SP487

Quad RS-485/RS-422 Line Drivers

Description

The SP486 and SP487 are low–power quad differential line drivers meeting RS-485 and RS-422 standards. The SP486 features a common driver enable control; the SP487 provides independent driver enable controls for each pair of drivers. Both feature tri–state outputs and wide common–mode input range. Both are available in 16–pin plastic DIP and SOIC packages.

For technical support or help choosing a product please email Exar’s Serial Technical Support group at:  serialtechsupport@exar.com.
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Features

  • RS-485 or RS-422 Applications
  • Quad Differential Line Drivers
  • Tri–state Output Control
  • 40ns Typical Driver Propagation Delays
  • 5ns Skew
  • –7V to +12V Common Mode Output Range
  • 100uA Supply Current
  • Single +5V Supply Operation
  • Pin Compatible with SN75172, SN75174, LTC486, and LTC487

Application

Design Tools

Packaging

Pkg Code Details Quantities Dimensions PDF
PDIP16
  • JEDEC Reference: MS-001
  • MSL Pb-Free: n/a
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 69.9ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: n/a
  • Quantity per Tube: 25
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): n/a
  • Tape & Reel Unit Orientation: n/a
  • Dimensions: inch
  • Length: 0.75
  • Width: 0.25
  • Thickness: 0.13
  • Lead Pitch: 0.10
WSOIC16
  • JEDEC Reference: MS-013
  • MSL Pb-Free: L3 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 69.1ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: 47
  • Quantity per Reel: 1500
  • Quantity per Tube: 47
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 330 x 16 x 12
  • Tape & Reel Unit Orientation: Quadrant 1
  • Dimensions: mm
  • Length: 10.30
  • Width: 7.50
  • Thickness: 2.65
  • Lead Pitch: 1.27

Parts & Purchasing

Part Number Pkg Code RoHS Min Temp Max Temp Status Buy Now Order Samples
SP487CN OBS
SP487CN-L OBS
SP487CP OBS
SP487CP-L OBS
SP487CT WSOIC16 0 70 OBS Suggested:
SP487CT-L
SP487CT/TR WSOIC16 0 70 OBS Suggested:
SP487CT-L/TR
SP487CT-L WSOIC16 0 70 Active
SP487CT-L/TR WSOIC16 0 70 Active
SP487ES PDIP16 -40 85 OBS
SP487ET WSOIC16 -40 85 OBS Suggested:
SP487ET-L
SP487ET/TR WSOIC16 -40 85 OBS Suggested:
SP487ET-L/TR
SP487ET-L WSOIC16 -40 85 OBS Suggested:
SP487CT-L/TR
SP487ET-L/TR WSOIC16 -40 85 OBS Suggested:
SP487CT-L/TR
Show obsolete parts
Part Status Legend
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.

Quality Documents

Part NumberMDS
SP487CT-LDownload
Additional Quality Documentation may be available, please contact customersupport@maxlinear.com.
Distribution Date Description File
08/10/2017 Qualification of alternate assembly subcon, ANST. PCN 17-0625-01 ANST-1033.pdf
07/11/2017 Product Discontinuation Notification PDN_17-0626-02-1033.pdf
11/16/2015 Updated information subsequent to original published PCN 15-0625-02 on 09/29/2015. Addendum: Update to package marking. PCN 15-0625-02A UPDATE-1033.pdf
09/29/2015 Greatek as alternate assembly site Addition of an alternate production site, Greatek, Taiwan for 16L, 24L and 28L SOICW PCN 15-0625-02 16L-24L-28L SOICW Greatek-1033.pdf
10/03/2013 Qualification of SiO2 5KÅ + SiN 7KÅ passivation to replace PSG 10KÅ passivation. Material & Process Changes. PCN_13-0522-02-1033.pdf
09/24/2012 Material Change - Bond wire is changed from gold to copper. To update our manufacturing to be compatible with current industry standards and maintain capacity. PCN_12-0914-01-1033.pdf
05/10/2011 Product Discontinuation Notice. Discontinued due to low market demand. PDN_11-0510-01-1033.pdf
07/30/2010 Process Change. Capacity enhancement. PCN_10-0715-01-1033.pdf
05/19/2009 Notice of Obsolescence Discontinued by Exar Corporation due to low market demand PDN 081126-01-1033.pdf
11/26/2008 Notice of Obsolescence Package Discontinuation Notice PDN_081126-01-1033.pdf
09/29/2008 Product assembly of 14/16/18 lead PDIP families will be transferred from Unisem-Ipoh (Malaysia) to Unisem-Batam (Indonesia). Business consolidation and use of environmental friendly material. pcn08-0929-01-1033.pdf
04/20/2007 Migrating product from Episil wafer foundry’s 5um CMOS process to Silan, Hangzhou, China, foundry’s 5um CMOS process. To assure continuity of supply of wafers for these products. PCN_07-0426-02-1033.pdf
02/02/2006 Announcing transfer of certain Power Management and Interface Products from Hillview fabrication and facility to wafer foundary Silan. See attached Product List Power Management and Interface products as listed are being transfer to external wafer foundry, due to cessation of operations of the sipex Hillview Fabrication manufacturing site PCN-06-0130-18-1033.pdf
01/17/2006 Announcing discontinuance of certain low volume Power Management and Interface Products and last dates to place lifetime. buy orders Low Volume Power Management and Interface products are being discontinued due to cessation of operations of the Sipex Hillview Fabrication manufacturing site. PCN-06-0117-01-1033.pdf

Frequently Asked Questions

For RS-232 it is 50 feet (15 meters), or the cable length equal to a capacitance of 2500 pF, at a maximum transmission rate of 19.2kbps. When we reduce the baud rate, it allows for longer cable length. For Example:

 

Baud Rate (bps)

Maximum RS-232 Cable Length (ft)

19200

50

9600

500

4800

1000

2400

3000

 
For RS-485 / RS-422 the data rate can exceed 10Mbps depending on the cable length. A cable length of 15 meters (50 feet) will do a maximum of 10Mbps. A cable length of 1200 meters (4000 feet) will do a maximum of 90kbps over 24 AWG gauge twisted pair cable (with 10 pF/ft). Refer to Annex A TIA/EIA-422-B.
 
