Datasheet - ST4E1216, ST4E1240 - High-speed 3.3 V / 5 V RS485 transceiver with ±12 kV IEC 61000-4-2 contact ESD protection
Document overview
- Manufacturer or author: STMICROELECTRONICS
- PDF pages: 35
Technical content
Datasheet sections
- 1 Pin configuration
- 2 Absolute maximum ratings and operating conditions
- 3 Electrical characteristics
- 4 Test circuits
- 5 Typical characteristics - All devices
- 5.1 Typical characteristics - ST4E1240 - SO8 package
- 5.2 Typical characteristics - ST4E1216 and ST4E1240 - DFN8 package
- 6 Detailed description
- 7 Package information
- 7.1 SO8 package information
- 7.2 DFN8 3x3 package information
- 8 Ordering information
Features
- Meets or exceeds TIA/EIA-485A standard requirements
- 3 V to 5.5 V supply voltage
- Differential output voltage (VOD) exceeds 2.1 V at 5 V supply for PROFIBUS compatibility
- High speed: up to 40 Mbps data rate
- More than 64 transceivers on the bus (up to 100 nodes)
- Integrated protections – Fail-safe receiver (bus open, idle, and shorted) – Thermal shutdown protection – Hot-swap capability (with parasitic capacitance up to 100 pF) – Bus I/O ESD protection ◦ ±12 kV IEC61000-4-2 contact discharge ◦ ±30 kV HBM ◦ ±4 kV IEC61000-4-4 class-A fast transient burst (EFT)
- Low quiescent current in shutdown mode
- Available in industry standard SO-8 and DFN8 for the ST4E1240
Applications
- Factory automation and control
- Motion controllers
- Building automation and safety
- Video surveillance (building, traffic monitoring)
- Backplane busses
- Grid infrastructure
- Data acquisition (smart meters, seismic networks)
Description
The ST4E1216 and ST4E1240 are low-power differential line transceivers for data transmission standard RS485 applications in half-duplex mode, compatible with either 3.3 V or 5 V rail power supplies, fully operating from 3 V to 5.5 V. The ST4E1216 and the ST4E1240 operate respectively up to 16 Mbps and 40 Mbps. They are ideal for multipoint applications over extended cable runs. They are robust to ESD transients. In particular, the bus pins support ±12 kV IEC 61000-4-2 contact discharge. They also feature robust hot-swap capability during switching on and off, or during hot insertion. The ST4E1216 is available in SO8 and up to 125 °C. The ST4E1240 is available in SO8 and DFN8 with two temperature ranges as stated in the device summary table. Maturity status link ST4E1216, ST4E1240 Device summary Part number Data rate (Mbps) Package Temperature range ST4E1240DT 40 SO8 -40°C; 85°C ST4E1240IQT 40 DFN8 -40°C; 125°C ST4E1216IDT 16 SO8 -40°C; 125°C High-speed 3.3 V / 5 V RS485 transceiver with ±12 kV IEC 61000-4-2 contact ESD protection ST4E1216, ST4E1240 Datasheet DS14542 - Rev 3 - November 2024 For further information contact your local STMicroelectronics sales office.
1 Pin configuration
Figure 1. Pin connections Table 1. Pin description
2 Absolute maximum ratings and operating conditions
Table 2. Absolute maximum ratings Note: All voltage values, except the differential voltage, are with respect to network ground terminal. Table 3. ESD ratings
- JEDEC document JEP155 states that 500 V HBM allows safe manufacturing with a standard ESD control process.
- JEDEC standard 22, test method A114, HBM (Human Boby Model), bus terminals (A, B), ≥ ±8 kV (limited by industrial tester
Measurement for 20 A peak, 100 ns Transmission-Line Pulse (TLP), package level at room temperature.
3 Electrical characteristics
Table 4. Operating conditions thermal shutdown circuit, which disables the driver outputs when the junction temperature reaches 165 °C. Table 5. Thermal information Table 6. Power dissipation
Electrical characteristics
Table 7. Receiver: operating conditions (VCC = +3.0 V to 5.5 V, TA = Tmin to Tmax, unless otherwise specified. Typical
- Guaranteed by design simulation in temperature.
