Rev Supports both full-duplex and half-duplex types! Introducing the Si858x series of isolators with built-in RS485 transceivers

RS-485,RS485,RS-422,RS422,RS-232C,RS232C,Si858x,Si85853D-IS,Si85833D-IS,Si85855D-IS,Si85835D-IS,Si85856D-IS,Si85836D-IS,Si85857D-IS,Si85837D-IS,Si85858D-IS,Si85838D-IS

Product Summary

Si858x is a new isolated RS-485 transceiver.

Compliant with EN 50170 (PROFIBUS), it is highly robust with fail-safe functionality, withstands bus faults of ±30V, and has strong ESD resistance to bus pins with HBM 15kV.

The 10Mbps required by the RS-485 standard is guaranteed, and the delay time is low at approximately 17ns (typ) on the driver side, and the skew |(tPHL–tPLH| is also low by 0.5ns (typ) (Si85855/56/58).

CMTI has a high robustness of 10KV/us (min).

Furthermore, the 1Mbps product has a slew rate control function, which suppresses unnecessary EMI (electromagnetic interference).

Product features

Compliant with TIA/EIA-485-A (RS-485) specifications / Compliant with EN 50170 (PROBIBUS) / Pin compatible with standard RS485 drivers
~10Mbps high data rate supported / 1Mbps product has low EMI due to slew rate control
Dielectric strength voltage: 5.0 kVrms max,/ Working voltage: 2121 Vpeak / High reliability High safety
±30V bus fault tolerance / HBM 15KV static tolerance
High CMTI characteristics 100kV/us(min)
Built-in fail-safe function/OPEN/SHORT detection
WB SOIC-16 Package/ Clearance/Creepage : 8 mm
Wide operating temperature range Ta: -40 to 125℃
Built-in thermal protection circuit

Block Diagram

Si858x3/5/6
Half-duplex product (optional product with isolated TX_EN output is also available)

Si858x7/8
full duplex product

lineup

part number	Communication specifications	SR function*/Communication speed Max (Mbps)	VDD2 voltage (V)*	Number of RS-485 nodes (#)
Si85853D-IS	half duplex	◯ / 1	5V	64
Si85833D-IS	half duplex	◯ / 1	3.3V	64
Si85855D-IS	half duplex	ー / 10	5V	256
Si85835D-IS	half duplex	ー / 10	3.3V	256
Si85856D-IS	Half duplex + isolated Tx_EN	ー / 10	5V	256
Si85836D-IS	Half duplex + isolated Tx_EN	ー / 10	3.3V	256
Si85857D-IS	full duplex	◯ / 1	5V	64
Si85837D-IS	full duplex	◯ / 1	3.3V	64
Si85858D-IS	full duplex	ー / 10	5V	256
Si85838D-IS	full duplex	ー / 10	3.3V	256

*SR function: Slew rate control function
* Primary side input power supply VDD1: 2.5 to 5.5V (common to all series regardless of model number)

Slew rate control function support

EMI, Slew rate control — Example of input/output waveforms from UG498 Figure 7.3

The Si858x series products with a Max Data Rate of 1Mbps support the slew rate control function.

This function makes the rise and fall times of the output signal gentler, as shown in the blue and red waveforms on the left, making it possible to alleviate EMI problems during signal output.

Si85858: No Slew Rate Control function
(10Mbps: Loopback Waveform)

Si85833 (with Slew Rate Control function)
(1Mbps: Loopback Waveform)