SP1485ECN-L/TR - Sipex Corporation

SP1485E

■+5V supply

■Low Power BiCMOS

■Driver/Receiver Enable for Multi-Drop

configurations

■Available in 8 Pin NSOIC or PDIP

packages

■Enhanced ESD Specifications:

+15KV Human Body Model

+15KV IEC1000-4-2 Air Discharge

+8KV IEC1000-4-2 Contact Discharge

Enhanced Lo w Power Half-Duplex

RS-485 Transceivers

PRELIMINARY

RO 1

RE 2

DE 3

DI 4

8 Vcc

7 B

6 A

5 GND

SP1485E

The SP1485E is a half-duplex transceiver that meets the specifications of RS-485 and RS-

422 serial protocols with enhanced ESD performance. The ESD tolerance has been improved

on this device to over +15KV for both Human Body Model and IEC1000-4-2 Air Discharge

Method. This device is pin-to-pin compatible with Sipex's SP485 devices as well as popular

industry standards. As with the original version, the SP1485E features Sipex's BiCMOS

design allowing low power operation without sacrificing performance. The SP1485E meets

the requirements of the RS-485 and RS-422 protocols up to 20Mbps under load.

DESCRIPTION

SP1485E

8 Pin - nSOIC

RE B

VCC

DI GND

BLOCK DIAGRAM

ABSOLUTE MAXIMUM RATINGS

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.

VCC............................................................................................................+7V

Input Voltages

Logic........................................................-0.3V to (VCC+0.5V)

Drivers..................................................-0.3V to (VCC+0.5V)

Receivers................................................................. ±15V

TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted.

PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS

SP1485E DRIVER

DC Characteristics

Differential Output Voltage 3.5 VCC Volts Unloaded; R = ∞;

see Figure 1

Differential Output Voltage 2 VCC Volts with load; R = 50Ω; (RS-422);

see Figure 1

Differential Output Voltage 1.5 VCC Volts with load; R = 27Ω; (RS-485);

see Figure 1

Change in Magnitude of Driver

Differential Output Voltage for

Complimentary States 0.2 Volts R = 27Ω or R = 50Ω;

see Figure 1

Driver Common-Mode

Output Voltage 3 Volts R = 27Ω or R = 50Ω;

see Figure 1

Input High Voltage 2.0 Volts Applies to DE, DI, RE

Input Low Voltage 0.8 Volts Applies to DE, DI, RE

Input Current ±10 µAApplies to DE, DI, RE

Driver Short-Circuit Current

VOUT = HIGH ±250 mA -7V ≤ VO ≤ +12V

VOUT = LOW ±250 mA -7V ≤ VO ≤ +12V

SP1485E DRIVER

AC Characteristics

Maximum Data Rate 20 Mbps RE = 5V, DE = 5V; RDIFF = 54Ω,

CL1 = CL2 = 100pF

Driver Input to Output 10 30 40 ns tPLH; RDIFF = 54Ω, CL1 = CL2 = 100pF;

see Figures 3 and 5

10 ns tPHL; RDIFF = 54Ω, CLI = CL2 = 100pF;

Driver Skew 3 ns

see Figures 3 and 5,

tSKEW = | tDPLH - tDPHL |

Driver Rise or Fall Time 8 20 ns From 10% to 90%; RDIFF = 54Ω,

CL1 = CL2 = 100pF;

ee Figures 3 &

Driver Enable to Output High 40 70 ns CL = 100pF;

see Figures 4 & 6;

closed

Driver Enable to Output Low 40 70 ns CL = 100pF;

see Figures 4 & 6;

closed

Driver Disable Time from Low 40 70 ns CL = 100pF;

see Figures 4 & 6;

closed

Driver Disable Time from High 40 70 ns CL = 100pF;

see Figures 4 & 6;

closed

Output Voltages

Logic........................................................-0.3V to (VCC+0.5V)

Drivers...................................................................... ±15V

Receivers............................................-0.3V to (VCC+0.5V)

Storage Temperature.......................................................-65˚C to +150˚C

Power Dissipation per Package

8-pin NSOIC (derate 6.60mW/oC above +70oC)...........................550mW

8-pin PDIP (derate 11.8mW/oC above +70oC)............................1000mW

ELECTRICAL CHARACTERISTICS

TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted.

PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS

SP148

5E RECEIVER

DC Characteristics

Differential Input Threshold -0.2 +0.2 Volts -7V ≤ VCM ≤ +12V

Differential Input Threshold -0.4 +0.4 Volts -7V ≤ VCM ≤ +12V

(SP1485EMN ONLY)

Input Hysteresis 20 mV VCM = 0V

Output Voltage High 3.5 Volts IO = -4mA, VID = +200mV

Output Voltage Low 0.4 Volts IO = +4mA, VID = -200mV

Three-State (High Impedance)

Output Current ±1µA 0.4V ≤ VO ≤ 2.4V; RE = 5V

Input Resistance 12 15 kΩ-7V ≤ VCM ≤ +12V

Input Current (A, B); VIN = 12V +1.0 mA DE = 0V, VCC = 0V or 5.25V, VIN = 12V

Input Current (A, B); VIN = -7V -0.8 mA DE = 0V, VCC = 0V or 5.25V, VIN = -7V

Short-Circuit Current 7 95 mA 0V ≤ VO ≤ VCC

SP1485E RECEIVER

AC Characteristics

Maximum Data Rate 20 Mbps RE = 0V, DE = 0V

Receiver Input to Output 15 40 50 ns tPLH; RDIFF = 54Ω,

CL1 = CL2 = 100pF;

Figures 3 & 7

15 ns tPHL; RDIFF = 54Ω, CLI = CL2 = 100pF

Diff. Receiver Skew ItPLH-tPHLI510nsR

DIFF = 54Ω; CL1 = CL2 = 100pF;

Figures 3 & 7

Receiver Enable to

Output Low 45 70 ns CRL = 15pF;

Figures 2 & 8;

S1 closed

Receiver Enable to

Output High 45 70 ns CRL = 15pF;

Figures 2 & 8;

S2 closed

Receiver Disable from Low 45 70 ns CRL = 15pF;

Figures 2 & 8;

S1 closed

Receiver Disable from High 45 70 ns CRL = 15pF;

Figures 2 & 8;

S2 closed

POWER REQUIREMENTS

Supply Voltage +4.75 +5.25 Volts

Supply Current

SP1485E

No Load 900 µARE, DI = 0V or VCC; DE = VCC

600 µARE = 0V, DI = 0V or 5V; DE = 0V

ENVIRONMENTAL

AND MECHANICAL

Operating Temperature

Commercial (_C_) 0 +70 °C

Industrial (_E_) -40 +85 °C

(_M_) -40 +125 °C

Storage Temperature -65 +150 °C

Package

Plastic DIP (_P)

NSOIC (_N)

SPECIFICATIONS (continued)

PIN FUNCTION

Pin 1 – RO – Receiver Output.

Pin 2 – RE – Receiver Output Enable Active LOW.

Pin 3 – DE – Driver Output Enable Active HIGH.

Pin 4 – DI – Driver Input.

Pin 5 – GND – Ground Connection.

Pin 6 – A – Driver Output/Receiver Input

Non-inverting.

Pin 7 – B – Driver Output/Receiver Input Inverting.

Pin 8 – Vcc – Positive Supply 4.75V<Vcc< 5.25V.

SP1485E

Pinout (Top View)

RO 1

RE 2

DE 3

DI 4

8 VCC

7 B

6 A

5 GND

SP485

Top View

Figure 5. Driver Propagation Delays

Figure 1. RS-485 Driver DC Test Load Circuit Figure 2. Receiver Timing Test Load Circuit

Figure 3. RS-485 Driver/Receiver Timing Test Circuit Figure 4. RS-485 Driver Timing Test Load #2 Circuit

