Datasheet SP385ECA, SP385ECT, SP385EEA, SP385EET Datasheet (Sipex Corporation)

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Page 1

SP385E

Enhanced +3V or +5V RS-232 Line

Driver/Receiver

■ Operates from 3.3V or 5V Power Supply

■ Meets All EIA-232D and V.28 Specifica-

tions 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

■ Improved ESD Specifications:

+15kV Human Body Model +15kV IEC1000-4-2 Air Discharge +8kV IEC1000-4-2 Contact Discharge

DESCRIPTION…

The Sipex SP385E is an enhanced version of the Sipex SP200 family of RS232 line drivers/ receivers. The SP385E offers +3.3V operation for EIA-562 and EIA-232 applications. The SP385E maintains the same performance features offered in its predecessors. The SP385E is available in plastic SOIC or SSOP packages operating over the commercial and industrial temperature ranges. The SP385E is pin compatible to the LTC1385 EIA-562 transceiver, except the drivers in the SP385E can only be disabled with the ON/OFF pin.

RS232 OUTPUTS

CHARGE

PUMP

TTL/CMOS INPUTS

RS232 INPUTS

TTL/CMOS OUTPUTS

Page 2

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.

.................................................................................................................................................................

cc +

....................................................................................................................

..............................................................................................................................................................

Input Voltages

.........................................................................................................................

............................................................................................................................................................

(Vcc-0.3V) to +13.2V

-0.3 to (Vcc +0.3V)

+6V

13.2V

±15V

Output Voltages

....................................................................................................

OUT

................................................................................................................

OUT

Short Circuit Duration

.........................................................................................................................................

OUT

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)

(V+, +0.3V) to (V-, -0.3V)

-0.3V to (Vcc +0.3V) Continuous

SPECIFICATIONS

VCC=+3.3V±10%; 0.1µF charge pump capacitors; T

PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS TTL INPUT

Logic Threshold

Low 0.8 Volts TIN ; ON/OFF Vcc = 3.3V

High 2.0 Volts TIN ; ON/OFF Vcc = 3.3V Logic Pullup Current 15 200 µATIN = 0V Maximum Data Rate 120 kbps CL = 2500pF, RL= 3kΩ

TTL OUTPUT

TTL/CMOS Output

Voltage, Low 0.5 Volts I

Voltage, High 2.4 Volts I Leakage Current; TA = +25°C 0.05 ±10 µA ON/OFF=0V, 0V ≤ V

EIA-562 OUTPUT

Output Voltage Swing ±3.7 ±4.2 Volts All transmitter outputs loaded Power-Off Output Resistance 300 Ω VCC = 0V; V

Output Short Circuit Current ±10 mA Infinite duration

EIA-562 INPUT

Voltage Range -15 +15 Volts Voltage Threshold

Low 0.8 1.2 Volts VCC = 3.3V, TA = +25°C

High 1.7 2.4 Volts VCC = 3.3V, TA = +25°C Hysteresis 0.2 0.5 1.0 Volts VCC = 3.3V, TA = +25°C Resistance 3 5 7 kΩ VIN = 15V to –15V

DYNAMIC CHARACTERISTICS

Driver Propagation Delay 4.0 µs TTL to RS-562 Receiver Propagation Delay 1.5 µs RS-562 to TTL Instantaneous Slew Rate 30 V/µsCL = 10pF, RL= 3kΩ - 7kΩ;

Transition Region Slew Rate 10 V/µsCL = 2500pF, RL= 3kΩ;

Output Enable Time 300 ns Output Disable Time 1000 ns

POWER REQUIREMENTS

VCC Power Supply Current 3 6 mA No load, TA= +25°C; VCC = 3.3V

Shutdown Supply Current 0.010 5 µAVCC = 3.3V, TA = +25°C

to T

unless otherwise noted.

MIN

MAX

8 mA All transmitters RL = 3kΩ

= 3.2mA; Vcc = 3.3V

OUT

= -1.0mA

OUT

with 3kΩ to ground

= ±2V

OUT

TA = +25°C measured from +2V to -2V

or -2V to +2V

TA = +25°C

≤ V

Page 3

SPECIFICATIONS

VCC=+5V±10%; 0.1µF charge pump capacitors; T

PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS TTL INPUT

Logic Threshold

Low 0.8 Volts TIN ; ON/OFF

High 2.0 Volts TIN ; ON/OFF Logic Pullup Current 15 200 µATIN = 0V Maximum Data Rate 120 kbps CL = 2500pF, RL= 3kΩ

