TRS3243
SLLS806C – JUNE 2007 – REVISED OCTOBER 2022
TRS3243 3-V to 5.5-V Multichannel RS-232 Line Driver and Receiver
With ±15-kV ESD (HBM) Protection
1 Features
2 Applications
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Operates with 3-V to 5.5-V VCC supply
Single-chip and single-supply interface
for IBM® PC/AT™ serial port
RS-232 bus-pin ESD protection of
±15 kV using human-body model (HBM)
Meets or exceeds the requirements of
TIA/EIA-232-F and ITU V.28 standards
Three drivers and five receivers
Operates up to 250 kbps
Low active current: 300-μA typical
Low standby current: 1-μA typical
External capacitors: 4 × 0.1 μF
Accepts 5-V logic input with 3.3-V supply
Always-active noninverting receiver
output (ROUT2B)
Operating temperature
– TRS3243C: 0°C to 70°C
– TRS3243I: –40°C to 85°C
Serial-mouse driveability
Automatic power-down feature to
disable driver outputs when
no valid RS-232 signal is sensed
Battery-powered systems
Tablets
Notebooks
Laptops
Hand-held equipment
3 Description
The TRS3243 device consists of three line drivers,
and five line receivers, which is ideal for DE-9 DTE
interface. A ±15-kV ESD (HBM) protection pin-to-pin
(serial-port connection pins, including GND). Flexible
power features save power automatically. Special
outputs ROUT2B and INVALID are always enabled
to allow checking for ring indicator and valid RS232
input.
Package Information
PART NUMBER
TRS3243
(1)
PACKAGE(1)
BODY SIZE (NOM)
SSOP (28)
10.20 mm × 5.30 mm
TSSOP (28)
9.70 mm × 4.40 mm
For all available packages, see the orderable addendum at
the end of the data sheet.
3.3 V, 5 V
POWER
FORCEON
FORCEOFF
3
3
TX
DIN
DOUT
RS232
5
ROUT
5
RX
RIN
RS232
INVALID
STATUS
Simplified Schematic
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TRS3243
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SLLS806C – JUNE 2007 – REVISED OCTOBER 2022
Table of Contents
1 Features............................................................................1
2 Applications..................................................................... 1
3 Description.......................................................................1
4 Revision History.............................................................. 2
5 Pin Configuration and Functions...................................3
6 Specifications.................................................................. 4
6.1 Absolute Maximum Ratings........................................ 4
6.2 ESD Ratings............................................................... 4
6.3 Recommended Operating Conditions.........................4
6.4 Thermal Information....................................................5
6.5 Electrical Characteristics—Power and Status.............5
6.6 Electrical Characteristics—Driver............................... 6
6.7 Electrical Characteristics—Receiver...........................6
6.8 Switching Characteristics—Power and Status............7
6.9 Switching Characteristics—Driver...............................7
6.10 Switching Characteristics—Receiver........................ 7
6.11 Typical Characteristics.............................................. 8
7 Parameter Measurement Information............................ 9
8 Detailed Description...................................................... 11
8.1 Overview................................................................... 11
8.2 Functional Block Diagram......................................... 11
8.3 Feature Description...................................................12
8.4 Device Functional Modes..........................................13
9 Application and Implementation.................................. 14
9.1 Application Information............................................. 14
9.2 Typical Application.................................................... 14
9.3 Power Supply Recommendations.............................15
9.4 Layout....................................................................... 15
10 Device and Documentation Support..........................17
10.1 Support Resources................................................. 17
10.2 Trademarks............................................................. 17
10.3 Electrostatic Discharge Caution..............................17
10.4 Glossary..................................................................17
11 Mechanical, Packaging, and Orderable
Information.................................................................... 17
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision B (June 2015) to Revision C (October 2022)
Page
• Changed the Thermal Information table............................................................................................................. 5
• Changed the MAX value of ICC Supply current auto-powerdown disabled from 1 mA to 1.2 mA in Electrical
Characteristics—Power and Status ................................................................................................................... 5
Changes from Revision A (September 2011) to Revision B (June 2015)
Page
• Added Pin Functions table, ESD Ratings table, Thermal Information table, Typical Characteristics section,
Detailed Description, Application and Implementation, Power Supply Recommendations, Layout, Device and
Documentation Support and Mechanical, Packaging, and Orderable Information sections...............................1
• Deleted Ordering Information table.....................................................................................................................3
2
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5 Pin Configuration and Functions
C2+
1
28
C1+
C2-
2
27
V+
V-
3
26
V
CC
RIN1
4
25
GND
RIN2
5
24
C1-
RIN3
6
23
FORCEON
RIN4
7
22
FORCEOFF
RIN5
8
21
INVALID
DOUT1
9
20
ROUT2B
DOUT2
10
19
ROUT1
DOUT3
11
18
ROUT2
DIN3
12
17
ROUT3
DIN2
13
16
ROUT4
DIN1
14
15
ROUT5
Not to scale
Figure 5-1. DB, PW Packages, 28-Pin SSOP, TSSOP
(Top View)
Table 5-1. Pin Functions
PIN
NO.
