19-4343; Rev 0; 10/08
KIT
ATION
EVALU
BLE
AVAILA
3Mbps RS-232 Transceivers with
Low-Voltage Interface
General Description
Features
♦
Data Rate Up to 3Mbps
♦
Low-Voltage Logic Interface
♦
+3V to +5.5V Supply Voltage
♦
AutoShutdown Plus
♦
1µA Shutdown Current
MAX13234E–MAX13237E
R1OUT
LOGIC-LEVEL TRANSLATION
The MAX13234E–MAX13237E are +3V to +5.5V pow-
ered EIA/TIA-232 and V.28/V.24 communications inter-
faces with high data-rate capabilities (up to 3Mbps), a
flexible logic voltage interface, and enhanced electro-
static discharge (ESD) protection. All receiver inputs
and transmitter outputs are protected to ±15kV IEC
61000–4-2 Air Gap Discharge, ±8kV IEC 61000-4-2
Contact Discharge, and ±15kV Human Body Model.
The MAX13234E/MAX13235E have two receivers and
two transmitters, while the MAX13236E/MAX13237E
have a single receiver and transmitter. The transmitters
have a low-dropout transmitter output stage, delivering
true RS-232 performance from a +3V to +5.5V supply
based on a dual charge pump. The charge pump
requires only four small 0.1µF capacitors for operation
from a +3.3V supply.
All devices achieve a 1µA supply current using Maxim’s
AutoShutdown Plus™ feature. These devices automati-
cally enter a low-power shutdown mode when the
RS-232 cable is disconnected or the devices driving
the transmitter and receiver inputs are inactive for more
than 30s.
The MAX13234E–MAX13237E are available in space-
saving TQFN and TSSOP packages and operate over
the -40°C to +85°C extended temperature range.
Functional Diagrams
1.62V to V
CC
3.0V to 5.5V
C
BYPASS1
C
BYPASS2
V
L
C1+
C1
C1-
C2+
C2
C2-
T1IN
TTL/CMOS
INPUTS
T2IN
V
CC
V+
C3
MAX13234E
MAX13235E
V-
C4
T1OUT
RS-232
OUTPUTS
T2OUT
R1IN
5kΩ
RS-232
INPUTS
Applications
Telematics
GPS Systems
Industrial Systems
Portable Devices
Wireless Modules
POS Systems
Communication Systems
Data Cables
TTL/CMOS
OUTPUTS
R2OUT
FORCEOFF
FORCEON
READY
R2IN
5kΩ
GND
AutoShutdown Plus is a registered trademark of Maxim
Integrated Products, Inc.
Functional Diagrams continued at end of data sheet.
Ordering Information/Selector Guide
PART
MAX13234EEUP+
MAX13234EETP+
MAX13235EEUP+
MAX13235EETP+
MAX13236EETE+
MAX13237EETE+
DRIVERS/
RECEIVERS
2x2
2x2
2x2
2x2
1x1
1x1
MAXIMUM
DATA RATE
250kbps
250kbps
3Mbps
3Mbps
250kbps
3Mbps
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
20 TSSOP
20 TQFN-EP*
20 TSSOP
20 TQFN-EP*
16 TQFN-EP*
16 TQFN-EP*
+Denotes
a lead-free/RoHS-compliant package.
