1
2
3
4
5
10
9
8
7
6
GND
C1+
V-
TOUTTIN
C1-
VCC
MAX3311
µMAX
TOP VIEW
RINROUT
SHDN
General Description
The MAX3311/MAX3313 are low-power, +5V EIA/TIA-
232-compatible transceivers. Both devices have one
transmitter and one receiver. The transceivers have a
proprietary low-dropout transmitter output stage
enabling RS-232-compatible operation from a +5V sup-
ply with a single inverting charge pump. These devices
require only three 0.1µF capacitors and will run at data
rates up to 460kbps while maintaining RS-232-compati-
ble output levels.
The MAX3311 features a 1µA shutdown mode. In shut-
down the device turns off the charge pump, pulls V- to
ground, and the transmitter output is disabled. The
MAX3313 features an INVALID output that asserts high
when an active RS-232 cable signal is connected, sig-
naling to the host that a peripheral is connected to the
communication port.
________________________Applications
Digital Cameras
PDAs
GPS
POS
Telecommunications
Handy Terminals
Set-Top Boxes
Features
♦1µA Low-Power Shutdown (MAX3311)
♦INVALID Output (MAX3313)
♦Receiver Active in Shutdown (MAX3311)
♦Single Transceiver (1Tx/1Rx) in 10-Pin µMAX
♦RS-232-Compatible Operation
MAX3311/MAX3313
460kbps, 1µA Supply Current,
RS-232-Compatible Transceivers in µMAX
________________________________________________________________ Maxim Integrated Products 1
Pin Configurations
19-1901; Rev 0; 2/01
Ordering Information
PART TEMP. RANGE PIN-PACKAGE
MAX3311CUB 0°C to +70°C 10 µMAX
MAX3311EUB -40°C to +85°C 10 µMAX
MAX3313CUB 0°C to +70°C 10 µMAX
MAX3313EUB -40°C to +85°C 10 µMAX
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.
Pin Configurations continued at end of data sheet.
Typical Operating Circuit
C1
0.1µF
C2
0.1µF
CBYPASS
0.1µF
98
1
10
7
6
3
2
4
5
C1+ V-
TOUT
C1-
TIN
RINROUT
VCC
GND
5kΩ
SHDN (MAX3311)
INVALID (MAX3313)
+5V
MAX3311
MAX3313
CAPACITORS MAY BE POLARIZED OR NONPOLARIZED.
MAX3311/MAX3313
460kbps, 1µA Supply Current,
RS-232-Compatible Transceivers in µMAX
2_________________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC = +5V, C1 and C2 = 0.1µF, TA= TMIN to TMAX. Typical values are at TA= +25°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.
VCC to GND..............................................................-0.3V to +6V
V- to GND .................................................................+0.3V to -7V
VCC +
|
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 (VCC + 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_CUB .......................................................0°C to +70°C
MAX331_EUB ....................................................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX U N IT S
DC CHARACTERISTICS
Supply Operation Range VCC 4.5 5 5.5 V
Supply Current SHDN = VCC, no load 100 250 µA
Shutdown Supply Current SHDN = GND (MAX3311 only) 1 10 µA
LOGIC INPUTS (TIN, SHDN)
Input Logic Threshold Low VIL 0.8 V
Input Logic Threshold High VIH 2.4 V
Transmitter Input Hysteresis 0.5 V
Input Leakage Current ±0.01 ±1 µA
RECEIVER OUTPUT
Output Voltage Low VOL IOUT = 1.6mA 0.4 V
Output Voltage High VOH IOUT = -1.0mA VCC -
0.6
VCC -
0.1 V
INVALID OUTPUT (MAX3313 ONLY)
Figure 5, positive threshold 2.7
Receiver Input Threshold to
INVALID Output High
Figure 5, negative threshold -2.7
V
Receiver Input Threshold to
INVALID Output Low Figure 5 -0.3 0.3 V
INVALID Output Low VOL IOUT = 1.6mA 0.4 V
INVALID Output High VOH IOUT = -1.0mA VCC - 0.6 V
Receiver Positive or Negative
Threshold to INVALID High Figure 5 0.1 µs
Receiver Positive or Negative
Threshold to INVALID Low Figure 5 30 µs
MAX3311/MAX3313
460kbps, 1µA Supply Current,
RS-232-Compatible Transceivers in µMAX
_______________________________________________________________________________________ 3
Note 1: Not tested—guaranteed by design.
