SP481E_技术文档

®

SP481E/SP485E

Enhanced Low Power Half-Duplex

RS-485 Transceivers

■ +5V Only

■ Low Power BiCMOS

■ Driver/Receiver Enable for Multi-Drop

configurations

■ Low Power Shutdown Mode

(SP481E)

■ Enhanced ESD Specifications:

+15KV Human Body Model

+15KV IEC1000-4-2 Air Discharge

+8KV IEC1000-4-2 Contact Discharge

DESCRIPTION

The SP481E and the SP485E are a family of half-duplex transceivers that meet the

specifications of RS-485 and RS-422 serial protocols with enhanced ESD performance. The

ESD tolerance has been improved on these devices to over +15KV for both Human Body

Model and IEC1000-4-2 Air Discharge Method. These devices are pin-to-pin compatible with

Sipex's SP481 and SP485 devices as well as popular industry standards. As with the original

versions, the SP481E and the SP485E feature Sipex's BiCMOS design allowing low power

operation without sacrificing performance. The SP481E and SP485E meet the requirements

of the RS-485 and RS-422 protocols up to 10Mbps under load. The SP481E is equipped with

a low power Shutdown mode.

8 Vcc

7 B

RO 1

RE 2

R

6 A

DE 3

DI 4

D

5 GND

SP481E and SP485E

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

1

ABSOLUTE MAXIMUM RATINGS

These are stress ratings only and functional operation of the device at

theseratingsoranyotherabovethoseindicatedintheoperationsections

ofthespecificationsbelowisnotimplied. Exposuretoabsolutemaximum

rating conditions for extended periods of time may affect reliability.

V_CC............................................................................................................+7V

Input Voltages

Output Voltages

Logic........................................................-0.3Vto(V_CC+0.5V)

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

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

StorageTemperature.......................................................-65˚Cto+150˚C

Power Dissipation per Package

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

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

Logic........................................................-0.3Vto(V_CC+0.5V)

Drivers..................................................-0.3Vto(V_CC+0.5V)

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

SPECIFICATIONS

T_MINto T_MAXand V_CC= 5V ± 5% unless otherwise noted.

PARAMETERS

MIN.

TYP.

MAX. UNITS CONDITIONS

SP481E/SP485E DRIVER

DC Characteristics

Differential Output Voltage

GND

2

V_CC

Volts

Unloaded; R = ∞ ; see Figure 1

with load; R = 50Ω; (RS-422);

see Figure 1

Differential Output Voltage

Change in Magnitude of Driver

Differential Output Voltage for

Complimentary States

Driver Common-Mode

Output Voltage

Input High Voltage

Input Low Voltage

Input Current

1.5

V_CC

Volts

with load; R = 27Ω; (RS-485);see Figure 1

0.2

3

R = 27Ω or R = 50Ω; see Figure 1

Volts

µA

R = 27Ω or R = 50Ω; see Figure 1

Applies to DE, DI, RE

2.0

0.8

±10

Applies to DE, DI, RE

Driver Short-Circuit Current

V_OUT= HIGH

V_OUT= LOW

±250 mA

-7V ≤ V_O≤ +12V

SP481E/SP485E DRIVER

AC Characteristics

Maximum Data Rate

10

20

Mbps

ns

RE = 5V, DE = 5V; R_DIFF= 54Ω,

C_L1= C_L2= 100pF

t_PLH; R_DIFF= 54Ω, C_L1= C_L2= 100pF;

see Figures 3 and 5

t_PLH; R_DIFF= 54Ω, C_LI= C_L2= 100pF;

See Figures 3 and 5

Driver Input to Output

30

60

80

Driver Input to Output

(SP485EMN ONLY)

ns

Driver Input to Output

20

30

5

60

80

10

40

70

ns

t_PHL; R_DIFF= 54Ω, C_L1= C_L2= 100pF;

see Figures 3 and 5

t_PHL; R_DIFF= 54Ω, C_L1= C_L2= 100pF;

see Figures 3 and 5

Driver Input to Output

(SP485EMN ONLY)

