19-1696; Rev 1; 3/01
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
General Description
The MAX3314E is a ±5V-powered EIA/TIA-232-compat-
ible 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 provid-
ing minimum RS-232-compatible ±3.7V output levels
while driving 3kΩ and 1000pF at 460kbps. Both +5V
and -5V must be supplied externally.
The MAX3314E has a
SHDN
function that reduces sup-
ply 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.
Features
o
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
o
1µA Low-Power Shutdown with Receiver Active
o
30µA Operating Supply Current
o
460kbps Guaranteed Data Rate
o
8-Pin SOT23 Package
o
±3.7V RS-232-Compatible Levels
MAX3314E
Ordering Information
PART
MAX3314ECKA-T
MAX3314ECUA
MAX3314ECSA
MAX3314EEKA-T
MAX3314EEUA
MAX3314EESA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SOT23-8
8
µMAX
8 SO
8 SOT23-8
8
µMAX
8 SO
________________________Applications
Digital Cameras
PDAs
GPS
POS
Telecommunications
Handy-Terminals
Set-Top Boxes
Typical Operating Circuit
+5V
C
BYPASS
0.1µF
1
V
CC
SHDN
V-
2
7
0.1µF
4 TIN
TOUT 5
Pin Configuration
TOP VIEW
MAX3314E
-5V
V
CC
1
SHDN
2
8
7
GND
V-
RIN
TOUT
MAX3314E
ROUT
3
6
5
TIN
4
3 ROUT
RIN 6
5kΩ
SOT23/µMAX/SO
GND
8
CAPACITORS MAY BE POLARIZED OR NONPOLARIZED.
________________________________________________________________
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.
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
MAX3314E
ABSOLUTE MAXIMUM RATINGS
V
CC
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 (V
CC
+ 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
(V
CC
= +5V, V- = -5V, T
A
= T
MIN
to T
MAX
. Typical values are at T
A
= +25°C.)
PARAMETER
DC CHARACTERISTICS
Positive Supply Operating Range
Negative Supply Operating Range
Positive Supply Current
Negative Supply Current
Shutdown Supply Current
LOGIC INPUTS
(TIN,
SHDN)
Input Logic Threshold Low
Input Logic Threshold High
Transmitter Input Hysteresis
Input Leakage Current
RECEIVER OUTPUT
Output Voltage Low
Output Voltage High
RECEIVER INPUT
Input Threshold Low
Input Threshold High
Input Hysteresis
Input Resistance
TRANSMITTER OUTPUT
Output Voltage Swing
Output Resistance (Note 1)
Output Short-Circuit Current
Output Leakage Current
V
OUT
=
±12V,
transmitter disabled
Human Body Model
ESD-Protection Voltage
IEC 1000-4-2 Air-Gap Discharge
IEC 1000-4-2 Contact Discharge
±15
±15
±8
kV
ESD PROTECTION
(Transmitter Output, Receiver Input)
Transmitter output loaded with 3kΩ to ground
V
CC
= V- = 0, transmitter output =
±2V
±3.7
300
±60
25
V
Ω
mA
µA
V
IL
V
IH
0.5
5
0.8
2.4
V
V
V
kΩ
V
OL
V
OH
I
OUT
= 1.6mA
I
OUT
= -1.0mA
V
CC
- 0.3
V
CC
- 0.1
0.4
V
V
V
IL
V
IH
0.5
±0.01
0.8
2.4
V
V
V
µA
V
CC
V-
SHDN
= V
CC
, no load
SHDN
= V
CC
, no load
SHDN
= GND
4.75
-4.75
5
-5
30
15
1
5.25
-5.25
100
30
10
V
V
µA
µA
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
TIMING CHARACTERISTICS
(V
CC
= +5V, V- = -5V, T
A
= T
MIN
to T
MAX
. Typical values are at T
A
= +25°C.)
PARAMETER
Maximum Data Rate
t
PLH
Receiver Propagation Delay
t
PHL
Transmitter Skew
Receiver Skew
Transition Region Slew Rate
R
L
= 3kΩ to 7kΩ, C
L
= 150pF to 1000pF,
measured from +3V to -3V or -3V to +3V
SYMBOL
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, transmitter
switching
Receiver input to receiver output,
C
L
= 150pF
Receiver input to receiver output,
C
L
= 150pF
MIN
460
0.15
µs
0.15
100
50
8
ns
ns
V/µs
TYP
MAX
UNITS
kbps
MAX3314E
Note 1:
Not tested, guaranteed by design.
Typical Operating Characteristics
(V
CC
= +5V, V- = -5V, 250kbps data rate, transmitter loaded with 3kΩ and C
L
, T
A
= +25°C, unless otherwise noted.)
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3314E-02
MAX3314E-01
SLEW RATE vs. LOAD CAPACITANCE
9
8
7
SLEW RATE (V/µs)
6
5
4
3
2
1
0
0
500
1000
1500
2000
2500
3000
LOAD CAPACITANCE (pF)
+SLEW
-SLEW
6
TRANSMITTER OUTPUT VOLTAGE (V)
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
0
SUPPLY CURRENT
vs. LOAD CAPACITANCE
5.0
4.5
SUPPLY CURRENT (mA)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
20kbps
250kbps
120kbps
460kbps
MAX3314E-03
5.5
20kbps/120kbps
460kbps/250kbps
20kbps/120kbps
460kbps/250kbps
500
1000
1500
2000
2500
3000
0
500
1000
1500
2000
2500
3000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________
3
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceiver
MAX3314E
Pin Description
PIN
1
2
3
4
5
6
7
8
NAME
V
CC
SHDN
ROUT
TIN
TOUT
RIN
V-
GND
FUNCTION
+5V
±5%
External Power Supply. Decouple with a 0.1µF capacitor to ground.
Shutdown, Active low (0 = off, 1 = on).
TTL/CMOS Receiver Output
TTL/CMOS Transmitter Input
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
The transmitter is an inverting level translator that con-
verts CMOS-logic levels to ±3.7V EIA/TIA-232-compati-
ble 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 pull-
up resistor. Connect to ground if unused.
parallel with 1000pF. The transmitter output displays no
ringing or undesirable transients as the MAX3314E
comes out of shutdown.
High Data Rates
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.
±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 engi-
neers have developed state-of-the-art structures to pro-
tect these pins against ESD of ±15kV without damage.
The ESD structures withstand high ESD in all states: nor-
mal 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 trans-
mitter 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
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 opera-
tion; either polarized or nonpolarized capacitors are
acceptable. If polarized capacitors are used, connect
polarity as shown in the
Typical Operating Circuit.
Bypass V
CC
and V- to ground with at least 0.1µF.
Transmitter Outputs When
Exiting Shutdown
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
L
H
TRANSMITTER
OUTPUT
High Z
Active
RECEIVER
OUTPUT
Active
Active
TOUT
TIN
ROUT
5V/div
0
TIN = GND
5µs/div
1.5V/div
0
SHDN
TOUT
Figure 3. Loopback Test Result at 120kbps
TIN = V
CC
TIN
1µs/div
Figure 1. Transmitter Outputs When Exiting Shutdown or
Powering Up
TOUT
+5V
0.1µF
V
CC
SHDN
V-
0.1µF
TIN
TOUT
-5V
2µs/div
ROUT
MAX3314E
Figure 4. Loopback Test Result at 250kbps
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.
1000pF
ROUT
RIN
5kΩ
Human Body Model
Figure 5 shows the Human Body Model, and Figure 6
shows the current waveform it generates when dis-
charged 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.
GND
Figure 2. Loopback Test Circuit
_______________________________________________________________________________________
5
综合技术交流
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
