SIPEX SP385A

®
SP385A
+3V to +5V RS-232 Line Driver/Receiver
■ Operates from 3.3V or 5V Power Supply
■ Meets All EIA-232D and V.28 Specifications at 5V
■ Meets EIA-562 Specifications at 3.3V
■ Two Drivers and Receivers
■ Operates with 0.1µF to 10µF Capacitors
■ High Data Rate — 120kbps Under Load
■ Low Power Shutdown ≤1µA
■ 3-State TTL/CMOS Receiver Outputs
■ Low Power CMOS — 5mA Operation
DESCRIPTION…
The Sipex SP385A is an enhanced version of the Sipex SP200 family of RS232 line drivers/
receivers. The SP385A offers +3.3V operation for EIA-562 and EIA-232 applications. The
SP385A maintains the same performance features offered in its predecessors. The SP385A is
available in plastic SOIC or SSOP packages operating over the commercial and industrial
temperature ranges. The SP385A is pin compatible to the LTC1385 EIA-562 transceiver, except
the drivers in the SP385A can only be disabled with the ON/OFF pin.
RS232 OUTPUTS
CHARGE
PUMP
T1
RS232 INPUTS
T2
R1
R2
TTL/CMOS INPUTS TTL/CMOS OUTPUTS
SP385ADS/05
SP385A Line Driver/Receiver
1
© Copyright 2000 Sipex Corporation
Output Voltages
TOUT .................................................................................................... (V+, +0.3V) to (V-, -0.3V)
ROUT ................................................................................................................ -0.3V to (Vcc +0.3V)
Short Circuit Duration
TOUT ......................................................................................................................................... Continuous
Power Dissipation
CERDIP .............................................................................. 675mW
(derate 9.5mW/°C above +70°C)
Plastic DIP .......................................................................... 375mW
(derate 7mW/°C above +70°C)
Small Outline ...................................................................... 375mW
(derate 7mW/°C above +70°C)
ABSOLUTE MAXIMUM RATINGS
This is a stress rating only and functional operation of the device at
these or any other conditions above those indicated in the operation
sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods of time may affect
reliability.
Vcc ................................................................................................................................................................. +6V
V+ .................................................................................................................... (Vcc-0.3V) to +13.2V
V- .............................................................................................................................................................. 13.2V
Input Voltages
TIN ......................................................................................................................... -0.3 to (Vcc +0.3V)
RIN ............................................................................................................................................................ ±15V
SPECIFICATIONS
VCC=+3.3V±10%; 0.1µF charge pump capacitors; TMIN to TMAX unless otherwise noted.
PARAMETERS
TTL INPUT
Logic Threshold
Low
High
Logic Pullup Current
Maximum Data Rate
TTL OUTPUT
TTL/CMOS Output
Voltage, Low
Voltage, High
Leakage Current; TA = +25°C
EIA-562 OUTPUT
Output Voltage Swing
MIN.
TYP.
MAX.