NAME
TYPE
DESCRIPTION
1
C2+
—
Positive terminal of the voltage-doubler charge-pump capacitor
2
C2-
—
Negative terminal of the voltage-doubler charge-pump capacitor
3
V-
4
RIN1
5
RIN2
6
RIN3
7
RIN4
8
RIN5
9
DOUT1
10
DOUT2
11
DOUT3
12
DIN3
13
DIN2
14
DIN1
15
ROUT5
16
ROUT4
17
ROUT3
18
ROUT2
19
ROUT1
20
21
Negative charge pump output voltage
I
RS-232 receiver inputs
O
RS-232 driver outputs
I
Driver inputs
O
Receiver outputs
ROUT2B
—
Always-active noninverting receiver output;
INVALID
O
Invalid Output Pin
22
FORCEOFF
I
Auto Powerdown Control input (Refer to Truth Table)
23
FORCEON
I
Auto Powerdown Control input (Refer to Truth Table)
24
C1-
—
Negative terminal of the voltage-doubler charge-pump capacitor
25
GND
—
Ground
26
VCC
—
3-V to 5.5-V supply voltage
27
V+
—
Positive charge pump output voltage
28
C1+
—
Positive terminal of the voltage-doubler charge-pump capacitor
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6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
Supply voltage(2)
VCC
voltage(2)
V+
Positive output supply
V–
Negative output supply voltage(2)
V+ – V–
Supply voltage
Input voltage
VO
Output voltage
TJ
Operating virtual junction temperature
Tstg
Storage temperature
(2)
MAX
UNIT
6
V
–0.3
7
V
0.3
–7
V
13
V
difference(2)
VI
(1)
MIN
–0.3
Driver, FORCEOFF, FORCEON
–0.3
6
Receiver
–25
25
Driver
–13.2
13.2
Receiver, INVALID
–0.3
VCC + 0.3
–65
V
V
150
°C
150
°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 under Recommended Operating
Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltages are with respect to network GND.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001
RIN , DOUT, and GND pins (1)
±15000
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001
All other pins(1)
±3000
Charged device model (CDM), per JEDEC specification JESD22-C101,
all pins(2)
±1000
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
(see Figure 9-1)(1)
VCC = 3.3 V
VCC Supply voltage
VCC = 5 V
NOM
3
3.3
3.6
4.5
5
5.5
V
2
5.5
5.5
DIN, FORCEOFF, FORCEON
0
0.8
V
DIN, FORCEOFF, FORCEON
0
5.5
V
–25
25
V
0
70
–40
85
Driver and control high-level input voltage
DIN, FORCEOFF,
FORCEON
VIL
Driver and control low-level input voltage
VI
Driver and control input voltage
VI
Receiver input voltage
VCC = 5 V
TRS3243C
TA
Operating free-air temperature
(1)
Test conditions are C1–C4 = 0.1 μF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 μF, C2–C4 = 0.33 μF at VCC = 5 V ± 0.5 V.
4
MAX UNIT
2.4
VIH
VCC = 3.3 V
MIN
TRS3243I
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6.4 Thermal Information
THERMAL METRIC(1)
{DB} (SSOP)
{PW} (TSSOP)
16 PINS
16 PINS
UNIT
RθJA
Junction-to-ambient thermal resistance
76.1
70.3
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
35.8
21.0
°C/W
RθJB
Junction-to-board thermal resistance
37.4
29.2
°C/W
ψJT
Junction-to-top characterization parameter
7.4
1.3
°C/W
ψJB
Junction-to-board characterization parameter
37.0
28.8
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
N/A
N/A
°C/W
(1)
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report (SPRA953).