 
As RS-422/RS-485 uses differential signaling, it is more immune to noise and longer cables and/or high data rates can be used, especially in noisy environments. Also, RS-485 allows for multi-point operation, up to 32 unit loads. Transceivers may use a fraction of a unit load, increasing the number of devices on the bus. For example, the XR33152 receiver input impedance is at least 120 k, which equates to 1/10 of a unit load. Therefore, XR33152 allows more than 320 devices (32 x 10) on the bus.
Yes, this is possible using one RS-485 transceiver. The microcontrollers will have to be addressable and have tri-state outputs. The RS-485 device can be controlled by the host via the DE/RE pin. The micros will have to be in either receiving mode or tri-state mode when the RS-485 transceiver is transmitting data. When the host transmits it will have to send an address to the specific micro. If any micro transmits the transceiver will have to be in receiving mode and all other micros will have to be in receive or tri-state. So the host would have to initiate this sequence by addressing the micro first then switch the transceiver to receive.
The half duplex system would have a bus with one transceiver and multiple microcontrollers all tied to the bus. For 5V systems the SP485 family can be used. For 3V systems the SP3070 family can be used. The require speed will determine the part number. The SP3078 part runs up to speeds of 16Mbps.  See the parametric search on https://www.exar.com/products/interface/serial-transceivers/rs485-422 for more options.
Care must be taken to assure the transceiver can drive the multiple micros in RX mode.
ESD tests are “destructive tests.” The part is tested until it suffers damage. Therefore parts cannot be 100% tested in production, instead a sample of parts are characterized during the product qualification. The test procedure consists of “zapping” pins with a given voltage using the appropriate model and then running the part through electrical tests to check for functionality or performance degradation.
ESD is caused by static electricity. In order for an ESD event to occur there must be a buildup of static charge. Very high charge levels are actually quite rare. In a normal factory environment, taking basic ESD precautions (grounding-straps, anti-static smocks, ionizers, humidity control, etc.) static levels can be kept below a few tens of volts. In an uncontrolled environment, like an office, static levels rarely get above 2000 volts. Under some worstcase conditions (wearing synthetic fabrics, rubbing against synthetic upholstered furniture, extremely low humidity)
levels can go as high as 12 to 15 thousand volts. Actually to get to 15000 volts or higher you would need to be in an uncomfortably dry environment (humidity below 10%) otherwise static charge will naturally dissipate through corona discharge. It would definitely be considered a “bad hair day.” Humans can generally feel a static shock only above 3000 volts. A discharge greater than 4000 volts can cause an audible “pop.” But repeated lower level discharges can be imperceptible and still may have a cumulative damaging effect on sensitive ICs. All ICs, even those with robust protection, can be damaged if they are hit hard enough or often enough.
Most ICs in a typical system are at greatest risk of ESD damage in the factory when the PCB is assembled and the system is being built. After the system is put together they are soldered onto the PCB and shielded within a metal or plastic system enclosure. Interface ICs are designed to attach to an external connector that could be exposed to ESD when a cable is plugged in or when a person or object touches the connector. These interface pins are most likely to see ESD exposure and therefore benefit from additional protection.
Actually the letter “E” could have two different meanings, depending on where it is in the part number. Most of our interface devices are available in different temperature grades. Commercial temperature (0 to 70C) has a “C” after the numeric part number. Industrial-extended temperature (-40 to +85C) use the letter E. So for example SP485CN is commercial and SP485EN is industrial. The second letter indicates the package type, in this case N for narrow-SOIC. Another E in the suffix indicates that this device has enhanced ESD protection, typically of ±15000Volts on the interface pins. Devices that do not have the enhanced ESD still contain built-in ESD protection of at least ±2000Volts. For example the SP485ECN is ESD rated up to ±15kV, and the SP485CN is rated for ±2kV HBM.
The best way to determine this is to go to exar.com and type the part into the search function. At or near the top of the results you should see something that looks like
 
 

In this example, we looked for XRA1201. When you hover over it, it will turn grey and you can click anywhere in the grey box. This brings you to the product page. For example:

 
 

Click on Parts & Purchasing, highlighted in yellow above. The screen changes to:

 

Notice the status column and the “Show obsolete parts” link:

 

A legend tells you the definition of the different statuses. Click on the “Show obsolete parts” link to see EOL or OBS part numbers along with the Active part numbers:

 
 

Another method to find out if a part is OBS or EOL is to click on SUPPORT:

 

And then Product Change Notifications

 
 

Type the part into the search, and click on one of the part numbers from the drop down menu. Then you can look for the Product Discontinuation Notice, which generally is at the top of the list, for example:

 
 

If you see this, it tells you that this particular orderable part has been discontinued and when the last order date is, or was. If you click on the file, then you can view the notice we sent about this if you purchased the part in the recent past. It may also advise of a replacement part. When an orderable part first becomes discontinued, Product Discontinuation Notices are sent are sent to those who have purchased the parts in the recent past, if purchased directly, with a dated opportunity to place a last order.

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