SP3244E-SP3245E
3.3V or 5V RS-232 Transceivers with Auto On-Line® Plus
FEATURES
• Contains 3-Drivers and 5-Receivers;
Single-chip DTE (PC or terminal) serial port transceiver
• Auto On-Line® Plus
• SP3244E slew-controlled to 250kbps under load
• SP3245E 1Mbps data rate for high-speed RS-232
• Meets true EIA/TIA-232-F and ITU V.28 standards
from a +3.0V to +5.5V power supply
• Adheres to EIA/TIA-562 for interoperability
with EIA/TIA-232 down to a +2.7V supply voltage
• Regulated charge pump yields stable RS-232
outputs regardless of VCC variations
• ESD Specifications:
±15KV Human Body Model
APPLICATIONS
• Portable RS-232
• Laptops and handheld PCs and PDA
• Cellular telephones, datacables, chargingcradles
• Diagnostic/upload ports on embedded applications
• Use in conjunction with low-voltage UART or
microcontroller
• SP3244 is cross-compatible with MAX3244,
ICL3244
• SP3245 is cross-compatible with MAX3245,
ICL3245
C2+ 1
C2- 2
V- 3
R1IN 4
28 C1+
27 V+
26 VCC
25 GND
24 C1R2IN 5
R3IN 6 SP3244E 23 ONLINE
SP3245E
22 SHUTDOWN
R4IN 7
21 STATUS
R5IN 8
T1OUT 9
T2OUT 10
T3OUT 11
20 R2OUT
19 R1OUT
T3IN 12
T2IN 13
17 R3OUT
T1IN 14
15 R5OUT
18 R2OUT
16 R4OUT
DESCRIPTION
The SP3244E/3245E is a 3-driver/5-receiver device ideal for mobile phone, consumer and PDA
applications. These devices use an internal high-efficiency, charge-pump power supply that requires
only 0.1μF capacitors for 3.3V single-supply operation. This charge pump and Exar’s driver architecture allow the SP3244E/3245E to deliver compliant RS-232 performance from a power supply
ranging from +3.0V to +5.5V. At voltages between +2.7V and +3.0V the driver outputs are compliant
with RS-562 and can interface to RS-232 in portable applications.
The Auto On-Line® Plus feature allows the device to automatically enter a low power shutdown
mode if all receiver and driver inputs have been idle for 30 seconds. The device will “wake-up” from
this automatic shutdown state upon detecting activity. This power saving feature functions without
system intervention or modifications to software or drivers.
SP3244E supports serial data rates of 250kbps minimum under full load and while maintaining
slew rates of less than 30V/μs. SP3245E is capable of high speed communication of up to 1Mbps.
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP3244E_SP3245E_100_121509
Pin Assignments
NAME
PIN NUMBER
FUNCTION
(T)SSOP
QFN
C2+
Positive terminal of the inverting charge pump capacitor.
1
29
C2-
Negative terminal of the inverting charge pump capacitor.
2
30
Regulated -5.5V output generated by the charge pump.
3
31
R1IN
RS-232 receiver input.
4
1
R2IN
RS-232 receiver input.
5
2
R3IN
RS-232 receiver input.
6
3
R4IN
RS-232 receiver input.
7
4
R5IN
RS-232 receiver input.
8
5
T1OUT
RS-232 driver output.
9
6
T2OUT
RS-232 driver output.
10
7
T3OUT
RS-232 driver output.
11
8
T3IN
TTL/CMOS driver input.
12
10
T2IN
TTL/CMOS driver input.
13
11
T1IN
TTL/CMOS driver input.
14
12
R5OUT
TTL/CMOS receiver output.
15
13
R4OUT
TTL/CMOS receiver output.
16
14
R3OUT
TTL/CMOS receiver output.
17
15
R2OUT
TTL/CMOS receiver output.
18
17
R1OUT
TTL/CMOS receiver output.
19
18
R2OUT
Non-inverting receiver 2 output; active in shutdown.
20
19
STATUS
Status output.
21
20
SHUTDOWN
Forced SHUTDOWN input. Drive low to shut down drivers, receivers
and charge pump. Will override Auto On-Line® Plus. Do not leave
this pin open.