6.5 Electrical Characteristics—Power and Status
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)(1) (see Figure 9-1)
PARAMETER
TEST CONDITIONS
MIN
TYP(2)
MAX
0.3
1.2
UNIT
Supply current
Automatic power down
disabled
No load, FORCEOFF and FORCEON at VCC.
TA = 25°C
Supply current
Powered off
No load, FORCEOFF at GND. TA = 25°C
1
10
Supply current
Automatic power down
enabled
No load, FORCEOFF at VCC, FORCEON at GND,
All RIN are open or grounded, All DIN are grounded.
TA = 25°C
1
10
Input leakage current
of FORCEOFF, FORCEON
VI = VCC or VI at GND
±0.01
±1
μA
VIT+
Receiver input threshold
for INVALID high-level output
voltage
FORCEON = GND,
FORCEOFF = VCC
2.7
V
VIT–
Receiver input threshold
for INVALID high-level output
voltage
FORCEON = GND,
FORCEOFF = VCC
–2.7
VT
Receiver input threshold
for INVALID low-level output
voltage
FORCEON = GND,
FORCEOFF = VCC
–0.3
VOH
INVALID high-level output voltage
IOH = –1 mA, FORCEON = GND,
FORCEOFF = VCC
VOL
INVALID low-level output voltage
IOL = 1.6 mA, FORCEON = GND,
FORCEOFF = VCC
ICC
II
(1)
(2)
mA
μA
V
0.3
VCC – 0.6
V
V
0.4
V
Test conditions are C1–C4 = 0.1 μF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 μF, C2–C4 = 0.33 μF at VCC = 5 V ± 0.5 V.
All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C.
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6.6 Electrical Characteristics—Driver
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)(1) (see Figure 9-1)
PARAMETER
TEST CONDITIONS
MIN
TYP(2)
MAX
UNIT
VOH
High-level output voltage
All DOUT at RL = 3 kΩ to GND
5
5.4
V
VOL
Low-level output voltage
All DOUT at RL = 3 kΩ to GND
–5
–5.4
V
VO
Output voltage
(mouse driveability)
DIN1 = DIN2 = GND, DIN3 = VCC, 3 kΩ to GND at DOUT3,
DOUT1 = DOUT2 = 2.5 mA
±5
IIH
High-level input current
VI = VCC
±0.01
±1
μA
IIL
Low-level input current
VI at GND
±0.01
±1
μA
Vhys
Input hysteresis
±1
V
IOS
Short-circuit output current(3)
±60
mA
ro
Ioff
(1)
(2)
(3)
VCC = 3.6 V,
VO = 0 V
VCC = 5.5 V,
VO = 0 V
Output resistance
VCC = 0 V, V+ = 0 V, and V– =
0 V,
VO = ±2 V
Output leakage current
FORCEOFF = GND,
V
±35
300
10M
Ω
VO = ±12 V,
VCC = 3 to 3.6 V
±25
VO = ±10 V,
VCC = 4.5 to 5.5 V
±25
μA
Test conditions are C1–C4 = 0.1 μF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 μF, C2–C4 = 0.33 μF at VCC = 5 V ± 0.5 V.
All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C.
Short-circuit durations must be controlled to prevent exceeding the device absolute power dissipation ratings, and not more than one
output should be shorted at a time.
6.7 Electrical Characteristics—Receiver
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)(1) (see Figure 9-1)
PARAMETER
VOH
High-level output voltage
IOH = –1 mA
VOL
Low-level output voltage
IOH = 1.6 mA
MIN
TYP(2)
VCC – 0.6
VCC – 0.1
MAX
0.4
1.6
2.4
VCC = 5 V
1.9
2.4
Positive-going input threshold voltage
VIT–
Negative-going input threshold voltage
Vhys
Input hysteresis (VIT+ – VIT–)
Ioff
Output leakage current (except ROUT2B)
FORCEOFF = 0 V
rI
Input resistance
VI = ±3 V or ±25 V
VCC = 3.3 V
0.6
1.1
VCC = 5 V
0.8
1.4
V
V
V
0.5
3
UNIT
V
VCC = 3.3 V
VIT+
(1)
(2)
6
TEST CONDITIONS
V
±0.05
±10
μA
5
7
kΩ
Test conditions are C1–C4 = 0.1 μF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 μF, C2–C4 = 0.33 μF at VCC = 5 V ± 0.5 V.
