Maxim MAX3318EEUP ±15kv esd-protected, 2.5v, 1î¼a, 460kbps, rs-232 compatible transceiver Datasheet

19-1616; Rev 0; 1/00
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
____________________________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
All devices are guaranteed at a data rate of 460kbps.
The transceivers have a proprietary low-dropout transmitter output stage enabling RS-232 compatible operation 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 logiclevel 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 shutdown 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.
♦ Guaranteed 4V/µs Slew Rate
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
♦ 300µA Operating Supply Current
♦ 1µA Low-Power Shutdown with Receivers Active
♦ Guaranteed 460kbps Data Rate
♦ RS-232 Compatible Down to 2.25V
Ordering Information
PART
TEMP. RANGE
0°C to +70°C
20 TSSOP
MAX3316ECAE
0°C to +70°C
16 SSOP
MAX3316EEUP
-40°C to +85°C
MAX3316EEAE
-40°C to +85°C
MAX3317ECUP
GPS
Handy Terminals
Hand-Held Electronic Books
Selector Guide and Typical Application Circuits appear at
end of data sheet.
AutoShutdown Plus is a trademark of Maxim Integrated Products.
16 SSOP
20 TSSOP
MAX3317ECAP
0°C to +70°C
20 SSOP
MAX3317EEUP
-40°C to +85°C
MAX3317EEAP
-40°C to +85°C
MAX3318ECUP
20 TSSOP
20 SSOP
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
READY 1
20 FORCEOFF
C1+ 2
19 VCC
V+ 3
18 GND
C1- 4
17 T1OUT
MAX3318E
C2- 6
Cellular Phones
20 TSSOP
0°C to +70°C
C2+ 5
Pagers
PIN-PACKAGE
MAX3316ECUP
16 R1IN
15 R1OUT
V- 7
14 FORCEON
T2OUT 8
13 T1IN
R2IN 9
12 T2IN
R2OUT 10
11 INVALID
SSOP/TSSOP
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
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.
MAX3316E–MAX3319E
_______________General Description
The MAX3316E–MAX3319E are 2.5V powered RS-232
compatible transceivers. These devices feature shutdown (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.
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
ABSOLUTE MAXIMUM RATINGS
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.
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 = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V,
TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS (VCC = +2.5V, TA = +25°C)
AutoShutdown Plus Supply
Current
FORCEON = GND, FORCEOFF = VCC,
all R_IN idle, all T_IN idle
(MAX3318E/MAX3319E)
1
10
µA
Shutdown Supply Current
SHDN = GND (MAX3317E); FORCEOFF =
GND (MAX3318E/MAX3319E)
1
10
µA
Supply Current
SHDN = VCC, no load (MAX3317E);
FORCEON = FORCEOFF = VCC, no load
(MAX3318E/MAX3319E)
0.3
1
mA
LOGIC INPUTS
Input Logic Threshold Low
T_IN, EN, SHDN, FORCEON, FORCEOFF
Input Logic Threshold High
T_IN, EN, SHDN, FORCEON, FORCEOFF
0.3 · VCC
0.7 · VCC
V
0.3
Transmitter Input Hysteresis
V
V
T_IN, EN, SHDN, FORCEON, FORCEOFF
±0.01
±1
µA
Output Leakage Current
EN = VCC (MAX3317E), receivers disabled
±0.05
±10
µA
Output Voltage Low
IOUT = 0.5mA
0.1 · VCC
V
Output Voltage High
IOUT = -0.5mA
Input Leakage Current
RECEIVER OUTPUTS
0.9 · VCC
V
RECEIVER INPUTS
-25
Input Voltage Range
Input Threshold Low
TA = +25°C
Input Threshold High
TA = +25°C
0.7 · VCC
TA = +25°C
3
5
±3.7
±4
Input Hysteresis
Input Resistance
+25
V
0.3 · VCC
V
V
0.3
V
7
kΩ
TRANSMITTER OUTPUTS
Output Voltage Swing
2
All transmitter outputs loaded with 3kΩ to
ground
_______________________________________________________________________________________
V
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
(V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V,
TA = +25°C.)