UNITS
0.8
Volts
Volts
µA
kbps
TIN ; ON/OFF Vcc = 3.3V
TIN ; ON/OFF Vcc = 3.3V
TIN = 0V
CL = 2500pF, RL= 3kΩ
Volts
Volts
µA
IOUT = 3.2mA; Vcc = 3.3V
IOUT = -1.0mA
ON/OFF=0V, 0V ≤ VOUT ≤ VCC
±4.2
Volts
±10
Ω
mA
All transmitter outputs loaded
with 3kΩ to ground
VCC = 0V; VOUT = ±2V
Infinite duration
2.0
15
200
120
0.5
2.4
0.05
±3.7
Power-Off Output Resistance 300
Output Short Circuit Current
EIA-562 INPUT
Voltage Range
-15
Voltage Threshold
Low
0.8
High
Hysteresis
0.2
Resistance
3
DYNAMIC CHARACTERISTICS
Driver Propagation Delay
Receiver Propagation Delay
Instantaneous Slew Rate
1.2
1.7
0.5
5
±10
+15
Volts
2.4
1.0
7
Volts
Volts
Volts
kΩ
VCC = 3.3V, TA = +25°C
VCC = 3.3V, TA = +25°C
VCC = 3.3V, TA = +25°C
VIN = 15V to –15V
30
µs
µs
V/µs
TTL to RS-562
RS-562 to TTL
CL = 10pF, RL= 3kΩ - 7kΩ;
TA = +25°C
CL = 2500pF, RL= 3kΩ;
measured from +2V to -2V
or -2V to +2V
4.0
1.5
Transition Region Slew Rate
10
Output Enable Time
Output Disable Time
POWER REQUIREMENTS
VCC Power Supply Current
300
1000
3
8
6
mA
mA
Shutdown Supply Current
0.010
5
µA
SP385ADS/05
CONDITIONS
V/µs
ns
ns
SP385A Line Driver/Receiver
2
No load, TA= +25°C; VCC = 3.3V
All transmitters RL = 3kΩ
TA = +25°C
VCC = 3.3V, TA = +25°C
© Copyright 2000 Sipex Corporation
SPECIFICATIONS
VCC=+5V±10%; 0.1µF charge pump capacitors; TMIN to TMAX unless otherwise noted.
PARAMETERS
TTL INPUT
Logic Threshold
Low
High
Logic Pullup Current
Maximum Data Rate
TTL OUTPUT
TTL/CMOS Output
Voltage, Low
Voltage, High
Leakage Current; TA = +25°C
EIA-232 OUTPUT
Output Voltage Swing
MIN.
TYP.
MAX.
UNITS
CONDITIONS
0.8
Volts
Volts
µA
kbps
TIN ; ON/OFF
TIN ; ON/OFF
TIN = 0V
CL = 2500pF, RL= 3kΩ
Volts
Volts
µA
IOUT = 3.2mA; Vcc = +5V
IOUT = -1.0mA
ON/OFF = O, 0V ≤ VOUT ≤ VCC
±9
Volts
±18
Ω
mA
All transmitter outputs loaded
with 3kΩ to ground
VCC = 0V; VOUT = ±2V
Infinite duration
2.0
15
200
120
0.4
3.5
±10
0.05
±5
Power-Off Output Resistance 300
Output Short Circuit Current
EIA-232 INPUT
Voltage Range
-15
Voltage Threshold
Low
0.8
High
Hysteresis
0.2
Resistance
3
DYNAMIC CHARACTERISTICS
Driver Propagation Delay
Receiver Propagation Delay
1.2
1.7
0.5
5
+15
Volts
2.4
1.0
7
Volts
Volts
Volts
kΩ
µs
µs
4.0
1.5
Instantaneous Slew Rate
30
TTL to RS-232
RS-232 to TTL
V/µs
Transition Region Slew Rate
10
V/µs
Output Enable Time
Output Disable Time
POWER REQUIREMENTS
VCC Power Supply Current
400
250
ns
ns
10
25
15
mA
mA
1
10
µA
Shutdown Supply Current
VCC = 5V, TA = +25°C
VCC = 5V, TA = +25°C
VCC = 5V, TA = +25°C
VIN = 15V to –15V
CL = 10pF, RL= 3kΩ - 7kΩ;
TA =+25°C
CL = 2500pF, RL= 3kΩ;
measured from +3V to -3V
or -3V to +3V
No load, TA= +25°C; VCC = 5V
All transmitters RL = 3kΩ;
TA = +25°C
VCC = 5V, TA = +25°C
PERFORMANCE CURVES
-11
12
30
10
25
VCC = 5V
-7
-6
20
ICC (mA)
V+ (Volts)
V– Voltage (Volts)
8
VCC = 6V
-8
VCC = 4V
6
15
VCC = 5V
