________________General Description
The MAX3316E–MAX3319E are 2.5V powered RS-232
compatible transceivers. These devices feature shut-
down (MAX3317E), AutoShutdown Plus™ (MAX3318E/
MAX3319E), and enhanced electrostatic discharge
(ESD) protection integrated into the chip. All transmitter
outputs and receiver inputs are protected to ±15kV
using the IEC 1000-4-2 Air-Gap Discharge method,
±8kV using the IEC 1000-4-2 Contact Discharge
method, and ±15kV using the Human Body Model.
All devices are guaranteed at a data rate of 460kbps.
The transceivers have a proprietary low-dropout trans-
mitter output stage enabling RS-232 compatible opera-
tion from a +2.25V to +3.0V supply with a dual charge
pump. The charge pump requires only four 0.1µF
capacitors. The MAX3318E/MAX3319E feature a logic-
level output (READY) that asserts when the charge
pump is regulating and the device is ready to begin
transmitting.
The MAX3318E/MAX3319E achieve a 1µA supply current
using Maxim’s revolutionary AutoShutdown Plus feature.
These devices automatically enter a low-power shut-
down mode when the RS-232 cable is disconnected or
the transmitters of the connected peripherals are inactive
for more than 30 seconds. They turn on again when
they sense a valid transition at any transmitter or receiver
input. AutoShutdown Plus saves power without
changes to the existing BIOS or operating system. The
MAX3317E also features a 1µA shutdown mode that
can be entered by driving SHDN low. The MAX3317E’s
receivers remain active while in shutdown mode, allowing
external devices such as modems to be monitored
using only 1µA supply current.
These devices are available in space-saving packages:
MAX3316E (16-pin SSOP and 20-pin TSSOP), MAX3317E/
MAX3318E (20-pin SSOP and 20-pin TSSOP), and
MAX3319E (16-pin SSOP).
________________________Applications
Palmtop Computers
Hand-Held Instruments
Pagers
Cellular Phones
GPS
Handy Terminals
Hand-Held Electronic Books
____________________________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
♦300µA Operating Supply Current
♦1µA Low-Power Shutdown with Receivers Active
♦Guaranteed 460kbps Data Rate
♦Guaranteed 4V/µs Slew Rate
♦RS-232 Compatible Down to 2.25V
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
________________________________________________________________ Maxim Integrated Products 1
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
FORCEOFF
VCC
GND
T1OUTC1-
V+
C1+
READY
R1IN
R1OUT
FORCEON
T1INT2OUT
V-
C2-
C2+
12
11
9
10
T2IN
INVALIDR2OUT
R2IN
MAX3318E
SSOP/TSSOP
Pin Configurations
19-1616; Rev 1; 6/00
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Ordering Information
Selector Guide and Typical Application Circuits appear at
end of data sheet.
AutoShutdown Plus is a trademark of Maxim Integrated Products.
PART
MAX3316ECUP 0°C to +70°C
TEMP. RANGE PIN-PACKAGE
20 TSSOP
MAX3316ECAE 0°C to +70°C 16 SSOP
MAX3316EEUP -40°C to +85°C 20 TSSOP
MAX3316EEAE -40°C to +85°C 16 SSOP
MAX3317ECUP 0°C to +70°C 20 TSSOP
MAX3317ECAP 0°C to +70°C 20 SSOP
MAX3317EEUP -40°C to +85°C 20 TSSOP
MAX3317EEAP -40°C to +85°C 20 SSOP
MAX3318ECUP 0°C to +70°C 20 TSSOP
MAX3318ECAP 0°C to +70°C 20 SSOP
MAX3318EEUP -40°C to +85°C 20 TSSOP
MAX3318EEAP -40°C to +85°C 20 SSOP
MAX3319ECAE 0°C to +70°C 16 SSOP
MAX3319EEAE -40°C to +85°C 16 SSOP
Pin Configurations continued at end of data sheet.
