ms whe re V
is s e t to 0V in s hutd own to
CC
PROTECTION
DIODE
accommodate peripherals, such as UARTs (Figure 2).
5k
MAX3 2 2 2 /MAX3 2 3 7 /MAX3 2 4 1
S h u t d o w n Mo d e
UART
Tx
Supply current falls to less than 1µA in shutdown mode
(SHDN = low). When shut down, the device’s charge
GND
SHDN = GND
pumps are turned off, V+ is pulled down to V , V- is
CC
pulled to ground, and the transmitter outputs are dis-
abled (high impedance). The time required to exit shut-
down is typically 100µs, as shown in Figure 3. Connect
a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM
ACTIVE RECEIVER OUTPUT IN SHUTDOWN.
SHDN to V if the shutdown mode is not used. SHDN
CC
has no effect on R_OUT or R_OUTB.
MAX3 2 2 2 /MAX3 2 3 7 /MAX3 2 4 1
En a b le Co n t ro l
V
CC
The inverting receiver outputs (R_OUT) are put into a
high-impedance state when EN is high. The complemen-
tary outputs R1OUTB and R2OUTB are always active,
regardless of the state of EN and SHDN (Table 1). EN
has no effect on T_OUT.
TO
µP
LOGIC
TRANSITION
DETECTOR
MAX3237
MAX3241
__________Ap p lic a t io n s In fo rm a t io n
R1OUTB
R1OUT
Ca p a c it o r S e le c t io n
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 capaci-
tors for 3.3V operation. For other supply voltages, refer to
Table 2 for required capacitor values. Do not use values
lower than those listed in Table 2. Increasing the capaci-
tor values (e.g., by a factor of 2) reduces ripple on the
transmitter outputs and slightly reduces power consump-
tion. 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).
V
CC
R1IN
Rx
PROTECTION
DIODE
7/MAX3241
EN = V
CC
5k
UART
T1OUT
T1IN
Tx
GND
SHDN = GND
b) NEW MAX3237/MAX3241: EN SHUTS DOWN RECEIVER OUTPUTS (EXCEPT FOR
B OUTPUTS), SO NO CURRENT FLOWS TO UART IN SHUTDOWN. B OUTPUTS
INDICATE RECEIVER ACTIVITY DURING SHUTDOWN WITH EN HIGH.
When using the minimum required capacitor values,
make sure the capacitor value does not degrade exces-
sively with temperature. If in doubt, use capacitors with a
higher nominal value. The capacitor’s equivalent series
resistance (ESR), which usually rises at low tempera-
tures, influences the amount of ripple on V+ and V-.
Figure 2. Detection of RS-232 Activity when the UART and
Interface are Shut Down; Comparison of MAX3237/MAX3241
(b) with Previous Transceivers (a).
8
_______________________________________________________________________________________
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241
P o w e r-S u p p ly De c o u p lin g
In most circumstances, a 0.1µF bypass capacitor is
adequate. In applications that are sensitive to power-
Table 1. MAX3222/MAX3237/MAX3241
Shutdown and Enable Control Truth Table
supply noise, decouple V
to ground with a capacitor
R_OUTB
CC
SHDN
EN
T_OUT
R_OUT
(MAX3237/
MAX3241)
of the same value as charge-pump capacitor C1. Connect
bypass capacitors as close to the IC as possible.
0
0
1
1
0
1
0
1
High-Z
High-Z
Active
Active
Active
High-Z
Active
High-Z
Active
Active
Active
Active
Op e ra t io n Do w n t o 2 .7 V
Tra ns mitte r outp uts will me e t EIA/TIA-562 le ve ls of
±3.7V with supply voltages as low as 2.7V.
Tra n s m it t e r Ou t p u t s w h e n
Ex it in g S h u t d o w n
Figure 3 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232 lev-
els (one transmitter input is high, the other is low).
Each transmitter is loaded with 3kΩ in parallel with
2500pF. 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.
Table 2. Required Minimum Capacitor Values
V
(V)
C1
(µF)
C2, C3, C4
(µF)
CC
MAX3222/MAX3232/MAX3241
3.0 to 3.6
4.5 to 5.5
3.0 to 5.5
MAX3237
3.0 to 3.6
3.15 to 3.6
4.5 to 5.5
3.0 to 5.5
0.1
0.047
0.1
0.1
0.33
0.47
Mo u s e Drive a b ilit y
The MAX3241 has been specifically designed to power
serial mice while operating from low-voltage power sup-
plies. It has been tested with leading mouse brands from
manufacturers such as Microsoft and Logitech. The
MAX3241 successfully drove all serial mice tested and
met their respective current and voltage requirements.
Figure 4a shows the transmitter output voltages under
increasing load current at 3.0V. Figure 4b shows a typical
mouse connection using the MAX3241.