1kTest Point

Receiver

Output

DIFF

15pF S

500

Output

Under

Test

+3V

DRIVER

OUTPUT

VO+

DIFFERENTIAL

OUTPUT

VA – VB

VO–

1.5V 1.5V

tPLH

tRtF

f = 1MHz; tR < 1.0ns; tF < 1.0ns

VO1/2VO1/2VO

tPHL

tDPLH tDPHL

tSKEW = | tDPLH - tDPHL |

INPUTS OUTPUTS

LINE

RE DE DI CONDITION B A

X11No Fault 0 1

X10No Fault 1 0

X0X X ZZ

X1X Fault Z Z

INPUTS OUTPUTS

RE DE A - B R

00 +0.2V 1

00 -0.2V 0

00Inputs Open 1

10 X Z

Table 1. Transmit Function Truth Table Table 2. Receive Function Truth Table

+3V

A, B 0V

1.5V 1.5V

f = 1MHz; t

< 1.0ns; t

< 1.0ns

A, B 2.3V

2.3V

0.5V

Output normally LOW

Output normally HIGH

+3V

R0V

1.5V 1.5V

f = 1MHz; t

< 1.0ns; t

< 1.0ns

R1.5V

1.5V

0.5V

Output normally LOW

Output normally HIGH

Figure 8. Receiver Enable and Disable Times

Figure 7. Receiver Propagation Delays

Figure 6. Driver Enable and Disable Times

VOH

VOL

R1.5V 1.5V

tPHL f = 1MHz; tR < 1.0ns; tF < 1.0ns

OUTPUT

V0D2+

V0D2–

A – B 0V 0V

tPLH

INPUT

tSKEW = | tPHL - tPLH |

fail-safe feature. Fail-safe guarantees that the

receiver output will be in a HIGH state when

the input is left unconnected.

ESD TOLERANCE

The SP1485E incorporates ruggedized ESD

cells on all driver output and receiver input pins.

The ESD structure is improved over our previ-

ous family for more rugged applications and

environments sensitive to electro-static dis-

charges and associated transients. The improved

ESD tolerance is at least ±15kV without damage

or latch-up.

There are different methods of ESD testing

applied: a) MIL-STD-883, Method 3015.7

b) IEC1000-4-2 Air-Discharge

c) IEC1000-4-2 Direct Contact

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 7. 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

DESCRIPTION

The SP1485E is half-duplex differential trans-

ceivers that meet the requirements of RS-485

and RS-422. Fabricated with a Sipex proprietary

BiCMOS process, this product requires a frac-

tion of the power of older bipolar designs.

The RS-485 standard is ideal for multi-drop

applications and for long-distance interfaces.

RS-485 allows up to 32 drivers and 32 receivers

to be connected to a data bus, making it an ideal

choice for multi-drop applications. Since the

cabling can be as long as 4,000 feet, RS-485

transceivers are equipped with a wide (-7V to

+12V) common mode range to accommodate

ground potential differences. Because RS-485 is

a differential interface, data is virtually immune

to noise in the transmission line.

Drivers

The driver outputs of the SP1485E are differen-

tial outputs meeting the RS-485 and RS-422

standards. The typical voltage output swing with

no load will be 0 Volts to +5 Volts. With worst

case loading of 54Ω across the differential out-

puts, the drivers can maintain greater than 1.5V

voltage levels. The drivers of the SP1485E have

an enable control line which is active HIGH. A

logic HIGH on DE (pin 3) will enable the differ-

ential driver outputs. A logic LOW on DE (pin

3) will tri-state the driver outputs.

The transmitters of the SP1485E will operate up

to at least 20Mbps.

Receivers

The SP1485E receivers have differential inputs

with an input sensitivity as low as ±200mV.

Input impedance of the receivers is typically

15kΩ (12kΩ minimum). A wide common mode

range of -7V to +12V allows for large ground

potential differences between systems. The re-

ceivers of the SP1485E have a tri-state enable

control pin. A logic LOW on RE (pin 2) will

enable the receiver, a logic HIGH on RE (pin 2)

will disable the receiver.

The receiver for the SP1485E will operate up to

at least 20Mbps. The receiver for each of the two

devices is equipped with the

IEC1000-4-2 is shown on Figure 8. There are

two methods within IEC1000-4-2, the Air

Discharge method and the Contact Discharge

method.

SW1 SW2

Device

Under

Test

DC Power

Source

SW1 SW2

Figure 7. ESD Test Circuit for Human Body Model

and

add up to 330Ω for IEC1000-4-2.

and

add up to 330Ω for IEC1000-4-2.