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC = +2.25V to +3.0V, C1–C4 = 0.1µF, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +2.5V,
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 (Note 1) ..................................................-0.3V to +7V
V- to GND (Note 1) ...................................................-7V to +0.3V
V+ + |V-| (Note 1) .................................................................+13V
Input Voltages
T_IN, EN, SHDN, FORCEON,
FORCEOFF to GND ...............................................-0.3V to +6V
R_IN to GND ..................................................................±25V
Output Voltages
T_OUT to GND............................................................±13.2V
R_OUT, INVALID, READY to GND .......-0.3V to (VCC + 0.3V)
Short-Circuit Duration, T_OUT to GND.......................Continuous
Continuous Power Dissipation (TA= +70°C)
16-Pin SSOP (derate 7.14mW/°C above +70°C) .......571mW
20-Pin SSOP (derate 8.00mW/°C above +70°C) .......640mW
20-Pin TSSOP (derate 7.00mW/°C above +70°C) .....559mW
Operating Temperature Range
MAX331_EC_ _ .................................................0°C to +70°C
MAX331_EE_ _ ..............................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
SHDN = GND (MAX3317E); FORCEOFF =
GND (MAX3318E/MAX3319E)
All transmitter outputs loaded with 3kΩto
ground
FORCEON = GND, FORCEOFF = VCC,
all R_IN idle, all T_IN idle
(MAX3318E/MAX3319E)
TA= +25°C
TA= +25°C
TA= +25°C
EN = VCC (MAX3317E), receivers disabled
T_IN, EN, SHDN, FORCEON, FORCEOFF
SHDN = VCC, no load (MAX3317E);
FORCEON = FORCEOFF = VCC, no load
(MAX3318E/MAX3319E)
T_IN, EN, SHDN, FORCEON, FORCEOFF
IOUT = -0.5mA
T_IN, EN, SHDN, FORCEON, FORCEOFF
IOUT = 0.5mA
CONDITIONS
V
±3.7 ±4
Output Voltage Swing
kΩ
357
Input Resistance
V0.3Input Hysteresis
V
0.7 ·VCC
Input Threshold High
V
0.3 ·VCC
Input Threshold Low
V
-25 +25
Input Voltage Range
V
0.9 ·VCC
Output Voltage High
V
0.1 ·VCC
Output Voltage Low
µA
110
Shutdown Supply Current
µA
110
AutoShutdown Plus Supply
Current
µA
±0.05 ±10
Output Leakage Current
µA
±0.01 ±1
Input Leakage Current
V
0.3
Transmitter Input Hysteresis
mA
0.3 1
Supply Current
V
0.3 ·VCC
Input Logic Threshold Low
V
0.7 ·VCC
Input Logic Threshold High
UNITSMIN TYP MAXSYMBOL
LOGIC INPUTS
RECEIVER OUTPUTS
RECEIVER INPUTS
MAX3316E–MAX3319E
PARAMETER
DC CHARACTERISTICS (VCC = +2.5V, TA= +25°C)
TRANSMITTER OUTPUTS
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +2.25V to +3.0V, C1–C4 = 0.1µF, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +2.5V,
TA= +25°C.)
TIMING CHARACTERISTICS
(VCC = +2.25V to +3.0V, C1–C4 = 0.1µF, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +2.5V,
TA= +25°C.)
VCC = 0 or 2.25V to 3.0V, VOUT = ±12V,
transmitters disabled
VCC = 0, transmitter output = ±2V
CONDITIONS
µA
±25
Output Leakage Current
mA
±25 ±60
Output Short-Circuit Current
Ω
300 10M
Output Resistance
UNITSMIN TYP MAXSYMBOLPARAMETER
VCC = 2.5V, Figure 4b
IOUT = -0.5mA
IOUT = 0.5mA
Figure 4a
Figure 4a
µs
1
tINVH
Receiver Positive or Negative
Threshold to INVALID High
V
0.9 ·VCC
INVALID, READY Output
Voltage High
V
0.1 ·VCC
INVALID, READY Output
Voltage Low
V
-0.3 0.3
Receiver Input Threshold to
INVALID Output Low
-2.7 V
2.7
Receiver Input Threshold to
INVALID Output High
Positive threshold
VCC = 2.5V, Figure 4b (Note 2)
VCC = 2.5V, Figure 4b (Note 2)
VCC = 2.5V, Figure 4b
Negative threshold
s
15 30 60
tAUTO-
SHDN
Receiver or Transmitter Edge to
Transmitters Shutdown
µs
100
tWU
Receiver or Transmitter Edge to
Transmitters Enabled
µs
30
tINVL
Receiver Positive or Negative
Threshold to INVALID Low
R_IN to R_OUT, CL= 150pF
RL= 3kΩ, CL= 1000pF, one transmitter
switching
Normal operation (MAX3317E)
Normal operation (MAX3317E)
(Note 3)
CONDITIONS
0.175
tPLH
µs
0.175
tPHL
kbps
460
Maximum Data Rate
Receiver Propagation Delay
ns
250
Receiver Output Enable Time
ns
250
Receiver Output Disable Time
ns
100
|tPHL - tPLH|
Transmitter Skew
ns
50
|tPHL - tPLH|
Receiver Skew
UNITSMIN TYP MAXSYMBOLPARAMETER
AutoShutdown Plus (FORCEON = GND, FORCEOFF = VCC) (MAX3318E/MAX3319E)
ESD PROTECTION
R_IN, T_OUT
±15
kV
±15
±8
Human Body Model
IEC 1000-4-2 Air-Gap Discharge method
IEC 1000-4-2 Contact Discharge method
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA= +25°C, unless otherwise noted.)