0.22
0.1
0.22
0.1
0.047
0.22
0.33
1.0
5V/div
2V/div
T2
T1
50µs/div
V
CC
= 3.3V
C1–C4 = 0.1µF
Figure 3. Transmitter Outputs when Exiting Shutdown or
Powering Up
_______________________________________________________________________________________
9
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
6
5
V
+
4
3
OUT
V
CC
= 3.0V
2
T1
T2
1
V
+
-
OUT
0
-1
-2
-3
-4
-5
-6
V
CC
V
OUT
T3
V
-
OUT
0
1
2
3
4
5
6
7
LOAD CURRENT PER TRANSMITTER (mA)
Figure 4a. MAX3241 Transmitter Output Voltage vs. Load Current per Transmitter
V
CC
= 3V
to 5.5V
0.1µF
26
27
3
28
24
V
CC
C1+
C1-
V+
V-
C
C3
C4
1
COMPUTER SERIAL PORT
1
2
C2+
MAX3241
C
2
C2-
9
T1IN
14
T1OUT
T2OUT
T3OUT
+V
+V
T2IN
10
11
13
T3IN
12
21
V
CC
-V
R1OUTB
GND
Tx
20
19
R2OUTB
R1OUT
R1IN
R2IN
R3IN
R4IN
4
5
6
7/MAX3241
5k
5k
18
17
16
R2OUT
R3OUT
5k
5k
5k
7
R4OUT
R5OUT
EN
MOUSE
15
23
R5IN
8
22
SHDN
GND
25
Figure 4b. Mouse Driver Test Circuit
10 ______________________________________________________________________________________
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241
V
CC
5V/div
T1IN
0.1µF
5V/div
5V/div
T1OUT
R1OUT
V
CC
C1+
V+
V-
C3
C4
C1
C1-
C2+
MAX3222
MAX3232
MAX3237
MAX3241
C2
5µs/div
C2-
V
= 3.3V
CC
T_ OUT
T_ IN
Figure 6. MAX3241 Loopback Test Result at 120kbps
R_ IN
5k
R_ OUT
EN*
0V
1000pF
5V/div
T1IN
V
CC
SHDN*
GND
5V/div
5V/div
T1OUT
R1OUT
* MAX3222/MAX3241 ONLY
Figure 5. Loopback Test Circuit
2µs/div
V
CC
= 3.3V
Figure 7. MAX3241 Loopback Test Result at 235kbps
Hig h Da t a Ra t e s
The MAX3222/MAX3232/MAX3241 maintain the RS-232
±5.0V minimum transmitter output voltage even at high
data rates. Figure 5 shows a transmitter loopback test
c irc uit. Fig ure 6 s hows a loop b a c k te s t re s ult a t
120kbps, and Figure 7 shows the same test at 235kbps.
For Figure 6, all transmitters were driven simultaneously
at 120kbps into RS-232 loads in parallel with 1000pF.
For Figure 7, a single transmitter was driven at 235kbps,
and all transmitters were loaded with an RS-232 receiver
in parallel with 1000pF.
+5V
T_IN
0V
+5V
0V
-5V
+5V
0V
T_OUT = R_IN
5k + 250pF
The MAX3237 maintains the RS-232 ±5.0V minimum
transmitter output voltage at data rates up to 1Mbps.
Figure 8 shows a loopback test result at 1Mbps with
R_OUT
150pF
MBAUD = V . For Fig ure 8, a ll tra ns mitte rs we re
loaded with an RS-232 receiver in parallel with 250pF.
200ns/div
CC
V
CC
= 3.3V
Figure 8. MAX3237 Loopback Test Result at 1000kbps
(MBAUD = V
)
CC
______________________________________________________________________________________ 11
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
In t e rc o n n e c t io n w it h 3 V a n d 5 V Lo g ic
The MAX3222/MAX3232/MAX3237/MAX3241 c a n
directly interface with various 5V logic families, includ-
ing ACT and HCT CMOS. See Table 3 for more informa-
tion on possible combinations of interconnections.
Table 3. Logic-Family Compatibility
with Various Supply Voltages
SYSTEM
POWER-
SUPPLY
VOLTAGE
(V)
MAX32_ _
V
CC
SUPPLY
VOLTAGE
(V)
COMPATIBILITY
Compatible with all CMOS
families.
3.3
5
3.3
5
Compatible with all TTL
and CMOS-logic families.
Compatible with ACT and
HCT CMOS, and with TTL.
Incompatible with AC, HC,
and CD4000 CMOS.