PARAMETER
SYMBOL
Output Resistance
CONDITIONS
VCC = 0, transmitter output = ±2V
MIN
TYP
300
10M
±25
Output Short-Circuit Current
VCC = 0 or 2.25V to 3.0V, VOUT = ±12V,
transmitters disabled
Output Leakage Current
MAX
UNITS
±60
mA
±25
µA
Ω
ESD PROTECTION
R_IN, T_OUT
Human Body Model
±15
IEC 1000-4-2 Air-Gap Discharge method
±15
IEC 1000-4-2 Contact Discharge method
±8
kV
AutoShutdown Plus (FORCEON = GND, FORCEOFF = VCC) (MAX3318E/MAX3319E)
Receiver Input Threshold to
INVALID Output High
Figure 4a
Receiver Input Threshold to
INVALID Output Low
Figure 4a
INVALID, READY Output
Voltage Low
IOUT = 0.5mA
INVALID, READY Output
Voltage High
IOUT = -0.5mA
2.7
Positive threshold
Negative threshold
-2.7
-0.3
0.3
0.1 · VCC
0.9 · VCC
V
V
V
V
Receiver Positive or Negative
Threshold to INVALID High
tINVH
VCC = 2.5V, Figure 4b
1
µs
Receiver Positive or Negative
Threshold to INVALID Low
tINVL
VCC = 2.5V, Figure 4b
30
µs
Receiver or Transmitter Edge to
Transmitters Enabled
tWU
VCC = 2.5V, Figure 4b (Note 2)
100
µs
Receiver or Transmitter Edge to
Transmitters Shutdown
tAUTOSHDN
VCC = 2.5V, Figure 4b (Note 2)
15
30
60
s
TIMING CHARACTERISTICS
(V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V,
TA = +25°C.)
PARAMETER
SYMBOL
Maximum Data Rate
Receiver Propagation Delay
CONDITIONS
RL = 3kΩ, CL = 1000pF, one transmitter
switching
tPHL
tPLH
Receiver Output Enable Time
R_IN to R_OUT, CL = 150pF
MIN
TYP
460
MAX
UNITS
kbps
0.175
0.175
µs
Normal operation (MAX3317E)
250
ns
Normal operation (MAX3317E)
250
ns
Transmitter Skew
|tPHL - tPLH| (Note 3)
100
ns
Receiver Skew
|tPHL - tPLH|
50
ns
Receiver Output Disable Time
_______________________________________________________________________________________
3
MAX3316E–MAX3319E
ELECTRICAL CHARACTERISTICS (continued)
TIMING CHARACTERISTICS (continued)
(V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V,
TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
VCC = 2.5V, TA = +25°C, RL = 3kΩ to 7kΩ,
measured from +3V to -3V or -3V to +3V,
CL = 150pF to 2500pF
Transition-Region Slew Rate
TYP
4
MAX
UNITS
30
V/µs
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.
Typical Operating Characteristics
(VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA = +25°C, unless otherwise noted.)
MAX3316E/MAX3317E
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX3316E/MAX3317E
SUPPLY CURRENT vs. SUPPLY VOLTAGE
230kbps
6
4
20kbps
T1 TRANSMITTING AT SPECIFIED
DATA RATE
T2 TRANSMITTING AT 20kbps
CL = 1000pF
2.25
2.45
2.65
2.85
3.05
3.25
0
MAX3316E TOC02
-2
T_OUT-
-4
-6
3.45
3.65
2.25
2.45
2.65
2.85
3.05
3.25
3.45
3.65
MAX3316E/MAX3317E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3316E/MAX3317E
SLEW RATE vs. LOAD CAPACITANCE
T_OUT+
3
10
0
-1
FOR DATA RATES UP TO 460kps
8
SLEW RATE (V/µs)
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
-SLEW
6
+SLEW
4
-2
2
-3
T_OUT-
-4
0
-5
0
1000
2000
LOAD CAPACITANCE (pF)
4
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
CL = 1000pF
VCC (V)
4
1
2
VCC (V)
5
2
4
MAX3316E TOC04
0
T_OUT+
MAX3316E TOC03
2
6
TRANSMITTER OUTPUT VOLTAGE (V)
460kbps
8
SUPPLY CURRENT (mA)
MAX3316E TOC01
10
TRANSMITTER OUTPUT VOLTAGE (V)
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
3000
0
1000
2000
3000
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
15
10
20kbps
20kbps
6
T1 TRANSMITTING AT SPECIFIED
DATA RATE
T2 TRANSMITTING AT 20kbps
CL = 1000pF
3