4
10
2
5
VCC = 4V
-5
8.0
VCC = 6V
VOH (Volts)
VCC = 6V
VCC = 5V
-9
0
2
4
6
8
10
Load Current (mA)
SP385ADS/05
12
14
0
5
10
15
20
25
30
35
0
-55
40
Load Current (mA)
-40
0
25
70
Temperature (°C)
SP385A Line Driver/Receiver
3
7.6
Load current = 0mA
TA = 25°C
7.4
7.0
VCC = 3V
0
7.8
7.2
VCC = 4V
-4
-3
8.4
8.2
-10
85
125
6.8
4.5
4.75
5.0
5.25
5.5
VCC (Volts)
© Copyright 2000 Sipex Corporation
PINOUT…
N/C
1
18
ON/OFF
N/C
1
20
ON/OFF
C1 +
2
17
VCC
C1 +
2
19
VCC
GND
C2 +
5
C2 -
6
V-
7
V+
3
15
T1 OUT
C1 -
4
17
T1 OUT
14
R1 IN
C2 +
5
16
R1 IN
13
R1 OUT
C2 -
6
15
R1 OUT
12
T1 IN
V-
7
14
T1 IN
8
13
T2 IN
9
12
R2OUT
10
11
N/C
T2 OUT
8
11
T2 IN
T2 OUT
R2 IN
9
10
R2 OUT
R2 IN
N/C
SP385A
4
SP385A
C1 -
GND
16
3
V+
18
TYPICAL OPERATING CIRCUIT…
+5V INPUT
+5V INPUT
+
0.1µ F +
16V
6
C +
V
1
+5V to +10V
Voltage Doubler
C 12
C 2-
0.1µ F
16V
CC
+10V to -10V
Voltage Inverter
3+
V+
V-
7
6.3V
+ 0.1µ F
16V
T 1OUT
400K Ω
T2 IN
R 1 OUT
11
13
T2
8
14
R1
T 2OUT
R 1 IN
5KΩ
R 2 OUT
10
9
R2
R 2 IN
TTL/CMOS OUTPUTS
T1
15
RS232 OUTPUTS
12
TTL/CMOS INPUTS
400K Ω
T1 IN
5KΩ
SP311A
SP385A
18
V
C +
1
4
5
C 1-
0.1µ F +
16V
6
C +
2
C 2-
CC
+5V to +10V
Voltage Doubler
V+
+10V to -10V
Voltage Inverter
V-
0.1µ F
16V
3+
7
+ 0.1µ F
16V
400K Ω
T1 IN
14
T1
17
T2
8
T 1OUT
400K Ω
T2 IN
R 1 OUT
13
15
16
R1
T 2OUT
R 1 IN
5KΩ
R 2 OUT
ON/OFF
12
9
R2
R 2 IN
5KΩ
SP311A
SP385A
GND 16
20
ON/OFF
GND 18
SOIC Package
SP385ADS/05
19
2
0.1µ F +
RS232 INPUTS
TTL/CMOS INPUTS
0.1µ F +
6.3V
4
5
C +
+
RS232 OUTPUTS
17
2
TTL/CMOS OUTPUTS
0.1µ F
RS232 INPUTS
0.1µ F
SSOP Package
SP385A Line Driver/Receiver
4
© Copyright 2000 Sipex Corporation
FEATURES…
The Sipex SP385A is a +3V to +5V EIA-232/EIA562 line transceiver. It is a pin-for-pin alternative for
the SP310A and will operate in the same socket with
capacitors ranging from 0.1µF to 10µF, either polarized or non–polarized, in +3V supplies. The SP385A
offers the same features such as 120kbps guaranteed
transmission rate, increased drive current for longer
and more flexible cable configurations, low power
dissipation and overall ruggedized construction for
commercial and industrial environments.
The SP385A also includes a shutdown feature that
tri-states the drivers and the receivers.
Driver/Transmitter
The drivers are inverting transmitters, which
accept TTL or CMOS inputs and output the
RS-232 signals with an inverted sense relative to
the input logic levels. Typically the RS-232 output
voltage swing is ±9V for 5V supply and ±4.2V
for 3.3V supply. Even under worst case loading
conditions of 3kΩ and 2500pF, the output is guaranteed to be ±5V for a 5V supply and ±3.7V for
a 3.3V supply which adheres to EIA-232 and EIA562 specifications, respecitively. The transmitter
outputs are protected against infinite short-circuits
to ground without degradation in reliability.
