Datasheet

ManualsBrandsSTMICROELECTRONICS ManualsInterface ICsInterface IC - transceivers RS422, RS485 1/1 SO 8

1/13June 2003

■ LOW QUIESCENT CURRENT: 300µA

■ DESIGNED FOR RS-485 INTERFACE

APPLICATIONS

■ -7V TO 12V COMMON MODE INPUT

VOLTAGE RANGE

■ DRIVER MAINTAINS HIGH IMPEDANCE IN

3-STATEORWITHTHEPOWEROFF

■ 70mV TYPICAL INPUT HYSTERESIS

■ 30ns PROPAGATION DELAYS, 5ns SKEW

■ OPERATE FROM A SINGLE 5V SUPPLY

■ CURRENT LIMITING AND THERMAL

SHUTDOWN FOR DRIVER OVERLOAD

PROTECTION

■ ALLOWS UP TO 64 TRANSCEIVERS ON

THE BUS

DESCRIPTION

The ST485 is al low power transceiver for RS-485

and RS-422 communication. Each part contains

one driver and one receiver.

This transceiver draw 300µA (typ.) of supply

current when unloaded or fully loaded with

disabled drivers.

It operates from a single 5V supply.

Driver is short-circuit current limited and is

protected against excessive power dissipation by

thermal shutdown circuitry that placed the driver

outputs into a high-impedance state. .

The ST485 is designed for bi-directional data

communications on multipoint bus transmission

line (half-duplex applciations).

The ST485 is available in three temperature

range: commercial (0°C to 70°C), industrial (-40°C

to 850°C) and automotive (-55°C to 125°C)

ORDERING CODES

Type

Temperature

Range

Package Comments

ST485CN 0 to 70 °C DIP-8 50parts per tube / 40tube per box

ST485BN -40 to 85 °C DIP-8 50parts per tube / 40tube per box

ST485XN -55 to 125 °C DIP-8 50parts per tube / 40tube per box

ST485CD 0 to 70 °C SO-8 (Tube) 100parts per tube / 20tube per box

ST485BD -40 to 85 °C SO-8 (Tube) 100parts per tube / 20tube per box

ST485XD -55 to 125 °C SO-8 (Tube) 100parts per tube / 20tube per box

ST485CDR 0 to 70 °C SO-8 (Tape & Reel) 2500 parts per reel

ST485BDR -40 to 85 °C SO-8 (Tape & Reel) 2500 parts per reel

ST485XDR -55 to 125 °C SO-8 (Tape & Reel) 2500 parts per reel

ST485

LOW POWER

RS-485/RS-422 TRANSCEIVER

DIP SOP

Summary of content (13 pages)