5
3.3
__________________________________________________Typ ic a l Op e ra t in g Circ u it s
+3.3V
0.1µF
+3.3V
0.1µF
17
16
V
V
CC
CC
3
7
2
4
5
6
2
6
1
3
4
5
C1+
C1+
V+
V+
C1
0.1µF
C3*
C3*
0.1µF
0.1µF
0.1µF
0.1µF
C1-
C1-
MAX3222
MAX3232
C2+
C2+
V-
V-
C2
0.1µF
C4
0.1µF
C4
0.1µF
C2-
C2-
12
T1OUT
T1IN
15
8
11
T1OUT
T1IN
14
7
TTL/CMOS
INPUTS
RS-232
OUTPUTS
TTL/CMOS
INPUTS
RS-232
OUTPUTS
T2IN
T2OUT
R1IN
11
T2IN
T2OUT
R1IN
10
7/MAX3241
14
9
13 R1OUT
10 R2OUT
13
8
12 R1OUT
TTL/CMOS
OUTPUTS
TTL/CMOS
OUTPUTS
RS-232
INPUTS
5k
RS-232
INPUTS
5k
R2IN
9
R2OUT
R2IN
5k
5k
EN
1
18
SHDN
GND
16
GND
15
PIN NUMBERS REFER TO DIP/SO PACKAGES.
* C3 CAN BE RETURNED TO EITHER V OR GROUND.
* C3 CAN BE RETURNED TO EITHER V OR GROUND.
CC
CC
SEE TABLE 2 FOR CAPACITOR SELECTION
12 ______________________________________________________________________________________
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241
_____________________________________Typ ic a l Op e ra t in g Circ u it s (c o n t in u e d )
0.1µF
+3.3V
26
26
0.1µF
0.1µF
0.1µF
V
V
CC
CC
27
4
28
27
3
28
C1+
C1+
V+
V-
V+
0.1µF
0.1µF
0.1µF
0.1µF
C3*
25
1
24
1
C1-
C1-
0.1µF
MAX3237
C2+
MAX3241
C2+
V-
C4
0.1µF
3
2
C2-
C2-
T1IN
T1IN
T1OUT
T2OUT
T3OUT
5
6
7
24
T1OUT
9
14
13
T1
T2
T2IN
T3IN
T2IN
23
22
T2OUT 10
TTL/CMOS
INPUTS
RS-232
OUTPUTS
T3IN
RS-232
OUTPUTS
11
12
21
LOGIC
INPUTS
T3OUT
R1IN
T3
T4
T5
R1OUTB
T4IN
T5IN
T4OUT 10
19
17
R2OUTB
R1OUT
20
19
12
T5OUT
R1IN
4
5
R1OUTB
R1OUT
16
21
5k
R2OUT
R3OUT
R4OUT
R2IN
R3IN
R4IN
R5IN
18
17
16
8
9
R1
R2
R3
5k
5k
TTL/CMOS
OUTPUTS
5k
6
7
8
RS-232
INPUTS
RS-232
INPUTS
R2OUT
R3OUT
R2IN
R3IN
20
18
LOGIC
OUTPUTS
5k
5k
11
5k
5k
R5OUT
EN
15
23
15
14
MBAUD
SHDN
EN
13
22
SHDN
GND
2
GND
25
* C3 CAN BE RETURNED TO EITHER V OR GROUND.
* C3 CAN BE RETURNED TO EITHER V OR GROUND.
CC
CC
______________________________________________________________________________________ 13
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
_____________________________________________P in Co n fig u ra t io n s (c o n t in u e d )
TOP VIEW
EN
C1+
V+
1
2
SHDN
20
19
18
17
16
15
14
13
12
11
V
CC
1
2
3
4
5
6
7
8
C1+
V+
V
CC
16
15
14
GND
T1OUT
R1IN
R1OUT
N.C.
3
GND
C1-
4
C1-
T1OUT
MAX3222
C2+
C2-
5
MAX3232
C2+
C2-
13 R1IN
12 R1OUT
11 T1IN
6
V-
7
V-
T2OUT
T1IN
T2IN
N.C.