*EP
= Exposed pad.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
3Mbps RS-232 Transceivers with
Low-Voltage Interface
MAX13234E–MAX13237E
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
V
CC
...................................................................... -0.3V to +6.0V
V
L
......................................................................... -0.3V to +6.0V
V+ ........................................................................ -0.3V to +7.0V
V- ......................................................................... +0.3V to -7.0V
(V+) + |(V-)| ..................................................................... +13.0V
T_IN,
FORCEOFF,
FORCEON ..................... -0.3V to (V
L
+ 0.3V)
R_IN ................................................................................... ±25V
T_OUT.............................................................................. ±13.2V
R_OUT, READY ........................................... -0.3V to (V
L
+ 0.3V)
Short-Circuit Duration
T_OUT to GND ......................................................... Continuous
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TQFN (derate 20.8mW/°C above +70°C) ..... 1666mW
20-Pn TSSOP (derate 10.9mW/°C above +70°C) ...... 879mW
20-Pin TQFN (derate 21.3mW/°C above +70°C) ..... 1702mW
Junction-to-Case Thermal Resistance (θ
JC
) (Note 1)
16-Pin TQFN ................................................................. 2°C/W
20-Pin TSSOP ............................................................. 20°C/W
20-Pin TQFN ................................................................. 2°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) (Note 1)
16-Pin TQFN ............................................................... 30°C/W
20-Pin TSSOP ............................................................. 73°C/W
20-Pin TQFN ............................................................... 29°C/W
Operating Temperature Range
MAX1323x Operating Temperature Range .... -40°C to +85°C
MAX1323x Operating Temperature Range .. -40°C to +105°C
Storage Temperature Range ........................... -65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300
º
C
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
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
CC
= +3V to +5.5V, V
L
= +1.62V to V
CC
, T
A
= -40°C to +85°C, C1–C4 = 0.1µF, V
CC
= V
L
, tested at 3.3V ±10%. Typical values are
at TA = +25°C.) (Note 2)
PARAMETER
Supply Voltage
Logic Supply Voltage
SYMBOL
V
CC
V
L
FORCEOFF
= FORCEON = V
L
, no loads
V
L
= 0V
V
CC
Supply Current
I
CC
AutoShutDown Plus,
FORCEOFF
= V
L
,
FORCEON = GND, all R_IN idle, all T_IN
idle.
FORCEOFF
= GND
V
CC
= +5.5V
FORCEOFF
= GND
Tested at room temperature only
Tested at room temperature only
2/3 x V
L
60
±0.01
V
OL
V
OH
I
OUT
= 0.8mA
I
OUT
= -0.5mA
V
L
- 0.6 V
L
- 0.1
±1
0.4
CONDITIONS
MIN
3
1.62
0.3
1
1
1
1
1
TYP
MAX
5.5
V
CC
1
10
10
10
10
10
1/3 x V
L
µA
UNITS
V
V
mA
V
CC
Shutdown Current
V
L
Supply Current
V
L
Shutdown Current
Input Threshold Low
Input Threshold High
Input Hysteresis
Input Leakage Current
RECEIVER OUTPUTS (READY)
Output-Voltage Low
Output-Voltage High
I
CCSH
I
L
I
LSH
V
IL
V
IH
µA
µA
µA
V
V
mV
µA
V
V
LOGIC INPUTS (T_IN, FORCEON,
FORCEOFF,
Referred to V
L
)
2
_______________________________________________________________________________________
3Mbps RS-232 Transceivers with
Low-Voltage Interface
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3V to +5.5V, V
L
= +1.62V to V
CC
, T
A
= -40°C to +85°C, C1–C4 = 0.1µF, V
