19-1696; Rev 1; 3/01
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
The MAX3314E has a SHDN function that reduces supply current to 1µA. The transmitter is disabled and put
into tristate while the receiver remains active.
The MAX3314E is available in 8-pin µMAX, SOT23, and
SO packages.
________________________Applications
Features
♦ ESD Protection for RS-232 I/O Pins
±15kV—Human Body Model
±8kV—IEC 1000-4-2 Contact Discharge
±15kV—IEC 1000-4-2 Air-Gap Discharge
♦ 1µA Low-Power Shutdown with Receiver Active
♦ 30µA Operating Supply Current
♦ 460kbps Guaranteed Data Rate
♦ 8-Pin SOT23 Package
♦ ±3.7V RS-232-Compatible Levels
Ordering Information
PART
MAX3314ECKA-T
TEMP. RANGE
0°C to +70°C
MAX3314ECUA
Digital Cameras
PDAs
GPS
POS
Telecommunications
Handy-Terminals
Set-Top Boxes
MAX3314ECSA
0°C to +70°C
8 µMAX
0°C to +70°C
8 SO
MAX3314EEKA-T
-40°C to +85°C
8 SOT23-8
MAX3314EEUA
-40°C to +85°C
8 µMAX
MAX3314EESA
-40°C to +85°C
8 SO
Typical Operating Circuit
+5V
PIN-PACKAGE
8 SOT23-8
Pin Configuration
TOP VIEW
CBYPASS
0.1µF
1
VCC
SHDN
V-
MAX3314E
2
7
-5V
0.1µF
4 TIN
TOUT 5
VCC 1
8
GND
7
V-
3
6
RIN
TIN 4
5
TOUT
SHDN 2
MAX3314E
ROUT
3 ROUT
RIN 6
5kΩ
SOT23/µMAX/SO
GND
8
CAPACITORS MAY BE POLARIZED OR NONPOLARIZED.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX3314E
General Description
The MAX3314E is a ±5V-powered EIA/TIA-232-compatible interface. It has one transmitter and one receiver in
a flow-through architecture. The transmitter output and
the receiver input are protected to ±15kV using IEC
1000-4-2 Air-Gap Discharge, ±8kV using IEC 1000-4-2
Contact Discharge, and ±15kV using the Human Body
Model.
The transmitter has a low-dropout output stage providing minimum RS-232-compatible ±3.7V output levels
while driving 3kΩ and 1000pF at 460kbps. Both +5V
and -5V must be supplied externally.
MAX3314E
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
ABSOLUTE MAXIMUM RATINGS
VCC to GND .............................................................-0.3V to +6V
V- to GND ...............................................................+0.3V to -6V
Input Voltages
TIN, SHDN to GND ...............................................-0.3V to +6V
RIN to GND ......................................................................±25V
Output Voltages
TOUT to GND................................................................±13.2V
ROUT .................................................…-0.3V to (VCC + 0.3V)
Short-Circuit Duration
TOUT to GND .........................................................Continuous
Continuous Power Dissipation
8-Pin SOT23 (derate 9.7mW/°C above +70°C)...........777mW
8-Pin µMAX (derate 4.1mW/°C above +70°C) ............300mW
8-Pin SO (derate 5.88mW/°C above +70°C)...............471mW
Operating Temperature Ranges
MAX3314EC_A ..................................................0°C to +70°C
MAX3314EE_A................................................-40°C to +85°C
Junction Temperature .....................................................+150°C
Storage Temperature Range ............................-65°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
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
(VCC = +5V, V- = -5V, TA = TMIN to TMAX. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS
Positive Supply Operating Range
VCC
4.75
5
5.25
V
Negative Supply Operating Range
V-
-4.75
-5
-5.25
V
Positive Supply Current
SHDN = VCC, no load
30
100
µA
Negative Supply Current
SHDN = VCC, no load
15
30
µA
Shutdown Supply Current
SHDN = GND
1
10
µA
LOGIC INPUTS (TIN, SHDN)
Input Logic Threshold Low
VIL
Input Logic Threshold High
VIH
0.8
V
2.4
Transmitter Input Hysteresis
Input Leakage Current
V
0.5
V
±0.01
µA
RECEIVER OUTPUT
Output Voltage Low
Output Voltage High
VOL
VOH
IOUT = 1.6mA
IOUT = -1.0mA
0.4
VCC
- 0.3
VCC
- 0.1
V
V
RECEIVER INPUT
Input Threshold Low
VIL
Input Threshold High
VIH
0.8
V
2.4
V
Input Hysteresis
0.5
V
Input Resistance
5
kΩ
TRANSMITTER OUTPUT
Output Voltage Swing
Transmitter output loaded with 3kΩ to ground
±3.7
Output Resistance (Note 1)
VCC = V- = 0, transmitter output = ±2V
300
V
Ω
Output Short-Circuit Current
Output Leakage Current
VOUT = ±12V, transmitter disabled
±60
mA
25
µA
ESD PROTECTION (Transmitter Output, Receiver Input)
ESD-Protection Voltage
2
Human Body Model
±15
IEC 1000-4-2 Air-Gap Discharge
±15
IEC 1000-4-2 Contact Discharge
±8
_______________________________________________________________________________________
kV
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
MAX3314E
TIMING CHARACTERISTICS
(VCC = +5V, V- = -5V, TA = TMIN to TMAX. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
RL = 3kΩ, CL = 1000pF, transmitter
switching
Maximum Data Rate
TYP
UNITS
460
kbps
tPLH
Receiver input to receiver output,
CL = 150pF
0.15
tPHL
Receiver input to receiver output,
CL = 150pF
0.15
Receiver Propagation Delay
MAX
µs
Transmitter Skew
100
ns
Receiver Skew
50
ns
8
V/µs
RL = 3kΩ to 7kΩ, CL = 150pF to 1000pF,
measured from +3V to -3V or -3V to +3V
Transition Region Slew Rate
Note 1: Not tested, guaranteed by design.
Typical Operating Characteristics
(VCC = +5V, V- = -5V, 250kbps data rate, transmitter loaded with 3kΩ and CL, TA = +25°C, unless otherwise noted.)
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
6
+SLEW
5
4
3
2
1
5
4
3
20kbps/120kbps
460kbps/250kbps
2
1
0
-1
-2
20kbps/120kbps
-3
-4
460kbps/250kbps
500
1000
1500
2000
LOAD CAPACITANCE (pF)
2500
3000
4.0
250kbps
3.5
120kbps
3.0
2.5
2.0
1.5
20kbps
0.5
-6
0
460kbps
4.5
1.0
-5
0
5.0
SUPPLY CURRENT (mA)
SLEW RATE (V/µs)
7
5.5
MAX3314E-02
-SLEW
6
TRANSMITTER OUTPUT VOLTAGE (V)
8
MAX3314E-01
9
SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3314E-03
SLEW RATE vs. LOAD CAPACITANCE
0
0
500
1000
1500
2000
LOAD CAPACITANCE (pF)
2500
3000
0
500
1000
1500
2000
2500
3000
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________
3
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
MAX3314E
Pin Description
PIN
NAME
FUNCTION
1
VCC
2
SHDN
Shutdown, Active low (0 = off, 1 = on).
3
ROUT
TTL/CMOS Receiver Output
4
TIN
TTL/CMOS Transmitter Input
5
TOUT
6
RIN
7
V-
8
GND
+5V ±5% External Power Supply. Decouple with a 0.1µF capacitor to ground.
RS-232-Compatible Transmitter Output
RS-232-Compatible Receiver Input
-5V ±5% External Power Supply. Decouple with a 0.1µF capacitor to ground.
Ground
Detailed Description
RS-232-Compatible Drivers
parallel with 1000pF. The transmitter output displays no
ringing or undesirable transients as the MAX3314E
comes out of shutdown.
The transmitter is an inverting level translator that converts CMOS-logic levels to ±3.7V EIA/TIA-232-compatible levels. It guarantees data rates up to 460kbps with
worst-case loads of 3kΩ in parallel with 1000pF. When
SHDN is driven low, the transmitter is disabled and put
into tristate. The transmitter input does not have a pullup resistor. Connect to ground if unused.
The MAX3314E maintains minimum RS-232-compatible
±3.7V transmitter output voltage even at high data rates.
Figure 2 shows a transmitter loopback test circuit.
Figure 3 shows the loopback test result at 120kbps, and
Figure 4 shows the same test at 250kbps.
RS-232-Compatible Receivers
The MAX3314E’s receiver converts RS-232 signals to
CMOS-logic output levels. The receiver is rated to
receive signals to ±25V. It will remain active during
shutdown mode.
MAX3314E Shutdown Mode
In shutdown mode, the transmitter output is put into high
impedance (Table 1). This reduces supply current to 1µA.
The time required to exit shutdown is less than 2.5µs.
Applications Information
Capacitor Selection
The capacitor type used is not critical for proper operation; either polarized or nonpolarized capacitors are
acceptable. If polarized capacitors are used, connect
polarity as shown in the Typical Operating Circuit.
Bypass VCC and V- to ground with at least 0.1µF.
Transmitter Outputs When
Exiting Shutdown
High Data Rates
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The MAX3314E driver outputs and receiver inputs have
extra protection against static discharge. Maxim’s engineers have developed state-of-the-art structures to protect these pins against ESD of ±15kV without damage.
The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an
ESD event, Maxim’s E versions keep working without
latchup, whereas competing products can latch and
must be powered down to remove latchup.
ESD protection can be tested in various ways. The transmitter outputs and receiver inputs of the product family
are characterized for protection to the following limits:
• ±15kV using the Human Body Model
• ±8kV using the Contact Discharge method specified
in IEC 1000-4-2
• ±15kV using the IEC 1000-4-2 Air-Gap method
Figure 1 shows the transmitter output when exiting
shutdown mode. The transmitter is loaded with 3kΩ in
4
_______________________________________________________________________________________
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
MAX3314E
Table 1. Shutdown Logic Truth Table
SHDN
TRANSMITTER
OUTPUT
RECEIVER
OUTPUT
L
High Z
Active
H
Active
Active
TIN
TOUT
ROUT
5V/div
0
SHDN
TIN = GND
5µs/div
1.5V/div
0
Figure 3. Loopback Test Result at 120kbps
TOUT
TIN = VCC
TIN
1µs/div
Figure 1. Transmitter Outputs When Exiting Shutdown or
Powering Up
TOUT
+5V
ROUT
0.1µF
VCC
SHDN
MAX3314E
2µs/div
-5V
V-
Figure 4. Loopback Test Result at 250kbps
0.1µF
TOUT
TIN
ROUT
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
RIN
5kΩ
GND
Figure 2. Loopback Test Circuit
1000pF
Human Body Model
Figure 5 shows the Human Body Model, and Figure 6
shows the current waveform it generates when discharged into low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the test device through a
1.5kΩ resistor.
_______________________________________________________________________________________
5
MAX3314E
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
RC
1MΩ
CHARGE-CURRENT
LIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
Cs
100pF
RC
50MΩ to 100MΩ
RD
1500Ω
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
HIGHVOLTAGE
DC
SOURCE
Cs
150pF
RD
330Ω
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 7. IEC 1000-4-2 ESD Test Model
Figure 5. Human Body ESD Test Model
I
IP 100%
90%
Ir
100%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
90%
AMPERES
I PEAK
36.8%
10%
0
0
tRL
TIME
tDL
CURRENT WAVEFORM
10%
Figure 6. Human Body Current Waveform
t r = 0.7ns to 1ns
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifically
refer to ICs. The MAX3314E helps design equipment
that meets Level 4 (the highest level) of IEC 1000-4-2
without the need for additional ESD-protection components.
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2 because series resistance is
lower in the IEC 1000-4-2 model. Hence, the ESD withstand voltage measured to IEC 1000-4-2 is generally
lower than that measured using the Human Body Model.
Figure 7 shows the IEC 1000-4-2 model, and Figure 8
shows the current waveform for the 8kV, IEC 1000-4-2,
Level 4, ESD Contact Discharge test.
The Air-Gap test involves approaching the device with a
charged probe. The Contact Discharge method connects
the probe to the device before the probe is energized.
t
30ns
60ns
Figure 8. IEC 1000-4-2 ESD Generator Current Waveform
contact that occurs with handling and assembly during
manufacturing. Of course, all pins require this protection during manufacturing, not just RS-232 inputs and
outputs. Therefore, after PC board assembly, the
Machine Model is less relevant to I/O ports.
Chip Information
TRANSISTOR COUNT: 128
Machine Model
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resistance. Its objective is to emulate the stress caused by
6
_______________________________________________________________________________________
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
SOT23, 8L.EPS
8LUMAXD.EPS
_______________________________________________________________________________________
7
MAX3314E
Package Information
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
SOICN.EPS
MAX3314E
Package Information (continued)
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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.