19-1910; Rev 0; 1/01
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceivers in µMAX
General Description
The MAX3311E/MAX3313E are low-power, 5V EIA/TIA-
232-compatible transceivers. All transmitter outputs
and receiver inputs are protected to ±15kV using the
Human Body Model, making these devices ideal for
applications where more robust transceivers are
required.
Both devices have one transmitter and one receiver.
The transmitters have a proprietary low-dropout trans-
mitter output stage enabling RS-232-compatible opera-
tion from a +5V supply with a single inverting charge
pump. These transceivers require only three 0.1µF
capacitors and will run at data rates up to 460kbps
while maintaining RS-232-compatible output levels.
The MAX3311E features a 1µA shutdown mode. In
shutdown the device turns off the charge pump, pulls
V- to ground, and the transmitter output is disabled.
The MAX3313E features an
INVALID
output that asserts
high when an active RS-232 cable signal is connected,
signaling to the host that a peripheral is connected to
the communication port.
±15kV—Human Body Model
o
1µA Low-Power Shutdown (MAX3311E)
o
INVALID
Output (MAX3313E)
o
Receiver Active in Shutdown (MAX3311E)
o
Single Transceiver (1Tx/1Rx) in 10-Pin µMAX
Package
Features
o
ESD Protection for RS-232-Compatible I/O Pins
MAX3311E/MAX3313E
Ordering Information
PART
MAX3311ECUB
MAX3311EEUB
MAX3313ECUB
MAX3313EEUB
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
10
µMAX
10
µMAX
10
µMAX
10
µMAX
________________________Applications
Digital Cameras
PDAs
GPS
POS
Telecommunications
Handy Terminals
Set-Top Boxes
C1
0.1µF
+5V
C
BYPASS
0.1µF
9
C1+
1
V
CC
V-
8
C2
0.1µF
C1-
Typical Operating Circuit
2
Pin Configurations
4 TIN
MAX3311E
MAX3313E
TOUT 7
TOP VIEW
5 ROUT
V
CC
1
C1-
SHDN
TIN
ROUT
2
3
4
5
10 GND
5k
9
C1+
V-
TOUT
RIN
SHDN (MAX3311E) 3
INVALID (MAX3313E)
GND
10
CAPACITORS MAY BE POLARIZED OR NONPOLARIZED.
RIN 6
MAX3311E
8
7
6
µMAX
Pin Configurations continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceivers in µMAX
MAX3311E/MAX3313E
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND .............................................................-0.3V to +6V
V- to GND ................................................................+0.3V to -7V
V
CC
+ |V-| ............................................................................+13V
Input Voltages
TIN,
SHDN
to GND ...............................................-0.3V to +6V
RIN to GND ......................................................................±25V
Output Voltages
TOUT to GND................................................................±13.2V
ROUT,
INVALID
to GND .....................…-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
TOUT to GND .........................................................Continuous
Continuous Power Dissipation
10-Pin µMAX (derate 5.6mW/°C above +70°C) ..........444mW
Operating Temperature Ranges
MAX331_ECUB .................................................0°C to +70°C
MAX331_EEUB ..............................................-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, C1 and C2 = 0.1µF, T
A
= T
MIN
to T
MAX
. Typical values are at T
A
= +25°C.)
PARAMETER
DC CHARACTERISTICS
Supply Operation Range
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
INVALID
OUTPUT (MAX3313E only)
Receiver Input Threshold to
INVALID
Output High
Receiver Input Threshold to
INVALID
Output Low
INVALID
Output Low
INVALID
Output High
Receiver Positive or Negative
Thresholds to
INVALID
High
Receiver Positive or Negative
Threshold to
INVALID
Low
V
OL
V
OH
Figure 7, positive threshold
Figure 7, negative threshold
Figure 7
I
OUT
= 1.6mA
I
OUT
= -1.0mA
Figure 7
Figure 7
V
CC
- 0.6
0.1
30
-2.7
-0.3
0.3
0.4
2.7
V
V
V
V
µs
µs
V
OL
V
OH
I
OUT
= 1.6mA
I
OUT
= -1.0mA
V
CC
- 0.6 V
CC
- 0.1
0.4
V
V
V
IL
V
IH
0.5
±0.01
±1
0.8
2.4
V
V
V
µA
V
CC
SHDN
= V
CC
, no load
SHDN
= GND (MAX3311E only)
4.5
5
100
1
5.5
250
10
V
µA
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceivers in µMAX
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +5V, C1 and C2 = 0.1µF, T
A
= T
MIN
to T
MAX
. Typical values are at T
A
= +25°C.)
PARAMETER
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
ESD-Protection Voltage
V
OUT
=
±12V,
transmitter disabled
Human Body Model
±15
ESD PERFORMANCE (TRANSMITTER OUTPUT, RECEIVER INPUT)
kV
Transmitter output loaded with 3kΩ to
V
CC
= 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
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX3311E/MAX3313E
Note 1:
Not tested—guaranteed by design.
TIMING CHARACTERISTICS
(V
CC
= +5V, C1 and C2 = 0.1µF, T
A
= T
MIN
to T
MAX
. Typical values are at T
A
= +25°C.)