5
0
0
0
1000
2000
LOAD CAPACITANCE (pF)
T_OUT+
3
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
1
0
-1
2.65
2.85
MAX3316E TOC07
2
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
CL = 1000pF
0
-2
T_OUT-
-4
3.05
3.25
3.45
3.65
2.25
2.45
2.65
2.85
3.05
3.25
3.45
VCC (V)
VCC (V)
MAX3318E/MAX3319E
SLEW RATE vs. LOAD CAPACITANCE
MAX3318E/MAX3319E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
8
SLEW RATE (V/µs)
2
2.45
10
MAX3316E TOC08
TRANSMITTER OUTPUT VOLTAGE (V)
4
T_OUT+
4
-6
2.25
3000
MAX3318E/MAX3319E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
5
MAX3316E TOC06
230kbps
9
TRANSMITTER OUTPUT VOLTAGE (V)
230kbps
12
6
-SLEW
6
35
+SLEW
4
-2
3.65
T1 TRANSMITTING AT SPECIFIED
DATA RATE
T2 TRANSMITTING AT 20kbps
30
SUPPLY CURRENT (mA)
460kbps
20
460kbps
MAX3316E TOC09
25
15
SUPPLY CURRENT (mA)
SUPPLY CURRENT (mA)
30
T1 TRANSMITTING AT SPECIFIED DATA RATE
T2 TRANSMITTING AT 20kbps
MAX3316E TOC05
35
MAX3318E/MAX3319E
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX3318E/MAX3319E
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX3316E TOC10
MAX3316E/MAX3317E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
25
460kbps
20
230kbps
15
10
20kbps
2
-3
T_OUT-
-4
5
FOR DATA RATES UP TO 460kbs
0
-5
0
1000
2000
LOAD CAPACITANCE (pF)
3000
0
1000
2000
LOAD CAPACITANCE (pF)
0
3000
0
1000
2000
LOAD CAPACITANCE (pF)
3000
_______________________________________________________________________________________
5
MAX3316E–MAX3319E
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.)
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.)
300
MAX3316E/MAX3317E
200
MAX3318E/MAX3319E
100
20
15
10
500
1000
1500
2000
2500
-40
3000
120
80
0
0
0
160
40
5
0
MAX3316E TOC13
25
200
READY TURN-OFF TIME (ns)
400
30
MAX3316E TOC12
T1 TRANSMITTING AT 460kbps
T2 TRANSMITTING AT 20kbps
READY TURN-ON TIME (µs)
MAX3316E TOC11
500
MAX3318E/MAX3319E
READY TURN-OFF TIME
vs. TEMPERATURE
MAX3318E/MAX3319E
READY TURN-ON TIME
vs. TEMPERATURE
TRANSMITTER SKEW vs.
LOAD CAPACITANCE (tPLH - tPHL)
TRANSMITTER SKEW (ns)
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
LOAD CAPACITANCE (pF)
Pin Description
PIN
NAME
MAX3316E
SSOP
TSSOP
1
2
2
2
2
C1+
2
3
3
3
3
V+
+2 · VCC Generated by the Charge Pump
3
4
4
4
4
C1-
Negative Terminal of Voltage-Doubler ChargePump Capacitor
4
5
5
5
5
C2+
Positive Terminal of Inverting Charge-Pump
Capacitor
5
6
6
6
6
C2-
Negative Terminal of Inverting Charge-Pump
Capacitor
6
7
7
7
7
V-
7, 14
8, 17
8, 17
8, 17
13
T_OUT
8, 13
9, 16
9, 16
9, 16
8
R_IN
RS-232 Receiver Inputs
9, 12
12, 15
10, 15
10, 15
9
R_OUT
CMOS Receiver Outputs
10, 11
13, 14
12, 13
12, 13
11
T_IN
CMOS Transmitter Inputs
15
18
18
18
14
GND
Ground
16
19
19
19
15
VCC
+2.25V to +3.0V Single-Supply Voltage
1
—
—
EN
Receiver Enable, Active Low
1, 10, 11, 20
11, 14
—
—
N.C.
—
—
6
FUNCTION
MAX3317E MAX3318E MAX3319E
Positive Terminal of Voltage-Doubler ChargePump Capacitor
-2 · VCC Generated by the Charge Pump
RS-232 Transmitter Outputs
No Connection
_______________________________________________________________________________________
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
PIN
MAX3316E
SSOP
TSSOP
NAME
FUNCTION
MAX3317E MAX3318E MAX3319E
—
20
—
—
SHDN
Shutdown Control, Active Low
—
—
1
1
READY
Ready to Transmit Output, Active High. READY is
enabled high when V- goes below -3.5V and the
device is ready to transmit.
