Appendix A - Specifications [U6 Datasheet]
Specifications at 25 degrees C and Vusb/Vext = 5.0V, except where noted.
| Parameter | Conditions | Min | Typical | Max | Units |
| General | |||||
| USB Cable Length | 5 | meters | |||
| Supply Voltage (1) | 4.75 | 5 | 5.25 | volts | |
| Supply Current (2) | 100 | mA | |||
| Operating Temperature | -40 | 85 | °C | ||
| Clock Error | ~ 25 °C | ±30 | ppm | ||
| -10 to 60 °C | ±50 | ppm | |||
| -40 to 85 °C | ±100 | ppm | |||
| Typ. Command Execution Time (3) | USB High-High | 0.6 | ms | ||
| USB Other | 4 | ms | |||
| Vs Outputs | |||||
| Typical Voltage (4) | Self-Powered | 4.75 | 5 | 5.25 | volts |
| Bus-Powered | 4.8 | 5 | 5.25 | ||
| Maximum Current (4) | Self-Powered | 400 | mA | ||
| Bus-Powered | 0 | mA | |||
| Vm+/Vm- Outputs | |||||
| Typical Voltage | No-load | ±13 | volts | ||
| @ 2.5 mA | ±12 | volts | |||
| Maximum Current | 2.5 | mA | |||
| 10UA & 200UA Current Outputs | |||||
| Absolute Accuracy (5) | ~ 25 °C | ±0.1 | ±0.2 | % | |
| Temperature Coefficient | See Section 2.5 | ppm/°C | |||
| Maximum Voltage | VS - 2.0 | volts | |||
| (1) Device should operate down to about 3.5 volts, with the following considerations. The hi-res converter on the U6-Pro is not specified for operation below 4.75 volts. The voltage drive capability of the current sources will be reduced. The maximum output of the DACs will be limited by VS. The input range of the analog inputs will be reduced approximately 3 volts for each 1 volt that VS is below 4.5 volts. | |||||
| (2) Typical current drawn by the U6 itself, not including any user connections | |||||
| (3) Total typical time to execute a single Feedback function with no analog inputs. Measured by timing a Windows application that performs 1000 calls to the Feedback function. See Section 3.1 for more timing information | |||||
| (4) These specifications are related to the power provided by the host/hub. Self- and bus-powered describes the host/hub. not the U6. Self-powered would apply to USB hubs with a power supply, all known desktop computer USB hosts, and some notebook computer USB hosts. And example of bus powered would be a hub with no power supply, or many PDA ports. The current rating is the maximum current that should be sourced through the U6 and out of the Vs terminals | |||||
| (5) This is compared to the value stored during factory calibration | |||||
| Parameter | Conditions | Min | Typical | Max | Units |
| Analog Inputs | |||||
| Typical Input Range (6) | Gain=1 | -10.6 | 10.1 | volts | |
| Gain=10 | -1.06 | 1.01 | volts | ||
| Gain=100 | -0.106 | 0.101 | volts | ||
| Gain=1000 | -0.0106 | 0.0101 | volts | ||
| Max AIN Voltage to GND (7) | Valid Readings | -11.5 | 11.5 | volts | |
| Max AIN Voltage to GND (8) | No Damage | -20 | 20 | volts | |
| Input Bias Current (9) | 20 | nA | |||
| Input Impedance (9) | 1 | GΩ | |||
| Source Impedance (9) | 1 | kΩ | |||
| Integral Linearity Error | Range=±10, ±1, ±0.1 | ±0.01 | % FS | ||
| Range=±0.01 | ±0.1 | % FS | |||
| Absolute Accuracy | Range=±10, ±1, ±0.1 | ±0.01 | % FS | ||
| Range=±10 | ±2000 | μV | |||
| Range=±1 | ±200 | μV | |||
| Range=±0.1 | ±20 | μV | |||
| Range=±0.01 | ±0.1 | % FS | |||
| Range=±0.01 | ±20 | μV | |||
| Temperature Drift | 15 | ppm/°C | |||
| Channel Crosstalk (10) | < 1kHz | -100 | dB | ||
| 1kHz - 50kHz | 20 | dB/dec | |||
| Noise (Peak-To-Peak) | See Appendix B | <1 | μV | ||
| Effective Resolution (RMS) | See Appendix B | 22 | bits | ||
| Noise-Free Resolution | See Appendix B | 20 | bits | ||
| Command/Response Speed | See Section 3.1 | ||||
| Stream Performance | See Section 3.2 | ||||
| (6) Differential or single-ended | |||||
| (7) This is the maximum voltage on any AIN pin compared to ground for valid measurements on that channel. For single-ended readings on the channel itself, inputs are limited by the "Typical Input Range" above, and for differential readings consult the signal range tables in Section 2.6.5. Further, if a channel has over 13.0 volts compared to ground, readings on other channels could be affected. Because all even channels are on 1 front-end mux, and all odd channels on a 2nd front-end mux, an overvoltage (>13V) on a single channel will generally affect only even or only odd channels. | |||||
