19-2128; Rev 0; 8/01
+2.35V to +5.5V, 1µA, 2Tx/2Rx RS-232 Transceivers
with ±15kV ESD-Protected I/O and Logic Pins
MAX3380E/MAX3381E
General Description
The MAX3380E/MAX3381E are +2.35V to +5.5V-pow-
ered EIA/TIA-232 and V.28/V.24 communication inter-
faces with low power requirements, high data-rate
capabilities, and enhanced electrostatic discharge
(ESD) protection on both the TTL and RS-232 sides.
The MAX3380E/MAX3381E have two receivers and two
transmitters. All RS-232 inputs, outputs, and logic input
pins are protected to ±15kV using IEC 1000-4-2 Air-
Gap Discharge method and the Human Body Model,
and ±8kV using IEC 1000-4-2 Contact Discharge
method.
The proprietary low-dropout transmitter output stage
enables true RS-232 performance from a +3.1V to
+5.5V supply with a dual charge pump. The parts
reduce the transmitter output levels to RS-232-compati-
ble levels with no increase in supply current for sup-
plies less than +3.1V and greater than +2.35V. The
+2.35V to +5.5V operating range is fully compatible
with lithium-ion (Li+) batteries. The charge pump
requires only four small 0.1µF capacitors for operation.
The MAX3380E/MAX3381E transceivers use Maxim’s
revolutionary AutoShutdown Plus™ feature to auto-
matically enter a 1µA shutdown mode. These
devices shut down the on-board power supply and
drivers when they do not sense a valid signal transi-
tion for 30 seconds on either the receiver or trans-
mitter inputs.
The MAX3380E is capable of transmitting data at
rates of 460kbps while maintaining RS-232 output
levels, and the MAX3381E operates at data rates up
to 250kbps. The MAX3381E offers a slower slew rate
for applications where noise and EMI are issues. The
MAX3380E/MAX3381E have a unique V
L
pin that
allows interoperation in mixed-logic voltage systems
down to +1.65V. Both input and output logic levels
are referenced to the V
L
pin. The MAX3380E/MAX3381E
are available in a space-saving TSSOP package.
Features
♦
±15kV ESD Protection on All CMOS and RS-232
Inputs and Outputs (Except
INVALID)
±15kV Human Body Model
±15kV IEC 1000-4-2 Air-Gap Discharge
±8kV IEC 1000-4-2 Contact Discharge
♦
Operates Over Entire Li+ Battery Range
♦
Low Logic Threshold Down to +1.65V for
Compatibility with Cell Phone Logic Supply Voltages
♦
1µA Low-Power AutoShutdown Plus Mode
♦
Compatible with Next-Generation GSM Data Rates
♦
20-Pin TSSOP Package
Ordering Information
PART
MAX3380ECUP
MAX3380EEUP
MAX3381ECUP
MAX3381EEUP
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
20 TSSOP
20 TSSOP
20 TSSOP
20 TSSOP
Typical Operating Circuit
+3.3V
C5
0.1μF
V
CC
C1+
C1-
C2+
C2-
T1IN
V
L
C1
0.1μF
FORCEOFF
FORCEON
V+
C2
0.1μF
MAX3380E/
MAX3381E
C3
0.1μF
V-
C4
0.1μF
Applications
Cell Phone Data Lump Cables
PDA Data Lump Cables
GPS Receivers
Digital Cameras
TTL/CMOS
INPUTS
T1OUT
RS-232
OUTPUTS
T2IN
V
L
R1OUT
T2OUT
R1IN
5kΩ
V
L
RS-232
INPUTS
TTL/CMOS
OUTPUTS
AutoShutdown Plus is a trademark of Maxim Integrated Products
Pin Configuration appears at end of data sheet.
R2OUT
R2IN
5kΩ
GND
________________________________________________________________
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.
