Key Specifications

 

The UM3090EESA is ±15kV ESD-protected, high-speed transceiver for RS-485 communication that contains one internal low-dropout regulator, one driver and one receiver. The internal LDO allows the device to operate from an unregulated power supply of up to 30V.

The internal LDO generates a 5V±5% power supply that is used to power its internal circuitry. The UM3090EESA brings the 5V to an output V_REG that allows the user to power additional external circuitry with up to 20mA to further reduce external components. The device features fail-safe circuitry, which guarantees a logic-high receiver output when the receiver inputs are open, shorted or idle. This means that the receiver output will be logic high if all transmitters on a terminated bus are disabled (high impedance). The UM3090EESA features reduced slew-rate driver that minimizes EMI and reduces reflections caused by improperly terminated cables, allowing error-free data transmission up to 500kbps. The device also features enhanced ESD protection. All transmitter outputs and receiver inputs are protected to ±8kV for JESD22 the Human Body Model and ±15kV for IEC61000-4-2 Air-Gap Discharge Model, ±8kV for IEC61000-4-2 Contact Discharge Model.

The device has a 1/8-unit-load receiver input impedance that allows up to 256 transceivers on the bus and is intended for half-duplex communications. The UM3090EESA is available in an 8-pin SOP8-EP package with an exposed paddle to improve power dissipation, and operates over the extended -40°C to +85°C temperature range.

 

- +5.5V to +30V Wide Input Supply Range

- +5V Output Supplies Up to 20mA to External Circuitry

- Extended ESD Protection

 ±8kV—Human Body Model

 ±15kV—IEC61000-4-2, Air-Gap Discharge

 ±8kV—IEC61000-4-2, Contact Discharge

- Enhanced Slew-Rate Limiting Facilitates Error-Free Data Transmission

- -7V to +12V Common-Mode Input Voltage Range

- Allows up to 256 Transceivers on the Bus

- Thermal Shutdown

- Current-Limiting for Driver Overload Protection

 

 

- Isolated RS-485 Interfaces

- Utility Meters

- Security and Protection

- Intelligent Sensors

- Industrial-Control Local Area Networks

- Transceivers for EMI-Sensitive Applications

 

 

                                  Top View

 

Table 1. Transmitting

X=Don’t care; High-Z=High Impedance

Table 2. Receiving

X=Don’t care; High-Z=High Impedance