19-1561; Rev 3; 6/10
3V, ±15kV ESD-Protected, AutoShutdown Plus
RS-232 Transceiver for PDAs and Cell Phones
General Description
The MAX3387E 3V powered TIA/EIA-232 and V.28/V.24
is a communications interface with low power require-
ments, high data-rate capabilities, and enhanced elec-
trostatic discharge (ESD) protection. The MAX3387E
has three receivers and three transmitters. All RS-232
inputs and outputs are protected to ±15kV using the
IEC 1000-4-2 Air-Gap Discharge method, ±8kV using
the IEC 1000-4-2 Contact Discharge method, and
±15kV using the Human Body Model.
A proprietary low-dropout transmitter output stage
enables true RS-232 performance from a +3.0V to
+5.5V supply with a dual charge pump. The charge
pump requires only four small 0.1µF capacitors for
operation from a +3.3V supply. The MAX3387E is capa-
ble of running at data rates up to 250kbps while main-
taining RS-232 compliant output levels.
The MAX3387E has a unique V
L
pin that allows interop-
eration in mixed-logic voltage systems. Both input and
output logic levels are pin programmable through the
V
L
pin. The MAX3387E is available in a space-saving
TSSOP package.
Features
♦
V
L
Pin for Compatibility with Mixed-Voltage
Systems
♦
±15kV ESD Protection on Rx Inputs and Tx Outputs
♦
Low 300µA Supply Current
♦
Guaranteed 250kbps Data Rate
♦
1µA AutoShutdown Plus™ with Receivers Active
♦
Meets TIA/EIA-232 Specifications Down to 3.0V
MAX3387E
Ordering Information
PART
MAX3387ECUG+
MAX3387EEUG+
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
24 TSSOP
24 TSSOP
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Typical Operating Circuit
+3.3V
C
BYPASS
C1
0.1μF
24
FORCEOFF
1 C1+
3
4
C2
0.1μF
5
C1-
C2+
C2-
T1OUT 21
T2OUT 20
T3OUT 19
V
L
14 R1OUT
R1IN 18
5k
R2IN 17
5k
V
L
12
9
R3OUT
INVALID
FORCEON
11
GND
22
R3IN 16
5k
RS-232
INPUTS
RS-232
OUTPUTS
23
V
CC
15
V
L
V+
2
C3
0.1μF
6
C4
0.1μF
Applications
Subnotebook/Palmtop Computers
PDAs and PDA Cradles
Cell Phone Data Cables
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
MAX3387E
V-
7 T1IN
TTL/CMOS
INPUTS
8 T2IN
10 T3IN
V
L
TTL/CMOS
OUTPUTS
13 R2OUT
AutoShutdown Plus is a trademark of Maxim Integrated
Products, Inc.
_______________________________________________________________
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.
3V, ±15kV ESD-Protected, AutoShutdown Plus
RS-232 Transceiver for PDAs and Cell Phones
MAX3387E
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ..............................................................-0.3V to +6V
V
L
to GND...................................................-0.3V to (V
CC
+ 0.3V)
V+ to GND ................................................................-0.3V to +7V
V- to GND .................................................................+0.3V to -7V
V+ +⏐ V-⏐(Note 1) .............................................................. +13V
Input Voltages
T_IN, FORCEON,
FORCEOFF
to GND ..................-0.3V to +6V
R_IN to GND .....................................................................±25V
Output Voltages
T_OUT to GND...............................................................±13.2V
R_OUT........................................................-0.3V to (V
L
+ 0.3V)
Short-Circuit Duration T_OUT to GND........................Continuous
Continuous Power Dissipation (T
A
= +70°C)
24-Pin TSSOP (derate 12.2mW/°C above +70°C) ........976mW
Operating Temperature Ranges
MAX3387ECUG ...................................................0°C to +70°C
MAX3387EEUG ................................................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°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.
DC ELECTRICAL CHARACTERISTICS
(V
CC
= V
L
= +3.0V to +5.5V; C1–C4 = 0.1µF, tested at +3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF, tested at +5.0V ±10%;
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
LOGIC INPUTS
Input Logic Threshold Low
T_IN, FORCEON,
FORCEOFF
V
L
= +3.3V or +5.0V
V
L
= +2.5V
V
L
= +5.0V
Input Logic Threshold High
T_IN, FORCEON,
FORCEOFF
V
L
= +3.3V
V
L
= +2.5V
V
L
= +1.8V
Transmitter Input Hysteresis
Input Leakage Current
RECEIVER OUTPUTS
Output Voltage Low
Output Voltage High
RECEIVER INPUTS
Input Voltage Range
Input Threshold Low
Input Threshold High
T
A
= +25°C
T
A
= +25°C
V
L
= +5.0V
V
L
= +3.3V
V
L
= +5.0V
V
L
= +3.3V
-25
0.8
0.6
1.5
1.2
1.8
1.5
2.4
2.4
+25
V
V
V
I
OUT
= 1.6mA
I
OUT
= -1mA
V
L
-
0.6
V
L
-
0.1
0.4
V
V
T_IN, FORCEON,
FORCEOFF
2.4
2.0
1.4
0.9