+2.35V to +5.5V, 1µA, 2Tx/2Rx RS-232 Transceivers
with ±15kV ESD-Protected I/O and Logic Pins
MAX3380E/MAX3381E
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ...........................................................-0.3V to +6.0V
V
L
to GND..............................................................-0.3V to +6.0V
V+ to GND .............................................................-0.3V to +7.0V
V- to GND ..............................................................+0.3V to -7.0V
V+ + |V-| (Note 1) .................................................................+13V
Input Voltages
T_IN, FORCEON,
FORCEOFF
to GND ...............-0.3V to +6.0V
R_IN to GND .....................................................................±25V
Output Voltages
T_OUT to GND...............................................................±13.2V
R_OUT,
INVALID
to GND ...........................-0.3V to (V
L
+ 0.3V)
Short-Circuit Duration T_OUT to GND........................Continuous
Continuous Power Dissipation (T
A
= +70°C)
20-Pin TSSOP (derate 10.9mW/°C over +70°C) .........879mW
Operating Temperature Ranges
MAX3380ECUP/MAX3381ECUP........................0°C to +70°C
MAX3380EEUP/MAX3381EEUP .....................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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 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
= +2.35V to +5.5V, V
L
= +1.65V to +5.5V. When V
CC
< +4.5V, C1 = C2 = C3 = C4 = 0.1µF; when V
CC
≥
+4.5V, C1 = 0.047µF,
C2 = C3 = C4 = 0.33µF; T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= V
L
= +3.3V, T
A
= +25°C.)
PARAMETER
Supply Current, AutoShutdown
Plus
Supply Current, Normal Operation
SYMBOL
I
CC
CONDITIONS
Receivers idle, V
T
_
IN
= V
CC
or GND,
FORCEON = GND,
FORCEOFF
= V
CC
FORCEOFF
= GND
I
CC
FORCEON =
FORCEOFF
= V
L
, no load
1
0.3
MIN
TYP
MAX
10
10
1
mA
UNITS
µA
LOGIC INPUTS (T_IN, FORCEON,
FORCEOFF)
Input Logic Threshold Low
Input Logic Threshold High
Transmitter Input Hysteresis
Input Leakage Current
RECEIVER OUTPUTS (R_OUT) AND
INVALID
Output Voltage Low
Output Voltage High
RECEIVER INPUTS (R_IN)
Input Voltage Range
Input Threshold Low
Input Threshold High
Input Hysteresis
Input Resistance
T
A
= +25°C
3
T
A
= +25°C
T
A
= +25°C
V
L
= +3.3V
V
L
= +5.0V
V
L
= +3.3V
V
L
= +5.0V
-25
0.6
0.8
1.2
1.5
1.5
1.8
0.3
5
7
2.4
2.4
+25
V
V
V
V
kΩ
I
OUT
= 500µA
I
OUT
= -500µA
V
L
- 0.4 V
L
- 0.2
0.5
V
V
V
IL
V
IH
V
CC
= +5.5V, V
L
= +5.5V
V
CC
= +2.5V, V
L
= +1.65V
V
CC
= +5.5V, V
L
= +5.5V
V
CC
= +2.5V, V
L
= +1.65V
0.5
±0.01
±1
0.4
0.4
V
L
✕
0.66
V
L
✕
0.66
1.2
V
V
V
µA
2
_______________________________________________________________________________________
+2.35V to +5.5V, 1µA, 2Tx/2Rx RS-232 Transceivers
with ±15kV ESD-Protected I/O and Logic Pins
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.35V to +5.5V, V
L
= +1.65V to +5.5V. When V
CC
< +4.5V, C1 = C2 = C3 = C4 = 0.1µF; when V
CC
≥
+4.5V, C1 = 0.047µF,
C2 = C3 = C4 = 0.33µF; T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= V
L
= +3.3V, T
A
= +25°C.)