CC
= V
L
, tested at 3.3V ±10%. Typical values are
at TA = +25°C.) (Note 2)
PARAMETER
RECEIVER INPUTS
Input-Voltage Range
Input Threshold Low
Input Threshold High
Input Hysteresis
Input Resistance
TRANSMITTER OUTPUTS
Output-Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
V
CC
= 0V or +3V to +5.5V, V
OUT
= ±12V,
transmitters disabled
Positive threshold, Figure 1
Negative threshold, Figure 1
Figure 1
t
WU
V
L
= 5V, Figure 1 (Note 3)
15
-2.7
-0.3
100
30
60
+0.3
All transmitter outputs loaded with 3kΩ to
GND
V
CC
= V+ = V- = 0V, transmitter outputs =
±2V
±5
300
-60
-25
±5.4
10M
+60
+25
V
Ω
mA
µA
3
V
IL
V
IH
T
A
= +25°C
T
A
= +25°C
V
CC
= +3.3V
V
CC
= +5V
V
CC
= +3.3V
V
CC
= +5V
-25
0.6
0.8
1.2
1.5
1.5
1.8
0.5
5
7
2.4
2.4
+25
V
V
V
V
kΩ
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX13234E–MAX13237E
AutoShutdown Plus (FORCEON = GND,
FORCEOFF
= V
L
)
Receiver Input Threshold Valid
Level
Receiver Input Threshold
Invalid Level
Receiver or Transmitter Edge-to-
Transmitters Enabled
Receiver or Transmitter Edge-to-
Transmitters Shutdown
2.7
V
V
V
µs
s
t
AUTOSHDN
V
L
= 5V, Figure 1 (Note 3)
TIMING CHARACTERISTICS (MAX13234E/MAX13236E)
Maximum Data Rate
Receiver Propagation Delay
Transmitter Skew
Receiver Skew
t
RPHL
,
t
RPLH
|t
TPHL
-
t
TPLH
|
|t
RPHL
-
t
RPLH
|
R
L
= 3kΩ, C
L
= 1000pF, one transmitter
switching
C
L
= 150pF, Figures 2, 3
Figures 4, 5 (Note 4)
Figures 2, 3
250
0.15
100
50
kbps
µs
ns
ns
_______________________________________________________________________________________
3
3Mbps RS-232 Transceivers with
Low-Voltage Interface
MAX13234E–MAX13237E
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3V to +5.5V, V
L
= +1.62V to V
CC
, T
A
= -40°C to +85°C, C1–C4 = 0.1µF, V
CC
= V
L
, tested at 3.3V ±10%. Typical values are
at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
V
CC
= +3.3V, T
A
= +25°C, R
L
= 3kΩ to 7kΩ,
measured from +3V to -3V or -3V to +3V,
one transmitter switching, C
L
= 150pF to
1000pF
R
L
= 3kΩ, C
L
= 250pF, one transmitter
switching
Maximum Data Rate
R
L
= 3kΩ, C
L
= 150pF, one transmitter
switching
t
RPHL
,
t
RPLH
|t
TPHL
–
t
TPLH
|
|t
RPHL
–
t
RPLH
|
C
L
= 150pF, Figures 2, 3
Figures 4, 5 (Note 4)
Figures 2, 3
V
CC
= +3.3V, T
A
= +25°C, R
L
= 3kΩ to 7kΩ,
measured from T
_OUT
= +3V to -3V or -3V
to +3V, one transmitter switching, C
L
=
150pF to 1000pF
Human Body Model
R_IN, T_OUT to GND
IEC 61000-4-2 Air Discharge
IEC 61000-4-2 Contact Discharge
MIN
TYP
MAX
UNITS
Transition-Region Slew Rate
6
30
V/µs
TIMING CHARACTERISTICS (MAX13235E/MAX13237E)
1
Mbps
3
0.15
25
50
µs
ns
ns
Receiver Propagation Delay
Transmitter Skew
Receiver Skew
Transition-Region Slew Rate
24
150
V/µs
ESD PROTECTION
±15
±15
±8
kV
Note 2:
All devices are 100% production tested at T
A
= +85°C. All temperature limits are guaranteed by design.
Note 3:
A transmitter/receiver edge is defined as a transition through the transmitter/receiver input-logic thresholds.
Note 4:
Transmitter skew is measured at the transmitter zero cross points.
4
_______________________________________________________________________________________
3Mbps RS-232 Transceivers with
Low-Voltage Interface
Test Circuits/Timing Diagram
MAX13234E–MAX13237E
RECEIVER
INPUTS
TRANSMITTER
INPUTS
TRANSMITTER
OUTPUTS
t
AUTOSHDN
V
CC
READY
0
V+
V+
V
CC
0
V-
V-
t
WU
t
AUTOSHDN
t
WU
Figure 1. AutoShutdown Plus, and READY Timing Diagram
T_IN
T_OUT R_IN
R_OUT
C
L
Figure 2. Receiver Test Circuit
_______________________________________________________________________________________
5
嵌入式系统
