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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3483_00_0092

DESCRIPTION

  • RS-485 and RS-422 Transceiver
  • Operates from a single +3.3V Supply
  • Interoperable with +5.0V logic
  • Driver/Receiver Enable
  • Low Power Shutdown mode
  • -7V to +2V Common-Mode Input Voltage Range
  • Allows up to 32 transceivers on the serial bus
  • Compatibility with the industry standard 7576 pinout
  • Driver Output Short-Circuit Protection
  • Slew Rate Limited Driver for Low EMI SP3483 +3.3V Low Power Slew Rate Limited Half-Duplex RS-485 Transceiver The SP3483 device is part of a family of +3.3V low power half-duplex transceivers that meet the specifications of the RS-485 and RS-422 serial protocols. This device is pin-to-pin compat- ible with the Exar SP483 device as well as popular industry standards. The SP3483 features Exar's BiCMOS design allowing low power operation without sacrificing performance. The SP3483 is slew rate limited to reduce EMI and can meet the requirements of the RS-485 and RS-422 protocols up to 250kbps. TRUTH TABLES INPUTS OUTPUTS RE DE DI LINE CONDITION B A X No Fault 0 X 0 No Fault 0 X 0 X X Z Z Table . Transmit Function Truth Table INPUTS OUTPUTS RE DE A - B R 0 0 +0.2V 0 0 -0.2V 0 0 0 Inputs Open

0 X Z

Table 2. Receive Function Truth Table

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3483_00_0092 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. Input Voltages Output Voltages Power Dissipation (derate 6.4mW/ºC above +70ºC)

ELECTRICAL CHARACTERISTICS

TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DRIVER DC Characteristics Differential Output Voltage GND Vcc Volts Unloaded; R = ∞ ; Figure 1 Differential Output Voltage 2 Vcc Volts With Load; R = 50Ω (RS-422); Figure Differential Output Voltage .5 Vcc Volts With Load; R = 27Ω (RS-485); Figure Change in Magnitude of Driver Differential Output Voltage for Complimentary states

0.2 Volts R = 27Ω or R = 50Ω; Figure 1

3 Volts R = 27Ω or R = 50Ω; 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 +/-0 µA Applies to DE, DI, RE Driver Short Circuit Current, VOUT = HIGH +/-250 mA -7V ≤ VO ≤ +12V; Figure 8 Driver Short Circuit Current, VOUT = LOW +/-250 mA -7V ≤ VO ≤ +12V; Figure 8 DRIVER AC Characteristics Max. Transmission Rate 250 kbps RE = Vcc, DE = Vcc Driver Input to Output, tPLH 400 900 500 ns Figures 2 & 9 Driver Input to Output, tPHL 400 900 500 ns Figures 2 & 9 Differential Driver Skew 0 ns |tDO - tDO2|, Figures 2 and 0, Driver Rise or Fall Time 700 000 ns From 0%-90%; Figures 3 and 0

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3483_00_0092 PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS DRIVER (continued) AC Characteristics Driver Enable to Output High 700 300 ns Figures 4 and , Driver Enable to Output Low 690 300 ns Figures 5 and Driver Disable Time from High 80 20 ns Figures 5 and Driver Disable Time from Low 90 20 ns Figures 4 and RECEIVER DC Characteristics Differential Input Threshold -0.2 +0.2 Volts -7V ≤ VCM ≤ +12V Input Hysteresis 20 mV VCM = 0V Output Voltage High Vcc-0.4 Volts IO = -.5mA, VID = +200mV Output Voltage Low 0.4 Volts IO = +2.5mA, VID = -200mV Three-State ( High Impedance) Output Current +/- µA 0V ≤ VO ≤ Vcc; RE = Vcc Input Resistance 2 5 kΩ -7V ≤ VCM ≤ +12V Input Current (A, B); VIN = 2V +.0 mA DE = 0V, VCC = 0V or 3.6V, VIN = 2V Input Current (A, B); VIN = -7V -0.8 mA DE = 0V, VCC = 0V or 3.6V, VIN = -7V Short Circuit Current 7 60 mA 0V ≤ VCM ≤ VCC RECEIVER AC Characteristics Max. Transmission Rate 250 kbps RE = 0V, DE = 0V Receiver Input to Output, tRPLH 35 70 20 ns Figures 6 and 2 Receiver Input to Output, tRPHL 35 70 20 ns Figures 6 and 2 Differential Receiver Skew 50 ns |tRPHL - tRPLH|, Figures 6 and 2 Receiver Enable to Output Low 45 70 ns Figures 7 and 3; S Closed, S2 open Receiver Enable to Output High 45 70 ns Figures 7 and 3; S2 Closed, S open Receiver Disable from LOW 45 70 ns Figures 7 and 3; S Closed, S2 open Receiver Disable from High 45 70 ns Figures 7 and 3; S2 Closed, S open TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted.