Table 8. Driver: operating conditions (VCC = +3.0 V to 5.5 V, TA = Tmin to Tmax, unless otherwise specified. Typical Table 9. Input logic interface (D, DE, RE): (VCC = +3.0 V to 5.5 V, TA = Tmin to Tmax, unless otherwise specified. Typical
Table 10. Supply current and protections: (VCC= +3.0 V to 5.5 V, TA = Tmin to Tmax, unless otherwise specified. Typical
4 Test circuits
In the schematics below, CL includes fixture and instrumentation capacitance. Figure 2. Driver differential output voltage with common-mode load Figure 3. Driver differential and common-mode output with RS-485 load Figure 4. Driver differential output rise and fall times and propagation delays
Figure 11. Typical half-duplex RS485 network
5 Typical characteristics - All devices
Figure 12. Driver output voltage vs. driver output current Figure 13. Driver differential output voltage vs. driver Figure 14. Receiver output vs. input @ VCC = 5.5 V Figure 15. Driver output voltage vs. driver output current
5.1 Typical characteristics - ST4E1240 - SO8 package
Figure 20. Shutdown supply current vs. temperature, DE = Figure 21. No-load supply current vs. temperature, DE = Figure 22. No-load supply current vs. temperature, DE = Figure 23. No-load supply current vs. temperature, DE =
5.2 Typical characteristics - ST4E1216 and ST4E1240 - DFN8 package
Figure 32. Shutdown supply current vs. temperature, DE = Figure 33. No-load supply current vs. temperature, DE = Figure 34. No-load supply current vs. temperature, DE = Figure 35. No-load supply current vs. temperature, DE =
6 Detailed description
dedicated pins DE and RE. Its functional block diagram is shown below. Figure 44. Block diagram The various functional modes of the ST4E1216 and ST4E1240 are detailed in the following function tables. state of the signal present on input D, that is VOD is positive if D is high, VOD is negative when D is low. Table 11. Driver truth table internal pull-up resistor, thus when left open, the receiver output is disabled by default.
Table 12. Receiver truth table and ambient temperature of 25 °C. at both ends with its characteristic impedance and stub lengths to be kept as short as possible from the main line. indeterminate state. The following conditions can be detected.
- Open bus such as a disconnected connector
- A shorted bus such as a damaged cable creating a short of the twisted pair
- An idle bus that occurs when no device on the bus is actively driving In any of these cases, the differential receiver drives a fail-safe logic high level so that the output of the receiver is not indeterminate. Hot-swap capability The enable pins DE and RE are critical pins during a switch-on or plug-in phase on the RS485 bus. To prevent these pins from driving into unwanted states on the bus due to possible disturbances during these steps, the ST4E1216 and ST4E1240 features an integrated hot-swap structure to avoid these potential problems. Assuming a parasitic capacitance may be present on the board between the nodes DE and GND, or RE and VCC; when the power supply rises, the MCU may drive an undetermined state on the nodes DE and RE. Depending on the input impedance on nodes DE and RE, it can generate an unwanted signal on bus pins A, B. A parasitic capacitance up to 100 pF is efficiently discharged with the hot-swap structure of the ST4E1216 and ST4E1240. The new ST RS485 transceivers manage dynamically the input impedance on DE and RE versus VCC. A typical transient resistor of 6 kΩ is seen during the rising edge of the power supply, during a defined time of 15 µs typically. This allows fast discharge of parasitic capacitance, preventing any unwanted signal on the bus pins. A second typical transient resistor of 20 kΩ is still present until the VCC supply is fully established. Then, the 2 MΩ resistors are the connected pull-up or pull-down resistor on both DE and RE terminals during normal ON operation for current consumption considerations. An example is shown below for the impedance management on the DE terminal. Such a structure is also present on RE versus VCC. ST4E1216, ST4E1240 Detailed description DS14542 - Rev 3 page 21/35
Figure 47. HBM JEDEC and IEC61000-4-2 waveforms comparison the equipment. IEC61000-4-2 8 kV protections are commonly implemented. reproducibility and is chosen to be the test method for IEC61000-4-2. The ST4E1216 and ST4E1240 comply with IEC61000-4-2 12 kV contact discharge.
7 Package information
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.
7.1 SO8 package information
Figure 48. SO8 package outline Table 13. SO8 package mechanical data
Package information
DS14542 - Rev 3 page 24/35
Figure 49. SO8 recommended footprint (mm) DS14542 - Rev 3 page 25/35
7.2 DFN8 3x3 package information
Figure 50. DFN8 3x3 package outline DS14542 - Rev 3 page 26/35
Table 14. DFN8 3x3 mechanical data DS14542 - Rev 3 page 27/35
Figure 51. DFN8 3x3 recommended footprint DS14542 - Rev 3 page 28/35
8 Ordering information
Table 15. Order code
Ordering information
DS14542 - Rev 3 page 29/35
Revision history
Table 16. Document revision history 09-Jan-2024 1 Initial release. Added new part number ST4E1216. Updated features and description on the cover page, Figure 1 and Table 14. Order code. Added new package DFN8 3 x 3 and Section 7.2.
Table 8. Driver: operating conditions (VCC = +3.0 V to 5.5 V, TA = Tmin to Tmax, unless otherwise specified. Typical values
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