Power output specifications

System power out limits (when powered with 12 VDC)

Temperature (°C) Current limit1 (A)
–40° 3.88
0° 2.98
20° 2.50
50° 1.80
70° 1.35
85° 1.00

1 Limited by self-resetting thermal fuse

12 V and SW12 V power output terminals

12V, SW12-1, and SW12-2: Provide unregulated 12 VDC power with voltage equal to the Power Input supply voltage. These are disabled when operating on USB power only. Voltage output is 0.3 VDC less than voltage at BAT terminals. The 12V terminal is limited to the current shown in the previous table. Each SW12 terminal has a thermal-fuse hold-current limited to the values in the following table.

SW12 current limits
Temperature (°C) Current limit 1 (mA)
–40° 1600
0° 1290
20° 1100
50° 830
70° 640
85° 500

1 Thermal fuse hold current. Overload causes voltage drop.
Disconnect and let cool to reset. Operate at limit if the application
can tolerate some fluctuation.

U and C as power output

Operating at the current limit is OK if voltage fluctuation can be tolerated. Drive capacity is determined by the logic level of the VDC supply and the output resistance (Ro) of the U terminal. It is expressed as: Vo = 5 V – (Ro • Io), where Vo is the drive limit, and Io is the current required by the external device. For example: if a device requires the maximum current limit of 20 mA, on U1 (odd number terminal) the voltage level would reduce from 5 V to 3.5 V. To operate the same device on U2 (even number terminal) the voltage would drop to 2.0 V. Many 5 V devices will not operate correctly at 2.0 V; so this device should be connected to an odd channel.

NOTE:

U terminals can be shorted to ground without damage.

  • C Terminals:

    • Output Resistance (Ro): 150 Ω
    • 5 V Logic Level Drive Capacity: 10 mA @ 3.5 VDC; Vo = 5 V - (150 Ω •Io)
    • 3.3 V Logic Level Drive Capacity: 10 mA @ 1.8 VDC; Vo = 3.3 V - (150 Ω •Io)

  • U Terminals:

    •  

    U odd terminals

    U even terminals
    Voltage Excitation Max Current @ ±2500 mV ±25 mA ±25 mA
    Current Excitation Max Current ±2500 µA ±2500 µA
    5 V Logic Level Output Resistance (Ro) 75 Ω 150 Ω
    5 V Logic Level Max Current @ 3.5 V 20 mA 10 mA
    3.3 V Logic Level Output Resistance (Ro) 73 Ω 145 Ω
    3.3 V Logic Level Max Current @1.85 V 20 mA 10 mA

    U odd terminals: U1, U3, U5, U7, U9, U11.
    U even terminals: U2, U4, U6, U8, U10, U12

CS I/O pin 1

5 V Logic Level Max Current: 200 mA