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3483_00_0092 PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS Shutdown Timing Time to Shutdown 50 200 600 ns RE = 5V, DE = 0V Driver Enable from Shutdown to Output High 2000 ns Figures 4 and Driver Enable from Shutdown to Output Low 2000 ns Figures 5 and Receiver Enable from Shutdown to Output High 2500 ns Figures 7 and 3; S2 Closed, S open Receiver Enable from Shutdown to Output Low 2500 ns Figures 7 and 3; S Closed, S2 open POWER REQUIREMENTS Supply Current No Load 000 2000 µA RE, DI = 0V or VCC; DE = VCC 800 500 µA RE = 0V, DI = 0V or 5V; DE = 0V Shutdown Mode 0 µA DE = 0V, RE = VCC PIN FUNCTION Pin - 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 TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted.

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3483_00_0092 The SP3483 device is part of a family of +3.3V low power half-duplex transceivers that meet the specifications of the RS-485 and RS-422 serial protocols. This device is pin-to-pin compatible with the Exar SP483 device as well as popular industry standards. The SP3483 features Exar's BiCMOS pro- cess allowing low power operation without sacrificing performance. The RS-485 standard is ideal for multi-drop applications and for long-distance interfaces. RS-485 allows up to 32 drivers and 32 receiv- ers 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 +2V) common mode range to accommodate ground potential differ - ences. Because RS-485 is a differential interface, data is virtually immune to noise in the transmission line. Drivers The driver outputs of the SP3483 are dif- ferential outputs meeting the RS-485 and RS-422 standards. The typical voltage output swing with no load will be 0 Volts to +3.3 Volts. With worst case loading of 54Ω across the differential outputs, the drivers can maintain greater than .5V voltage levels. The drivers have an enable control line which is active HIGH. A logic HIGH on DE (pin 3) will enable the differential driver outputs. A logic LOW on the DE (pin 3) will force the driver outputs into high impedance (high-Z). The SP3483 has internally slew rate lim - ited driver outputs to minimize EMI. The transceivers will operate up to 250kbps. The 250mA ISC maximum limit on the driver output allows the SP3483 to withstand an infinite short circuit over the -7.0V to +12V common mode range without catastrophic damage to the IC. Receivers The SP3483 receiver has 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 +2V allows for large ground potential differences between sys - tems. The receiver of the SP3483 has a tri- state enable control input RE (Pin 2). A logic LOW on RE will enable the receiver, a logic HIGH on RE will disable the receiver. The receiver of the SP3483 will operate up to 250kbps. The receiver is equipped with the fail-safe feature. Fail-safe guar- antees that the receiver output will be in a HIGH state when the input is left uncon- nected (open circuit). Shutdown Mode The SP3483 is equipped with a Shutdown mode. To enable the shutdown state, both driver and receiver must be disabled simul- taneously. A logic LOW on DE (pin 3) and a Logic HIGH on RE (pin 2) will put the SP3483 into Shutdown mode. In Shutdown, supply current will drop to typically µA, 0µA maximum.

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3483_00_0092

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3483_00_0092

ORDERING INFORMATION

Model Temperature Range Package Types

REVISION HISTORy

06/23/04 -- Legacy Sipex Datasheet 0/09/2 .0.0 Convert to Exar Format. Update ordering information as a result of discontinued Lead type package options. Add new Figure 8 - Driver Short Circuit Current Limit Test Circuit. Correct type error for no load supply current. Notice EXAR Corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reliabil- ity. EXAR Corporation assumes no representation that the circuits are free of patent infringement. Charts and schedules contained herein are only for illustration purposes and may vary depending upon a user's specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized ; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. Copyright 202 EXAR Corporation Datasheet January 202 Send your serial transceiver technical inquiry with technical details to: serialtechsupport@exar.com Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. Note: /TR = Tape and Reel