PARAMETER
Receiver Input Threshold to
INVALID
Output High
Receiver Input Threshold to
INVALID
Output Low
Receiver Positive or Negative
Threshold to
INVALID
High
Receiver Positive or Negative
Threshold to
INVALID
Low
Receiver or Transmitter Edge to
Transmitters Enabled
Receiver or Transmitter Edge to
Transmitters Shutdown
TRANSMITTER OUTPUTS
V
CC
Mode Switch Point
(V
CC
Falling)
V
CC
Mode Switch Point
(V
CC
Rising)
V
CC
Mode Switch Point
Hysteresis
All transmitter
outputs loaded
with 3kΩ to ground
V
CC
= +3.25V to +5.5V,
V
CC
falling
V
CC
= +2.5V to +2.95V,
V
CC
falling
±5
±3.7
300
10M
±60
V
OUT
=
±12V,
transmitters disabled
Human Body Model
R_IN, T_OUT, R_OUT, T_IN,
FORCEON,
FORCEOFF
IEC 1000-4-2 Air-Gap Discharge Method
IEC 1000-4-2 Contact Discharge Method
±15
±15
±8
kV
±25
Ω
mA
µA
T_OUT =
±5.0V
to
±3.7V
T_OUT =
±3.7V
to
±5.5V
2.95
3.3
3.1
3.5
400
±5.4
V
3.25
3.7
V
V
mV
t
INVL
t
INVH
t
WU
SYMBOL
CONDITIONS
Positive threshold
Negative threshold
-2.7
-0.3
0.3
30
15
30
0.3
MIN
TYP
MAX
2.7
UNITS
MAX3380E/MAX3381E
AutoShutdown Plus (FORCEON = GND,
FORCEOFF
= VL)
Figure 3
Figure 3
V
CC
= +5.0V, Figure 4
V
CC
= +5.0V, Figure 4
V
CC
= +5.0V, Figure 4
V
V
µs
µs
µs
s
t
AUTOSHDN
V
CC
= +5.0V, Figure 4
Output Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
ESD PROTECTION
V
CC
= 0, transmitter output =
±2.0V
_______________________________________________________________________________________
3
+2.35V to +5.5V, 1µA, 2Tx/2Rx RS-232 Transceivers
with ±15kV ESD-Protected I/O and Logic Pins
MAX3380E/MAX3381E
TIMING CHARACTERISTICS
(V
CC
= +2.35V to +5.5V, V
L
= +1.65V to +5.5V. When V
CC
< +4.5V, C1 = C2 = C3 = C4 = 0.1µF; when V
CC
≥
+4.5V, C1 = 0.047µF,
C2 = C3 = C4 = 0.33µF; T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= V
L
= +3.3V, T
A
= +25°C.)
PARAMETER
Maximum Data Rate
Receiver Propagation Delay
Transmitter Skew
Receiver Skew
Transition Region Slew Rate
(MAX3380E)
Transition Region Slew Rate
(MAX3381E)
Transition Region Slew Rate
(MAX3380E)
Transition Region Slew Rate
(MAX3381E)
t
PLH
t
PHL
⏐t
PHL
- t
PLH
⏐
V
CC
= +4.2V, -3.0V < T_OUT< +3.0V,
R
L
= 3kΩ, C
L
= 250pF to 1000pF, T
A
= +25°C
V
CC
= +4.2V, -3.0V < T_OUT< +3.0V,
R
L
= 3kΩ, C
L
= 150pF to 1000pF, T
A
= +25°C
V
CC
= +2.35V, -3.0V < T_OUT< +3.0V,
R
L
= 3kΩ, C
L
= 250pF to 1000pF, T
A
= +25°C
V
CC
= +2.35V, -3.0V < T_OUT< +3.0V,
R
L
= 3kΩ, C
L
= 250pF to 1000pF, T
A
= +25°C
20
6
30
10
SYMBOL
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, one
transmitter switching
MAX3381E
MAX3380E
MIN
250
460
0.15
0.15
200
50
100
30
TYP
MAX
UNITS
kbps
µs
ns
ns
V/µs
V/µs
V/µs
V/µs
Receiver input to receiver output, C
L
= 100pF
⏐t
PHL
- t
PLH
⏐
(Note 2)
Note 2:
Transmitter skew is measured at the transmitter zero crosspoint.