0
2
6
4
8
10
2.25 2.652.45 2.85 3.05 3.25 3.45 3.65
MAX3316E/MAX3317E
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX3316E TOC01
V
CC
(V)
SUPPLY CURRENT (mA)
T1 TRANSMITTING AT SPECIFIED
DATA RATE
T2 TRANSMITTING AT 20kbps
C
L
= 1000pF
460kbps
230kbps
20kbps
-6
-2
-4
2
0
4
6
2.25 2.85 3.052.45 2.65 3.25 3.45 3.65
MAX3316E/MAX3317E
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX3316E TOC02
V
CC
(V)
TRANSMITTER OUTPUT VOLTAGE (V)
T_OUT+
T_OUT-
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
CL = 1000pF
-5
-2
-3
-4
-1
0
1
2
3
4
5
0 1000 2000 3000
MAX3316E/MAX3317E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3316E TOC03
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
T_OUT+
T_OUT-
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
0
2
6
4
8
10
MAX3316E/MAX3317E
SLEW RATE vs. LOAD CAPACITANCE
MAX3316E TOC04
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
0 20001000 3000
-SLEW
+SLEW
FOR DATA RATES UP TO 460kps
TIMING CHARACTERISTICS (continued)
(VCC = +2.25V to +3.0V, C1–C4 = 0.1µF, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +2.5V,
TA= +25°C.)
Note 2: A transmitter/receiver edge is defined as a transition through the transmitter/receiver input logic thresholds.
Note 3: Transmitter skew is measured at the transmitter zero crosspoints.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
V/µs
430
VCC = 2.5V, TA= +25°C, RL= 3kΩto 7kΩ,
measured from +3V to -3V or -3V to +3V,
CL= 150pF to 2500pF
Transition-Region Slew Rate
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
_______________________________________________________________________________________ 5
0
3
9
6
12
15
2.25 2.652.45 2.85 3.05 3.25 3.45 3.65
MAX3318E/MAX3319E
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX3316E TOC06
V
CC
(V)
SUPPLY CURRENT (mA)
460kbps
230kbps
20kbps
T1 TRANSMITTING AT SPECIFIED
DATA RATE
T2 TRANSMITTING AT 20kbps
C
L
= 1000pF
-6
-2
-4
2
0
4
6
2.25 2.85 3.052.45 2.65 3.25 3.45 3.65
MAX3318E/MAX3319E
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX3316E TOC07
V
CC
(V)
TRANSMITTER OUTPUT VOLTAGE (V)
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
C
L
= 1000pF
T_OUT+
T_OUT-
-5
-2
-3
-4
-1
0
1
2
3
4
5
0 1000 2000 3000
MAX3318E/MAX3319E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3316E TOC08
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
T_OUT+
T_OUT-
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
0
2
6
4
8
10
MAX3318E/MAX3319E
SLEW RATE vs. LOAD CAPACITANCE
MAX3316E TOC09
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
020001000 3000
-SLEW
+SLEW
FOR DATA RATES UP TO 460kbs 0
10
5
20
15
30
25
35
MAX3318E/MAX3319E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3316E TOC10
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
0 1000 2000 3000
460kbps
230kbps
20kbps
T1 TRANSMITTING AT SPECIFIED
DATA RATE
T2 TRANSMITTING AT 20kbps
Typical Operating Characteristics (continued)
(VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA= +25°C, unless otherwise noted.)
