TS1581

5A Dual Input LDO

4/9

Version: A07

Application Information (Continue)

Grounding and Output Sensing

The TS1581 allows true Kelvin sensing for both the high & low side of the load. A result the voltage regulation at the

load can be easily optimized. Voltage drops due to parasitic resistances between the regulator and the load can be

placed inside the regulation loop. The advantages of remote sensing are illustrated in Figure 1 through 3.

Figure 1 show the device connected as a conventional 3 terminal regulator with the Sense lead connected directly to

the output of the device. Rp is the parasitic resistance of the connections between the device and the load. Trace A of

Figure 3 illustrates the effect of Rp.

Figure 2 show the device connected to take advantage of the remote sense feature. The Sense Pin and the top of the

resistor divider are connected to the top of the load; the bottom of the resistor divider is connected to the bottom of the

load.

Figure 1. Conventional Load Sensing

Figure 2. Remote Load Sensing

The effect on output regulation can be seen in trace B of Figure 3. It is important to note that the voltage drops due to

Rp are not eliminated; they will add to the dropout voltage of the regulator regardless. The TS1581 can control the

voltage at the load as long as the input-output voltage is greater than the total of the dropout voltage of the device plus

the voltage drop across Rp

Figure 3. Remote Sensing Improves Load

Regulation

Figure 4. Illustrates there transient effects