22
21
ONLINE
Auto On-line® Plus input. Active low enabled automatic power saving
feature. Equivalent to competitor's FORCEON pin. Do not leave this
pin open.
23
22
V-
Negative terminal of the voltage doubler charge pump capacitor.
24
23
GND
C1-
Ground connection.
25
24
VCC
Device power supply pin (3.0V to 5.5V).
26
26
Regulated +5.5V output generated by the charge pump.
27
27
C1+
Positive terminal of the voltage doubler charge pump capacitor.
28
28
NC
No connection.
-
9, 16, 25, 32
V+
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP3244E_SP3245E_100_121509
Absolute Maximum Ratings
Supply Voltage (Vcc).......................-0.3V to + 6.0V
V+ (Note 1)......................................-0.3V to + 7.0V
V- (Note 1).......................................+0.3V to - 7.0V
|V+| + |V-| .......................................................+13V
Input voltage at TTL input pin.. -0.3V toVCC +0.3V
RxIN..............................................................+/-16V
Driver output (from Ground)...................... +/-13.2V
RxOUT, /STATUS.....................-0.3V to VCC + 0.3V
Short Circuit Duration, TxOUT to GND, Continuous
(One output at a time maximum)
Storage Temperature.....................-65°C to +150°C
Operating Temperature SP32__EC_.............0°C to +70°C
Operating Temperature SP32__EE_........-40°C to +85°C
Lead Temperature (soldering, 10s)............. +300°C
SOIC-28, øJA = 58.6ºC/W
SSOP-28, øJA = 67.1ºC/W
TSSOP-28, øJA = 83.6ºC/W
QFN-32, øJA = 22.4ºC/W
These are stress ratings only and functional
operation of the device at these ratings or
any other above those indicated in the operation sections of the specifications below is not
implied. Exposure to absolute maximum rating
conditions for extended periods of time may
affect reliability.
NOTE 1: V+ and V- can have maximum
magnitudes of 7V, but their absolute difference
cannot exceed 13V.
ELECTRICAL CHARACTERISTICS
Unless otherwise noted VCC = +3.0V to +5.5V, TAMB = TMIN to TMAX, C1–C4 = 0.1μF.
Typical values are at TAMB = +25°C, VCC = 3.3V.
Parameters
Test Conditions
SymB
Min.
Typ.
Max.
Unit
DC CHARACTERISTICS
Supply Current,
Auto On-Line® Plus
Icc3
Receivers idle, TxIN = Vcc or
GND, ONLINE = GND,
SHUTDOWN = Vcc
1
10
μA
Supply Current, Shutdown
Icc2
SHUTDOWN = GND
1
10
μA
Supply Current, Active
Icc1
ONLINE = SHUTDOWN = Vcc,
No Load
1
5
mA
Driver Input and Logic Input Pins:
Logic
Input
Voltage
High
Vih
Low
Vil
Logic Threshold
Vt
Logic Input Leakage Current
Logic Input Hysteresis
Vcc = 3.3V
2
Vcc = 5.0V
2.4
0.8
V
1.5
Iil
0.01
Vhys
100
±1.0
μA
mV
Receiver Outputs and STATUS Output
Receiver Output Voltage Low
Vol
Iout = -1.6mA
Receiver Output Voltage
High
Voh
Iout = 1mA
Receiver Output Leakage
Current
Ioz
Receivers Disabled,
0.4V < Vo < 5.5V
0.4
Vcc
-0.6
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
V
V
±0.02
±1
μA
SP3244E_SP3245E_100_121509
ELECTRICAL CHARACTERISTICS
Parameters
Test Conditions
Symb
Min.
Typ.
Max.
