What is ideal diode? What is the difference from discrete?

The diode whose forward voltage is 0 equipped with characteristics of passing current in only one direction is called ideal diode.

An IC (integrated circuit) that reproduces the characteristics of this ideal diode is called ideal diode IC. As the ideal diode has no forward voltage drop or current leakage, it has no forward voltage drop, loss, or current leakage that have occurred in discrete diode.

With an actual ideal diode IC, it is possible to completely eliminate forward voltage or current leakage because there are on-resistance and current leakage of FET in IC, however, forward voltage drop and power loss can be considerably reduced compared to diode.

Advantages / disadvantages of ideal diode IC

The ideal diode IC has various advantages compared to discrete diode.

Advantages

• Low loss due to such a small VF & low current leakage
  (XC8110/XC8111: VF = 20 mV, discrete SBD: VF = 0.3 to 0.4 V)
• As VF is small, output voltage fluctuation is small and it contributes to stable operation of system
• Equipped with various built-in protection functions
• Small PKG

Disadvantages

• Maximum output current and output voltage are restricted
• Number of products is small / less compatible compared to discrete diode