XC8110/11 6.0V 500mA/1.0A Load Switch and Ideal Diode
The XC8110/11 is a Load switch with Ideal Diode function. The perfect Ideal Diode has a Forward Voltage (VF) of zero Volts, resulting in a Diode with no voltage drop. Whilst this perfect Diode remains elusive our new IC comes very close to the achieving this goal.
Essentially, this new series is a small Line Switch with ultra-low On Resistance and Ideal Diode functionality, where the Ideal Diode portion has very low VF - only 20 mV. The typical VF of a standard Schottky Barrier Diode is 300 ~ 400 mV in comparison and although this is still not so large, if used in a battery powered application, this loss will greatly shorten the life of the battery. As a result, the voltage and power loss with the XC8110/11 is much smaller than that of a Schottky Barrier Diode and it helps extend battery life and reduce thermal issues.
The XC8110/11 features several protection & prevention circuits including over current limit with foldback, thermal shutdown, inrush current prevention (which operates like a soft-start at start-up) and not just reverse current prevention, but “true” reverse current prevention. To block reverse current, VOUT is regulated as ‘VIN - 20 mV’ and this operation realizes to detect reverse bias and prevents reverse current with a comparator. It should be noted that VOUT is 20 mV lower than VIN under all conditions so even if IOUT = 0. The XC8110/11 is the perfect choice for an OR circuit to connect multiple power lines, and because the quiescent current of VIN is 0 μA when reverse biased it is also ideal for use in back-up circuits.
|1.5 V ~ 6.0 V
(VIN > 1.7 V)
(VIN > 2.0 V)
|Over Current Limit
|Reverse Bias Current
|Ideal Diode Function
|Inrush Current Prevention
|Over Current Limit
|Op. Amb. Temp.
|-40℃ ~ +105℃
|WLP-4-02, USP-6B06 or SOT-25
(0.82 x 0.82 x 0.5mm)
(1.5 x 1.8 x 0.33mm)
(2.8 x 2.9 x 1.3mm)
The XC8110/11 is perfect for OR circuits because of its low VF and 0 μA VIN Iq when Reverse biased.
The OR circuit above switches between two power supplies without voltage drop.
Primary Battery, Li Battery re-chargeable by LDO (LTO Battery) or using a Supercapacitor
The ideal diode function has a low VF drop and this is an important consideration for designs using MCUs or SoC that operate at lower voltages (1.6V ~ 3.8V). These low power MCUs and SoCs can be powered directly from the new generation of Li batteries that are re-chargeable using an LDO, alternatively, the MCU can also be powered from a Supercap and in both cases, the XC8110/11's ultra-low VF ensures the stored energy is used efficiently with minimum wastage.
The XC8110/11 can also be shut down by adding a resistor (R) and a switch (SW) to the CE pin and this allows the engineer to implement a Storage Mode function that will disconnect the battery during storage or shipping thereby reducing battery drain over long periods.
- Shutdown: Turn off by applying "H" pulse to Gate of Nch Tr of SW
- Wake-up: Turn on by applying the external power supply
The circuit can be woken up later by applying an external power supply and if the voltage from the external power supply is high, the current consumption from the Li battery and Supercap will be 0μA
The XC8110/11 can be used to enhance the charging circuit for a Li-ion battery.
The XC8110/11 can also be used to implement a Current Path Function for a Li-Ion battery Charger as shown above.
When the USB power supply is active the voltage loss from the Li battery will be almost 0. The shut-down function (described above) means the battery can also be disconnected during shipment or storage to conserve battery life whilst in transit.
XC8110/11 with two Schottky Barrier Diodes to realize a Reverse polarity connection prevention circuit for batteries and external power supplies.
When connecting in the forward direction
The VIN-VSS bias of XC 8110/11 is applied via SBD2, and XC8110/11 operates to turn ON between VIN and VOUT.
When connecting in the reverse polarity direction
The VOUT-VSS of XC8110/11 is biased through the load circuit and SBD1, and the VIN-VOUT of XC8110/11 is turned off with a reverse connection and CE = "L". Only a small operation current (0.8μA) of XC8110/11 flows through the load in the order of VOUT to VSS and to SBD1, but of course there is no problem at all.
When connected in the forward direction, the power supply starts up with the inrush current prevention function, and the overcurrent limit and thermal shutdown help protect the equipment and power supply.
The XC8110/11 can be configured in a parallel connection for large current and/or low Ron.