All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C.
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6.8 Switching Characteristics—Power and Status
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) (see Figure 7-5)
PARAMETER
TYP(1)
TEST CONDITIONS
UNIT
tvalid
Propagation delay time, low- to high-level output
VCC = 5 V
1
μs
tinvalid
Propagation delay time, high- to low-level output
VCC = 5 V
30
μs
ten
Supply enable time
VCC = 5 V
100
μs
(1)
All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C.
6.9 Switching Characteristics—Driver
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)(1) (see Figure 9-1)
TRS3243C, TRS3243I
PARAMETER
TEST CONDITIONS
Maximum data rate
RL = 3 kΩ
One DOUT switching,
CL = 1000 pF
See Figure 7-1
tsk(p)
Pulse skew(3)
RL = 3 kΩ to 7 kΩ
CL = 150 pF to 2500 pF
See Figure 7-3
SR(tr)
Slew rate, transition region
(see Figure 7-1)
VCC = 3.3 V,
RL = 3 kΩ to 7 kΩ
(1)
(2)
(3)
MIN
TYP(2)
150
250
kbps
100
ns
MAX
CL = 150 pF to 1000 pF
6
30
CL = 150 pF to 2500 pF
4
30
UNIT
V/μs
Test conditions are C1–C4 = 0.1 μF at VCC = 3.3 V + 0.3 V; C1 = 0.047 μF, C2–C4 = 0.33 μF at VCC = 5 V ± 0.5 V.
All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C.
Pulse skew is defined as |tPLH – tPHL| of each channel of the same device.
6.10 Switching Characteristics—Receiver
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)(1)
PARAMETER
tPLH
Propagation delay time, low- to high-level output
tPHL
Propagation delay time, high- to low-level output
ten
Output enable time
tdis
Output disable time
tsk(p)
(1)
(2)
(3)
Pulse
skew(3)
TYP(2)
TEST CONDITIONS
UNIT
CL = 150 pF,
See Figure 7-3
150
ns
150
ns
CL = 150 pF, RL = 3 kΩ,
See Figure 7-4
200
ns
200
ns
See Figure 7-3
50
ns
Test conditions are C1–C4 = 0.1 μF at VCC = 3.3 V ± 0.3 V; C1 = 0.047 μF, C2–C4 = 0.33 μF at VCC = 5 V ± 0.5 V.
All typical values are at VCC = 3.3 V or VCC = 5 V, and TA = 25°C.
Pulse skew is defined as |tPLH - tPHL| of each channel of the same device.
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6.11 Typical Characteristics
VCC = 3.3 V
0
6
5
-1
4
-2
VOL (V)
VOH (V)
VOH
3
-3
2
-4
1
-5
0
-6
VOL
0
5
10
15
20
25
30
Load Current (mA)
0
5
10
15
20
25
30
Load Current (mA)
C001
Figure 6-1. DOUT VOH vs Load Current
8
35
35
C001
Figure 6-2. DOUT VOL vs Load Current
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7 Parameter Measurement Information
3V
Generator
(see Note B)
50 Ω
RL
TEST CIRCUIT
0V
CL
(see Note A)
3V
FORCEOFF
A.
B.
Input
RS-232
Output
t TLH
t THL
−3 V
−3 V
6V
SR(tr) =
t THL or t TLH
VOH
3V
3V
Output
VOL
VOLTAGE WAVEFORMS
CL includes probe and jig capacitance.
The pulse generator has the following characteristics: PRR = 250 kbps, (MAX3243C/I) and 1 Mbit/s (MAX3243FC/I), ZO = 50 Ω, 50%
duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.
Figure 7-1. Driver Slew Rate
3V
Generator
(see Note B)
RS-232
Output
50 Ω
RL
Input
0V
CL
(see Note A)
t PHL
t PLH
VOH
3V
FORCEOFF
50%
50%
Output
VOL
TEST CIRCUIT
A.
B.
1.5 V
1.5 V
VOLTAGE WAVEFORMS
CL includes probe and jig capacitance.