—
—
11
10
INVALID
Valid Signal Detector Output, Active Low. A logic
high indicates that a valid RS-232 level is present
on a receiver input.
—
—
14
12
FORCEON
Force-On Input, Active High. Drive high to override
AutoShutdown Plus, keeping transmitters and
receivers on (FORCEOFF must be high) (Table 1).
FORCEOFF
Force-Off Input, Active Low. Drive low to shut
down transmitters, receivers, and charge pump.
This overrides AutoShutdown Plus and FORCEON
(Table 1).
—
—
20
16
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 discontinuous 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 3kΩ in 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’
LapLink is a trademark of Traveling Software.
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 disabled (high impedance). The time required to exit shut-
_______________________________________________________________________________________
7
MAX3316E–MAX3319E
Pin Description (continued)
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
Table 1. Output Control Truth Table (MAX3318E/MAX3319E)
OPERATION
STATUS
RECEIVER OR
VALID RECEIVER TRANSMITTER
LEVEL
EDGE WITHIN
30s
FORCEON
FORCEOFF
Shutdown (Forced
Off)
X
0
X
Normal Operation
(Forced On)
1
1
Normal Operation
(AutoShutdown Plus)
0
Shutdown
(AutoShutdown Plus)
T_OUT
R_OUT
X
High-Z
Active
X
X
Active
Active
1
X
Yes
Active
Active
0
1
X
No
High-Z
Active
Normal Operation
INVALID*
1
Yes
X
Active
Active
Normal Operation
INVALID*
1
X
Yes
Active
Active
Shutdown
INVALID*
1
No
No
High-Z
Active
Normal Operation
(AutoShutdown)
INVALID**
INVALID**
Yes
X
Active
Active
Shutdown
(AutoShutdown)
INVALID**
INVALID**
No
X
High-Z
Active
X = Don’t care
*INVALID connected to FORCEON
**INVALID connected to FORCEON and FORCEOFF
Table 2. Shutdown and Enable Control
Truth Table (MAX3317E)
SHDN
0
EN
0
T_OUT
High-Z
Active
0
1
High-Z
High-Z
1
0
Active
Active
1
1
Active
High-Z
R_OUT
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
8
sense a valid signal transition on any receiver or transmitter 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 voltage levels. INVALID indicates the receiver input’s condition 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 transmitter 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).
_______________________________________________________________________________________
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
MAX3316E–MAX3319E
+2.5V
CBYPASS
0.1µF
VCC
C1+
C1
0.1µF
C3
0.1µF
C1C2+
C2
0.1µF
V+
C2-
MAX3316E
MAX3317E
MAX3318E
MAX3319E
V-
+5V
C4
0.1µF
T_ OUT
T_ IN
RX
1000pF
R_ IN
R_ OUT
TX
RS-232
COMPLIANT
TRANSCEIVER
GND
Figure 1a. RS-232 Compatibility Circuit
VCC OR SHDN
(MAX3317E)
5V/div
T1 IN
MAX3316E–MAX3319E
FORCEOFF
(MAX3318E/MAX3319E)
2V/div
T1
5V/div
T1 OUT
MAX3316E–MAX3319E
2V/div
T2
RS-232 COMPLIANT
RECEIVER OUTPUT
5V/div
10µs/div
Figure 1b. MAX3316E–MAX3319E Transmitter Output
Compatibility with an RS-232 Receiver
Figure 2. Transmitter Outputs when Exiting Shutdown or
Powering Up
_______________________________________________________________________________________
9
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 transmitters 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 protected against ESDs encountered during handling and
assembly. The driver outputs and receiver inputs have
extra protection against static electricity. Maxim’s engineers have developed state-of-the-art structures to protect 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 transmitter 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.
Hot Sync is a trademark of 3Com.
10
+0.3V
R_IN
30µs
TIMER
R
-0.3V
INVALID
INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR
AT LEAST 30µs.
Figure 3a. INVALID Functional Diagram, INVALID Low
+2.7V
R_IN
30µs
TIMER
R
-2.7V
INVALID
INVALID DEASSERTED IF ANY RECEIVER INPUT HAS BEEN BETWEEN +2.7V AND -2.7V
FOR LESS THAN 30µs.
