XC9131 Series

1A Driver Transistor Built-in, Step-Up DC/DC Converters with Load Disconnection Function

XC9131 series are synchronous step-up DC/DC converters with a 0.2Ω(TYP.) N-ch driver transistor and a 0.2Ω(TYP.) synchronous P-ch switching transistor built-in. A highly efficient and stable current can be supplied up to 1.0A by reducing ON resistance of the built-in transistors.

The series are able to start operation under the condition which has 0.9V input voltage to generate 3.3V output voltage with a 33Ωload resistor, suitable for mobile equipment using only one Alkaline battery or one Nickel metal hydride battery.

During the operation of a shutdown, the load disconnection function enables to cut the current conduction path from the input to the output.

The XC9131 series has 0.5V±0.01V reference voltage integrated and being able to set an output voltage with external components.

Typical Application Circuit


Input Voltage Range 0.65V~5.5V
Output Voltage Range VFB=0.50V±0.01V Set up with external components
Oscillation Frequency 1.2MHz(Accuracy ±15%)
Input Voltage 1.0A
Output Current 500mA@VOUT=3.3V,VIN=1.8V(TYP.)
Control Methods PWMControl、PWM/PFM auto
Load Transient Response 100mV@VOUT=3.3V、VIN=1.8V、IOUT=1mA→200mA
Protection Circuits Thermal Shut Down、Over Current Limit
Functions Soft-start, Load Disconnection Function, CL Discharge Function, Flag-out Function
Capacitor Low ESR Ceramic



Quality Reports


QuestionHow does the GO function of DC/DC converters work? Does it work just like a regulator?

Torex regard the PWM/PFM automatic switch control function as Green Operation (GO) in the case of DC/DC. The GO function is defined as the switching operation between the PFM mode for a small output current and the PWM mode for a large output current. The PFM control method controls the output current by increasing and decreasing the fall time according to the output current while keeping a pulse width. The PWM control method controls the output current by adjusting the pulse width of the rise time, which keeps the rise/fall time interval constant and increases the efficiency at a heavy load. By switching between the PFM control for a small output current and the PWM control for a large output current, the quiescent current can be controlled for both of heavy and light loads.

QuestionWhat is the soft-start function?

The function to soften the rise to prevent the inrush current.

QuestionWhat is the standby current?

The current that flows through the IC in the standby mode. The standby mode means the state where the IC has been turned off by the CE function.

QuestionWhat does the FB product mean?

An IC for which any output voltage can be set by the reference voltage of the FB pins and the external dividing resistor. The output voltage is determined by the RFB1 and RFB2 values, using the following formula: VOUT = Vref × (RFB1 + RFB2)/RFB2