Unit
-15
V
Receiver Inputs
Input Voltage Range
+15
Input Threshold Low
Vcc = 3.3V
0.6
1.0
Vcc = 5.0V
0.8
1.2
Input Threshold High
V
Vcc = 3.3V
1.2
2.4
V
Vcc = 5.0V
1.7
2.4
V
Input Hysteresis
200
Input Resistance
Ta = 25ºC
3
5
±5.0
±5.4
mV
7
kΩ
Driver Outputs
Output Voltage Swing
Short Circuit Current
Vo
All transmitter outputs loaded
with 3kΩ to GND
V
Output load = Open Circuit
±15.0
Vout = 0V
±100
Power-Off Impedance
Vcc = V+ = V- = 0, transmitter
outputs = ±2V
Output Leakage Current
Vcc = 0 or 3V to 3.3V,
Vout = ±12V, Drivers disabled
Mouse Drivability
T1IN = T2IN = GND, T3IN =
Vcc, T3 loaded with 3kΩ to
GND, T1OUT and T2OUT
loaded with 2.5mA each, Ta =
25ºC
300
10M
mA
Ω
±25
±5.0
µA
V
ESD Protection
ESD Protection for RxIn,
TxOut pins
All Other Pins
Human Body Model
Human Body Model
±15
kV
±2
kV
Auto On-Line® Plus (ONLINE = GND, SHUTDOWN = Vcc)
Rx Input Threshold to
STATUS Output High
±2.7
Rx Input Threshold to
STATUS Output Low
±0.3
V
V
Threshold to STATUS High
tsth
0.4
μs
Threshold to STATUS Low
tstl
30
μs
100
μs
Rx or Tx Transition to
Drivers Enabled
tonline
Last Rx or Tx Transition to
Drivers Disabled
toffline
Note 1
15
30
60
sec
Note 1: Characterized, not 100% tested
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP3244E_SP3245E_100_121509
TIMING CHARACTERISTICS
Unless otherwise noted VCC = +3.0V to +5.5V, TAMB = TMIN to TMAX, C1–C4 = 0.1μF. Typical values are
at TAMB = +25°C, VCC = 3.3V.
Parameters
Symbol
Test Conditions
Min.
Rl = 3kΩ, Cl = 1000pF. One
transmitter switching.
250
Typ.
Max.
Unit
SP3244E
Maximum Data Rate
Driver Propagation Delay
tDPHL, tDPLH
Transition-Region Slew
Rate
Driver Skew
CL = 1000pF
Rl=3kΩ to 7kΩ, Cl=150pF
to 1000pF, measurements
taken from +3V to -3V or
from -3V to +3V. Ta = 25ºC
trphl,trplh
RIN to ROUT, Cl = 150pF
Receiver Output Enable
Time
trzh , trzl
Receiver Output Disable
Time
trhz , trlz
Receiver Skew
Parameters
4
|trphl - trplh| at 1.5V
Symbol
Test Conditions
ns
1600
|tdphl - tdplh| at zero crossing
Receiver Propagation
Delay
kbps
30
50
ns
0.15
µs
0.4
2.0
µs
0.1
2.0
µs
40
Min.
V/μs
Typ.
ns
Max.
Unit
SP3245E
Maximum Data Rate
Driver Propagation Delay
Rl = 3kΩ, Cl = 250pF. One
transmitter switching.
1000
kbps
Rl = 3kΩ, Cl = 1000pF. One
transmitter switching.
500
kbps
tDPHL, tDPLH
Transition-Region Slew
Rate
Driver Skew
CL = 250pF
Rl=3kΩ to 7kΩ, Cl=150pF to
250pF, measurements taken
from +3V to -3V or from -3V
to +3V. Ta = 25ºC
trphl,trplh
RIN to ROUT, Cl = 150pF
Receiver Output Enable
Time
trzh , trzl
Receiver Output Disable
Time
trzh , trlz
24
|tdhpl - tdplh| at zero
crossing
Receiver Propagation
Delay
Receiver Skew
ns
700
|trphl - trplh| at 1.5V
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
150
V/μs
100
ns
0.15
µs
0.05
2.0
µs
0.1
2.0
µs
90
ns
SP3244E_SP3245E_100_121509
400
3
350
2.5
Tin to Rout Propagation Delay (µs)
Charge Pump Turn-on Time (µs)
TYPICAL PERFORMANCE CHARACTERISTICS
300
250
200
Charge Pump Turn-on Time (us)
2
1.5
1
Tin0.5
to Rout Propagation Delay (us)
150
0
100
-55
-30
-5
20
45
70
0
95
500
1000
1500
Turn on Time vs. Temperature
2500
3000
3500
4000
4500
5000
Transmitter Input to Receiver Output Propagation Delay vs. Load Capacitance
40
30
30
Transmitter Output Slew Rate (V/µs)
35
Supply Current (mA)
2000
Load Capacitiance (pF)
Temperature (ºC)
1Mbps
25
20
250kbps
15