TTL OUTPUT

TTL/CMOS Output

Voltage, Low 0.4 Volts I

Voltage, High 3.5 Volts I Leakage Current; TA = +25°C 0.05 ±10 µA EN = VCC, 0V ≤ V

EIA-232 OUTPUT

Output Voltage Swing ±5 ±9 Volts All transmitter outputs loaded Power-Off Output Resistance 300 Ω VCC = 0V; V

Output Short Circuit Current ±18 mA Infinite duration

EIA-232 INPUT

Voltage Range -15 +15 Volts Voltage Threshold

Low 0.8 1.2 Volts VCC = 5V, TA = +25°C

High 1.7 2.4 Volts VCC = 5V, TA = +25°C Hysteresis 0.2 0.5 1.0 Volts VCC = 5V, TA = +25°C Resistance 3 5 7 kΩ VIN = 15V to –15V

DYNAMIC CHARACTERISTICS

Propagation Delay, RS-232 to TTL 1.5 µs Instantaneous Slew Rate 30 V/µsCL = 10pF, RL= 3kΩ - 7kΩ;

Transition Region Slew Rate 10 V/µsCL = 2500pF, RL= 3kΩ;

Output Enable Time 400 ns Output Disable Time 250 ns

POWER REQUIREMENTS

VCC Power Supply Current 10 15 mA No load, TA= +25°C; VCC = 5V

Shutdown Supply Current 1 10 µAVCC = 5V, TA = +25°C

to T

unless otherwise noted.

MIN

MAX

= 3.2mA; Vcc = +5V

OUT

= -1.0mA

OUT

≤ V

with 3kΩ to ground

= ±2V

OUT

TA =+25°C measured from +3V to -3V

or -3V to +3V

25 mA All transmitters RL = 3kΩ;

TA = +25°C

PERFORMANCE CURVES

-11

-10

-9

= 6V

-8

-7

-6

V– Voltage (Volts)

-5

-4

-3 02468101214

= 5V

Load Current (mA)

= 4V

V+ (Volts)

0 5 10 15 20

= 5V

= 4V

Load Current (mA)

= 6V

25 30 35 40

(mA)

-55 -40 0 25 70 85 125

= 6V

= 5V

= 4V

= 3V

Temperature (°C)

8.4

8.2

8.0

7.8

7.6

(Volts)

7.4

7.2

7.0

6.8

4.5 4.75 5.0 5.25 5.5

Load current = 0mA T

= 25°C

(Volts)

Page 4

PINOUT

N/C C +

V+ C -

C +

C -

VT OUT

R IN

1 2 3 4

SP385E

5 6 7 8 9

18 17 16 15 14 13 12 11 10

18-pin SOIC 20-pin SSOP

TYPICAL OPERATING CIRCUIT

ON/OFF V

GND T OUT

R IN

R OUT

T IN

R OUT

N/C C +

V+ C -

C +

C -

VT OUT

R IN

N/C

20 19 18 17 16 15 14 13 12 11

ON/OFF V

GND T OUT

R IN

R OUT

T IN

R OUT

N/C

1 2 3 4

SP385E

5 6 7 8 9

0.1 F

6.3V

4 5

0.1 F

16V

T IN

TTL/CMOS INPUTS

TTL/CMOS OUTPUTS

+5V INPUT

0.1 F

C + C C + C -

400K

+5V to +10V

Voltage Doubler

+10V to -10V

Voltage Inverter

Ω

SP311E

SP385E

16GND

SOIC Package

+5V INPUT

0.1 F

16V

V+

0.1 F

V-

Ω

16V

T OUT

RS232 OUTPUTS

R INR OUT

RS232 INPUTS

ON/OFF

TTL/CMOS INPUTS

TTL/CMOS OUTPUTS

0.1 F

6.3V

0.1 F 16V

T IN

C +

C -

C +

C -

400K

SP385E

+5V to +10V

Voltage Doubler

+10V to -10V

Voltage Inverter

Ω

SP311E

18GND

0.1 F

16V

V+

0.1 F

V-

Ω

16V

T OUT

RS232 OUTPUTS

R INR OUT

RS232 INPUTS

ON/OFF

SSOP Package

Page 5

FEATURES…

The Sipex SP385E is a +3V to +5V EIA-232/EIA- 562 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 SP385E 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 SP385E 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 EIA-562 specifications, respecitively. The transmitter outputs are protected against infinite short-circuits to ground without degradation in reliability.

The SP385E includes a charge pump voltage converter which allows it to operate from a single +3.3V or +5V supply. These converters double the V voltage input in order to generate the EIA-232 or EIA-

562 output levels. For +5V operation, the SP385E 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 SP385E has a single control line which simul- taneously shuts down the internal DC/DC converter and puts all transmitter and receiver outputs into a high impedance state.