0
10
5
20
15
30
25
35
MAX3316E/MAX3317E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3316E TOC05
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
0 1000 2000 3000
T1 TRANSMITTING AT SPECIFIED DATA RATE
T2 TRANSMITTING AT 20kbps
460kbps
230kbps
20kbps
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
6 _______________________________________________________________________________________
0
100
300
200
400
500
0 1000500 1500 2000 2500 3000
TRANSMITTER SKEW vs.
LOAD CAPACITANCE (tPLH - tPHL
)
MAX3316E TOC11
LOAD CAPACITANCE (pF)
TRANSMITTER SKEW (ns)
MAX3316E/MAX3317E
MAX3318E/MAX3319E
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
0
10
5
20
15
25
30
-40 0 20-20 40 60 80
MAX3318E/MAX3319E
READY TURN-ON TIME
vs. TEMPERATURE
MAX3316E TOC12
TEMPERATURE (°C)
READY TURN-ON TIME (µs)
0
40
120
80
160
200
-40 0-20 20 40 60 80
MAX3318E/MAX3319E
READY TURN-OFF TIME
vs. TEMPERATURE
MAX3316E TOC13
TEMPERATURE (°C)
READY TURN-OFF TIME (ns)
Typical Operating Characteristics (continued)
(VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA= +25°C, unless otherwise noted.)
Pin Description
—
—
MAX3318E
2
3
4
8, 17
7
6
5
19
18
12, 13
10, 15
9, 16
No Connection
Receiver Enable, Active Low
FUNCTION
Positive Terminal of Voltage-Doubler Charge-
Pump Capacitor
+2 · VCC Generated by the Charge Pump
Negative Terminal of Voltage-Doubler Charge-
Pump Capacitor
RS-232 Transmitter Outputs
-2 · VCC Generated by the Charge Pump
Negative Terminal of Inverting Charge-Pump
Capacitor
Positive Terminal of Inverting Charge-Pump
Capacitor
+2.25V to +3.0V Single-Supply Voltage
Ground
CMOS Transmitter Inputs
CMOS Receiver Outputs
RS-232 Receiver Inputs
—
—
MAX3319E
2
3
4
13
7
6
5
15
14
11
9
8
N.C.
EN
NAME
C1+
V+
C1-
T_OUT
V-
C2-
C2+
VCC
GND
T_IN
R_OUT
R_IN
—1, 10, 11, 20 11, 14
— 1
MAX3316E MAX3317E
1 2 2
PIN
2 3 3
3 4 4
7, 14 8, 17 8, 17
6 7 7
5 6 6
4 5 5
16 19 19
15 18 18
10, 11 13, 14 12, 13
9, 12 12, 15 10, 15
8, 13 9, 16 9, 16
SSOP TSSOP
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
_______________________________________________________________________________________ 7
Pin Description (continued)
Detailed Description
Dual Charge-Pump Voltage Converter
The MAX3316E–MAX3319Es’ internal power supply
consists of a regulated dual charge pump that provides
output voltages of +4.4V (doubling charge pump) and
-4.3V (inverting charge pump), over the +2.25V to
+3.0V range. The charge pump operates in discontinu-
ous mode: if the output voltages are less than 4.4V, the
charge pump is enabled; if the output voltages exceed
4.4V, the charge pump is disabled. Each charge pump
requires a flying capacitor (C1, C2) and a reservoir
capacitor (C3, C4) to generate the V+ and V- supplies.
The READY output (MAX3318E/MAX3319E) is low
when the charge pumps are disabled in shutdown
mode. The READY signal asserts high when V- goes
below -2.75V.
RS-232 Compatible Transmitters
The MAX3316E–MAX3319Es’ transmitters are inverting
level translators that convert CMOS-logic levels to
RS-232 compatible voltage levels. They guarantee a
460kbps data rate with worst-case loads of 3kΩin parallel
with 1000pF, providing compatibility with PC-to-PC
communication software (such as LapLink™).
The MAX3317E’s transmitters are turned off (high
impedance) when SHDN is asserted low, putting the
device in shutdown mode. The MAX3318E/MAX3319Es’
transmitters are turned off (high impedance) when
FORCEOFF is asserted low, or when the AutoShutdown
Plus circuitry senses that all receiver and transmitter
inputs are inactive for more than 30 seconds.
The transmitter outputs can be driven to ±12V when
power is off. The transmitter inputs do not have internal
pull-up resistors. Connect unused inputs to GND or VCC.
