ST3485EB, ST3485EC ST3485EI, ST3485EIY Datasheet 3.3 V powered, 15 kV ESD protected, up to 12 Mbps RS-485/ RS-422 transceiver 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 A 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. Product status link These devices transmit and receive at a guaranteed data rate of at least 12 Mbps. ST3485EB, ST3485EC, ST3485EI and All transmitter outputs and receiver inputs are protected to 15 kV IEC 61000-4-2 air ST3485EIY 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. DS2947 - Rev 12 - March 2021 www.st.com For further information contact your local STMicroelectronics sales office.ST3485EB, ST3485EC, ST3485EI, ST3485EIY Pin configuration 1 Pin configuration Figure 1. Pin connections RO 1 8 VCC RE 2 7 B DE 3 6 A DI 4 5 GND Table 1. Pin description Pin n Symbol Name and function 1 RO Receiver output. If A > B by 200 mV, RO will be high if A < B by 200 mV, RO will be low. Receiver output enable. RO is enabled when RE is low RO is high impedance when RE is 2 RE high. If RE is high and DE is low, the device will enter a low power shutdown mode. Driver output enable. The driver outputs are enabled by bringing DE high. They are high impedance when DE is low. If RE is high DE is low, the device will enter a low-power 3 DE shutdown mode. If the driver outputs are enabled, the part functions as line driver, while they are high impedance, it functions as line receivers if RE is low. Driver input. A low on DI forces output A low and output B high. Similarly, a high on DI 4 DI forces output A high and output B low. 5 GND Ground. 6 A Non-inverting receiver input and non-inverting driver output. 7 B Inverting receiver input and inverting driver output. 8 VCC Supply voltage: V = 3 V to 3.6 V. CC DS2947 - Rev 12 page 2/23