The SP385E 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 SP385E 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.

THEORY OF OPERATION

The SP385E device is made up of three basic circuit blocks — 1) a driver/transmitter, 2) a receiver and 3) a charge pump.

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 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.

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.

Page 6

CHARGE PUMP

The charge pump is a Sipex–patented design (5,306,954) and uses a unique approach compared to older less–efficient designs. The charge pump still requires four external capacitors, but uses a four–phase voltage shifting technique to attain symmetrical 10V power supplies. There is a free–running oscillator that controls the four phases of the voltage shifting. A description of each phase follows.

Phase 1

— VSS charge storage —During this phase of the clock cycle, the positive side of capacitors C1 and C2 are initially charged to +5V. C then switched to ground and the charge in C transferred to C

–

. Since C

is connected to

–

+5V, the voltage potential across capacitor C2 is now 10V.

Phase 4

— VDD transfer — The fourth phase of the clock connects the negative terminal of C2 to ground, and transfers the generated l0V across C2 to C4, the VDD storage capacitor. Again, simultaneously with this, the positive side of capacitor C1 is switched to +5V and the negative side is connected to ground, and the cycle begins again.

Since both V+ and V– are separately generated from VCC; in a no–load condition V+ and V– will be symmetrical. Older charge pump approaches that generate V– from V+ will show a decrease in the magnitude of V– compared to V+ due to the inherent inefficiencies in the design.

The clock rate for the charge pump typically operates at 15kHz. The external capacitors can be as low as 0.1µF with a 16V breakdown voltage rating.

Phase 2

— VSS transfer — Phase two of the clock connects the negative terminal of C2 to the V

storage capacitor and the positive terminal of C to ground, and transfers the generated –l0V to C3. Simultaneously, the positive side of capacitor C 1 is switched to +5V and the negative side is connected to ground.

Phase 3

— VDD charge storage — The third phase of the clock is identical to the first phase — the charge transferred in C1 produces –5V in the negative terminal of C1, which is applied to the negative side of capacitor C2. Since C

is at +5V, the

voltage potential across C2 is l0V.

+10V

a) C

GND

–

b) C

–10V

VCC = +5V

–5V –5V

Figure 1. Charge Pump — Phase 1

VCC = +5V

Figure 2. Charge Pump — Phase 2

+5V

––

–10V

–

Storage Capacitor

–

Storage Capacitor

–

Storage Capacitor

–

Storage Capacitor

Figure 3. Charge Pump Waveforms

Page 7

VCC = +5V

–5V

+5V

––

–5V

–

Storage Capacitor

–

Storage Capacitor

Figure 4. Charge Pump — Phase 3

VCC = +5V

+10V

––

–

Storage Capacitor

–

Storage Capacitor

Figure 5. Charge Pump — Phase 4

Shutdown (ON/OFF)

The SP385E 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 SP385E 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.

The Human Body Model has been the generally accepted ESD testing method for semiconductors. This method is also specified in MIL-STD-883, Method 3015.7 for ESD testing. The premise of this ESD test is to simulate the human body’s potential to store electro-static energy and discharge it to an integrated circuit. The simulation is performed by using a test model as shown in Figure 6. This method will test the IC’s capability to withstand an ESD transient during normal handling such as in manufacturing areas where the ICs tend to be handled frequently.

The IEC-1000-4-2, formerly IEC801-2, is generally used for testing ESD on equipment and systems. For system manufacturers, they must guarantee a certain amount of ESD protection since the system itself is exposed to the outside environment and human presence. The premise with IEC1000-4-2 is that the system is required to withstand an amount of static electricity when ESD is applied to points and surfaces of the equipment that are accessible to personnel during normal usage. The transceiver IC receives most of the ESD current when the ESD source is applied to the connector pins. The test circuit for IEC1000-4-2 is shown on Figure 7. There are two methods within IEC1000-4-2, the Air Discharge method and the Contact Discharge method.

ESD Tolerance

The SP385E device incorporates ruggedized ESD cells on all driver output and receiver input pins. The ESD structure is improved over our

DC Power Source

SW1

SW1SW1

SW2

SW2SW2

Device Under Test

previous family for more rugged applications and environments sensitive to electro-static discharges and associated transients.The improved ESD tolerance is at least ±15KV without damage nor latch-up.