Supply Current (mA)
10
25
20
15
10
5
Transmitter Output Slew Rate (V/us)
5
0
0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0
5000
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Load Capacitiance (pF)
Load Capacitiance (pF)
ICC vs. Load Capacitance
Transmitter Output Slew Rate vs. Load Capacitance
400
6
350
V+
4
300
3
2
250
1
Skew (µs)
Transmitter Output Voltage (V)
5
0
-1
3245, 1Mbps
200
Skew (ns)
150
-2
-3
100
-4
Transmitter Output Voltage (V)
-5
V-
50
-6
0
500
1000
1500
2000
2500
3000
3500
4000
4500
3244, 250kbps
0
5000
0
Load Capacitiance (pF)
250
500
750
1000 1250 1500 1750 2000 2250 2500 2750 3000 3250 3500
Load Capacitance (pF)
Transmitter Skew vs. Load Capacitance
Transmitter Output vs. Load Capacitance
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP3244E_SP3245E_100_121509
TYPICAL PERFORMANCE CHARACTERISTICS
SP3244 Charge Pump Levels Out of Shutdown
SP3244 Waveforms for 1Mbps Clock Rate
RL=3kΩ CL=1000pF
SP3244 Charge Pump Levels Into Shutdown
SP3244 Waveforms for 1Mbps Clock Rate
RL=3kΩ CL=250pF
SP3244 Charge Pump Power On Time
- Vcc=3.3V, T=85ºC
SP3244 Charge Pump Waveforms for 250kbps
Clock Rate
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP3244E_SP3245E_100_121509
TYPICAL PERFORMANCE CHARACTERISTICS
SP3244 Charge Pump Power On Time Vcc=3.3V, T=-40C
SP3244 Charge Pump Power On
SP3244 Waveforms for 250kpbs Clock Rate
RL=3kΩ CL=1000pF
SP2345 Waveforms for 1Mbps Clock Rate
- RL=3k, CL=250pF
TimeVcc=3.3V, T=27C
SP3244 Waveforms for 250kpbs Clock Rate
RL=3kΩ CL=4700pF
SP3244 C2+ Charge Pump Waveforms - Vcc=3.3V,
All channels switching
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP3244E_SP3245E_100_121509
TYPICAL PERFORMANCE CHARACTERISTICS
SP3244 C2+ Charge Pump Waveforms Vcc=5.0V, All channels switching
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP3244E_SP3245E_100_121509
DESCRIPTION
The SP3244E and SP3245E are 3-driver/5-receiver devices ideal for serial ports in batterypowered, portable, or handheld applications
such as notebook or handheld computers.
SP3244E/3245E transceivers meet the EIA/
TIA-232 and ITU-T V.28/V.24 communication
protocols for reliable serial communication. The
SP3244E/3245E devices feature Exar’s proprietary and patented (U.S. 5,306,954) on-board
charge pump circuitry that generates ±5.5V
RS-232 voltage levels from a single +3.0V to
+5.5V power supply.
(EIA RS-232D 2.1.7, Paragraph 5). The slew
rate of SP3245E is not limited to enable higher
speed data transfers. The transition of the
loaded output from HIGH to LOW also meets
the monotonic signal transition requirements of
the standard.
Receivers
The receivers convert EIA/TIA-232 signal
levels to TTL or CMOS logic output levels. Receivers remain active unless the device is put
into manual shutdown using the SHUTDOWN
pin. The non-inverted output of Receiver
2 (R2OUT) will continue to be active in all
modes, including shutdown.
Since receiver input is usually from a transmission line where long cable lengths and system
interference can degrade the signal, the inputs
have a typical hysteresis margin of 500mV.
This ensures that the receiver is virtually immune to noisy transmission lines. Should an
input be left unconnected, an internal 5KΩ pulldown resistor to ground will commit the output
of the receiver to a HIGH state.
