A-5 General Specs [T-Series Datasheet]

All specifications are at 25 °C and Vsupply = 5.0 V unless otherwise noted.

Power Supply Input

The following table shows the supply voltage that is required. The USB hub or 5V USB adapter in use should fall within the acceptable range.

Table A5-1.

[1] With no connected loads, the supply current is just the "Power Consumption" from the tables below. The total supply current is this power consumption plus the current provided to any loads (e.g. out of VS terminals). Total supply current should be kept to 500 mA or less on the T4 and T7.

VS Outputs

The following table provides specifications for the VS outputs.

Table A5-2.

[1] VS voltage is the same as the power supply voltage.

[2] The max total supply current is 500 mA, so the max current available from VS is 500 mA minus the power consumption of the device from the tables below.

Core Clock

The following table provides specifications for the core clock.

Table A5-3.

Physical

Table A5-4.

[1] The device operates across this temperature range, but note that many specs in this appendix are specified at room temperature. In particular, analog input absolute accuracy specs are valid at room temperature, and beyond that there is a tempco that describes how readings might change with temperature.

[2] There is no specific limit on humidity, but the environment must be non-condensing. The T7 must be protected from moisture and particulates.

Power Consumption

At this time USB and Core speed are not intended for user level control, but have been included in the following table to show the capabilities of the device. The values shown are typical.

T4 Power Consumption

Table A5-5.  T4 Power Consumption

[1] Ethernet and USB require that the core be running at least 20MHz.

T7 Power Consumption

Table A5-6.  T7 Power Consumption

[1] Ethernet and USB require that the core be running at least 20MHz.

T8 Power Consumption

The T8 has several switching power supplies which maintain the voltages necessary for proper operation. Those supplies will adjust the amount of current they pull in order to keep the downstream voltages constant. If the supply voltage reduces, the required supply current will be increased. The specs in Table A5-7 were measured with Vs at 5.0 V.

The T8 can be powered from USB, Power Over Ethernet (POE), or the J5 header. When using USB or J5, the current drawn from those sources will match the values specified in Table A5-7.

Table A5-7. T8 Supply Current (USB power with Vs = 5.0V)

Additional considerations when calculating current draw or power dissipation:

1. DAC outputs - Each 1 mA sourced by a DAC output will increase the device draw about 5 mA.

2. Digital outputs - Each 1 mA sourced by a digital output will increase the device draw about 0.8 mA.

3. 3.3V reference output - Each 1 mA sourced by a the 3.3V reference output will increase the device draw about 0.7 mA.

4. VS outputs - Each 1 mA sourced by a VS output will increase the device draw about 1 mA.

5. Power Over Ethernet (POE) - The table above is for 5V supply (USB or J5).  To estimate the power consumption when using the internal POE supply, multiply the power numbers (Watts) in the table by 1.3 to account for the efficiency of the 48V to 5V converter.

T7 Current Sources

Table A5-8.

[1] First spec is the accuracy compared to the value stored during calibration. The second spec is the accuracy compared to the nominal value (e.g. 200.0 µA for the 200µA source).

[2] The temperature coefficient varies strongly with temperature. See the charts in 12.0 200uA and 10uA.

VM+ and VM- (T7)

Table A5-9.

3.3V RefOut (T8)

The 3.3V Reference output is a load compensated supply which is intended for bridge circuits etc.

Table A5-10.