SP3494EN-L EXAR | Alldatasheet

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Technical content

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3494_00_0702

DESCRIPTION

  • Operates From A Single +3.3V Supply
  • Interoperable With +5.0V Logic
  • +/-200mV Receiver Input Sensitivity
  • -7V to +2V Common-Mode Input Voltage Range
  • Allows Up To 32 transceivers On The Serial Bus
  • Driver/Receiver Enable Lines
  • 0µA Low-Power Shutdown Mode
  • Compatibility with the MAX3486 and 7576 Industry Standard Pinout SP3494 +3.3V Low Power RS-485/RS-422 Transceiver The SP3494 device is a +3.3V low power half-duplex transceiver that meets the specifications of the RS-485 and RS-422 serial protocols. This device is pin-to-pin compatible with the Exar SP348 device as well as other popular industry standards. The SP3494 features the Exar BiCMOS process, allowing low power operation without sacrificing performance. The partially slew-rate limited drivers minimize EMI and reduce reflections caused by improperly terminated cables allowing error-free data transmission.The SP3494 is a half-duplex partially slew-rate limited transceiver that will deliver a data transmission rate up to 2.5Mbps. The SP3494 is equipped with a low-power shutdown mode and driver/receiver high-Z enable lines.

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3494_00_0702 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 6.90mW/ºC above +70ºC)

ELECTRICAL CHARACTERISTICS

TAMB = TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS SP3494 DRIVER DC Characteristics Differential Output Voltage GND Vcc Volts Unloaded; R = ∞Ω ; 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 SP3494 DRIVER AC Characteristics Maximum Data Rate 2.5 Mbps RE = VCC, DE = VCC Driver Input to Output, tPLH 20 45 75 ns Figures 2 & 9 Driver Input to Output, tPHL 20 45 75 ns Figures 2 & 9 Differential Driver Skew 0 ns |tDO- tDO2|, Figures 2 and 0 Driver Rise or Fall Time 30 70 ns From 0%-90%; Figures 3 and 0

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3494_00_0702 PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS SP3494 DRIVER AC Characteristics continued Driver Enable to Output High 52 20 ns Figures 4 and Driver Enable to Output Low 60 20 ns Figures 5 and Driver Disable Time from Low 40 20 ns Figures 5 and Driver Disable Time from High 60 20 ns Figures 4 and SP3494 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 VID = +200mV, -.5mA Output Voltage LOW 0.4 Volts VID = -200mV, 2.5mA 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 SP3485 RECEIVER AC Characteristics Maximum Data Rate 2.5 Mbps RE = 0V, DE = 0V Receiver Input to Output, tPLH 40 70 00 ns Figures 6 and 2 Receiver Input to Output, tPHL 40 70 00 ns Figures 6 and 2 Differential Receiver Skew 0 ns tRSKEW = |tRPHL- tRPLH|, Figures 6 and 2 Receiver Enable to Output Low 35 60 ns Figures 7 and 3, S closed, S2 open Receiver Enable to Output High 35 60 ns Figures 7 and 3, S2 closed, S open Receiver Disable from Low 35 60 ns Figures 7 and 3, S closed, S2 open Receiver Disable from High 35 60 ns Figures 7 and 3, S2 closed, S open TAMB = 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 SP3494_00_0702 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 - Non-Inverting Driver Output/Receiver Input Pin 7 - B - Inverting Driver Output/Receiver Input Pin 8 - Vcc - Positive Supply +3.3V +/-5% Pin Function SP3494 TAMB = TMIN to TMAX and VCC = +3.3V +/-5% unless otherwise noted. PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS SP3494 SHUTDOWN TIMING Time to Shutdown 50 75 200 ns RE = 3.3V, DE =0V Driver Enable from Shutdown to Output High 65 50 ns Figures 4 and Driver Enable from Shutdown to Output Low 65 50 ns Figures 5 and Receivers Enabled from Shutdown to Output High 50 200 ns Figures 7 and 3, S2 closed, S open Receivers Enabled from Shutdown to Output Low 50 200 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 Supply Current , No Load 800 500 µA RE = 0V, DI = 0V or VCC, DE = 0V Shutdown Mode 0 µA DE = 0V, RE = VCC

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3494_00_0702 The SP3494 is a +3.3V low power half- duplex transceiver that meets the electrical specifications of the RS-485 and RS-422 serial protocols. This device is pin-to-pin compatible with the Exar SP348 and SP48 devices as well as popular industry standards such as the MAX3486 and the 7576. The SP3494 feature Exar's BiCMOS process allowing low power operation without sacrificing performance. The SP3494 has a partially slew rate limited driver with a data transmission rate of 2.5Mbps. Driver The driver outputs of the SP3494 are dif- ferential outputs. The typical voltage output swing with no load will be 0 volts to V CC. With worst case loading of 54Ω across the differential outputs, the driver can maintain greater than .5V voltage levels. The SP3494 driver has 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 to high impedance (high-Z). The SP3494 driver will operate up to 2.5Mbps. In addition to adhering to the 250mA ISC maximum limit on the driver out- put, the driver output short-circuit protection will allow the device to withstand an infinite short circuit over the -7.0V to +2V common mode range without damage. Receiver The receiver has differential inputs with an input sensitivity of ±200mV. Input imped - ance of the receiver is typically 15kΩ (12kΩ minimum). A wide common mode range of -7V to +2V allows for large ground potential differences between systems. The receiver is equipped with a fail-safe feature which guarantees that the receiver output will be in a high state when the input is left uncon- nected. The receiver of the SP3494 operate up to 2.5Mbps. The receiver of the SP3494 has an enable control line which is active LOW. A logic LOW on RE (pin 2) of the SP3494 will enable the differential receiver. A logic HIGH on RE (pin 2) will disable the receiver. The SP3494 is equipped with a shutdown mode. To enable the shutdown state, both the driver and receiver must be disable simultaneously. A logic LOW on DE (pin 3) and a logic HIGH on RE (pin 2) will put the SP3494 into shutdown. In shutdown, the supply current will drop to less than 0µA. 0 0 +0.2V 0 0 -0.2V 0 0 0 Inputs Open

0 X Z

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

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3494_00_0702

Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com SP3494_00_0702

ORDERING INFORMATION

Model Temperature Range Package Types

REVISION HISTORy

0/5/02 -- Legacy Sipex Datasheet 07/0/2 .0.0 Convert to Exar Format. Update ordering information and add new Figure 8 - Driver Short Circuit Current Limit Test Circuit. Remove EOL device SP3493. 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 July 202 For technical support please email Exar's Serial Technical Support group at: serialtechsupport@exar.com Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. Note: /TR = Tape and Reel, -L = RoHS Packaging