0.5
±0.01
±1
V
µA
V
0.8
0.6
V
SYMBOL
CONDITIONS
All R_IN idle, FORCEON = GND,
FORCEOFF
= V
CC
, all T_IN idle
FORCEOFF
= FORCEON = V
CC
, no load
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS
(V
CC
= +3.3V or +5V, T
A
= +25°C)
1.0
0.3
10
1
µA
mA
2
_______________________________________________________________________________________
3V, ±15kV ESD-Protected, AutoShutdown Plus
RS-232 Transceiver for PDAs and Cell Phones
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= V
L
= +3.0V to +5.5V; C1–C4 = 0.1µF, tested at +3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF, tested at +5.0V ±10%;
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
Input Hysteresis
Input Resistance
TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
ESD PROTECTION
Human Body Model
R_IN, T_OUT
ESD Protection
IEC 1000-4-2 Air-Gap Discharge method
IEC 1000-4-2 Contact Discharge method
AutoShutdown Plus
(FORCEON = GND,
FORCEOFF
= V
CC)
Receiver Input Threshold to
INVALID
Output High
Receiver Input Threshold to
INVALID
Output Low
INVALID
Output Voltage Low
INVALID
Output Voltage High
Receiver Positive or Negative
Threshold to
INVALID
High
Receiver Positive or Negative
Threshold to
INVALID
Low
Receiver or Transmitter Edge to
Transmitters Enabled
t
INVH
t
INVL
t
WU
Figure 3a
Figure 3a
I
OUT
= -1.6mA
I
OUT
= -1.0mA
V
CC
= +5V, Figure 3b
V
CC
= +5V, Figure 3b
V
CC
= +5V, Figure 3b
15
V
L
- 0.6
1
30
100
30
60
Positive threshold
Negative threshold
-2.7
-0.3
0.3
0.4
2.7
V
V
V
V
µs
µs
µs
s
±15
±15
±8
kV
All transmitter outputs loaded with 3kΩ to
ground
V
CC
= V+ = V- = 0V, transmitter output = ±2V
V
T_OUT
= 0V
V
T_OUT
= ±12V, transmitters disabled;
V
CC
= 0V or +3.0V to +5.5V
±5
300
±5.4
10M
±60
±25
V
Ω
mA
µA
T
A
= +25°C
3
SYMBOL
CONDITIONS
MIN
TYP
0.5
5
7
MAX
UNITS
V
kΩ
MAX3387E
Receiver or Transmitter Edge to
t
AUTOSHDN
V
CC
= +5V, Figure 3b
Transmitters Shutdown
_______________________________________________________________________________________
3
3V, ±15kV ESD-Protected, AutoShutdown Plus
RS-232 Transceiver for PDAs and Cell Phones
MAX3387E
TIMING CHARACTERISTICS
(V
CC
= V
L
= +3V to +5.5V; C1–C4 = 0.1µF, tested at +3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF, tested at +5.0V ±10%; 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
Time to Exit Shutdown
Transmitter Skew
Receiver Skew
Transition-Region Slew
Rate
t
PHL
t
PLH
SYMBOL
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF,
one transmitter switching
Receiver input to receiver output,
C
L
= 150pF
MIN
250
0.15
0.15
100
100
50
C
L
= 150pF to
1000pF
C
L
= 150pF to
2500pF
6
4
30
V/µs
30
TYP
MAX
UNITS
kbps
µs
µs
ns
ns
⏐
V
T_OUT
⏐
> +3.7V
⏐
t
PHL
- t
PLH
⏐
(Note 2)
⏐
t
PHL
- t
PLH
⏐
V
CC
= +3.3V,
T
A
= +25°C,
R
L
= 3kΩ to 7kΩ,
measured from +3V
to -3V or -3V to +3V
Note 2:
Transmitter skew is measured at the transmitter zero crosspoints.
Typical Operating Characteristics
(V
CC
= V
L
= +3.3V, T
A
= +25°C, unless otherwise noted.)
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3387E-01
SLEW RATE vs. LOAD CAPACITANCE
14
12
SLEW RATE (V/µs)
SLEW RATE -
10
8
6
4
SLEW RATE +
MAX3387E-02
7.5
5.0
OUTPUT VOLTAGE (V)
2.5
0
-2.5
-5.0
DATA RATE = 250kbps
LOAD = 3kΩ IN PARALLEL WITH C
L
16
2
-7.5
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
0
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
4
_______________________________________________________________________________________
3V, ±15kV ESD-Protected, AutoShutdown Plus
RS-232 Transceiver for PDAs and Cell Phones
Typical Operating Characteristics (continued)
(V
CC
= V
L
= +3.3V, T
A
= +25°C, unless otherwise noted.)
MAX3387E
TRANSMITTER OUTPUT VOLTAGE
vs. DATA RATE
MAX3387E-03
SUPPLY CURRENT vs. LOAD CAPACITANCE
LOAD = 3kΩ,
ONE TRANSMITTER
SWITCHING AT DATA
RATE, OTHER
TRANSMITTERS
250kbps
AT 1/8 DATA RATE
120kbps
MAX3387E-04
7.5
5.0
OUTPUT VOLTAGE (V)
2.5
0
-2.5
-5.0
-7.5
0
50
100
150
200
LOAD = 3kΩ, 1000pF
ONE TRANSMITTER
SWITCHING AT DATA
RATE, OTHER
TRANSMITTERS
AT 1/8 DATA RATE
60
50
SUPPLY CURRENT (mA)
40
30
20
10
0
20kbps
250
0
1000
2000
3000
4000
5000
DATA RATE (kbps)
LOAD CAPACITANCE (pF)
Pin Configuration
TOP VIEW
C1+ 1
V+ 2
C1- 3
C2+ 4
C2- 5
V- 6
T1IN 7
T2IN 8
INVALID 9
T3IN 10
FORCEON 11
R3OUT 12
+
24 FORCEOFF
23 V
CC
22 GND
21 T1OUT
MAX3387E
20 T2OUT
19 T3OUT
18 R1IN
17 R2IN
16 R3IN
15 V
L
14 R1OUT
13 R2OUT
TSSOP
_______________________________________________________________________________________
5
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