The SP3244E/3245E is an ideal choice
for power sensitive designs. With the Auto
On-Line® Plus enabled the SP3244E/3245E
reduces power consumption to a 1μA supply
current whenever the transceiver is idle. In
shutdown, the internal charge pump and the
drivers will shut down. Receivers remain active
unless the device is put into manual shutdown
using the SHUTDOWN pin. This feature allows
design engineers to address power saving
concerns without major design changes.
Theory Of Operation
The SP3244E/3245E is made up of four basic
circuit blocks:
1. Drivers, 2. Receivers, 3. the Exar proprietary charge pump, and 4. Auto On-line® Plus
circuitry.
Highly Efficient Charge Pump
The charge pump is used to generate positive
and negative signal voltages for the RS-232
drivers. This enables fully compliant RS-232
and V.28 signals from a single 3.0 or 5.5V
power supply.
Drivers
The drivers are inverting level transmitters that
convert TTL or CMOS logic levels to 5.0V EIA/
TIA-232 levels with an inverted sense relative
to the input logic levels. Typically, the RS-232
output voltage swing is +5.4V with no load and
+5V minimum fully loaded. The driver outputs
are protected against infinite short circuits to
ground without degradation in reliability. These
drivers comply with the EIA/TIA-232-F and
all previous RS-232 versions. Unused driver
inputs should be connected to GND or VCC.
The charge pumps use four external capacitors to hold and transfer electrical charge. The
Exar patented design (US Patent #5,306,954)
uses a unique approach compared to older less
efficient designs. The pumps use a four–phase
voltage shifting technique to attain symmetrical
V+ and V- power supplies. An intelligent control
oscillator regulates the operation of the charge
pump to maintain the proper voltages at maximum efficiency.
Phase 1
VSS charge store and double the positive
terminals of capacitors C1 and C2 are charged
from VCC with their negative terminals initially
connected to ground. C1+ is then connected
to ground and the stored charge from C1– is
superimposed onto C2– . Since C2+ is still
connected to VCC the voltage potential across
capacitor C2 is now 2 x Vcc.
The SP3244E/3245E devices operate at this
typical data rate when fully loaded. The drivers
can guarantee output data rates fully loaded
with 3KΩ in parallel with 1000pF (SP3244E), or
250pF (SP3245E) ensuring compatibility with
popular PC-to-PC communication software.
The slew rate of the driver output on the
SP3244E is internally limited to a maximum
of 30V/μs in order to meet the EIA standards
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
10
SP3244E_SP3245E_100_121509
DESCRIPTION
+
V
CC
-
Phase 2 – Vss transfer from C2 to C4.
Meanwhile C1 is charged to Vcc
+
+
V
CC
-
C
Phases 1 and 3: Store/Double.
Double charge from C1 onto C2.
C2 is now charged to -2xVcc
+
1
C
e-
+
2
V+
e-
e-
C
3
+
C
Vss
4
+
C
+
1
C
+
2
ee-
V+
C
V-
+
Patented 5,306,954 (Sipex, inc.)
3
C
+
V
CC
-
4
Phase 4 VDD transfer from C2 to C3.
Meanwhile C1 is charged to Vcc
V
e+
C
+
1
e-
C
DD
+
e+
+
V+
C
3
2
V-
+
C
4
Charge Pump Phases
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11
SP3244E_SP3245E_100_121509
DESCRIPTION
Phase 2
VSS transfer and invert: Phase two connects
the negative terminal of C2 to the VSS storage capacitor and the positive terminal of C2 to
ground. This transfers the doubled and inverted
(V–) voltage onto C3. Meanwhile, capacitor
C1 charged from VCC to prepare it for its next
phase.
surface mount ceramic capacitors (such as are
widely used for power-supply decoupling) are
ideal for use on the charge pump. The charge
pumps are designed to be able to function properly with a wide range of capacitor styles and values. If polarized capacitors are used the positive
and negative terminals should be connected as
shown on the Typical Operating Circuit.
Phase 3
Vdd charge store and double: Phase three is
identical to the first phase. The positive terminals of capacitors C1 and C2 are charged
from Vcc with their negative terminals initially
connected to ground. C1+ is then connected
to ground and the stored charge from C1– is
superimposed onto C2–. Since C2+ is still
connected to Vcc the voltage potential across
capacitor C2 is now 2 x Vcc.