The pulse generator has the following characteristics: PRR = 250 kbps, (MAX3243C/I) and 1 Mbit/s (MAX3243FC/I), ZO = 50 Ω, 50%
duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.
Figure 7-2. Driver Pulse Skew
3 V or 0 V
FORCEON
3V
Input
1.5 V
1.5 V
−3 V
Output
Generator
(see Note B)
50 Ω
3V
FORCEOFF
t PHL
CL
(see Note A)
t PLH
VOH
50%
Output
50%
VOL
TEST CIRCUIT
VOLTAGE WAVEFORMS
A.
CL includes probe and jig capacitance.
B.
The pulse generator has the following characteristics: ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.
Figure 7-3. Receiver Propagation Delay Times
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3V
Input
VCC
3 V or 0 V
FORCEON
1.5 V
GND
S1
0V
t PZH
(S1 at GND)
t PHZ
(S1 at GND)
RL
3 V or 0 V
1.5 V
VOH
Output
50%
Output
CL
(see Note A)
FORCEOFF
Generator
(see Note B)
0.3 V
t PZL
(S1 at VCC)
t PLZ
(S1 at VCC)
50 Ω
0.3 V
Output
50%
VOL
TEST CIRCUIT
A.
B.
C.
D.
VOLTAGE WAVEFORMS
CL includes probe and jig capacitance.
The pulse generator has the following characteristics: ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.
tPLZ and tPHZ are the same as tdis.
tPZL and tPZH are the same as ten.
Figure 7-4. Receiver Enable and Disable Times
2.7 V
2.7 V
0V
Receiver
Input
0V
50 Ω
−2.7 V
−2.7 V
ROUT
Generator
(see Note B)
3V
−3 V
t valid
t invalid
VCC
50% VCC
0V
INVALID
Output
Automatic
power down
t en
INVALID
CL = 30 pF
(see Note A)
50% VCC
V+
≈V+
0.3 V
VCC
0V
0.3 V
Supply
Voltages
FORCEOFF
DIN
FORCEON
DOUT
V−
≈V−
TEST CIRCUIT
VOLTAGE WAVEFORMS
Valid RS-232 Level, INVALID High
2.7 V
Indeterminate
0.3 V
0V
If Signal Remains Within This Region
For More Than 30 µs, INVALID Is Low (see Note C)
−0.3 V
Indeterminate
−2.7 V
Valid RS-232 Level, INVALID High
A.
B.
C.
CL includes probe and jig capacitance.
The pulse generator has the following characteristics: PRR = 5 kbps, ZO = 50 Ω, 50% duty cycle, tr ≤ 10 ns, tf ≤ 10 ns.
Automatic power down disables drivers and reduces supply current to 1 μA.
Figure 7-5. INVALID Propagation Delay Times and Supply Enabling Time
10
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8 Detailed Description
8.1 Overview
The TRS3243 device consists of three line drivers, five line receivers, and a dual charge-pump circuit with
±15-kV ESD (HBM) protection pin-to-pin (serial-port connection pins, including GND). The TRS3243 device
meets the requirements of TIA/EIA-232-F and provides the electrical interface between an asynchronous
communication controller and the serial-port connector. This combination of drivers and receivers matches
what is needed for the typical serial port used in an IBM PC, AT, or compatible device. The charge pump and
four small external capacitors allow operation from one 3-V to 5.5-V supply. In addition, the device includes
an always-active noninverting output (ROUT2B), which allows applications using the ring indicator to transmit
data while the device is powered down. Flexible control options for power management are available when the
serial port is inactive. The automatic power-down feature functions when FORCEON is low and FORCEOFF
is high. During this mode of operation, if the device does not sense a valid RS-232 signal, the driver outputs
are disabled. If FORCEOFF is set low, both drivers and receivers (except ROUT2B) are shut off, and the
supply current is reduced to 1 µA. Disconnecting the serial port or turning off the peripheral drivers causes
the automatic power-down condition to occur. Automatic power down can be disabled when FORCEON and
FORCEOFF are high and must be done when driving a serial mouse. With automatic power down enabled, the
device is activated automatically when a valid signal is applied to any receiver input. The INVALID output is used
to notify the user if an RS-232 signal is present at any receiver input. INVALID is high (valid data) if any receiver
input voltage is greater than 2.7 V, is less than –2.7 V, or has been between –0.3 V and 0.3 V for less than 30
µs. INVALID is low (invalid data) if all receiver input voltages are between –0.3 V and 0.3 V for more than 30 µs.