PAGE 1
ST485 LOW POWER RS-485/RS-422 TRANSCEIVER ■ ■ ■ ■ ■ ■ ■ ■ ■ LOW QUIESCENT CURRENT: 300µA DESIGNED FOR RS-485 INTERFACE APPLICATIONS -7V TO 12V COMMON MODE INPUT VOLTAGE RANGE DRIVER MAINTAINS HIGH IMPEDANCE IN 3-STATE OR WITH THE POWER OFF 70mV TYPICAL INPUT HYSTERESIS 30ns PROPAGATION DELAYS, 5ns SKEW OPERATE FROM A SINGLE 5V SUPPLY CURRENT LIMITING AND THERMAL SHUTDOWN FOR DRIVER OVERLOAD PROTECTION ALLOWS UP TO 64 TRANSCEIVERS ON THE BUS DESCRIPTION The ST485 is al low power transceiver for RS-485
PAGE 2
ST485 PIN CONFIGURATION PIN DESCRIPTION PlN N° SYMBOL 1 2 3 4 5 6 7 RO RE DE DI GND A B VCC 8 NAME AND FUNCTION Receiver Output Receiver Output Enable Driver Output Enable Driver Input Ground Non-inverting Receiver Input and Non-inverting Driver Output Inverting Receiver Input and Inverting Driver Output Supply Voltage TRUTH TABLE (RECEIVER) TRUTH TABLE (DRIVER) INPUTS OUTPUTS INPUTS OUTPUT RE DE DI B A RE DE A-B RO X X X H H L H L X L H Z H L Z L L L H L L L L ≥ +0.2V ≤ -0.
PAGE 3
ST485 DC ELECTRICAL CHARACTERISTICS (VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C) (See Note 1) Value Symbol Parameter Test Conditions -40 to 85 °C Min. VOD1 VOD2 ∆VOD Differential Driver Output (No Load) Differential Driver Output (With Load) Typ. -55 to 125 °C Max. Min. 5 RL = 27Ω (RS-485) (See Fig.1) RL = 50Ω (RS-422) (See Fig.1) 1.5 5 5 1.4 Unit Max. 5 V 5 5 V V RL = 27Ω or 50Ω (See Fig. 1) 0.2 0.
PAGE 4
ST485 DRIVER SWITCHING CHARACTERISTICS (VCC = 5V ± 5%, TA = TMIN to TMAX , unless otherwise specified. Typical values are referred to TA = 25°C) (See Note 1) Value Symbol Parameter Test Conditions Typ. Max. 30 60 70 ns 5 10 10 ns 15 40 45 ns S2 = Closed 70 90 90 ns S1 = Closed 70 90 90 ns S1 = Closed 70 90 90 ns S2 = Closed 70 90 90 ns RDIFF = 54Ω CL1 = CL2 = 100pF (See Fig.
PAGE 5
ST485 TEST CIRCUITS AND TYPICAL CHARACTERISTICS Figure 1 : Driver DC Test Load Figure 3 : Drive/Receiver Timing Test Circuit Figure 2 : Receiver Timing Test Load Figure 4 : Driver Timing Test Load 5/13
PAGE 6
ST485 Figure 5 : Driver Propagation Delay Figure 6 : Driver Enable and Disable Time 6/13
PAGE 7
ST485 Figure 7 : Receiver Propagation Delay Figure 8 : Receiver Enable and Disable Time 7/13
PAGE 8
ST485 Figure 9 : Receiver Output Current vs Output Low Voltage Figure 12 : Driver Output Current vs Output High Voltage Figure 10 : Receiver Output Current vs Output High Voltage Figure 13 : Supply Current vs Temperature Figure 11 : Driver Output Current vs Output Low Voltage Figure 14 : Receiver High Level Output Voltage vs Temperature 8/13
PAGE 9
ST485 Figure 15 : Receiver Low Level Output Voltage vs Temperature Figure 16 : Differential Driver Output Voltage vs Temperature 9/13
PAGE 10
ST485 Plastic DIP-8 MECHANICAL DATA mm. inch DIM. MIN. A TYP MAX. MIN. 3.3 TYP. MAX. 0.130 a1 0.7 B 1.39 1.65 0.055 0.065 B1 0.91 1.04 0.036 0.041 b b1 0.028 0.5 0.38 0.020 0.5 D 0.015 0.020 9.8 0.386 E 8.8 0.346 e 2.54 0.100 e3 7.62 0.300 e4 7.62 0.300 F 7.1 0.280 I 4.8 0.189 L Z 3.3 0.44 0.130 1.6 0.017 0.
PAGE 11
ST485 SO-8 MECHANICAL DATA DIM. mm. MIN. TYP inch MAX. MIN. TYP. MAX. A 1.35 1.75 0.053 0.069 A1 0.10 0.25 0.04 0.010 A2 1.10 1.65 0.043 0.065 B 0.33 0.51 0.013 0.020 C 0.19 0.25 0.007 0.010 D 4.80 5.00 0.189 0.197 E 3.80 4.00 0.150 0.157 e 1.27 0.050 H 5.80 6.20 0.228 0.244 h 0.25 0.50 0.010 0.020 L 0.40 1.27 0.016 0.050 k ddd 8˚ (max.) 0.1 0.
PAGE 12
ST485 Tape & Reel SO-8 MECHANICAL DATA mm. inch DIM. MIN. A MAX. MIN. 330 13.2 TYP. MAX. 12.992 C 12.8 D 20.2 0.795 N 60 2.362 T 12/13 TYP 0.504 22.4 0.519 0.882 Ao 8.1 8.5 0.319 0.335 Bo 5.5 5.9 0.216 0.232 Ko 2.1 2.3 0.082 0.090 Po 3.9 4.1 0.153 0.161 P 7.9 8.1 0.311 0.
PAGE 13
ST485 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice.