Linear Technology LTC489, LTC488 Datasheet

LTC488/LTC489

Quad RS485 Line Receiver

EATU

F

■

Low Power: ICC = 7mA Typ

■

Designed for RS485 or RS422 Applications

■

Single 5V Supply

■

–7V to 12V Bus Common Mode Range Permits ±7V

RE

S

Ground Difference Between Devices on the Bus

■

60mV Typical Input Hysteresis

■

Receiver Maintains High Impedance in Three-State or
with the Power Off

■

28ns Typical Receiver Propagation Delay

■

Pin Compatible with the SN75173 (LTC488)

■

Pin Compatible with the SN75175 (LTC489)

U

O

PPLICATI

A

■

Low Power RS485/RS422 Receivers

■

Level Translator

S

DUESCRIPTIO

The LTC®488 and LTC489 are low power differential bus/
line receivers designed for multipoint data transmission
standard RS485 applications with extended common mode
range (12V to –7V). They also meet the requirements of
RS422.

The CMOS design offers significant power savings over its
bipolar counterpart without sacrificing ruggedness against
overload or ESD damage.

The receiver features three-state outputs, with the receiver
output maintaining high impedance over the entire com­mon mode range.

The receiver has a fail-safe feature which guarantees a
high output state when the inputs are left open.

Both AC and DC specifications are guaranteed 4.75V to

5.25V supply voltage range.

, LTC and LT are registered trademarks of Linear Technology Corporation.

A

U

O

PPLICATITYPICAL

EN

EN

2

DI

DI

DRIVER
1/4 LTC486

EN12

DRIVER
1/4 LTC487

120Ω

4000 FT 24 GAUGE TWISTED PAIR

120Ω

4000 FT 24 GAUGE TWISTED PAIR

120Ω

120Ω

1

2

1

EN

4

RECEIVER
1/4 LTC488

EN12

4

RECEIVER
1/4 LTC489

EN

12

3

RO

3

RO

LTC488/9 TA01

1

LTC488/LTC489

A

W

O

LUTEXI T

S

A

WUW

ARB

U
G

I

(Note 1)

S

Supply Voltage (VCC) .............................................. 12V

Control Input Currents ........................ – 25mA to 25mA

Control Input Voltages ................ –0.5V to (VCC + 0.5V)

Receiver Input Voltages ........................................ ±14V

Receiver Output Voltages ........... – 0.5V to (VCC + 0.5V)

WU

/

PACKAGE

1

B1

2

A1

3

RO1

4

EN

5

RO2

6

A2

7

B2

8

GND

N PACKAGE

16-LEAD PLASTIC DIP

T

= 150°C, θJA = 70°C/W (N PKG)

JMAX

= 150°C, θJA = 90°C/W (S PKG)

T

JMAX

O

TOP VIEW

R

R

16-LEAD PLASTIC SOL

RDER I FOR ATIO

ORDER PART

V

16
15

R

14
13
12
11
10

R

9

S PACKAGE

CC

B4
A4
RO4
EN
RO3
A3
B3

NUMBER

LTC488CN
LTC488CS
LTC488IN
LTC488IS

Operating Temperature Range

LTC488C/LTC489C ................................. 0°C to 70°C

LTC488I/LTC489I .............................. –40°C to 85°C

Storage Temperature Range ................ – 65°C to 150°C

Lead Temperature (Soldering, 10 sec)................. 300°C

U

TOP VIEW

1

B1
A1

RO1

EN12

RO2

A2
B2

GND

N PACKAGE

16-LEAD PLASTIC DIP

R

2
3
4
5
6

R

7
8

T

= 150°C, θJA = 70°C/W (N PKG)

JMAX

= 150°C, θJA = 90°C/W (S PKG)

T

JMAX

V

16

CC

B4

15

R

R

16-LEAD PLASTIC SOL

14
13
12
11
10

9

S PACKAGE

A4
RO4
EN34
RO3
A3
B3

ORDER PART

NUMBER

LTC489CN
LTC489CS
LTC489IN
LTC489IS

Consult factory for Military grade parts.

LECTRICAL C CHARA TERIST

E

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

INH

V

INL

I

IN1

I

IN2

V

TH

∆V

TH

V

OH

V

OL

I

OZR

I

CC

RINReceiver Input Resistance –7V ≤ VCM ≤ 12V, VCC = 0V ● 12 kΩ
I

OSR

t

PLH

t

PHL

t

SKD

Input High Voltage EN, EN, EN12, EN34 ● 2.0 V
Input Low Voltage EN, EN, EN12, EN34 ● 0.8 V
Input Current EN, EN, EN12, EN34 ● ±2 µA
Input Current (A, B) VCC = 0V or 5.25V, VIN = 12V ● 1.0 mA

Differential Input Threshold Voltage for Receiver –7V ≤ VCM ≤ 12V ● – 0.2 0.2 V
Receiver Input Hysteresis VCM = 0V 60 mV
Receiver Output High Voltage IO = – 4mA, VID = 0.2V ● 3.5 V
Receiver Output Low Voltage IO = 4mA, VID = – 0.2V ● 0.4 V
Three-State Output Current at Receiver VCC = Max 0.4V ≤ VO ≤ 2.4V ● ±1 µA
Supply Current No Load, Digital Pins = GND or V

Receiver Short-Circuit Current 0V ≤ VO ≤ V
Receiver Input to Output CL = 15pF (Figures 1, 3) ● 12 28 55 ns
Receiver Input to Output CL = 15pF (Figures 1, 3) ● 12 28 55 ns
| t

– t

PLH

Differential Receiver Skew

|C

PHL

VCC = 5V (Notes 2, 3), unless otherwise noted.