Driver Skew

see Figures 3 and 5,

t_SKEW= | t_DPLH- t_DPHL

|

Driver Rise or Fall Time

3

15

40

From 10% to 90%; R_DIFF= 54Ω,

C_L1= C_L2= 100pF; see Figures 3 &

C_L= 100pF; see Figures 4 & 6; S₂

6

Driver Enable to Output High

closed

Driver Enable to Output Low

closed

Driver Disable Time from Low

closed

Driver Disable Time from High

closed

C_L= 100pF; see Figures 4 & 6; S₁

C_L= 100pF; see Figures 4 & 6; S₂

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

2

SPECIFICATIONS (continued)

T_MINto T_MAXand V_CC= 5V ± 5% unless otherwise noted.

PARAMETERS

MIN.

TYP.

MAX. UNITS CONDITIONS

SP481E/SP485E RECEIVER

DC Characteristics

Differential Input Threshold

(SP485EMN ONLY)

-0.2

-0.4

+0.2 Volts

+0.4 Volts

-7V ≤ V_CM≤ +12V

Input Hysteresis

Output Voltage High

Output Voltage Low

Three-State (High Impedance)

Output Current

20

15

mV

Volts

V_CM= 0V

I_O= -4mA, V_ID= +200mV

I_O= +4mA, V_ID= -200mV

3.5

0.4

±1

µA

kΩ

+1.0 mA

0.4V ≤ V_O≤ 2.4V; RE = 5V

-7V ≤ V_CM≤ +12V

DE = 0V, V_CC= 0V or 5.25V, V_IN= 12V

DE = 0V, V_CC= 0V or 5.25V, V_IN= -7V

0V ≤ V_O≤ V_CC

Input Resistance

12

7

Input Current (A, B); V_IN= 12V

Input Current (A, B); V_IN= -7V

Short-Circuit Current

-0.8

95

mA

SP481E/SP485E RECEIVER

AC Characteristics

Maximum Data Rate

10

20

Mbps

ns

RE = 0V, DE = 0V

t_PLH; R_DIFF= 54Ω,

Receiver Input to Output

45

13

100

C_L1= C_L2= 100pF; Figures 3 & 7

t_PHL; R_DIFF= 54Ω,

Receiver Input to Output

20

ns

C_L1= C_L2⁼100pF; Figures 3 & 7

R_DIFF= 54Ω; C_L1= C_L2= 100pF;

Figures 3 & 7

Diff. Receiver Skew It_PLH-t_PHL

I

Receiver Enable to

Output Low

45

70

ns

C_RL= 15pF; Figures 2 & 8; S₁closed

Receiver Enable to

Output High

Receiver Disable from Low

Receiver Disable from High

45

70

ns

C_RL= 15pF; Figures 2 & 8; S₂closed

C_RL= 15pF; Figures 2 & 8; S₁closed

C_RL= 15pF; Figures 2 & 8; S₂closed

SP481E

Shutdown Timing

Time to Shutdown

Driver Enable from Shutdown

to Output High

Driver Enable from Shutdown

to Output Low

Receiver Enable from

Shutdown to Output High

Receiver Enable from

Shutdown to Output Low

50

200

40

600

100

ns

RE = 5V, DE = 0V

C_L= 100pF; See Figures 4 & 6; S₂closed

C_L= 100pF; See Figures 4 & 6; S₁closed

C_L= 15pF; See Figures 2 & 8; S₂closed

C_L= 15pF; See Figures 2 & 8; S₁closed

40

300

1000 ns

POWER REQUIREMENTS

Supply Voltage

Supply Current

SP481E/485E

+4.75

+5.25 Volts

No Load

900

600

µA

RE, DI = 0V or V_CC; DE = V_CC

RE = 0V, DI = 0V or 5V; DE = 0V

SP481E

Shutdown Mode

10

µA

DE = 0V, RE=V_CC

ENVIRONMENTAL AND MECHANICAL

Operating Temperature

Commercial (_C_)

Industrial (_E_)

(_M_)

Storage Temperature

Package

0

+70

+85

+125 °C

+150 °C

°C

-40

-65

Plastic DIP (_P)

NSOIC (_N)

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

3

PIN FUNCTION

Pin 1 – RO – Receiver Output.