TIMING CHARACTERISTICS
(VCC = +5V, C1 and C2 = 0.1µF, TA= TMIN to TMAX. Typical values are at TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX U N IT S
Maximum Data Rate RL = 3kΩ, C
L = 1000p F 460 kbps
Receiver Propagation Delay
tPLH,
tPHL
Recei ver i np ut to r ecei ver outp ut
C
L = 150p F 0.15 µs
Transmitter Skew 100 ns
Receiver Skew 50 ns
Transition Region Slew Rate RL = 3kΩ to 7kΩ, CL = 150pF to 1000p F,
m easur ed from +3V to - 3V or fr om - 3V to + 3V
11
V/µs
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +5V, C1 and C2 = 0.1µF, TA= TMIN to TMAX. Typical values are at TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX U N IT S
RECEIVER INPUT
Input Threshold Low VIL 0.8 V
Input Threshold High VIH 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 V
Output Resistance (Note 1) VCC = 0, transmitter output = ±2V 300 Ω
Output Short-Circuit Current ±60 mA
Output Leakage Current VOUT = ±12V, transmitter disabled ±25 µA
MAX3311/MAX3313
460kbps, 1µA Supply Current,
RS-232-Compatible Transceivers in µMAX
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VCC = +5V, 0.1µF capacitors, transmitter loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)
0
4
2
8
6
12
10
14
0 1000 1500500 2000 2500 3000
SLEW RATE
vs. LOAD CAPACITANCE
MAX3311/13 toc01
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
+SLEW
250 kbps DATA RATE
-SLEW
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
0 500 10001500200025003000
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3311/13 toc02
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
460kbps/250kbps/120kbps
460kbps/250kbps/120kbps
0
4
2
8
6
12
10
14
0 1000 1500500 2000 2500 3000
SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3311/13 toc03
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
20kbps
120kbps
250kbps
460kbps
Pin Description
PIN
MAX3311 MAX3313 NAME FUNCTION
11V
CC +5V External Power Supply. Decouple with a 0.1µF capacitor to ground.
2 2 C1- Negative Terminal of the Voltage Inverter Charge-Pump Capacitor
3—SHDN Shutdown Active-Low (0 = off, 1 = on)
—3INVALID Valid Signal Detector Output, Active-Low. A logic high indicates that a valid
RS-232 level is present on the receiver input.
4 4 TIN TTL/CMOS Transmitter Input
5 5 ROUT TTL/CMOS Receiver Output
6 6 RIN RS-232 Receiver Input
7 7 TOUT RS-232-Compatible Transmitter Output
8 8 V- -4.3V generated by the charge pump. Connect a 0.1µF capacitor to ground.
9 9 C1+ Positive Terminal of the Voltage Inverter Charge-Pump Capacitor
10 10 GND Ground
MAX3311/MAX3313
460kbps, 1µA Supply Current,
RS-232-Compatible Transceivers in µMAX
_______________________________________________________________________________________ 5
Detailed Description
Single Charge-Pump Voltage Converter
The MAX3311/MAX3313 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.
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 3kΩin parallel with 1000pF. When
SHDN is driven low, the transmitter is disabled and put
into three state. The transmitter input does not have an
internal pullup resistor.
RS-232 Receiver
The MAX3311/MAX3313 receiver converts RS-232 sig-
nals to CMOS-logic output levels. The MAX3311 receiv-
er will remain active during shutdown mode. The
MAX3313 INVALID indicates when an RS-232 signal is
present at the receiver input, and therefore when the
port is in use.
The MAX3313 INVALID output is pulled low when no
valid RS-232 signal level is detected on the receiver
input.
MAX3311 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 typically less than
100µs.
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
increased without changing C1’s value. However, do
not increase C1’s value without also increasing the
value of C2 and CBYPASS 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 VCC to ground with at least 0.1µF. In applica-
tions sensitive to power-supply noise generated by the
charge pump, decouple VCC to ground with a capaci-
tor the same size as (or larger than) charge-pump
capacitors C1 and C2.
Transmitter Output when Exiting
Shutdown
Figure 1 shows the transmitter output when exiting
shutdown mode. The transmitter is loaded with 3kΩin
parallel with 1000pF. The transmitter output displays no
ringing or undesirable transients as the MAX3311
comes out of shutdown. Note that the transmitter is
enabled only when the magnitude of V- exceeds
approximately -3V.
Table 1. MAX3311 Shutdown Logic Truth
Table
SHDN TRANSMITTER
OUTPUT
RECEIVER
OUTPUT
CHARGE
PUMP
L High Z Active Inactive
H Active Active Active
Figure 1. Transmitter Output when Exiting Shutdown or
Powering Up
10µs/div
SHDN
TOUT
5V/div
0
1.5V/div
0
TIN = GND
TIN = VCC
MAX3311/MAX3313
High Data Rates
The MAX3311/MAX3313 maintain RS-232-compatible
transmitter output voltage (±3.7V minimum) 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.
460kbps, 1µA Supply Current,
RS-232-Compatible Transceivers in µMAX
6 _______________________________________________________________________
Figure 2. Loopback Test Circuit
C1 C2
0.1µF
V-
TOUT
TIN
ROUT
1000pF
RIN
VCC
GND
5kΩ
+5V
MAX3311
MAX3313
C1+
C1-
Figure 4. Loopback Test Results at 250kbps
2µs/div
TOUT
TIN
ROUT
Figure 3. Loopback Test Results at 120kbps
5µs/div
TOUT
TIN
ROUT
Figure 5. Receiver Positive/Negative Thresholds for
INVALID
RECEIVER INPUT LEVELS
-2.7V
-0.3V
+2.7V
+0.3V
0
INDETERMINATE
INVALID HIGH
INVALID LOW
INVALID HIGH
INDETERMINATE
460kbps, 1µA Supply Current,
RS-232-Compatible Transceivers in µMAX
MAX3311/MAX3313
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7
© 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
10LUMAX.EPS
Package Information
Chip Information
TRANSISTOR COUNT: 278
1
2
3
4
5
10
9
8
7
6
GND
C1+
V-
TOUTTIN
C1-
VCC
µMAX
RINROUT
INVALID
MAX3313
Pin Configurations (continued)
