19-1628; Rev 0; 2/00
1Mbps, 1µA RS-232 Transmitters in SOT23-6
General Description
The MAX3188/MAX3189 single RS-232 transmitters in a
SOT23-6 package are for space- and cost-constrained
applications requiring minimal RS-232 communications.
These devices consume only 150µA of supply current
from ±4.5V to ±6V supplies. RS-232 data transmission
is guaranteed up to 250kbps with the MAX3188 and up
to 1Mbps with the MAX3189.
The MAX3188/MAX3189 transmitters are inverting level
translators that convert CMOS-logic levels to 5V
EIA/TIA-232 levels. They feature a shutdown input that
reduces current consumption to only 1µA and forces
the transmitter output into a high-impedance state. The
MAX3188/MAX3189 transmitters have a standard
inverting output.
o
Small 6-Pin SOT23 Package
o
150µA Supply Current
o
Shutdown Reduces Supply Current to 1µA
o
Guaranteed Data Rate
1Mbps (MAX3189)
250kbps (MAX3188)
o
Three-State RS-232 Transmitter Output
o
No External Components Required
Features
MAX3188/MAX3189
Applications
Diagnostic Ports
Telecommunications
Networking Equipment
Set-Top Boxes
Digital Cameras
Hand-Held Equipment
PART
MAX3188EUT-T
MAX3189EUT-T
Ordering Information
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
6 SOT23-6
6 SOT23-6
TOP
MARK
AAHJ
AAHK
Typical Operating Circuit
TOP VIEW
SHDN
V
CC
MAX3188
MAX3189
3 TIN
GND
2
CAPACITORS MAY BE
POLARIZED OR UNPOLARIZED.
TOUT 4
V
EE
5
-5.4V
C
BYPASS2
0.1µF
GND
2
SHDN
1
Pin Configuration
1
+5.4V
C
BYPASS1
0.1µF
6
6
V
CC
MAX3188
MAX3189
5
VEE
TIN
3
4
TOUT
SOT23-6
________________________________________________________________
Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
1Mbps, 1µA RS-232 Transmitters in SOT23-6
MAX3188/MAX3189
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND (Note 1) ................................................-0.3V to +7V
V
EE
to GND (Note 1) ................................................+0.3V to –7V
V
CC
to V
EE
(Note 1) .............................................................+13V
TIN,
SHDN
to GND ...................................................-0.3V to +7V
TOUT to GND (SHDN = GND)..........................................±13.2V
TOUT to GND (SHDN = V
CC
) ................................................±7V
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C)..........691mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
V
CC
and V
EE
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
(V
CC
= +4.5V to +6V, V
EE
= -4.5V to -6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5.4V, V
EE
= -5.4V,
and T
A
= +25°C.) (Note 2)
PARAMETER
DC CHARACTERISTICS
Positive Supply Voltage
Negative Supply Voltage
Positive Supply Current
Negative Supply Current
Shutdown Supply Current
INPUT LOGIC
(TIN,
SHDN)
Input Logic Threshold Low
Input Logic Threshold High
Input Leakage
TIN Input Hysteresis
TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
TIMING CHARACTERISTICS
Maximum Data Rate
Transmitter Skew
t
TS
R
L
= 3kΩ,
C
L
= 1000pF
|t
PHL
- t
PLH
|,
Figure 1
MAX3188EUT
MAX3189EUT
MAX3188EUT
MAX3189EUT
6
0.25
1
100
25
30
V/µs
24
2
150
µs
Mbps
ns
I
TOUT
V
OUT
= ±12V; V
CC
= V
EE
= 0 or V
CC
= +5.4V,
V
EE
= -5.4V;
SHDN
= 0
V
TOUT
R
TOUT
V
CC
= 4.5V, V
EE
= -4.5V, R
L
= 3kΩ
V
CC
= 5.4V, V
EE
= -5.4V, R
L
= 3kΩ
V
CC
= V
EE
= 0, V
TOUT
= ±2V
±3.7
±5
300
±35
±60
±25
V
Ω
mA
µA
V
IL
V
IH
2.0
±0.01
100
±1
0.8
V
V
µA
mV
V
CC
V
EE
I
CC
I
EE
V
SHDN
= 5V
V
SHDN
= 5V
V
SHDN
= 0
45
4.5
-6
110
34
0.2
1
6
-4.5
170
V
V
µA
µA
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Transition-Region Slew Rate
R
L
= 3kΩ to 7kΩ,
C
L
= 150pF to 1000pF, MAX3188EUT
measured from -3V
to +3V or +3V to -3V,
V
CC
= 5.4V, V
EE
=
MAX3189EUT
-5.4V, T
A
= +25°C
t
EN
Transmitter Enable Time
2
Note 2:
All devices are 100% tested at T
A
= +25°C. All limits over temperature are guaranteed by design.