8.2 Functional Block Diagram
DIN1
DIN2
DIN3
FORCEOFF
14
9
DOUT1
13
10
DOUT2
12
11
DOUT3
22
21
Automatic Power Down
INVALI D
23
FORCEON
ROUT1
19
4
20
5 kΩ
18
5
RIN1
ROUT2B
ROUT2
RIN2
5 kΩ
17
6
ROUT3
RIN3
5 kΩ
ROUT4
7
16
RIN4
5 kΩ
ROUT5
15
8
RIN5
5 kΩ
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8.3 Feature Description
8.3.1 Automatic Power Down
Automatic power down can be used to automatically save power when the receivers are unconnected or when
they are connected to a powered down remote RS232 port. FORCEON being high overrides automatic power
down and the drivers are active. FORCEOFF being low overrides FORCEON and powers down all outputs
except for ROUT2B and INVALID.
8.3.2 Charge Pump
The charge pump increases, inverts, and regulates voltage at V+ and V– pins. The charge pump requires four
external capacitors.
8.3.3 RS232 Driver
Three drivers interface standard logic level to RS232 levels. All DIN inputs must be valid high or low.
8.3.4 RS232 Receiver
Five receivers interface RS232 levels to standard logic levels. An open input results in a high output on ROUT.
Each RIN input includes an internal standard RS232 load.
8.3.5 ROUT2B Receiver
ROUT2B is an always-active, noninverting output of RIN2 input, which allows applications using the ring
indicator to transmit data while the device is powered down.
8.3.6 Invalid Input Detection
The INVALID output goes active low when all RIN inputs are unpowered. The INVALID output goes inactive high
when any RIN input is connected to an active RS232 voltage level.
12
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8.4 Device Functional Modes
Table 8-1. Each Driver(1)
INPUTS
DIN
(1)
FORCEON
OUTPUT
FORCEOFF
VALID RIN
RS-232 LEVEL
DRIVER STATUS
DOUT
X
X
L
X
Z
Powered off
L
H
H
X
H
H
H
H
X
L
Normal operation with
automatic power down disabled
L
L
H
YES
H
H
L
H
YES
L
X
L
H
NO
Z
Normal operation with
automatic power down enabled
Power off by
automatic power down feature
H = high level, L = low level, X = irrelevant, Z = high impedance, YES = any RIN valid, NO = all RIN invalid
Table 8-2. Each Receiver(1)
INPUTS
(1)
OUTPUTS
RIN
FORCEON
FORCEOFF
ROUT
X
X
L
Z
L
X
H
H
H
X
H
L
Open
X
H
H
RECEIVER STATUS
Powered off
Normal operation
H = high level, L = low level, X = irrelevant, Z = high impedance (off), Open = input disconnected or connected driver off
Table 8-3. INVALID and ROUT2B Outputs(1)
INPUTS
VALID RIN
RS-232 LEVEL
(1)
OUTPUTS
RIN2
FORCEON
FORCEOFF
INVALID
YES
L
X
X
H
L
YES
H
X
X
H
H
YES
OPEN
X
X
H
L
NO
OPEN
X
X
L
L
OUTPUT STATUS
ROUT2B
Always Active
Always Active
H = high level, L = low level, X = irrelevant, Z = high impedance (off),
OPEN = input disconnected or connected driver off, YES = any RIN valid, NO = all RIN invalid
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9 Application and Implementation
Note
Information in the following applications sections is not part of the TI component specification,
and TI does not warrant its accuracy or completeness. TI’s customers are responsible for
determining suitability of components for their purposes, as well as validating and testing their design
implementation to confirm system functionality.
9.1 Application Information
The TRS3243 device is designed to convert single-ended signals into RS232-compatible signals, and viceversa.
This device can be used in any application where RS232 line driver or receiver is required. One benefit of this
device is its ESD protection, which helps protect other components on the board when the RS232 lines are tied
to a physical connector. The device also features an automatic power-down circuit.