Figure 3b. INVALID Functional Diagram, INVALID High
INVALID HIGH
+2.7V
RECEIVER INPUT LEVELS
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
INDETERMINATE
+0.3V
0
INVALID LOW
-0.3V
INDETERMINATE
-2.7V
INVALID HIGH
Figure 4a. Receiver Positive/Negative Thresholds for INVALID
Human Body Model
Figure 6a shows the Human Body Model, and Figure 6b
shows the current waveform it generates when discharged 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.
______________________________________________________________________________________
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
MAX3316E–MAX3319E
RECEIVER
INPUTS
INVALID
} REGION
TRANSMITTER
INPUTS
TRANSMITTER
OUTPUTS
INVALID
OUTPUT
VCC
tINVL
tINVH
0
tAUTOSHDN
tAUTOSHDN
tWU
tWU
*VCC
OUTPUT
0
V+
VCC
0
V-
MAX3318E/MAX3319E
Figure 4b. AutoShutdown Plus, INVALID, and READY Timing Diagram
POWERMANAGEMENT
UNIT
RC
1M
MASTER SHDN LINE
0.1µF
1M
CHARGE-CURRENT
LIMIT RESISTOR
FORCEOFF FORCEON
MAX3318E
MAX3319E
Figure 5. AutoShutdown Plus Initial Turn-On to Wake Up a
Mouse or Another System
HIGHVOLTAGE
DC
SOURCE
Cs
100pF
RD
1500Ω
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 6a. Human Body ESD Test Model
______________________________________________________________________________________
11
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment; it does not specifically 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 ESDprotection 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 withstand 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.
IP 100%
90%
Applications Information
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
AMPERES
36.8%
10%
0
0
TIME
tRL
tDL
CURRENT WAVEFORM
Figure 6b. Human Body Current Waveform
RC
50M to 100M
CHARGE-CURRENT
LIMIT RESISTOR
Machine Model
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resistance. 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.
Ir
HIGHVOLTAGE
DC
SOURCE
Cs
150pF
RD
330Ω
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 7a. IEC 1000-4-2 ESD Test Model
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 3kΩ and 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 switchedmode power supply.
I
100%
90%
I PEAK
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
10%
t r = 0.7ns to 1ns
t
30ns
60ns
Figure 7b. IEC 1000-4-2 ESD Generator Current Waveform
12
______________________________________________________________________________________
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
VCC
CBYPASS
VCC
C1+
C1
C1C2+
C2
Transmitter Outputs when
Exiting Shutdown
Figure 2 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two transmitter outputs are shown going to opposite RS-232 compatible levels (one transmitter input is high, the other is
low). Each transmitter is loaded with 3kΩ in 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.
V+
C3*
MAX3316E
MAX3317E
MAX3318E
MAX3319E
VC4
C2-
T_ OUT
T_ IN
R_ IN
R_ OUT
Power-Supply Decoupling
In most circumstances, a 0.1µF bypass capacitor is
adequate. In applications that are sensitive to powersupply 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.
MAX3316E–MAX3319E
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 capacitors. 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 excessively with temperature. If in doubt, use capacitors with
a higher nominal value. The capacitor’s equivalent
series resistance (ESR), which usually rises at low temperatures, influences the amount of ripple on V+ and V-.
5k
FORCEON**
VCC
FORCEOFF**
1000pF
GND
*C3 CAN BE RETURNED TO VCC OR GND.
**MAX3318E/MAX3319E
Figure 8. Loopback Test Circuit
2V/div
T1 IN
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
5V/div
T1 OUT
R1 OUT
2V/div
Figure 9. Loopback Test Result at 230kbps
______________________________________________________________________________________
13
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
MAX3316E–MAX3319E
Pin Configurations (continued)
