Datasheet - ST3485EB, ST3485EC, ST3485EI, ST3485EIY - 3.3 V powered, 15 kV ESD protected, up to 12 Mbps RS-485/ RS-422 transceiver
Document overview
- Manufacturer or author: STMICROELECTRONICS
- PDF pages: 23
Technical content
Datasheet sections
- 1 Pin configuration
- 2 Truth tables
- 3 Maximum ratings
- 4 Electrical characteristics
- 5 Test circuits and typical characteristics
- 6 Package information
- 6.1 SO8 package information
- 6.2 SO8 tape and reel information
- 7 Ordering information
Features
- ESD protection – ±15 kV IEC 61000-4-2 air discharge – ±8 kV IEC 61000-4-2 contact discharge
- Operate from a single 3.3 V supply - no charge pump required
- Interoperable with 5 V logic
- 1 µA low current shutdown mode max.
- Guaranteed 12 Mbps data rate
- -7 to 12 V common mode input voltage range
- Half duplex versions available
- Industry standard 75176 pinout
- Current limiting and thermal shutdown for driver overload protection
- Guaranteed high receiver output state for floating inputs with no signal present
- Allow up to 64 transceivers on the bus
- Available in SO8 package
- Automotive grade (ST3485EIY)
Description
The ST3485EB, ST3485EC, ST3485EI and ST3485EIY devices are ±15 kV ESD protected, 3.3 V low power transceiver for RS-485 and RS-422 communications. These devices contain one driver and one receiver in half duplex configuration. These devices transmit and receive at a guaranteed data rate of at least 12 Mbps. All transmitter outputs and receiver inputs are protected to ±15 kV IEC 61000-4-2 air discharge. The driver is short-circuit current limited and is protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high impedance state. Product status link ST3485EB, ST3485EC, ST3485EI and ST3485EIY
3.3 V powered, 15 kV ESD protected, up to 12 Mbps RS-485/ RS-422 transceiver
ST3485EB, ST3485EC ST3485EI, ST3485EIY Datasheet DS2947 - Rev 12 - March 2021 For further information contact your local STMicroelectronics sales office.
1 Pin configuration
Figure 1. Pin connections Table 1. Pin description 1 RO Receiver output. If A > B by 200 mV, RO will be high; if A < B by 200 mV, RO will be low. high. If RE is high and DE is low, the device will enter a low power shutdown mode. they are high impedance, it functions as line receivers if RE is low. forces output A high and output B low. 6 A Non-inverting receiver input and non-inverting driver output. 7 B Inverting receiver input and inverting driver output. 8 VCC Supply voltage: VCC = 3 V to 3.6 V.
2 Truth tables
Table 2. Truth table (driver) Table 3. Truth table (receiver)
3 Maximum ratings
under these condition is not implied. Table 4. Absolute maximum ratings
- Human body model: 100 pF discharged through a 1.5 kΩ resistor between two pins of the device, done for all couples of pin
combinations with other pins floating.
- Charged device model: all pins plus package are charged together to the specified voltage and then discharged directly to
4 Electrical characteristics
Table 5. Electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for the Table 6. Logic input electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for Table 7. Transmitter electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for
- ∆V OD and ∆VOC are the changes in VOD and VOC, respectively, when the DI input changes state.
Electrical characteristics
5 Test circuits and typical characteristics
Figure 2. Driver and VOC test load Figure 3. Driver VOD with varying common mode voltage test load Figure 4. Receiver VOH and VOL test circuit Figure 5. Drive differential output delay transition time test circuit
- The input pulse is supplied by a generator with the following characteristics: PRR = 250 kHz, 50 % duty
- C L includes probe and stray capacitance
Figure 6. Drive differential output delay transition time waveform Figure 7. Drive enable and disable times test circuit (pull-down configuration)
0 V or 3 V
- The input pulse is supplied by a generator with the following characteristics: PRR = 250 kHz, 50 % duty
- C L includes probe and stray capacitance
Figure 8. Drive enable and disable times waveforms (pull-down configuration)
- t PZH is valid if the driver is initially disabled ( RE is high), tPSH is valid if the driver is initially in shutdown
Figure 26. Driver short-circuit current (test 2)
6 Package information
In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ECOPACK is an ST trademark.
6.1 SO8 package information
Figure 27. SO8 package outline Table 11. SO8 package mechanical data
Package information
DS2947 - Rev 12 page 16/23
6.2 SO8 packing information
Figure 28. SO8 tape and reel outline Table 12. SO8 tape and reel mechanical data
7 Ordering information
Table 13. Order codes
- Qualification and characterization according to AEC Q100 and Q003 or equivalent, advanced screening
according to AEC Q001 and Q 002 or equivalent.
Ordering information
DS2947 - Rev 12 page 18/23
Revision history
Table 14. Document revision history 20-Jun-2005 2 Mistake on table 12 tZL(SHDN) ms ==> µs. DVTH values are changed in table 10. 07-Apr-2006 4 Order codes updated. 12-Nov-2007 5 Added Table 1. by ±15 kV IEC 61000-4-2 air discharge). Removed ST3485ECN device from Table 1. Updated Table 10 to Table 12 (updated data, cross-references). highlighted some parts of Figure 6 and Figure 12). Removed DIP-8 package from Section 6: "Package information" and whole document. and Table 14, reversed order of figures and table). Minor corrections throughout document. Added order code ST3485EIYDT and pointed out in Features it is automotive grade. Removed "Table 6: ESD performance: transmitter outputs, receiver inputs (A, B)". Table 1: "Device summary": added information for new part number ST3485EI. "RE is low" in note 1 of figures 8 and 12. 25-Aug-2016 10 Table 14: "Order codes": updated order codes ST3485EBDR and ST3485ECDR. characteristics" and Figure 26: "Driver short-circuit current (test 2)". 05-Mar-2021 12 Updated Table 4. Absolute maximum ratings.
Table 6. Logic input electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for the Table 7. Transmitter electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for the Table 8. Receiver electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for Table 9. Driver switching characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for the ST3485ECDR, TA = -40 to 85 °C for the Table 10. Receiver switching characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for ST3485ECDR, TA = -40 to 85 °C for