| (8) Maximum voltage, compared to ground, to avoid damage to the device. Protection level is the same whether the device is powered or not. This spec is continuous. The device can handle brief transients with much higher voltages (e.g. ESD). | |||||
| (9) The key specification here is the maximum source impedance. As long as the source impedance is not over this value, there will be no substantial errors due to impedance problems. For source impedance greater than this value, there are two error sources that need to be considered. First, there is a simple offset error due to the input bias current flowing through the source impedance. Second, if sampling more than 1 channel, there can be a more complex settling error if the analog input system needs to quickly swing from one voltage to another. Required settling time to meet specifications can depend on the source impedance of the signal, channel order, resolution index, and gain/range. | |||||
| (10) Typical crosstalk on a grounded AIN pin, with 20Vpp sine wave on adjacent AIN pin. An adjacent AIN pin refers to multiplexer channel location not channel number, e.g. AIN0-AIN2 or AIN1-AIN3 pairs. | |||||
| Parameter | Conditions | Min | Typical | Max | Units |
| Analog Outputs (DAC) | |||||
| Nominal Output Range (11) | No Load | 0.04 | 4.95 | volts | |
| @ ±2.5 mA | 0.255 | 4.775 | volts | ||
| Resolution | 12 | bits | |||
| Absolute Accuracy | 5% to 95% FS | ±0.1 | % FS | ||
| Integral Linearity Error | ±0.35 | ±1 | counts | ||
| Differential Linearity Error | ±0.1 | ±0.5 | counts | ||
| Error Due To Loading | @ 100 µA | 0.1 | % | ||
| @ 1 mA | 1 | % | |||
| Source Impedance | 50 | Ω | |||
| Short Circuit Current (12) | Max to GND | 50 | mA | ||
| Time Constant | 300 | μs | |||
| Digital I/O, Timers, Counters | |||||
| Low Level Input Voltage | -0.3 | 0.8 | volts | ||
| High Level Input Voltage | 2 | 5.8 | volts | ||
| Maximum Input Voltage (13) | FIO | -10 | 10 | volts | |
| EIO/CIO | -6 | 6 | volts | ||
| Output Low Voltage (14) | No Load | 0 | volts | ||
| --- FIO | Sinking 1 mA | 0.55 | volts | ||
| --- EIO/CIO | Sinking 1 mA | 0.18 | volts | ||
| --- EIO/CIO | Sinking 5 mA | 0.9 | volts | ||
| Output High Voltage (14) | No Load | 3.3 | volts | ||
| --- FIO | Sourcing 1 mA | 2.75 | volts | ||
| --- EIO/CIO | Sourcing 1 mA | 3.12 | volts | ||
| --- EIO/CIO | Sourcing 5 mA | 2.4 | volts | ||
| Short Circut Current (14) | FIO | 6 | mA | ||
| EIO/CIO | 16 | mA | |||
| Output Impedance (14) | FIO | 550 | Ω | ||
| EIO/CIO | 180 | Ω | |||
| Counter Input Frequency (15) | 8 | MHz | |||
| Input Timer Total Edge Rate (16) | No Stream | 30000 | edges/s | ||
| While Streaming | 7000 | edges/s | |||
| (11) Maximum and minimum analog output voltage is limited by the supply voltages (Vs and GND). The specifications assume Vs is 5.0 volts. Also, the ability of the DAC output buffer to driver voltages close to the power rails, decreases with increasing output current, but in most applications the output is not sinking/source much current as the output voltage approaches GND. | |||||
| (12) Continuous short circuit will not cause damage. | |||||
| (13) Maximum voltage to avoid damage to the device. Protection works whether the device is powered or not, but continuous voltages over 5.8 volts or less than -0.3 volts are not recommended when the U3 is unpowered, as the voltage will attempt to supply operating power to the U3 possibly causing poor start-up behavior. | |||||
| (14) These specifications provide the answer to the question. "How much current can the digital I/O sink or source?". For instance, if EIO0 is configured as output-high and shorted to ground, the current sourced by EIO0 into ground will be about 16 mA (3.3/180). If connected to a load that draws 5 mA, EIO0 can provide that current but the voltage will droop to about 2.4 volts instead of the nominal 3.3 volts. If connected to a 180 ohm load to ground, the resulting voltage and current will be about 1.65 volts @ 9 mA. | |||||
| (15) Hardware counters. 0 to 3.3 volt square wave. | |||||
| (16) To Avoid missing edges, keep the total number of applicable edges on all applicable timers below this limit. See Section 2.9 for more information. | |||||