MUR414_NM485.jpg


Compact data communication devices from Murata

Murata Power Solutions has unveiled two low power electrically isolated data communication devices that provide RS485 or TTL interfaces with isolated power.

The NM485D6S5MC and NMTTLD6S5MC have no external components and a single 5V supply allows function on either side of the isolation boundary. The combination of isolated data communication and power in a single module means that these devices also save space and design time.

The NM485D6S5MC is designed for single channel, full duplex, data communication or multipoint bus transmission. It combines a tri-state differential line driver and a differential input line receiver. The driver and receiver have active high and active low enables respectively that can be connected to function as direction control. It is designed for industrial applications with an operating temperature range from -40 to +85 °C and a tested isolation of 3 kVac RMS in a surface-mount package measuring only 18.16 mm x 14.5 mm.

Single channel full duplex isolation is provided for the NM485; the device has UL60950 approval pending for reinforced insulation to 250 VAC.

Providing quad channel digital isolation for NMTTL, the NMTTLD6S5MC has two transmit and two receive lines for data rates up to 25 Mbps. It is also designed for industrial applications and features an operating temperature range from -40 to +95 °C and a tested isolation of 1500 Vac RMS in a surface-mount package measuring only 16.9 mm x 14.5 mm. The device has UL60950 approval pending for basic insulation to 250 VAC.

Both devices provide a regulated 5V output for digital circuitry, as well as unregulated ±6V isolated outputs for powering analogue circuitry, A/D or OP-AMPs. Similarly, both devices have ANSI/AAMI ES60601-1, 2 x MOOPs (NMTTL has just one) and 1 x MOPPs safety recognition pending at 250 VAC, offering ease of system approval for medical systems safety approval purposes.

The devices’ very low coupling capacitance figure of 5 pF typical also reduces system EMI problems.

Author
Neil Tyler