Capacitance values may be increased if operating at higher Vcc or to provide greater stability as
the capacitors age.
Phase 4
Vdd transfer: The fourth phase connects the
negative terminal of C2 to ground and the positive terminal of C2 to the Vdd storage capacitor.
This transfers the doubled (V+) voltage onto C4.
Meanwhile, capacitor C1 charged from Vcc to
prepare it for its next phase.
RS-232 signals use both positive and negative
voltages of greater than ±5V magnitude. Receivers have nominal 5kΩ impedance to ground.
Even when idle, drivers will maintain output
signal voltage creating a continuous current
flow. In low power, battery operated devices this
constant current drain can decrease battery life
significantly.
Auto On-Line® Plus devices may be configured
Auto On-Line® Plus Circuitry
The SP3244E/3245E devices have the advanced
Auto On-Line® Plus feature that saves power by
turning off the charge pumps and driver outputs
when the transceiver inputs are idle for more
than 30 seconds.
The Exar charge pump generates V+ and
V– independently from Vcc. Hence in a no–load
condition V+ and V- will be symmetrical. Older
charge pump approaches generate V+ and then
use part of that stored charge to generate V-.
Because of inherent losses the magnitude of Vwill be smaller than V+ on these older designs.
Receiver
5kΩ
Under lightly loaded conditions the intelligent
pump oscillator maximizes efficiency by running
only as needed to maintain V+ and V–. Since
interface transceivers often spend much of their
time at idle this power-efficient innovation can
greatly reduce total power consumption. This
improvement is made possible by the independent phase sequence of the Exar charge-pump
design.
Reciever 5kΩ Current path to
to emulate the behavior of devices with our
earlier Auto On-line® feature. Auto On-Line®
Plus puts the device into a low power mode
when driver or receiver inputs are idle and
re-awakes upon detecting signal transitions.
Auto On-Line® puts the device into a low power
mode when receiver inputs are left floating and
re-awakes when receivers are driven greater
than ±2.7V magnitude by incoming RS-232
signal.
The clock rate for the charge pump typically operates at greater than 70kHz allowing the pump
to run efficiently with small 0.1μF capacitors.
Efficient operation depends on rapidly charging
and discharging C1 and C2, therefore capacitors
should be mounted close to the IC and have low
ESR (equivalent series resistance). Inexpensive
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
12
SP3244E_SP3245E_100_121509
DESCRIPTION
Auto On-Line® Plus provides greater power
savings in typical operation because the transceiver will go into low power standby mode
unless a communication link is in use. Signals
such as CTS, RTS, DTR, DSR, or RI will typically change signal-state to establish handshaking before any actual data-communication
takes place. Transitions on these handshake
signals will wake up the Auto On-Line® Plus
transceiver to prepare it for sending data
(tONLINE 100μs typical).
Receivers remain active to detect incoming
signals in Auto On-Line® Plus standby mode.
Receiver outputs may be disabled by entering manual shutdown by driving SHUTDOWN
pin to logic 0. A special non-inverted receiver
output R2OUT remains active in all modes,
including SHUTDOWN pin at logic 0.
In some applications if there is a significant
delay (greater than tOFFLINE) between the
handshaking transitions and the start of data
communication the transceiver may enter
Auto On-Line® Plus standby mode before data
communication begins. The tOFFLINE interval
is at least 15 seconds and no longer than 60
seconds.
In applications where the transceiver needs to
remain active anytime it is connected to live
RS-232 signals, even if those signals remain
idle for longer than tOFFLINE, then the STATUS
output may be used to drive the ONLINE pin.
The STATUS output pin functions the same
in both Auto On-Line® and Auto On-line® Plus
devices. STATUS will output logic 1 if any of
the receiver inputs are driven greater than
±2.7V magnitude by incoming RS-232 signals
and drives logic 0 if receiver inputs are floating or driven to ground (see page 14). Driving the ONLINE pin with the STATUS output
disables Auto On-line® Plus (Forced On-Line)
whenever RS-232 voltages are seen on any
receiver inputs. If no RS-232 voltages are seen
on the receiver inputs the Auto On-Line® Plus
transceiver will still activate its charge pump
and driver outputs when the driver inputs are
active. This allows the transceiver to signal a
remote Auto On-Line® or Auto On-Line® Plus,
on the other end of the data cable, to wake up.