RO

RE

DE

DI

1

2

3

4

8

7

6

5

V

B

A

R

CC

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.

D

GND

6 – A – Driver Output/Receiver Input

SP485

Non-inverting.

Top View

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

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

SP481E and SP485E

Pinout (Top View)

A

Test Point

C_RL

1k

Receiver

Output

R

V_CC

S₁

S₂

V_OD

1k

V_OC

R

B

Figure 1. RS-485 Driver DC Test Load Circuit

Figure 2. Receiver Timing Test Load Circuit

C_L1

V_CC

A

B

R_DIFF

DI

A

B

500

RO

S₁

S₂

Output

Under

Test

C_L

C_L2

15pF

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

Figure 3. RS-485 Driver/Receiver Timing Test Circuit

f = 1MHz; t_R< 10ns; t_F< 10ns

1.5V

+3V

0V

B

1.5V

DI

t_PLH

t_PHL

1/2V_O

DRIVER

OUTPUT

V_O

A

t_DPLH

t_DPHL

+

DIFFERENTIAL

OUTPUT

V_O

0V

–

V_O

V_A– V_B

t_R

t_F

t_{SKEW =}t_{DPLH - DPHL}

t

|

Figure 5. Driver Propagation Delays

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

4

INPUTS

OUTPUTS

INPUTS

OUTPUTS

LINE

RE DE DI CONDITION

RE

DE

0

A - B

+0.2V

R

1

B

0

A

1

0

1

X

1

0

1

0

No Fault

X

0

-0.2V

0

1

0

Inputs Open

X

1

X

Z

0

Z

Fault

Table 2. Receive Function Truth Table

Table 1. Transmit Function Truth Table

f = 1MHz; t_R< 10ns; t_F< 10ns

1.5V

+3V

1.5V

DE

0V

t_ZL

2.3V

t_LZ

5V

A, B

Output normally LOW

Output normally HIGH

0.5V

V_OL

V_OH

A, B

2.3V

t_ZH

0V

t_HZ

Figure 6. Driver Enable and Disable Times

+

–

V_0D2

0V

A – B

R

INPUT

V_0D2

V_OH

V_OL

1.5V

OUTPUT

t_PLH

t_PHL

f = 1MHz; t_R< 10ns; t_F< 10ns

t_{SKEW =}t_{PHL -}t_PLH

|

Figure 7. Receiver Propagation Delays

+3V

1.5V

RE

R

f = 1MHz; t < 10ns; t < 10ns

R

F

0V

5V

t

LZ

ZL

1.5V

Output normally LOW

Output normally HIGH

0.5V

V

IL

V

IH

R

1.5V

0V

t

HZ

ZH

Figure 8. Receiver Enable and Disable Times

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

5

DESCRIPTION

Receivers

TheSP481EandSP485Earehalf-duplexdiffer-

ential transceivers that meet the requirements of

RS-485 and RS-422. Fabricated with a Sipex

proprietary BiCMOS process, all three products

require a fraction of the power of older bipolar

designs.

The SP481E and SP485E receivers have differ-

ential inputs with an input sensitivity as low as

±200mV. Input impedance of the receivers is

typically 15kΩ (12kΩ minimum). A wide com-

mon mode range of -7V to +12V allows for large

ground potential differences between systems.

The receivers of the SP481E and SP485E have

a tri-state enable control pin. A logic LOW on

RE(pin2)willenablethereceiver, alogicHIGH

on RE (pin 2) will disable the receiver.