RS-232 Receivers
The MAX3316E–MAX3319Es’ receivers convert ±3.7V
to ±13.2V RS-232 signal levels into CMOS-logic output
levels. The receivers are rated to receive signals up to
±25V. The MAX3316E/MAX3318E/MAX3319Es’
receivers feature inverting outputs that always remain
active (Table 1). The MAX3317E’s receivers have
inverting, three-state outputs. In shutdown, the
receivers can be active or inactive (Table 2).
The MAX3318E/MAX3319E feature an INVALID output
that is asserted low when no valid RS-232 voltage levels
have been detected on all receiver inputs. Because
INVALID indicates the receiver’s input condition, it
is independent of the states of FORCEON and
FORCEOFF.
MAX3317E Shutdown Mode
Supply current falls to less than 1µA in shutdown mode
(SHDN = low). When shut down, the device’s charge
pumps are turned off, V+ is pulled down to VCC, V- is
pulled to ground, and the transmitter outputs are dis-
abled (high impedance). The time required to exit shut-
LapLink is a trademark of Traveling Software.
PIN
MAX3316E MAX3317E MAX3318E MAX3319E
NAME FUNCTION
Shutdown Control, Active Low
Ready to Transmit Output, Active High. READY is
enabled high when V- goes below -3.5V and the
device is ready to transmit.
Valid Signal Detector Output, Active Low. A logic
high indicates that a valid RS-232 level is present
on a receiver input.
Force-On Input, Active High. Drive high to override
AutoShutdown Plus, keeping transmitters and
receivers on (FORCEOFF must be high) (Table 1).
Force-Off Input, Active Low. Drive low to shut
down transmitters, receivers, and charge pump.
This overrides AutoShutdown Plus and FORCEON
(Table 1).
FORCEOFF
FORCEON
INVALID
READY
SHDN
—
1
10
12
1620
14
11
1
—20
—
—
—
—
—
—
—
—
—
SSOP TSSOP
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
8 _______________________________________________________________________________________
down is typically 30µs, as shown in Figure 2. Connect
SHDN to VCC if the shutdown mode is not used; SHDN
has no effect on R_OUT.
MAX3318E/MAX3319E
AutoShutdown Plus Mode
Maxim’s AutoShutdown Plus feature on the MAX3318E/
MAX3319E allows the supply current to fall to 1µA.
These devices will enter the AutoShutdown Plus mode if
FORCEOFF is high, FORCEON is low, and they do not
sense a valid signal transition on any receiver or trans-
mitter input for 30 seconds. This may occur if the RS-232
cable is disconnected or if the peripheral transmitters
are turned off, and the UART driving the transmitter
inputs is inactive. The system turns on again when a
valid transition is applied to any RS-232 receiver or
transmitter input. As a result, the system saves power
without changes to the existing BIOS or operating system.
Figure 4a depicts valid and invalid RS-232 receiver volt-
age levels. INVALID indicates the receiver input’s condi-
tion and is independent of FORCEON and FORCEOFF
states. Figure 3 and Table 1 summarize the operating
modes of the MAX3318E/MAX3319E. FORCEON and
FORCEOFF override AutoShutdown Plus circuitry. When
neither control is asserted, the IC selects between these
states automatically based on the last receiver or trans-
mitter edge received.
When shut down, the device’s charge pumps turn off,
V+ is pulled to VCC, V- is pulled to ground, the transmitter
outputs are high impedance, and READY is driven low.
The time required to exit shutdown is typically 30µs
(Figure 2).