9.2 Typical Application
C1+
1
+
C2
−
2
3
−
V−
GND
C1−
RIN2
RIN3
RIN4
RIN5
DOUT1
RS-232 Outputs
VCC
+
RIN1
RS-232 Inputs
C2−
DOUT2
4
27
+
−
26
25
C3(A) +
+ CBYPASS
− = 0.1 µF
−
C1
24
23
FORCEON
5
Automatic
Power down
C4
V+
C2+
28
6
7
22
FORCEOFF
8
21
9
20
10
19
INVALID
ROUT2B
ROUT1
5 kΩ
DOUT3
18
11
ROUT2
5 kΩ
DIN3
12
Logic Outputs
17
ROUT3
5 kΩ
Logic Inputs
DIN2
13
16
ROUT4
5 kΩ
DIN1
14
15
ROUT5
5 kΩ
A.
B.
C.
C3 can be connected to VCC or GND.
Resistor values shown are nominal.
Nonpolarized ceramic capacitors are acceptable. If polarized tantalum or electrolytic capacitors are used, they must be connected as
shown.
Figure 9-1. Typical Operating Circuit and Capacitor Values
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9.2.1 Design Requirements
•
•
VCC minimum is 3 V and maximum is 5.5 V
Maximum recommended bit rate is 250 kbps
Table 9-1. VCC versus Capacitor Values
VCC
C1
C2, C3, C4
3.3 V ± 0.3 V
0.1 µF
0.1 µF
5 V ± 0.5 V
0.047 µF
0.33 µF
3 V to 5.5 V
0.1 µF
0.47 µF
9.2.2 Detailed Design Procedure
It is recommended to add capacitors as shown in Figure 9-1.
All DIN, FORCEOFF and FORCEON inputs must be connected to valid low or high logic levels.
Select capacitor values based on VCC level for best performance.
9.2.3 Application Curve
Voltage (V)
VCC= 3.3 V
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
DIN
DOUT to RIN
ROUT
0
1
2
3
4
5
Time (µs)
6
7
C001
Figure 9-2. Driver to Receiver Loopback Timing Waveform
9.3 Power Supply Recommendations
VCC must be between 3 V and 5.5 V. Charge pump capacitors must be chosen using Table 9-1.
9.4 Layout
9.4.1 Layout Guidelines
Keep the external capacitor traces short. This is more important on C1 and C2 nodes that have the fastest rise
and fall times.
Figure 9-3 shows only critical layout sections. Input and output traces will vary in shape and size depending
on the customer application. FORCEON and FORCEOFF must be pulled up to VCC or GND through a pullup
resistor, depending on which configuration is desired upon powerup.
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9.4.2 Layout Example
C1
1
C2+
C1+
28
2
C2-
V+
27
C2
Ground
C3
Ground
3
V-
VCC 26
4
RIN1
GND
25
5
RIN2
C1-
24
6
RIN3
FORCEON 23
7
RIN4
FORCEOFF 22
8
RIN5
INVALID 21
9
DOUT1
ROUT2B 20
10
DOUT2
ROUT1 19
11
DOUT3
ROUT2 18
12
DIN3
ROUT3 17
13
DIN2
ROUT4 16
14
DIN1
ROUT5 15
C4
VCC
0.1 μF
Ground
Figure 9-3. Layout Diagram
16
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10 Device and Documentation Support
10.1 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
10.2 Trademarks
PC/AT™ is a trademark of IBM.
TI E2E™ is a trademark of Texas Instruments.
IBM® is a registered trademark of IBM.
All trademarks are the property of their respective owners.
10.3 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
10.4 Glossary
TI Glossary
This glossary lists and explains terms, acronyms, and definitions.
11 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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PACKAGE OPTION ADDENDUM
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PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
TRS3243CDBR
ACTIVE
SSOP
DB
28
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
TRS3243C
TRS3243CPW
LIFEBUY
TSSOP
PW
28
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
RS43C
TRS3243CPWR
LIFEBUY
TSSOP
PW
28
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
RS43C
TRS3243IDB
LIFEBUY
SSOP
DB
28
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TRS3243I
TRS3243IDBR
ACTIVE
SSOP
DB
28
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
TRS3243I
TRS3243IPW
LIFEBUY
TSSOP
PW
28
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
RS43I
TRS3243IPWR
LIFEBUY
TSSOP
PW
28
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
RS43I
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of