Contact-Discharge Module

SW1 SW2

Device

Under

Test

DC Power

Source

SW1 SW2

Contact-Discharge Module

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

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 Contact Discharge Method applies the ESD

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.

The circuit model in Figures 7 and 8 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-1000-4-

2, 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.

Figure 9. ESD Test Waveform for IEC1000-4-2

t=0ns t=30ns

15A

30A

t ➙

i ➙

HUMAN BODY IEC1000-4-2

MODEL Air Discharge Direct Contact Level

Driver Outputs ±15kV ±15kV ±8kV 4

Receiver Inputs ±15kV ±15kV ±8kV 4

SP1481E,

SP1485E

FAMILY

ALTERNATE

END PINS

(BOTH ENDS)

D1 = 0.005" min.

(0.127 min.)

PACKAGE: PLASTIC

DUAL–IN–LINE

(NARROW)

DIMENSIONS (Inches)

Minimum/Maximum

(mm)

A = 0.210" max.

(5.334 max).

LA2

A1 = 0.015" min.

(0.381min.)

e = 0.100 BSC

(2.540 BSC) e

= 0.300 BSC

(7.620 BSC)

0.115/0.195

(2.921/4.953)

0.014/0.022

(0.356/0.559)

0.045/0.070

(1.143/1.778)

0.008/0.014

(0.203/0.356)

0.355/0.400

(9.017/10.160)

0.300/0.325

(7.620/8.255)

0.240/0.280

(6.096/7.112)

0.115/0.150

(2.921/3.810)

0°/ 15°

(0°/15°)

8–PIN

SEE VIEW C

Ø1

1.65

DIMENSIONS

Minimum/Maximum

(mm)

8 Pin NSOIC

(JEDEC MS-012,

AA - VARIATION)

COMMON HEIGHT DIMENSION

1.35

4.90 BSC

0.40

0.31 0.51

SYMBOL MIN NOM MAX

0.10 - 0.25

1.75

1.25

0.17 0.25

6.00 BSC

3.90 BSC

1.27 BSC1.27

1.04 REF

0.25 BSC

0º

5º 8º

15º

AA2

SEATING PLANE

SIDE VIEW

Ø1

Seating Plane

Gauge Plane

VIEW C

TOP VIEW

E/2

INDEX AREA

(D/2 X E1/2)

E1/2

8 PIN NSOIC

PACKAGE:

WITH PLATING

BASE METAL

CONT ACT AREA

PACKAGE: 8 PIN NSOIC

ORDERING INFORMATION

Model Temperature Range Package

SP1485ECN .....................................................0˚C to +70˚C............................................... 8-pin Narrow SOIC

SP1485ECP......................................................0˚C to +70˚C...................................................8-pin Plastic DIP

SP1485EEN.................................................... -40˚C to +85˚C .............................................8-pin Narrow SOIC

SP1485EEP.................................................... -40˚C to +85˚C .................................................8-pin Plastic DIP

SP1485EMN .................................................. -40˚C to +125˚C ............................................ 8-pin Narrow SOIC

Please consult the factory for pricing and availability on a Tape-On-Reel option.

Corporation

ANALOG EXCELLENCE

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 herein; neither does it convey any license under its patent rights nor the rights of others.

Sipex Corporation

Headquarters and

Sales Office

233 South Hillview Drive

Milpitas, CA 95035

TEL: (408) 934-7500

FAX: (408) 935-7600

Sales Office

22 Linnell Circle

Billerica, MA 01821

TEL: (978) 667-8700

FAX: (978) 670-9001

e-mail: sales@sipex.com

DATE REVISION DESCRIPTION

11/11/03 A Implemented tracking revision.

12/18/03 B Added Driver and Receiver TPLH/TPHL AC Characteristics.

02/26/04 C Changed Driver Input to Output values from 20ns (typ), 30ns (max) to

30ns (typ), 40ns (max). Changed Receiver Input to Output values from

25ns (typ), 70ns (max) to 40ns (typ), 50ns (max) .

REVISION HISTORY