X
X
X
X
VALID RECEIVER
LEVEL
Active
Active
Active
Active
R_OUT
No
Yes
X
X
RECEIVER OR
TRANSMITTER
EDGE WITHIN
30s
High-Z
Active
Active
High-Z
T_OUT
Shutdown
(AutoShutdown Plus) 0 1
Normal Operation
(AutoShutdown Plus) 0 1
Normal Operation
(Forced On) 1 1
Shutdown (Forced
Off) X 0
OPERATION
STATUS FORCEON FORCEOFF
No
Yes
No
X
Yes
Active
Active
Active
Active
Active
X
X
No
Yes
X
High-Z
Active
High-Z
Active
Active
Shutdown
(AutoShutdown) INVALID** INVALID**
Normal Operation
(AutoShutdown) INVALID** INVALID**
Shutdown INVALID*1
Normal Operation INVALID*1
Normal Operation INVALID*1
Table 1. Output Control Truth Table (MAX3318E/MAX3319E)
Table 2. Shutdown and Enable Control
Truth Table (MAX3317E)
X = Don’t care
*
INVALID
connected to FORCEON
**
INVALID
connected to FORCEON and
FORCEOFF
SHDN EN T_OUT R_OUT
0 0 High-Z Active
0 1 High-Z High-Z
1 0 Active Active
1 1 Active High-Z
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
_______________________________________________________________________________________ 9
MAX3316E
MAX3317E
MAX3318E
MAX3319E
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
VCC
C2
0.1µF
C1
0.1µF
CBYPASS
T_ OUT
T_ IN
GND
0.1µF
C3
0.1µF
C4
0.1µF
1000pF
+2.5V
RS-232
COMPLIANT
TRANSCEIVER
+5V
RX
TX
Figure 1a. RS-232 Compatibility Circuit
5V/div
5V/div
5V/div
T1 IN
MAX3316E–MAX3319E
T1 OUT
MAX3316E–MAX3319E
RS-232 COMPLIANT
RECEIVER OUTPUT
2V/div
2V/div
10µs/div
VCC OR SHDN
(MAX3317E)
FORCEOFF
(MAX3318E/MAX3319E)
T1
T2
Figure 1b. MAX3316E–MAX3319E Transmitter Output
Compatibility with an RS-232 Receiver
Figure 2. Transmitter Outputs when Exiting Shutdown or
Powering Up
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
10 ______________________________________________________________________________________
By connecting FORCEON to INVALID, the MAX3318E/
MAX3319E shut down when no valid receiver level is
detected and wake up when a valid receiver level is
detected.
A system with AutoShutdown Plus may need time to
wake up. Figure 5 shows a circuit that forces the trans-
mitters on for 100ms, allowing enough time for the other
system to realize that the MAX3318E/MAX3319E is
awake. If the other system outputs valid RS-232 signal
transitions within that time, the RS-232 ports on both
systems remain enabled.
Connecting to the PC
(MAX3318E/MAX3319E)
If direct software control is desired, use INVALID to
indicate DTR or ring indicator (RI) signal. This can be
used to connect a hand-held device to a PC. One
example is using the Hot Sync™ function on a personal
digital assistant (PDA). The transmitter and receiver
signals (T_OUT and R_IN) are used for communication,
while INVALID causes a change of state on RI. The
change of state on RI will trigger an interrupt on the PC
and allow communication to begin between the device
and the PC. This eliminates the need for the PC to poll
constantly the receiver or transmitter lines to determine
if the device is connected.
±15kV ESD Protection
All the pins on the MAX3316E–MAX3319E are protect-
ed against ESDs encountered during handling and
assembly. The driver outputs and receiver inputs have
extra protection against static electricity. 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:
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 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 IEC 1000-4-2 Contact Discharge
method
• ±15kV using IEC 1000-4-2 Air-Gap method
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.
Human Body Model
Figure 6a shows the Human Body Model, and Figure 6b
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
1.5kΩresistor.
+0.3V
-0.3V
INVALID
R_IN
INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR
AT LEAST 30µs.
30µs
TIMER
R
Figure 3a.
INVALID
Functional Diagram,
INVALID
Low
+2.7V
-2.7V
INVALID
R_IN
INVALID DEASSERTED IF ANY RECEIVER INPUT HAS BEEN BETWEEN +2.7V AND -2.7V
FOR LESS THAN 30µs.
30µs
TIMER
R
Figure 3b.
INVALID
Functional Diagram,
INVALID
High
RECEIVER INPUT LEVELS
-2.7V
-0.3V
+2.7V
+0.3V
0
INDETERMINATE
INVALID HIGH
INVALID LOW
INVALID HIGH
INDETERMINATE
Figure 4a. Receiver Positive/Negative Thresholds for
INVALID
Hot Sync is a trademark of 3Com.