_______________________________________________________________________________________
1Mbps, 1µA RS-232 Transmitters in SOT23-6
Typical Operating Characteristics
(V
CC
= +5.4V, V
EE
= -5.4V, R
L
= 3kΩ, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. DATA RATE
(C
L
= 150pF)
MAX3188/9 toc01
MAX3188/MAX3189
SUPPLY CURRENT vs. DATA RATE
(C
L
= 1000pF)
MAX3188/9 toc02
MAX3188
SUPPLY CURRENT
vs. OUTPUT CAPACITANCE
3.5
SUPPLY CURRENT (mA)
3.0
2.5
2.0
1.5
1.0
0.5
0
40kbps
120kbps
250kbps
MAX3188/9 toc03
2.5
I
CC
(MAX3189)
7
6
SUPPLY CURRENT (mA)
5
4
3
2
MAX3188
1
MAX3189
4.0
2.0
SUPPLY CURRENT (mA)
I
CC
(MAX3188)
1.5
I
EE
(MAX3189)
1.0
I
EE
(MAX3188)
0.5
0
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
DATA RATE (Mbps)
0
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
DATA RATE (Mbps)
0
500
1000
1500
2000
2500
OUTPUT CAPACITANCE (pF)
MAX3189
SUPPLY CURRENT
vs. OUTPUT CAPACITANCE
MAX3188/9 toc04
MAX3188
SLEW RATE vs. OUTPUT CAPACITANCE
MAX3188/9 toc05
MAX3189
SLEW RATE vs. OUTPUT CAPACITANCE
80
70
SLEW RATE (V/µs)
60
50
40
30
20
+SLEW
-SLEW
MAX3188/9 toc06
14
12
SUPPLY CURRENT (mA)
1Mbps
10
8
6
240kbps
4
2
0
0
500
1000
1500
2000
40kbps
500kbps
14
12
SLEW RATE (V/µs)
10
8
6
4
2
0
-SLEW
90
+SLEW
10
0
0
500
1000
1500
2000
2500
0
500
1000
1500
2000
2500
OUTPUT CAPACITANCE (pF)
OUTPUT CAPACITANCE (pF)
2500
OUTPUT CAPACITANCE (pF)
MAX3188
TRANSMITTER OUTPUT
SHUTDOWN WAVEFORM
MAX3188/9 toc07
MAX3189
TRANSMITTER OUTPUT
SHUTDOWN WAVEFORM
MAX3188/9 toc08
C
L
= 150pF
SHDN
+2V
0
+5V
SHDN
C
L
= 150pF
+2V
0
+5V
TOUT
0
TOUT
0
-5V
-5V
1µs/div
1µs/div
_______________________________________________________________________________________
3
1Mbps, 1µA RS-232 Transmitters in SOT23-6
MAX3188/MAX3189
Pin Description
PIN
1
2
3
4
5
6
NAME
SHDN
GND
TIN
TOUT
V
EE
V
CC
FUNCTION
Active-Low Shutdown. Pull low to reduce the supply current and to force TOUT into a high-impedance state.
Ground
TTL/CMOS Transmitter Input
RS-232 Transmitter Output
Negative Supply Voltage
Positive Supply Voltage
Detailed Description
The transmitter is an inverting level translator that
converts CMOS-logic levels to 5V EIA/TIA-232 levels.
The MAX3188 guarantees a 250kbps data rate, and the
MAX3189 guarantees a 1Mbps data rate with worst-case
loads of 3kΩ in parallel with 1000pF. The transmitter
input does not have a pull-up resistor and should be
connected to GND if unused.
+5V
TOUT
-5V
t
PLH
t
PHL
V
IH
TIN
V
IL
50%
50%
50%
50%
Shutdown
The MAX3188/MAX3189 feature a shutdown input.
Drive
SHDN
low to reduce the supply current to 1µA
(max). Shutdown also forces TOUT into a high-
impedance state that allows the signal line to be safely
controlled by other transmitters. Drive
SHDN
high for
normal operation.
Figure 1. Transmitter Propagation-Delay Timing
Power-Supply Decoupling
In most circumstances, 0.1µF bypass capacitors are
adequate for power-supply decoupling. Connect the
bypass capacitors as close to the IC as possible.
Applications Information
Power-Supply Sources
The MAX3188/MAX3189 require ±4.5V to ±6V dual
supplies. For applications where these supply voltages
are not present, a DC-DC converter must be added.
Due to the devices’ low current consumption, a charge
pump can provide the proper supply voltages and
requires a minimal amount of board space and cost.
When using another RS-232 device containing an internal
regulated charge pump (Table 1), the MAX3188/
MAX3189 may be powered from the internal charge
pump (Figure 2). This eliminates the need for additional
external DC-DC converters to generate the required
±4.5V to ±6V dual supplies.
4
_______________________________________________________________________________________
1Mbps, 1µA RS-232 Transmitters in SOT23-6
MAX3188/MAX3189
Table 1. RS-232 Devices with Internal Regulated Charge Pumps
PART
MAX3221
MAX3221E
MAX3222
MAX3222E
MAX3223
MAX3223E
MAX3224
MAX3224E
MAX3225
MAX3225E
MAX3226
MAX3226E
MAX3227
MAX3227E
MAX3232
MAX3232E
MAX3237
MAX3238
MAX3241
MAX3241E
MAX3243
MAX3243E
MAX3244
MAX3244E
MAX3245
MAX3245E
NO. OF Tx/Rx
1/1
1/1
2/2
2/2
2/2
2/2
2/2
2/2
2/2
2/2
1/1
1/1
1/1
1/1
2/2
2/2
5/3
5/3
3/5
3/5
3/5
3/5
3/5
3/5
3/5
3/5
±15kV ESD
PROTECTION
AutoShutdown
Plus™
AutoShutdown™
DATA RATE
(bps)
120k
250k
120k
250k
120k
250k
250k
250k
1M
1M
250k
250k
1M
1M
120k
250k
1M
250k
120k
250k
120k
250k
250k
250k
1M
1M
AutoShutdown and AutoShutdown Plus are trademarks of Maxim Integrated Products.
_______________________________________________________________________________________
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