The STATUS output pin remains active in all
modes, including SHUTDOWN pin at logic 0.
Connecting STATUS output to drive both
ONLINE and SHUTDOWN will wake the transceiver if any receiver inputs are driven greater
than ±2.7V magnitude and put the transceiver
into Forced Shutdown mode if all receiver inputs
are floating or driven to ground.
±15KV ESD PROTECTION
ESD-protection structures are incorporated
on all pins to protect against electrostatic
discharges encountered during handling and
assembly. The driver output and receiver inputs
of the SP3244E/3245E have extra protection
against static electricity. Exar uses state-of-theart 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, the SP3244E/3245E keep working
without latch-up or damage.
ESD protection can be tested in various ways.
The transmitter outputs and receiver inputs of
the SP3244/3245 are characterized for protection to the following limits:
• ±15kV using the Human Body Model
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
13
SP3244E_SP3245E_100_121509
DESCRIPTION
Auto On-Line® Plus Truth Table
Operating mode
ONLINE
SHUTDOWN
|RxIN| > ± 2.7 V
Idle inputs
(RxIN & TxIN)
TxOUT
RxOUT
R2OUT
Forced Shutdown
X
0
X
X
high-Z
high-Z
active
Forced Online
1
1
X
X
active
active
active
Auto On-line® Plus
(Wake When Active)
0
1
X
active
active
active
active
0
1
X
idle > 30s
high-Z
active
active
Auto On-line® Plus
(Off-Line When Idle)
Auto On-line® Plus
STATUS
1
yes
X
active
active
active
Auto On-line® Plus
(Wake When Active)
STATUS
1
no
active
active
active
active
Auto On-line® Plus
(Off-Line When Idle)
STATUS
1
no
idle > 30s
high-Z
active
active
STATUS
STATUS
yes
X
active
active
active
STATUS
STATUS
no
X
high-Z
active
active
(Wake On Cable)
Auto On-line®
(Wake On Cable)
Auto On-line®
(Auto Shutoff)
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
14
SP3244E_SP3245E_100_121509
DESCRIPTION
SHUTDOWN
Valid RS232 Level: STATUS = 1
2.7V
0.3V
Edge
Detect
T_IN
Indeterminate
Invalid Level: STATUS = 0
IDLE
R
-0.3V
Edge
Detect
R_IN
Indeterminate
-2.7V
S
30 second
timer
ONLINE
Valid RS232 Level: STATUS = 1
Auto On-Line® Plus Logic
Receiver Positive and Negative Threshold versus
STATUS Output Signal
SHUTDOWN
Low-Power Shutdown
ONLINE
IDLE
STATUS Output Logic
SHUTDOWN
Low-Power Shutdown
ONLINE
IDLE
Shutdown Logic
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
15
SP3244E_SP3245E_100_121509
AUTO ON-LINE® PLUS
RECEIVER
INPUTS
INVALID
} REGION
TRANSMITTER
INPUTS
TRANSMITTER
OUTPUTS
STATUS Vcc t
TSTL
OUTPUT
0
Vcc
OUTPUT
t STH
t OFFLINE
t OFFLINE
tONLINE
tONLINE
0
V+
Vcc
0
V-
Auto On-Line® Plus Timing Diagram
tstl (=30µs typ.)
tsth (=0.4µs typ.)
toffline (=30s typ.)
tonline (=100µs typ.)