8
10
9
T2OUT
R2IN
T2IN
R2IN
9
R2OUT
R2OUT
10
DIP/SO/TSSOP
SSOP/TSSOP
28
1
28
27
26
25
24
23
22
1
C2+
GND
C2+
C2-
C1+
V+
C1+
V+
2
3
27
26
2
3
4
5
6
7
8
9
V
CC
C2-
V-
V
CC
V-
25 C1-
4
R1IN
R2IN
R3IN
R4IN
R5IN
T1OUT
GND
C1-
T1IN
T1OUT
T2OUT
T3OUT
5
24
23
MAX3237
MAX3241
6
T2IN
EN
7/MAX3241
7
22 T3IN
21
SHDN
8
21 R1OUTB
R1IN
R2IN
R1OUT
9
20
19
R2OUTB
R1OUT
20
19
R2OUT
T4IN
10
11
12
13
14
T4OUT
R3IN
T2OUT 10
18 R3OUT
T5IN
T3OUT
T3IN
11
12
13
14
18 R2OUT
17 R3OUT
17
T5OUT
EN
16 R1OUTB
16
15
R4OUT
R5OUT
T2IN
15
MBAUD
T1IN
SHDN
SSOP
SO/SSOP/TSSOP
14 ______________________________________________________________________________________
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
7/MAX3241
Ord e rin g In fo rm a t io n (c o n t in u e d )
PART
TEMP. RANGE
-40°C to +85°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
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
20 TSSOP
PART
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
PIN-PACKAGE
16 Wide SO
16 Plastic DIP
28 SSOP
MAX3222EUP
MAX3222EAP
MAX3222EWN
MAX3222EPN
MAX3222C/D
MAX3232CUE
MAX3232CSE
MAX3232CWE
MAX3232CPE
MAX3232EUE
MAX3232ESE
MAX3232EWE
MAX3232EPE
MAX3237CAI
MAX3237EAI
MAX3241CUI
MAX3241CAI
MAX3241CWI
MAX3241EUI
MAX3241EAI
MAX3241EWI
20 SSOP
18 SO
18 Plastic DIP
Dice*
-40°C to +85°C
0°C to +70°C
28 SSOP
28 TSSOP
28 SSOP
0°C to +70°C
16 TSSOP
0°C to +70°C
28 SO
16 Narrow SO
16 Wide SO
16 Plastic DIP
16 TSSOP
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
28 TSSOP
28 SSOP
28 SO
16 Narrow SO
* Dice are tested at T = +25°C, DC parameters only.
A
______3 V-P o w e re d EIA/TIA-2 3 2 a n d EIA/TIA-5 6 2 Tra n s c e ive rs fro m Ma x im
GUAR-
ANTEED
DATA
RATE
(kbps)
POWER-
SUPPLY
VOLTAGE
(V)
No. OF
No. OF
TRANSMITTERS/
RECEIVERS
EIA/
RECEIVERS
ACTIVE IN
SHUTDOWN
PART
TIA-232
OR 562
FEATURES
MAX212
MAX218
3.0 to 3.6
3/5
2/2
5
2
120
120
232
232
Drives mice
Operates directly from batteries
without a voltage regulator
1.8 to 4.25
MAX562
MAX563
2.7 to 5.25
3.0 to 3.6
3/5
2/2
5
2
230
230
562
562
Wide supply range
0.1µF capacitors
AutoShutdown, complementary
receiver, drives mice, transient
detection
MAX3212
2.7 to 3.6
3/5
5
235
232
MAX3222
MAX3223
MAX3232
3.0 to 5.5
3.0 to 5.5
3.0 to 5.5
2/2
2/2
2/2
2
2
120
120
120
232
232
232
0.1µF capacitors
0.1µF capacitors, AutoShutdown
0.1µF capacitors
N/A
0.1µF capacitors, 1 complemen-
tary receiver, MegaBaud
operation
MAX3237
MAX3241
MAX3243
3.0 to 5.5
3.0 to 5.5
3.0 to 5.5
5/3
3/5
3/5
3
5
1
250/1000
120
232
232
232
0.1µF capacitors, 2 complemen-
tary receivers, drives mice
0.1µF capacitors, AutoShutdown,
complementary receiver,
drives mice
120
______________________________________________________________________________________ 15
3.0V to 5.5V, Low -Pow e r, up to 1Mbps , True RS-232
Tra ns c e ive rs Us ing Four 0.1µF Exte rna l Ca pa c itors
___________________Ch ip To p o g ra p h y
___________________Ch ip In fo rm a t io n
MAX3222
PART
TRANSISTOR COUNT
SHDN
V+ C1+
EN
V
CC
MAX3222
MAX3232
MAX3237
MAX3241
339
339
GND
1212
894
C1-
C2+
T1OUT
R1IN
0. 127"
(3. 225mm)
C2-
V-
R1OUT
T2IN T1IN
T2OUT R2IN R2OUT
0. 087"
(2. 209mm)
TRANSISTOR COUNT: 339
SUBSTRATE CONNECTED TO GND
________________________________________________________P a c k a g e In fo rm a t io n
7/MAX3241
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.
16 ____________________Ma x im In t e g ra t e d P ro d u c t s , 1 2 0 S a n Ga b rie l Drive , S u n n yva le , CA 9 4 0 8 6 4 0 8 -7 3 7 -7 6 0 0
© 1999 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
相关型号:
MAX3222E
【15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 Transceivers
MAXIM
MAX3222E-MAX3246E
【15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 Transceivers
MAXIM
MAX3222EAP
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232 Transceivers Using Four 0.1レF External Capacitors
MAXIM
MAX3222EC/D
【15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 Transceivers
MAXIM
MAX3222EC/D+
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 Transceivers
MAXIM
©2020 ICPDF网 联系我们和版权申明