The SP385A includes a charge pump voltage converter which allows it to operate from a single +3.3V
or +5V supply. These converters double the VCC
voltage input in order to generate the EIA-232 or EIA562 output levels. For +5V operation, the SP385A
driver outputs adhere to all EIA-232D and CCITT
V.28 specifications. While at +3.3V operation, the
outputs adhere to EIA-562 specifications. Due to
Sipex's efficient charge pump design, the charge
pump levels and the driver outputs are less noisy
than other 3V EIA-232 transceivers.
The instantaneous slew rate of the transmitter
output is internally limited to a maximum of 30V/
µs in order to meet the standards [EIA 232-D 2.1.7,
Paragraph (5)]. However, the transition region
slew rate of these enhanced products is typically
10V/µs. The smooth transition of the loaded output
from VOL to VOH clearly meets the monotonicity
requirements of the standard [EIA 232-D 2.1.7,
Paragraphs (1) & (2)].
Receivers
The receivers convert RS-232 input signals to
inverted TTL signals. Since the 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.
The SP385A has a single control line which simultaneously shuts down the internal DC/DC converter and puts all transmitter and receiver outputs
into a high impedance state.
The SP385A is available in 18-pin plastic SOIC
and 20-pin plastic SSOP packages for operation
over commercial and industrial temperature
ranges. Please consult the factory for surfacemount packaged parts supplied on tape-on-reel
as well as parts screened to MIL-M-38510.
The input thresholds are 0.8V minimum and 2.4V
maximum, again well within the ±3V RS-232
requirements. The receiver inputs are also protected against voltages up to ±15V. Should an
input be left unconnected, a 5kΩ pull-down resistor to ground will commit the output of the receiver
to a high state.
The SP385A is ideal for +3.3V battery applications requiring low power operation. The charge
pump strength allows the drivers to provide
±4.0V signals, plenty for typical EIA-232
applications since the EIA-232 receivers have
input sensitivity levels of less than ±3V.
In actual system applications, it is quite possible
for signals to be applied to the receiver inputs
before power is applied to the receiver circuitry.
This occurs for example when a PC user attempts
to print only to realize the printer wasn’t turned on.
In this case an RS-232 signal from the PC will
appear on the receiver input at the printer. When
the printer power is turned on, the receiver will
operate normally. All of these enhanced devices
are fully protected.
THEORY OF OPERATION
The SP385A device is made up of three
basic circuit blocks — 1) a driver/transmitter,
2) a receiver and 3) a charge pump.
SP385ADS/05
SP385A Line Driver/Receiver
5
© Copyright 2000 Sipex Corporation
S1
S3
V
S1
V+ = 2VCC
CC
+
S2
C1
+
S4
FROM
VOLTAGE DOUBLER
C3
GND
S3
V+
V
CC
GND
+
S2
C2
+
S4
GND
INTERNAL
OSCILLATOR
C4
V- = -(V+)
INTERNAL
OSCILLATOR
Figure 1. Charge Pump Voltage Doubler
Figure 2. Charge Pump Voltage Inverter
voltages exceeding ±15V, two back-to-back zener
diodes connected from each output to ground will
clamp the outputs to an acceptable voltage level.
Charge Pump
The charge pump section of the these devices
allows the circuit to operate from a single +5V
±10% power supply by generating the required
operating voltages internal to the devices. The
charge pump consists of two sections — 1) a
voltage doubler and 2) a voltage inverter.
Shutdown (ON/OFF)
The SP385A has a shut-down/standby mode to
conserve power in battery-powered systems. To
activate the shutdown mode, which stops the operation of the charge pump, a logic “0” is applied
to the appropriate control line. The shutdown
mode is controlled on the SP385A by a logic “0”
on the ON/OFF control line (pin 18 for the SOIC
and pin 20 for the SSOP packages); this puts the
transmitter outputs in a tri–state mode.
