GT95000 Interface Card

The GT95000 (the figure below) can connect two DIO boards to a UUT. It provides termination resistance networks for all 64 channels. In addition, it has a Custom Circuit Pad that you can populate for special interface needs.

GT95000 Interface Board

DIO headers J1, J4 and J7 are provided. 330W pull-up resistors and 390W pull-down resistors in SIP packages are standard. You may elect to use different values by ordering the GT95000 with SIP sockets instead of soldered-in resistors, or provide his own terminations.

Card Features

Two high-density 50-pin headers (50-mil pin pitch), 32 I/O channels each, for DIO-side connections. These headers accept standard GT25/50-DIO DIO ribbon cables.

One high-density, 50-pin header for the DIO Timing and Control Module (Master GT25/50-DIO). This header also accepts a DIO ribbon cable.

Two 50-hole, 100-mil pitch pads for user-provided UUT-side connections. All but eight control pins are connected to DIO headers. Standard headers can be inserted into the pads.

One 50-pin header with 100-mil pin pitch, for UUT side timing connection. Pads are wired to the DIO header.

Pull-up/down I/O line terminations on board (default  330W/390W).

External Vcc and GND power connection pads.

Custom Circuit Pad: 27 x 30 matrix @ 100 mils (about 2.7” x 3” footprint).

30-pin pad for custom circuit connection.

Five mounting holes to secure the card to your test fixture. Mounting hardware is not included. Holes are at corners and center.

Pads J2, J3, J5 and J6 can accept 50-pin headers that mate with UUT connectors, or headers for wire wrap pins. The board can also terminate UUT cables by soldering wires directly to the pads.

J1 and J4, pins 1- 41 are routed to J2 and J3, and to J5 and J6, respectively. Pins 42 - 45 and 47- 50 are special. They are used by GT25/50-DIO for pin group direction control and status. These pins are routed to a separate pad located directly above the Custom Circuit Pad area. These pins are not available at J2, J3, J5 or J6.

Pull-up/pull-down resistor networks RN1 – RN8 provide termination values of 330W/390W per I/O pin. The open circuit voltage is about 2.7 volts for Vcc of 5 volts. The equivalent source/termination resistance is about 180W. This resistance provides a good match to reduce signal degradation due to cross-talk and reactance.

I/O interconnections for header J1 to pads J2 and J3, and header J4 to pads J5 and J6, are called out in in the table GT95000 DIO Connections.

DIO timing uses 50-pin header, J7. J7 connects to a 50-mil pitch DIO connector. J7 connects pin-for-pin to a nearby 50-pin, 100-mil pitch header. This header provides a separate UUT timing cable connection for timing and control.

If a Master board is not connected, J7 headers are available for other use, such as interfacing with the Custom Circuit Pad area.

J7 Timing signals and pins are specified in table Timing Signal Connections.

Connecting GT95000 Interface Cards

This Interface Card (the figure GT95000 Interface Board) has pads for custom circuits and for external power and ground.

It accepts ribbon cables from two GT25/50-DIO boards at connectors J1 and J4 for 64 total I/O channels. It also accepts a ribbon cable from a 50-pin DIO Timing module at J7.

Resistor termination networks are mounted both above and below J1 and J4. They are used to terminate I/O lines. Recommended pull-up and pull-down values are 330/390 W for up to 2 feet of cable.

I/O connections to J1 and J4 are wired directly to 100-mil spaced pads J2, J3, J5 and J6. DIO control pins 42-45 and 47-50 on J1 and J4, respectively, are routed to pads marked as J1 and J4, pins 42-50, to the left of the DIO signal connectors. These control pins are not available at pads J2, J3, J5 and J6.

I/O signals at J2 and J5 are wired directly to J3 and J6, respectively. The header for a UUT cable connection can be installed at one pair (say J3 and J6) while the other pair (J2 and J5) can have terminal blocks installed to support wire wrap, jumpers, solder, etc. Terminal blocks can be jumped to the Custom Circuit Pad as needed.

Header J7 supports the timing interface and cables to the DIO Timing module. It is also wired to a 50-pin, 100-mil pad that can be used as an interface to the Custom Circuit Pad.

The 30-pin pad J10, near the left edge can be used to mount a header for Custom Circuit Pad I/O. The 100-mil pad to the right is wired to J10 and can be used to interconnect holes on the Custom Circuit Pad using direct soldering or wire wrap.

The DIO cable can be used to supply power to the Custom Circuit Pad. Headers mounted at the Power & GND pads connect to the Vcc and GND layers of the card

DIO and UUT Interconnections

This card facilitates DIO and UUT interconnections by providing an open interface to DIO signal, timing and power.

There are many possible UUT cabling schemes and connector types. Therefore, the GT9500 provides standard pitch solder pads on which you can install UUT-side mating connectors appropriate for his connection needs. The pads are hard wired to DIO connector pins in accordance with the connection tables given below.

A Custom Circuit Pad area is provided to allow you to construct special circuits. Power and ground are available from the DIO host and brought out to a separate pad area near the Custom Circuit Pad.

Pull-up and Pull-down resistor network sockets provide for DIO signal line termination. Termination sockets for timing signals are not provided, but you can provide this in the Custom Circuit Pad area as needed.

DIO I/O Pins

The table GT95000 DIO Connections defines interconnections for header J1with pads J2 and J3 and header J4 with pads J5 and J6. Because connections within each group are identical, slash notation like “J1/J4”, etc. is used here to indicate applicable terminations.

While J1/J4 and J7 are 50-pin, high-density headers, J2/J3 and J5/J6 are 50-pin, 100-mil pitch pads that you can implement either as headers, or pins for jumpers, wire wrap or solder connections.

                                       GT95000 DIO Connections

J2 and J3 are 100-mil spaced pads. These can accommodate various connectors or wire wrap pins or can be used for direct soldering.

In J1/J4 pins 42-45 and 47-50 are used for pin group direction control and status. These are routed to pads located to the left of J4, marked as J1 and J4 (not to be confused with connectors J1 and J4). These pins are not accessible at J2, J3, J5, and J6.

Timing Connector

J7 (50-mil pitch, high-density connector) can be used to connect DIO timing to the Custom Circuit Pad area. J7 can connect to a Master board’s Timing module. A 100-mil pitch header is situated below. This connects pin for pin to J7. It can be used to connect DIO timing to the Custom Circuit Pad area.

                          Timing Signal Connections

The left part of pad J10 is used for a high-density (50-mil pitch) header that connects with UUT synchronization and control signals. The right side connects pin for pin with the left side. It is a 100-mil pitch pad that can hold terminals for connecting the Custom Circuit Pad area.

The table below shows characteristics of some GT95000 parts, including some specific product reference examples.

Examples of GT95000 Compatible Standard Parts