TOP VIEW
C1+ 1
16 VCC
V+ 2
15 GND
C1- 3
C2+ 4
14 T1OUT
MAX3316E
C2- 5
12 R1OUT
V- 6
11 T1IN
10 T2IN
T2OUT 7
9
R2IN 8
SSOP
14
13 R1IN
R2OUT
N.C. 1
20 N.C.
EN 1
C1+ 2
19 VCC
C1+ 2
19 VCC
V+ 3
18 GND
V+ 3
18 GND
C1- 4
C2+ 5
MAX3316E
C2- 6
17 T1OUT
C1- 4
16 R1IN
C2+ 5
15 R1OUT
C2- 6
20 SHDN
17 T1OUT
MAX3317E
16 R1IN
15 R1OUT
V- 7
14 T1IN
V- 7
14 N.C.
T2OUT 8
13 T2IN
T2OUT 8
13 T1IN
R2IN 9
12 T2IN
R2OUT 10
11 N.C.
R2IN 9
12 R2OUT
N.C. 10
11 N.C.
TSSOP
SSOP/TSSOP
READY 1
16 FORCEOFF
C1+ 2
15 VCC
V+ 3
14 GND
C1- 4
MAX3319E
13 T1OUT
C2+ 5
12 FORCEON
C2- 6
11 T1IN
10 INVALID
V- 7
9
R1IN 8
SSOP
______________________________________________________________________________________
R1OUT
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
PART
NO. OF DRIVERS/
RECEIVERS
GUARANTEED
DATA RATE (kbps)
READY OUTPUT
SHUTDOWN
MAX3316E
2/2
460
—
MAX3317E
2/2
460
—
✓
MAX3318E
2/2
460
—
✓
MAX3319E
1/1
460
✓
AutoShutdown
Plus
—
—
—
✓
—
✓
Typical Application Circuits
+2.5V
+2.5V
19
0.1µF
C1
0.1µF
2 C1+
4
5
C2
0.1µF
6
V+
3
C3*
0.1µF
C1-
MAX3317E
C2+
V-
0.1µF
0.1µF
T1OUT 17
T2OUT 8
12 T2IN
CMOS
OUTPUTS
5k
10 R2OUT
R2IN 9
5
VCC
V+
RS-232
COMPATIBLE
OUTPUTS
C2+
MAX3316E
GND
18
SHDN
V-
6
C4
0.1µF
T1OUT 14
CMOS
INPUTS
T2OUT 7
10 T2IN
RS-232
COMPATIBLE
OUTPUTS
R1IN 13
CMOS
OUTPUTS
5k
9 R2OUT
R2IN 8
5k
EN
C3*
0.1µF
C2-
12 R1OUT
RS-232
COMPATIBLE
INPUTS
2
C1-
11 T1IN
R1IN 16
15 R1OUT
3
4
C4
0.1µF
CMOS
INPUTS
1
1 C1+
7
C2-
13 T1IN
16
0.1µF
VCC
RS-232
COMPATIBLE
INPUTS
5k
20
*C3 CAN BE RETURNED TO EITHER VCC OR GROUND.
GND
15
CIRCUIT SHOWN IS FOR THE 16-PIN SSOP.
Typical Application Circuits continue on next page.
______________________________________________________________________________________
15
MAX3316E–MAX3319E
Selector Guide
MAX3316E–MAX3319E
±15kV ESD-Protected, 2.5V, 1µA, 460kbps,
RS-232 Compatible Transceivers
Typical Application Circuits (continued)
+2.5V
CBYPASS
C1
0.1µF
+2.5V
2 C1+
4
5
C2
0.1µF
CMOS
INPUTS
19
0.1µF
6
C1-
3
V+
MAX3318E
C2+
V-
C3
0.1µF
2 C1+
C1
0.1µF
4
7
C2-
13 T1IN
T1OUT 17
12 T2IN
T2OUT 8
C4
0.1µF
RS-232 COMPATIBLE
OUTPUTS
15
0.1µF
CBYPASS
VCC
5
C2
0.1µF
6
CMOS
INPUT
CMOS
OUTPUT
C1-
VCC
3
V+
MAX3319E
C2+
V-
C3
0.1µF
7
C2-
11 T1IN
T1OUT 13
R1IN 8
9 R1OUT
5k
CMOS
OUTPUTS
RS-232 COMPATIBLE
INPUTS
5k
12
5k
14
1
READY
R2IN 9
10 R2OUT
READY
RS-232
COMPATIBLE
OUTPUT
RS-232
COMPATIBLE
INPUT
R1IN 16
15 R1OUT
1
C4
0.1µF
AutoShutdown
Plus
INVALID 11
FORCEOFF 20
FORCEON
GND
AutoShutdown
Plus
FORCEOFF 16
FORCEON
GND
TO POWERMANAGEMENT
UNIT
INVALID 10
TO POWERMANAGEMENT
UNIT
VCC
14
VCC
18
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
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Printed USA
is a registered trademark of Maxim Integrated Products.