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
______________________________________________________________________________________ 11
FORCEON
MASTER SHDN LINE
0.1µF 1M
FORCEOFF
MAX3318E
MAX3319E
POWER-
MANAGEMENT
UNIT
Figure 5. AutoShutdown Plus Initial Turn-On to Wake Up a
Mouse or Another System
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RD
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
RC
1M
Figure 6a. Human Body ESD Test Model
VCC
0
0
V+
V-
VCC
0
INVALID
OUTPUT
OUTPUT
TRANSMITTER
INPUTS
RECEIVER
INPUTS }INVALID
REGION
MAX3318E/MAX3319E
TRANSMITTER
OUTPUTS
*VCC
tAUTOSHDN tWU tWU
tINVL tINVH tAUTOSHDN
Figure 4b. AutoShutdown Plus,
INVALID
, and READY Timing Diagram
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
12 ______________________________________________________________________________________
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment; it does not specifi-
cally refer to ICs. The MAX3316E–MAX3319E help you
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 with-
stand voltage measured to IEC 1000-4-2 is generally
lower than that measured using the Human Body
Model. Figure 7a shows the IEC 1000-4-2 model, and
Figure 7b shows the current waveform for the 8kV, IEC
1000-4-2, Level 4, ESD Contact Discharge test.
The Air-Gap Discharge test involves approaching the
device with a charged probe. The Contact Discharge
method connects the probe to the device before the
probe is energized.
Machine Model
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resis-
tance. Its objective is to emulate the stress caused by
contact that occurs with handling and assembly during
manufacturing. 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.
Applications Information
RS-232 Compatible Operation
The MAX3316E–MAX3319E do not meet EIA-232
requirements for transmitter output voltage levels. EIA-232
compliance specifies transmitter output voltage swings
of ±5V when loaded with 3kΩand 2500pF.
The receiver inputs are fully EIA-232 compliant.
The MAX3316E–MAX3319E will function properly with
most modern RS-232 interfaces. This allows RS-232
compatible communication in low-voltage systems without
the added expense of a voltage tripler or switched-
mode power supply.
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPERES
Figure 6b. Human Body Current Waveform
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
150pF
RC
50M to 100M
RD
330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 7a. IEC 1000-4-2 ESD Test Model
tr = 0.7ns to 1ns
30ns
60ns
t
100%
90%
10%
IPEAK
I
Figure 7b. IEC 1000-4-2 ESD Generator Current Waveform
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
______________________________________________________________________________________ 13
Capacitor Selection
The capacitor type used for C1–C4 is not critical for
proper operation; polarized or nonpolarized capacitors
can be used. The charge pump requires 0.1µF capaci-
tors. Increasing the capacitor values (e.g., by a factor of
2) reduces ripple on the transmitter outputs and slightly
reduces power consumption. C2, C3, and C4 can be
increased without changing C1’s value. However, do
not increase C1 without also increasing the values of
C2, C3, C4, and CBYPASS to maintain proper ratios
(C1 to other capacitors).
When using the minimum-required capacitor values,
make sure the capacitor value does not degrade exces-
sively with temperature. If in doubt, use capacitors with
a higher nominal value. The capacitor’s equivalent
series resistance (ESR), which usually rises at low tem-
peratures, influences the amount of ripple on V+ and V-.
Power-Supply Decoupling
In most circumstances, a 0.1µF bypass capacitor is
adequate. In applications that are sensitive to power-
supply noise, decouple VCC to ground with a capacitor
of the same value as charge pump capacitor C1.
Connect bypass capacitors as close to the IC as possible.
Transmitter Outputs when
Exiting Shutdown
Figure 2 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232 com-
patible levels (one transmitter input is high, the other is
low). Each transmitter is loaded with 3kΩin parallel with
2500pF. The transmitter outputs display no ringing or
undesirable transients as they come out of shutdown.
Note that the transmitters are enabled only when the
magnitude of V- exceeds approximately -3V.
High Data Rates
The MAX3316E–MAX3319E maintain RS-232 compatible
±3.7V minimum transmitter output voltage even at high
data rates. Figure 8 shows a transmitter loopback test
circuit. Figure 9 shows a loopback test result at
230kbps. For Figure 9, all transmitters were driven
simultaneously at 230kbps into EIA/TIA-562 loads in
parallel with 1000pF.
Chip Information
TRANSISTOR COUNT: 1130
MAX3316E
MAX3317E
MAX3318E
MAX3319E
5k
R_ IN
R_ OUT
FORCEON**
C2-
C2+
C1-
C1+
V-
V+
VCC
C4
C3*
C1
C2
CBYPASS
VCC
FORCEOFF**
*C3 CAN BE RETURNED TO VCC OR GND.