PARAMETER
Maximum Data Rate
Receiver Propagation Delay
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
t
PLH
/t
PHL
SYMBOL
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF
Receiver input to receiver output,
C
L
= 150pF
MIN
460
0.15
100
50
11
TYP
MAX
UNITS
kbps
µs
ns
ns
V/µs
_______________________________________________________________________________________
3
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceivers in µMAX
MAX3311E/MAX3313E
Typical Operating Characteristics
(V
CC
= +5V, 0.1µF capacitors, transmitter loaded with 3kΩ and C
L
, T
A
= +25°C, unless otherwise noted.)
SLEW RATE
vs. LOAD CAPACITANCE
MAX3311E/13E-01
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
TRANSMITTER OUTPUT VOLTAGE (V)
5
4
3
2
1
0
-1
-2
-3
-4
-5
460kbps/250kbps/120kbps
460kbps/250kbps/120kbps
MAX3311E/13E-02
SUPPLY CURRENT
vs. LOAD CAPACITANCE
460kbps
250kbps
10
8
6
4
2
0
20kbps
120kbps
MAX3311E/13E-03
14
250 kbps DATA RATE
12
SLEW RATE (V/µs)
10
8
6
4
2
0
0
500
1000
1500
2000
2500
-SLEW
+SLEW
6
14
12
SUPPLY CURRENT (mA)
3000
0
500
1000
1500
2000
2500
3000
0
500
1000
1500
2000
2500
3000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
Pin Description
PIN
MAX3311E
1
2
3
—
4
5
6
7
8
9
10
MAX3313E
1
2
—
3
4
5
6
7
8
9
10
NAME
V
CC
C1-
SHDN
INVALID
TIN
ROUT
RIN
TOUT
V-
C1+
GND
FUNCTION
+5V External Power Supply. Decouple with a 0.1µF capacitor to ground.
Negative Terminal of the Voltage Inverter Charge-Pump Capacitor
Shutdown Active Low (0 = off, 1 = on)
Valid Signal Detector Output, Active Low. A logic high indicates that a valid
RS-232 level is present on the receiver input.
TTL/CMOS Transmitter input
TTL/CMOS Receiver output
±15kV ESD-Protected, RS-232 Receiver Input
±15kV ESD-Protected, RS-232-Compatible Transmitter Output
-4.3V generated by the charge pump. Connect a 0.1µF capacitor to ground.
Positive Terminal of the Voltage Inverter Charge-Pump Capacitor
Ground
4
_______________________________________________________________________________________
±15kV ESD-Protected, 460kbps, 1µA,
RS-232-Compatible Transceivers in µMAX
Detailed Description
Single Charge-Pump Voltage Converter
The MAX3311E/MAX3313E internal power supply has a
single inverting charge pump that provides a negative
voltage from a single +5V supply. The charge pump
operates in a discontinuous mode and requires a flying
capacitor (C1) and a reservoir capacitor (C2) to gener-
ate the V- supply.
increased without changing C1’s value. However, do
not increase C1’s value without also increasing the
value of C2 and C
BYPASS
to maintain the proper ratios
(C1 to the other capacitors).
When using the minimum 0.1µF capacitors, make sure
the capacitance does not degrade excessively with
temperature. If in doubt, use capacitors with a larger
nominal value. The capacitor’s equivalent series resis-
tance (ESR) usually rises at low temperatures and influ-
ences the amount of ripple on V-.
To reduce the output impedance at V-, use larger
capacitors (up to 10µF).
Bypass V
CC
to ground with at least 0.1µF. In applica-
tions sensitive to power-supply noise generated by the
charge pump, decouple V
CC
to ground with a capaci-
tor the same size as (or larger than) charge-pump
capacitors C1 and C2.
MAX3311E/MAX3313E
RS-232-Compatible Driver
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 tri-state. The transmitter input does not have an
internal pullup resistor.
RS-232 Receiver
The MAX3311E/MAX3313E receiver converts RS-232
signals to CMOS-logic output levels. The MAX3311E
receiver will remain active during shutdown mode. The
MAX3313E
INVALID
indicates when an RS-232 signal
is present at the receiver input, and therefore when the
port is in use.
The MAX3313E
INVALID
output is pulled low when no
valid RS-232 signal level is detected on the receiver
input.
Transmitter Output when Exiting
Shutdown
Figure 1 shows the transmitter output when exiting
shutdown mode. The transmitter is loaded with 3kΩ in
parallel with 1000pF. The transmitter output displays no
ringing or undesirable transients as the MAX3311E
comes out of shutdown. Note that the transmitter is
enabled only when the magnitude of V- exceeds
approximately -3V.
High Data Rates
The MAX3311E/MAX3313E maintain RS-232-compati-
ble ±3.7V minimum transmitter output voltage even at
MAX3311E Shutdown Mode
In shutdown mode, the charge pump is turned off, V- is
pulled to ground, and the transmitter output is disabled
(Table 1). This reduces supply current typically to 1µA.
The time required to exit shutdown is less than 25ms.
Applications Information
Capacitor Selection
The capacitor type used for C1 and C2 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.
The charge pump requires 0.1µF
capacitors. Increasing the capacitor values (e.g., by a
factor of 2) reduces power consumption. C2 can be
5V/div
0
TIN = GND
SHDN
1.5V/div
0
TOUT
TIN = V
CC
Table 1. MAX3311E Shutdown Logic
Truth Table
10
µ
s/div
SHDN
L
H
TRANSMITTER
OUTPUT
High Z
Active
RECEIVER
OUTPUT
Active
Active
CHARGE
PUMP
Inactive
Active
Figure 1. Transmitter Output when Exiting Shutdown or
Powering Up
5
_______________________________________________________________________________________
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