ICSCD

= 0V or 5.25V, VIN = – 7V ● – 0.8 mA

V

CC

● 710 mA

CC

CC

= 15pF (Figures 1, 3) 4 ns

L

● 785mA

2

LTC488/LTC489

OUTPUT VOLTAGE (V)

0

0

OUTPUT CURRENT (mA)

16

1.0

488 G04

8

0.5 1.5

24

32

2.0

4

12

20

28

36

LECTRICAL C CHARA TERIST

E

VCC = 5V ± 5% (Notes 2, 3), unless otherwise noted.

ICSCD

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

t

ZL

t

ZH

t

LZ

t

HZ

The ● denotes specifications that apply over the operating temperature
range.

Note 1: Absolute Maximum Ratings are those beyond which the safety of
the device may be impaired.

Receiver Enable to Output Low CL = 15pF (Figures 2, 4) S1 Closed ● 30 60 ns
Receiver Enable to Output High CL = 15pF (Figures 2, 4) S2 Closed ● 30 60 ns
Receiver Disable from Low CL = 15pF (Figures 2, 4) S1 Closed ● 30 60 ns
Receiver Disable from High CL = 15pF (Figures 2, 4) S2 Closed ● 30 60 ns

Note 2: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to device ground unless
otherwise specified.

Note 3: All typicals are given for V

= 5V and TA = 25°C.

CC

UW

LPER

F

O

R

ATYPICA

Receiver Output Low Voltage vs
Temperature at I = 8mA

0.9

0.8

0.7

0.6

0.5

0.4

0.3

OUTPUT VOLTAGE (V)

0.2

0.1

0

–25 125

–50

0
TEMPERATURE (°C)

50

25

CCHARA TERIST

E

C

75 100

488 G01

ICS

4.8

4.6

4.4

4.2

4.0

3.8

3.6

OUTPUT VOLTAGE (V)

3.4

3.2

3.0

Receiver Output High Voltage vs
Temperature at I = 8mA

–25 125

–50

0

25

TEMPERATURE (°C)

50

75 100

488 G02

Receiver Output High Voltage vs
Output Current at TA = 25°C

–18

–16

–14

–12

–10

–8

–6

OUTPUT CURRENT (mA)

–4

–2

0

5

43

OUTPUT VOLTAGE (V)

Receiver Output Low Voltage vs
Output Current at TA = 25°C

2

488 G03

3

LTC488/LTC489

TEMPERATURE (°C)

–50

5.4

SUPPLY CURRENT (mA)

6.2

50

488 G07

5.8

–25 125

6.6

7.0

0

25

75 100

LPER

F

O

R

ATYPICA

UW

CCHARA TERIST

E

C

ICS

TTL Input Threshold vs
Temperature

1.63

1.61

1.59

1.57

INPUT THRESHOLD VOLTAGE (V)

1.55
–50

0

–25 125

25

TEMPERATURE (°C)

U

75 100

50

488 G05

UU

Receiver |t
Temperature

5

4

3

TIME (ns)

2

1

–50

PLH

0

–25 125

TEMPERATURE (°C)

PI FU CTIO S

B 1 (Pin 1) Receiver 1 Input.
A1 (Pin 2) Receiver 1 Input.
RO1 (Pin 3) Receiver 1 Output. If the receiver output is

enabled, then if A > B by 200mV, RO1 will be high. If
A < B by 200mV, then RO1 will be low.

EN (Pin 4) (LTC488) Receiver Output Enabled. See
Function Table for details.

EN12 (Pin 4) (LTC489) Receiver 1, Receiver 2 Output
Enabled. See Function Table for details.

RO2 (Pin 5) Receiver 2 Output. Refer to RO1.
A2 (Pin 6) Receiver 2 Input.
B2 (Pin 7) Receiver 2 Input.
GND (Pin 8) Ground Connection.

– t

| vs

PHL

25

75 100

50

488 G06

Supply Current vs Temperature

B3 (Pin 9) Receiver 3 Input.
A3 (Pin 10) Receiver 3 Input.
RO3 (Pin 11) Receiver 3 Output. Refer to RO1.
EN (Pin 12)(LTC488) Receiver Output Disabled. See

Function Table for details.
EN34 (Pin 12)(LTC489) Receiver 3, Receiver 4 output

enabled. See Function Table for details.

RO4 (Pin 13) Receiver 4 Output. Refer to RO1.
A4 (Pin 14) Receiver 4 Input.
B4 (Pin 15) Receiver 4 Input.
V

(Pin 16) Positive Supply; 4.75V ≤ VCC ≤ 5.25V.

CC

4