**MAX3318E/MAX3319E
T_ OUT
T_ IN
GND
VCC
1000pF
Figure 8. Loopback Test Circuit
2V/div
5V/div
2V/div
T1 IN
T1 OUT
R1 OUT
Figure 9. Loopback Test Result at 230kbps
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
14 ______________________________________________________________________________________
Pin Configurations (continued)
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
READY FORCEOFF
VCC
GND
T1OUT
FORCEON
T1IN
INVALID
R1OUT
MAX3319E
SSOP
C1+
V+
C2-
C1-
C2+
V-
R1IN
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
SHDN
VCC
GND
T1OUTC1-
V+
C1+
EN
TOP VIEW
R1IN
R1OUT
N.C.
T1INT2OUT
V-
C2-
C2+
12
11
9
10
T2IN
N.C.R2OUT
R2IN
MAX3317E
SSOP/TSSOP
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
N.C.
VCC
GND
T1OUTC1-
V+
C1+
N.C.
R1IN
R1OUT
T1IN
T2INT2OUT
V-
C2-
C2+
12
11
9
10
R2OUT
N.C.N.C.
R2IN
MAX3316E
TSSOP
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
C1+ VCC
GND
T1OUT
R1IN
R1OUT
T1IN
T2IN
R2OUT
MAX3316E
SSOP
V+
C1-
V-
C2+
C2-
T2OUT
R2IN
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
______________________________________________________________________________________ 15
MAX3317E
R2OUT10
1
R1OUT15
R2IN 9
20
GND
18
RS-232
COMPATIBLE
OUTPUTS
CMOS
INPUTS
T2IN
12
T1IN
13
C2-
6
C2+
5
C1-
4
C1+
2
R1IN 16
T2OUT 8
T1OUT 17
V- 7
V+ 3
VCC
19
C1
0.1µF
C2
0.1µF
0.1µF
+2.5V
RS-232
COMPATIBLE
INPUTS
CMOS
OUTPUTS 5k
5k
EN
SHDN
C3*
0.1µF
C4
0.1µF
*C3 CAN BE RETURNED TO EITHER VCC OR GROUND.
MAX3316E
R2OUT9
R1OUT12
R2IN 8
GND
15
RS-232
COMPATIBLE
OUTPUTS
CMOS
INPUTS
T2IN
10
T1IN
11
C2-
5
C2+
4
C1-
3
C1+
1
R1IN 13
T2OUT 7
T1OUT 14
V- 6
V+ 2
VCC
C4
0.1µF
16
0.1µF
0.1µF
0.1µF
+2.5V
RS-232
COMPATIBLE
INPUTS
CMOS
OUTPUTS
C3*
0.1µF
5k
5k
CIRCUIT SHOWN IS FOR THE 16-PIN SSOP.
Typical Application Circuits
Selector Guide
PART NO. OF DRIVERS/
RECEIVERS
GUARANTEED
DATA RATE (kbps) READY OUTPUT SHUTDOWN AutoShutdown
Plus
MAX3316E 2/2 460 — — —
MAX3317E 2/2 460 —✓—
MAX3318E 2/2 460 ✓—✓
MAX3319E 1/1 460 ✓—✓
Typical Application Circuits continue on next page.
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
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.
16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
MAX3319E
FORCEON
READY AutoShutdown
Plus
12
1
R1OUT9
FORCEOFF 16
INVALID 10
GND
14
T1IN
11
C2-
6
C2+
5
C1-
4
C1+
2
R1IN 8
T1OUT 13
V- 7
V+ 3
VCC
VCC
C4
0.1µF
C3
0.1µF
0.1µF 15
C1
0.1µF
C2
0.1µF
CBYPASS
+2.5V
TO POWER-
MANAGEMENT
UNIT
5k
CBYPASS
MAX3318E
FORCEON
READY
14
1
R2OUT10
R1OUT15
FORCEOFF 20
INVALID 11
R2IN 9
GND
18
RS-232 COMPATIBLE
OUTPUTS
CMOS
INPUTS
CMOS
INPUT
T2IN
12
T1IN
13
C2-
6
C2+
5
C1-
4
C1+
2
R1IN 16
T2OUT 8
T1OUT 17
V- 7
V+ 3
VCC
VCC
C4
0.1µF
C3
0.1µF
0.1µF 19
C1
0.1µF
C2
0.1µF
+2.5V
RS-232 COMPATIBLE
INPUTS
RS-232
COMPATIBLE
OUTPUT
RS-232
COMPATIBLE
INPUT
TO POWER-
MANAGEMENT
UNIT
CMOS
OUTPUTS
CMOS
OUTPUT
5k
5k
AutoShutdown
Plus
Typical Application Circuits (continued)
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