As shown in Figure 1, an internal oscillator triggers the charge accumulation and voltage inversion. The voltage doubler momentarily stores a
charge on capacitor C1 equal to Vcc, referenced to
ground. During the next transition of the oscillator
this charge is boot-strapped to transfer charge to
capacitor C3. The voltage across C3 is now from
Vcc to V+.
In the inverter section (Figure 2), the voltage
across C3 is transferred to C2 forcing a range of 0V
to V+ across C2. Boot-strapping of C2 will then
transfer charge to C4 to genrate V-.
One of the significant enhancements over previous products of this type is that the values of the
capacitors are no longer critical and have been
decreased in size considerably to 0.1µF. Because
the charge pump runs at a higher frequency, the
0.1µF capacitors are sufficient to transfer and
sustain charges to the two transmitters.
APPLICATION HINTS
Protection From Shorts to ±15V
The driver outputs are protected against shorts
to ground, other driver outputs, and V+ or V-. If
the possibility exists that the outputs could be
inadvertently connected to voltages higher than
±15V, then it is recommended that external
protection be provided. For protection against
SP385ADS/05
SP385A Line Driver/Receiver
6
© Copyright 2000 Sipex Corporation
PACKAGE:
E
PLASTIC
SMALL OUTLINE (SOIC)
(WIDE)
H
D
A
Ø
e
B
A1
L
DIMENSIONS (Inches)
Minimum/Maximum
(mm)
SP385ADS/05
18–PIN
A
0.093/0.104
(2.352/2.649)
A1
0.004/0.012
(0.102/0.300)
B
0.013/0.020
(0.330/0.508)
D
0.447/0.463
(11.35/11.74)
E
0.291/0.299
(7.402/7.600)
e
0.050 BSC
(1.270 BSC)
H
0.394/0.419
(10.00/10.64)
L
0.016/0.050
(0.406/1.270)
Ø
0°/8°
(0°/8°)
SP385A Line Driver/Receiver
7
© Copyright 2000 Sipex Corporation
PACKAGE:
E
PLASTIC SHRINK
SMALL OUTLINE
(SSOP)
H
D
A
Ø
e
B
A1
L
DIMENSIONS (Inches)
Minimum/Maximum
(mm)
SP385ADS/05
20–PIN
A
0.068/0.078
(1.73/1.99)
A1
0.002/0.008
(0.05/0.21)
B
0.010/0.015
(0.25/0.38)
D
0.278/0.289
(7.07/7.33)
E
0.205/0.212
(5.20/5.38)
e
0.026 BSC
(0.65 BSC)
H
0.301/0.311
(7.65/7.90)
L
0.022/0.037
(0.55/0.95)
Ø
0°/8°
(0°/8°)
SP385A Line Driver/Receiver
8
© Copyright 2000 Sipex Corporation
ORDERING INFORMATION
Model ....................................................................................... Temperature Range ................................................................................ Package
SP385ACA ..................................................................................... 0°C to +70°C ............................................................................... 20–pin SSOP
SP385AEA ................................................................................... –40°C to +85°C ............................................................................. 20–pin SSOP
SP385ACT ..................................................................................... 0°C to +70°C ................................................................................ 18–pin SOIC
SP385AET ................................................................................... –40°C to +85°C .............................................................................. 18–pin SOIC
CT and ET packages available Tape–on–Reel. Please consult the factory for pricing and availability for this option, and for parts screened to
MIL–STD–883.
Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Far East:
Headquarters and
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: [email protected]
JAPAN:
Nippon Sipex Corporation
Yahagi No. 2 Building
3-5-3 Uchikanda, Chiyoda-ku
Tokyo 101
TEL: 81.3.3256.0577
FAX: 81.3.3256.0621
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.
SP385ADS/05
SP385A Line Driver/Receiver
9
© Copyright 2000 Sipex Corporation