NanoBoard 3000 - Relays

The NanoBoard 3000 provides four isolated IM relay channels – each channel utilizing an IM03GR, 5V non-latching DPDT relay with one coil (from Tyco Electronics). This device has a maximum switching capacity of 60W, a typical operation time of 1ms (3ms max) and a typical release time of 3ms (5ms max).

Although DPDT in nature, the two pins in each case – Common (C, pins 3 and 6), Normally-Open (NO, pins 4 and 5) and Normally-Closed (NC, pins 2 and 7) – are joined on the motherboard. The resulting three signals for each channel (labeled on board as 'NC0 COM0 NO0' to 'NC3 COM3 NO3') are delivered to a 12-way screw terminal block.

Switching is controlled using an N-channel 'enhancement mode' metal-oxide semiconductor field-effect transistor (NMOSFET). Each NMOSFET device (a 2N7002, from STMicroelectronics) supports a maximum Drain-Source voltage of 60V, with maximum continuous Drain current of 0.2A. In terms of switching, the maximum turn-on delay time is 5ns, with a maximum turn-off delay time of 7ns.

Relay interface.

A 40V/400mA Schottky diode (ZHCS400, from Zetex Semiconductors) across the coil terminals is used to dissipate energy when the relay is de-energized – therefore protecting against voltage spikes.

An LED associated with each relay channel is used to indicate channel activity, lighting (ORANGE – 200mcd) when the corresponding line from the User FPGA is taken High.

Location on Board

The relay device for each channel (designated RLY1 to RLY4 respectively), the screw terminal block (designated J14), the NMOSFET device for each channel (designated Q4, Q6, Q7 and Q8 respectively) and the protection diode for each channel (designated D3 to D6 respectively), are all located on the component side of the board, to the right of the PWM channel activity LEDs.

The channel activity LEDs (designated LED11, LED13, LED14 and LED15 respectively) and labeled '0' to '3' respectively) are located between the main PWM interface and the 'SYSTEM JTAG' header.

Channel activity LEDs for
the Relay interface.

Schematic Reference

The Relay circuitry can be found on the following sheets of the motherboard schematics:

• Sheet 44 (RELAY_X4_IM03GR.SchDoc, entitled Power Control x4)

• Sheet 45 (RELAY_SMT_5V_IM03GR.SchDoc, entitled Power Control)

• Sheet 46 (CON_RELAYx4_KMRJIO3_5MM_12WAY.SchDoc, entitled Screw Header For Relays)

Design Interface Component

Table 1 summarizes the available design interface component that can be placed from the FPGA NB3000 Port-Plugin.IntLib, to access and use the Relay interface.

Further Device Information

For more information on the IM03GR device, refer to the datasheet (im.pdf) available at www.tycoelectronics.com.

For more information on the 2N7002 device, refer to the datasheet (2N7002.pdf) available at www.st.com.

For more information on the ZHCS400 device, refer to the datasheet (ZHCS400.pdf) available at www.zetex.com.