Typical Operating Characteristics
(V
CC
= V
L
= +4.2V, C1 = 0.22µF, C2 = C3 = C4 = 1µF, C5 = 0.1µF parallel with 47µF, R
L
= 3kΩ, C
L
= 1000pF, data rate is 250kbps,
T
A
= +25°C, unless otherwise noted.)
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3380E toc01
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3380E toc02
MAX3380E
SLEW RATE vs. LOAD CAPACITANCE
35
30
SLEW RATE (V/μs)
25
20
15
10
5
0
V
CC
= +2.5V
V
CC
= +4.2V
MAX3380E toc03
8
V
CC
= +4.2V
TRANSMITTER OUTPUT VOLTAGE (V)
6
4
2
0
-2
-4
V
OUT-
-6
0
500
1000
1500
2000
2500
V
OUT+
8
V
CC
= +2.5V
TRANSMITTER OUTPUT VOLTAGE (V)
6
V
OUT+
4
2
0
-2
-4
-6
V
OUT-
40
3000
0
500
1000
1500
2000
2500
3000
0
500
1000
1500
2000
2500
3000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
4
_______________________________________________________________________________________
+2.35V to +5.5V, 1µA, 2Tx/2Rx RS-232 Transceivers
with ±15kV ESD-Protected I/O and Logic Pins
MAX3380E/MAX3381E
Typical Operating Characteristics (continued)
(V
CC
= V
L
= +4.2V, C1 = 0.22µF, C2 = C3 = C4 = 1µF, C5 = 0.1µF parallel with 47µF, R
L
= 3kΩ, C
L
= 1000pF, data rate is 250kbps,
T
A
= +25°C, unless otherwise noted.)
MAX3381E
SLEW RATE vs. LOAD CAPACITANCE
MAX3380E toc04
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA
MAX3381E toc05
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE (V
CC
FALLING)
TRANSMITTER OUTPUT VOLTAGE (V)
MAX3380E toc06
14
13
12
SLEW RATE (V/μs)
11
10
9
8
7
6
0
500
1000
1500
2000
2500
V
CC
= +2.5V
V
CC
= +4.2V
80
1 TRANSMITTER SWITCHING
70
SUPPLY CURRENT (mA)
60
50
40
30
20
10
0
20kbps
250kbps
460kbps
8
6
4
2
0
-2
-4
-6
V
OUT-
V
OUT+
3000
0
500
1000
1500
2000
2500
3000
2.5
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
3.5
4.5
SUPPLY VOLTAGE (V)
5.5
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE (V
CC
RISING)
MAX3380E toc07
SUPPLY CURRENT
vs. SUPPLY VOLTAGE (V
CC
FALLING)
1 TRANSMITTER SWITCHING
20
SUPPLY CURRENT (mA)
MAX3380E toc08
8
TRANSMITTER OUTPUT VOLTAGE (V)
6
4
2
0
-2
-4
-6
2.5
3.5
4.5
SUPPLY VOLTAGE (V)
V
OUT-
V
OUT+
25
15
10
5
0
5.5
2.5
3.5
4.5
5.5
SUPPLY VOLTAGE (V)
MAX3380E
DATASTREAM V
CC
= +4.2V
MAX3380E toc09
MAX3380E
DATASTREAM V
CC
= +2.5V
MAX3380E toc10
T_IN
5V/div
5V
0
T_IN
5V/div
5V
0
5V
T_OUT
5V/div
0
-5V
V
CC
= V
L
=
+2.5V
1μs/div
1μs/div
T_OUT
5V/div
5V
0
-5V
_______________________________________________________________________________________
5