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

groundpotentialdifferences. BecauseRS-485is

a differential interface, data is virtually immune

to noise in the transmission line.

The receiver for the SP481E and SP485E will

operate up to at least 10Mbps. The receiver for

each of the two devices is equipped with the

fail-safe feature. Fail-safe guarantees that the

receiver output will be in a HIGH state when

the input is left unconnected.

Shutdown Mode

SP481E

Drivers

The driver outputs of the SP481E and SP485E

are differential outputs meeting the RS-485 and

RS-422 standards. The typical voltage output

swing with no load will be 0 Volts to +5 Volts.

Withworstcaseloadingof54Ωacrossthediffer-

ential outputs, the drivers can maintain greater

than 1.5V voltage levels. The drivers of the

SP481E, and SP485E have an enable control

line which is active HIGH. A logic HIGH on DE

(pin3)willenablethedifferentialdriveroutputs.

A logic LOW on DE (pin 3) will tri-state the

driver outputs.

TheSP481EisequippedwithaShutdownmode.

To enable the Shutdown state, both the driver

and receiver must be disabled simultaneously.

A logic LOW on DE (pin 3) and a logic HIGH on

RE (pin 2) will put the SP481E into Shutdown

mode. In Shutdown, supply current will drop to

typically 1µA.

ESD TOLERANCE

The SP481E Family incorporates ruggedized

ESD cells on all driver output and receiver input

pins. The ESD structure is improved over our

previous family for more rugged applications

and environments sensitive to electro-static dis-

chargesandassociatedtransients. Theimproved

ESD tolerance is at least ±15kV without damage

nor latch-up.

The transmitters of the SP481E and SP485E

will operate up to at least 10Mbps.

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

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

6

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

equipmentthatareaccessibletopersonnelduring

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 8. There are

two methods within IEC1000-4-2, the Air

Discharge method and the Contact Discharge

method.

The Human Body Model has been the generally

acceptedESDtestingmethodforsemiconductors.

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

duringnormalhandlingsuchasinmanufacturing

areaswheretheICstendtobehandledfrequently.

The IEC-1000-4-2, formerly IEC801-2, is

generallyusedfortestingESDonequipmentand

R

S

R

C

SW2

SW1

Device

Under

Test

DC Power

Source

C

S

Figure 7. ESD Test Circuit for Human Body Model

Contact-Discharge Module

R

S

R

V

C

SW2

SW1

Device

Under

Test

DC Power

Source

C

S

R

and R add up to 330Ω for IEC1000-4-2.

S

V

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

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

7

With the Air Discharge Method, an ESD voltage

is applied to the equipment under test (EUT)

throughair. Thissimulatesanelectricallycharged

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.

30A

15A

0A

t=0ns

t=30ns

t ➙

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

voltage stored in the capacitor is then applied

throughR_S, thecurrentlimitingresistor, ontothe

device under test (DUT). In ESD tests, the SW2

switch is pulsed so that the device under test

receives a duration of voltage.

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

handheldsystems,theESDchargecanbedirectly

dischargedtotheequipmentfromapersonalready

holdingtheequipment. Thecurrentistransferred

ontothekeypadortheserialportoftheequipment

directly andthentravelsthroughthePCBandfinally

to the IC.

FortheHumanBodyModel, thecurrentlimiting

resistor (R ) and the source capacitor (C ) are

1.5kΩ an 1^S00pF, respectively. For IEC-10^S00-4-

2,thecurrentlimitingresistor(R_S)andthesource

capacitor (C_S) are 330Ω an 150pF, respectively.

The higher C value and lower R_Svalue in the

IEC1000-4-2^Smodel are more stringent than the

HumanBodyModel. Thelargerstoragecapacitor

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.

The circuit model in Figures 7 and 8 represent

the typical ESD testing circuit used for all three

methods. TheC_SisinitiallychargedwiththeDC

power supply when the first switch (SW1) is on.