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
16
SP3244E_SP3245E_100_121509
TYPICAL OPERATING CIRCUIT
C5
VCC
+
0.1µF
28 C1+
+
C1 0.1µF
24 C1-
C2
+
26
VCC
V+ 27
SP3244E
1 C2+ SP3245E
0.1µF
TTL/CMOS
INPUTS
V- 3
2 C214 T1IN
T1OUT 9
13 T2IN
T2OUT 10
12 T3IN
T3OUT 11
C3
C4
+
+
0.1µF
0.1µF
RS-232
OUTPUTS
20 R2OUT
R1IN 4
19 R1OUT
5kΩ
18 R2OUT
TTL/CMOS
OUTPUTS
5kΩ
17 R3OUT
5kΩ
16 R4OUT
VCC
Online Control
To µP Supervisor
Circuit
5kΩ
15 R5OUT
22
23
R2IN 5
SHUTDOWN
R3IN 6
R4IN 7
RS-232
INPUTS
R5IN 8
5kΩ
ONLINE
21 STATUS
GND
25
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
17
SP3244E_SP3245E_100_121509
PACKAGE PINOUT
C2+ 1
C2- 2
V- 3
R1IN 4
28 C1+
27 V+
26 VCC
25 GND
24 C1R2IN 5
R3IN 6 SP3244E 23 ONLINE
SP3245E
22 SHUTDOWN
R4IN 7
21 STATUS
R5IN 8
V-
C2-
C2+
C1+
V+
V
NC
31
30
29
28
27
26
25
CC
NC
32
2
23
C1-
22
ONLINE
3
SP3244/SP3245
QFN-32
4
5
21
SHUTDOWN
20
STATUS
6
19
R2
7
18
R1
8
17
R2
OUT
OUT
16
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
18
OUT
NC
15
OUT
R3
14
OUT
R4
13
OUT
R5
IN
12
TOP VIEW
T1
OUT
GND
11
T3
OUT
24
IN
T2
OUT
1
T2
T1
IN
15 R5OUT
10
R5
IN
T1IN 14
IN
R4
IN
17 R3OUT
16 R4OUT
T3
R3
IN
T3IN 12
T2IN 13
9
R2
IN
20 R2OUT
19 R1OUT
18 R2OUT
NC
R1
T1OUT 9
T2OUT 10
T3OUT 11
SP3244E_SP3245E_100_121509
32 Pin QFN
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
19
SP3244E_SP3245E_100_121509
28 Pin TSSOP
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
20
SP3244E_SP3245E_100_121509
20 Pin SSOP
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
21
SP3244E_SP3245E_100_121509
Ordering INFORMATION
Part number
Temperature range
Package Type
SP3244ECA-L
From 0º to +70ºC
28 pin SSOP
SP3244ECY-L
From 0º to +70ºC
28 pin TSSOP
SP3244EEA-L
From -40º to +85ºC
28 pin SSOP
SP3244EEY-L
From -40º to +85ºC
28 pin TSSOP
SP3244EER1-L
From -40º to +85ºC
32 pin QFN
SP3245ECA-L
From 0º to +70ºC
28 pin SSOP
SP3245ECY-L
From 0º to +70ºC
28 pin TSSOP
SP3245EEA-L
From -40º to +85ºC
28 pin SSOP
SP3245EEY-L
From -40º to +85ºC
28 pin TSSOP
SP3245EER1-L
From -40º to +85ºC
32 pin QFN
Available in lead free packaging.
Available in Tape and Reel. To order add "/TR" suffix to part number,
Example: SP3244ECA-L= Standard; SP3244ECA-L/TR =Tape and Reel
DATE
REVISION
10-09-06
M
12-15-09
1.0.0
DESCRIPTION
Legacy Sipex Datasheet
Update to Exar Format. Change revision to 1.0.0. Change driver short circuit current
limit from +/-60mA to +/-100mA. Add Ta = 25ºC to test conditions for Transition Region Slew Rate and Mouse Drivability parameters . Delete / remove all reference to
IEC ESD protection. Change RX input voltage ABS Maximum Rating from +/-18V to
+/-16V.
Notice
EXAR Corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no representation that the circuits are free of patent infringement. Charts and schedules contained herein are only for
illustration purposes and may vary depending upon a user's specific application. While the information in this publication has been carefully checked;
no responsibility, however, is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can
reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for
use in such applications unless EXAR Corporation receives, in writting, assurances to its satisfaction that: (a) the risk of injury or damage has been
minimized ; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances.
Copyright 2009 EXAR Corporation
Datasheet December 2009
Send your Interface technical inquiry with technical details to: uarttechsupport@exar.com
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
22
SP3244E_SP3245E_100_121509
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