19-1725; Rev 1a; 3/01
460kbps, 1µA, RS-232-Compatible Transceiver
General Description
The MAX3314 is a ±5V powered EIA/TIA-232-compati-
ble interface. It has one transmitter and one receiver in
a flow-through architecture. The transmitter has a low-
dropout output stage providing minimum RS-232-com-
patible ±3.7V output levels while driving 3kΩ and
1000pf at 460kbps. Both +5V and -5V are supplied
externally.
The MAX3314 has a
SHDN
function that reduces sup-
ply current to 1µA. The transmitter is disabled and put
into 3-state mode while the receiver remains active.
The MAX3314 is available in 8-pin SOT23, µMAX and
SO packages.
o
30µA Operating Supply Current
o
460kbps (min) Data Rate
o
8-Pin SOT23 Package
o
RS-232-Compatible Levels
Features
o
1µA Low-Power Shutdown with Receiver Active
MAX3314
Ordering Information
PART
MAX3314CKA
MAX3314CUA
MAX3314CSA
MAX3314EKA
MAX3314EUA
MAX3314ESA
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
µMAX
8 SO
8 SOT23
8
µMAX
8 SO
________________________Applications
Digital Cameras
PDA
GPS
POS
Telecommunications
Handy Terminals
Set-Top Boxes
Typical Operating Circuit
+5V
C
BYPASS
0.1µF
1
V
CC
SHDN
2
7
0.1µF
Pin Configuration
TOP VIEW
4 TIN
MAX3314
V-
-5V
TOUT 5
3 ROUT
V
CC
1
SHDN
ROUT
2
8
7
GND
V-
RIN
TOUT
GND
8
RIN 6
5kΩ
MAX3314
3
6
5
TIN
4
SOT23/µMAX/SO
CAPACITORS MAY BE POLARIZED OR UNPOLARIZED.
________________________________________________________________
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.
460kbps, 1µA, RS-232-Compatible Transceiver
MAX3314
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
MAX3314C_A.....................................................0°C to +70°C
MAX3314E_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
, unless otherwise noted. 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
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
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
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
Note 1:
Not tested—guaranteed by design.
2
_______________________________________________________________________________________
460kbps, 1µA, RS-232-Compatible Transceiver
TIMING CHARACTERISTICS
(V
CC
= +5V, V- = -5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. 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 from -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
MAX3314
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.)
SLEW RATE vs. LOAD CAPACITANCE
MAX3314-01
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
0
500
1000
1500
2000
2500
3000
MAX3314-02
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
0
500
1000
1500
2000
2500
3000
20kbps
120kbps
460kbps
250kbps
MAX3314-03
9
8
7
SLEW RATE (V/us)
6
5
4
3
2
1
0
0
500
1000
1500
2000
2500
SLEW+
SLEW-
5.5
TRANSMITTER OUTPUT VOLTAGE (V)
20kbps/120kbps
460kbps/250kbps
20kbps/120kbps
460kbps/250kbps
3000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
Pin Description
PIN
1
2
3
4
5
6
7
8
NAME
V
CC
SHDN
ROUT
TIN
TOUT
RIN
V-
GND
FUNCTION
±
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
±5%
External Power Supply. Decouple with a 0.1µF capacitor to ground.
Ground
_______________________________________________________________________________________
3
460kbps, 1µA, RS-232-Compatible Transceiver
MAX3314
Detailed Description
RS-232-Compatible Drivers
The transmitter is an inverting level translator that con-
verts CMOS-logic levels to EIA/TIA-232-compatible lev-
els. 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 3-state mode. The transmitter input does not have a
pull-up resistor. Connect to ground if unused.
5V/div
0
TIN = GND
SHDN
1.5V/div
0
TOUT
RS-232-Compatible Receivers
The MAX3314’s receiver converts RS-232 signals to
CMOS-logic output levels. The receiver is rated to sig-
nals up to ±25V. The MAX3314’s receiver will remain
active during shutdown mode.
TIN = V
CC
1µs/div
MAX3314 Shutdown Mode
In shutdown mode, the transmitter output is put into
high impedance. This reduces the supply current to
1µA. The time required to exit shutdown is less than
2.5µs. Table 1 is the shutdown logic truth table.
Figure 1. Transmitter Output When Exiting Shutdown or
Powering Up
+5V
0.1µF
V
CC
SHDN
V-
0.1µF
TIN
TOUT
-5V
Table 1. Shutdown Logic Truth Table
SHDN
L
H
TRANSMITTER
OUTPUT
High-Z
Active
RECEIVER
OUTPUT
Active
Active
MAX3314
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.
ROUT
RIN
5kΩ
1000pF
GND
Transmitter Output When
Exiting Shutdown
Figure 1 shows the transmitter output when exiting shut-
down mode. The transmitter is loaded with 3kΩ in par-
allel with 1000pF. The transmitter output displays no
ringing or undesirable transients as the MAX3314
comes out of shutdown. Note that the transmitter is
enabled only when the magnitude of V- exceeds
approximately -3V.
CAPACITORS MAY BE POLARIZED OR NONPOLARIZED.
Figure 2. Loopback Test Circuit
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.
High Data Rates
The MAX3314 maintains minimum RS-232-compatible
±3.7V transmitter output voltage even at high data rates.
4
Chip Information
TRANSISTOR COUNT: 128
_______________________________________________________________________________________
460kbps, 1µA, RS-232-Compatible Transceiver
MAX3314
TIN
TIN
TOUT
TOUT
ROUT
ROUT
5µs/div
2µs/div
Figure 3. Loopback Test Results at 120kbps
Figure 4. Loopback Test Results at 250kbps
Package Information
_______________________________________________________________________________________
5
stm32/stm8
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