Now that the capacitor is charged, the second

switch(SW2)isonwhileSW1switchesoff. The

SP481E, SP485E

FAMILY

HUMAN BODY

MODEL

IEC1000-4-2

Air Discharge Direct Contact

Level

Driver Outputs

Receiver Inputs

±15kV

±8kV

4

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

8

PACKAGE: PLASTIC

DUAL–IN–LINE

(NARROW)

E1

E

D1 = 0.005" min.

(0.127 min.)

A1 = 0.015" min.

(0.381min.)

D

A = 0.210" max.

(5.334 max).

C

A2

Ø

L

B1

B

e

= 0.300 BSC

(7.620 BSC)

e = 0.100 BSC

(2.540 BSC)

A

ALTERNATE

END PINS

(BOTH ENDS)

DIMENSIONS (Inches)

Minimum/Maximum

(mm)

8–PIN

0.115/0.195

(2.921/4.953)

A2

0.014/0.022

(0.356/0.559)

B

0.045/0.070

B1

C

(1.143/1.778)

0.008/0.014

(0.203/0.356)

0.355/0.400

(9.017/10.160)

D

0.300/0.325

(7.620/8.255)

E

0.240/0.280

E1

L

(6.096/7.112)

0.115/0.150

(2.921/3.810)

0°/ 15°

(0°/15°)

Ø

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

9

PACKAGE: PLASTIC

SMALL OUTLINE (SOIC)

(NARROW)

E

H

h x 45°

D

A

Ø

A1

L

e

B

DIMENSIONS (Inches)

Minimum/Maximum

(mm)

8–PIN

A

A1

B

D

E

0.053/0.069

(1.346/1.748)

0.004/0.010

(0.102/0.249

0.014/0.019

(0.35/0.49)

0.189/0.197

(4.80/5.00)

0.150/0.157

(3.802/3.988)

e

0.050 BSC

(1.270 BSC)

H

h

0.228/0.244

(5.801/6.198)

0.010/0.020

(0.254/0.498)

L

0.016/0.050

(0.406/1.270)

Ø

0°/8°

(0°/8°)

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

10

ORDERING INFORMATION

Model

Temperature Range

Package

SP481ECN ....................................................... 0˚C to +70˚C............................................... 8-pin Narrow SOIC

SP481ECP........................................................ 0˚C to +70˚C...................................................8-pin Plastic DIP

SP481EEN...................................................... .-40˚C to +85˚C............................................. 8-pin Narrow SOIC

SP481EEP ...................................................... -40˚C to +85˚C .................................................8-pin Plastic DIP

SP485ECN ....................................................... 0˚C to +70˚C............................................... 8-pin Narrow SOIC

SP485ECP........................................................ 0˚C to +70˚C...................................................8-pin Plastic DIP

SP485EEN...................................................... -40˚C to +85˚C ............................................. 8-pin Narrow SOIC

SP485EEP ...................................................... -40˚C to +85˚C .................................................8-pin Plastic DIP

SP485EMN .................................................... -40˚C to +125˚C ............................................ 8-pin Narrow SOIC

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

Corporation

SIGNAL PROCESSING EXCELLENCE

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

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.

Rev. 5/16/03

SP481E Low Power Half-Duplex RS485 Transceivers

11


型号：	SP481E
厂家：	SIPEX CORPORATION
描述：	Enhanced Low Power Half-Duplex RS-485 Transceivers 增强型低功耗半双工RS- 485收发器
文件：	总11页 (文件大小：519K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

SP481E [SIPEX]

相关型号：

SP481ECN

SP481ECN-L

SP481ECN-L/TR

SP481ECN-L/TR

SP481ECN/TR

SP481ECP

SP481ECP-L

SP481ECS

SP481EEN

SP481EEN-L

SP481EEN-L

SP481EEN-L/TR