There are different methods of ESD testing applied:

a) MIL-STD-883, Method 3015.7 b) IEC1000-4-2 Air-Discharge

Figure 6. ESD Test Circuit for Human Body Model

Contact-Discharge Module

Contact-Discharge ModuleContact-Discharge Module

SW2

SW2SW2

DC Power Source

SW1

SW1SW1

Device Under Test

c) IEC1000-4-2 Direct Contact

RS and RV add up to 330Ω for IEC1000-4-2.

andand RR

add up to 330add up to 330ΩΩ f for IEC1000-4-2.or IEC1000-4-2.

S S

V V

Figure 7. ESD Test Circuit for IEC1000-4-2

Page 8

30A

15A

The Contact Discharge Method applies the ESD

i ➙

current directly to the EUT. This method was devised to reduce the unpredictability of the ESD arc. The discharge current rise time is constant since the energy is directly transferred without the air-gap arc. In situations such as hand held systems, the ESD charge can be directly discharged to the equipment from a person already holding the equipment. The current is transferred on to the keypad or the serial port of the equipment directly and then travels through the PCB and finally to the IC.

t=0ns t=30ns

Figure 8. ESD Test Waveform for IEC1000-4-2

t ➙

With the Air Discharge Method, an ESD voltage is applied to the equipment under test (EUT) through air. This simulates an electrically charged person ready to connect a cable onto the rear of the system only to find an unpleasant zap just before the person touches the back panel. The high energy potential on the person discharges through an arcing path to the rear panel of the system before he or she even touches the system. This energy, whether discharged directly or through air, is predominantly a function of the discharge current rather than the discharge voltage. Variables with an air discharge such as approach speed of the object carrying the ESD potential to the system and humidity will tend to change the discharge current. For example, the rise time of the discharge current varies with the approach speed.

The circuit models in Figures 6 and 7 represent the typical ESD testing circuit used for all three methods. The CS is initially charged with the DC power supply when the first switch (SW1) is on. Now that the capacitor is charged, the second switch (SW2) is on while SW1 switches off. The voltage stored in the capacitor is then applied through RS, the current limiting resistor, onto the device under test (DUT). In ESD tests, the SW2 switch is pulsed so that the device under test receives a duration of voltage.

For the Human Body Model, the current limiting resistor (RS) and the source capacitor (CS) are

1.5kΩ an 100pF, respectively. For IEC-1000-42, the current limiting resistor (RS) and the source capacitor (CS) are 330Ω an 150pF, respectively.

The higher CS value and lower RS value in the IEC1000-4-2 model are more stringent than the Human Body Model. The larger storage capacitor injects a higher voltage to the test point when SW2 is switched on. The lower current limiting resistor increases the current charge onto the test point.

SP385E HUMAN BODY IEC1000-4-2 Family MODEL Air Discharge Direct Contact Level

Driver Outputs ±15kV ±15kV ±8kV 4 Receiver Inputs ±15kV ±15kV ±8kV 4

Table 1. Transceiver ESD Tolerance Levels

Page 9

PACKAGE: PLASTIC

SMALL OUTLINE (SOIC) (WIDE)

DIMENSIONS (Inches)

Minimum/Maximum

(mm)

18–PIN

0.093/0.104

(2.352/2.649)

0.004/0.012

(0.102/0.300)

0.013/0.020

(0.330/0.508)

0.447/0.463

(11.35/11.74)

0.291/0.299

(7.402/7.600)

0.050 BSC

(1.270 BSC)

0.394/0.419

(10.00/10.64)

0.016/0.050

(0.406/1.270)

0°/8°

(0°/8°)

Page 10

PACKAGE: PLASTIC SHRINK

SMALL OUTLINE (SSOP)

DIMENSIONS (Inches)

Minimum/Maximum

(mm) A

20–PIN

0.068/0.078 (1.73/1.99)

0.002/0.008 (0.05/0.21)

0.010/0.015 (0.25/0.38)

0.278/0.289 (7.07/7.33)

0.205/0.212 (5.20/5.38)

0.026 BSC

(0.065 BSC)

0.301/0.311 (7.65/7.90)

0.022/0.037 (0.55/0.95)

0°/8°

(0°/8°)

Page 11

Model .......................................................................................Temperature Range................................................................................ Package

ORDERING INFORMATION

SP385ECA ..................................................................................... 0°C to +70°C ............................................................................... 20–pin SSOP

SP385EEA ................................................................................... –40°C to +85°C ............................................................................. 20–pin SSOP

SP385ECT ..................................................................................... 0°C to +70°C ................................................................................ 18–pin SOIC

SP385EET ................................................................................... –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 Headquarters and

Sales Office

22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: sales@sipex.com

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.

Datasheet SP385ECA, SP385ECT, SP385EEA, SP385EET Datasheet (Sipex Corporation)

Specifications and Main Features

Frequently Asked Questions

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