XC9515 Series

Dual Synchronous Step-Down DC/DC Converter with Manual Reset

The XC9515 series consists of 2 channel synchronous step-down DC/DC converters and a voltage detector with delay circuit built-in.

The DC/DC converter block incorporates a P-channel 0.35Ω (TYP.) driver transistor and a synchronous N-channel 0.35Ω (TYP.) switching transistor. By minimizing ON resistance of the built-in transistors, the XC9515 series can deliver highly efficient and a stable output current up to 800mA. With high switching frequencies of 1MHz, a choice of small inductor is possible. The series has a built-in UVLO (under-voltage lock-out) function, therefore, the internal P-channel driver transistor is forced OFF when input voltage becomes 1.8V or lower (for XC9515A, 2.7V or lower). The voltage detector block can be set delay time freely by connecting an external capacitor. With the manual reset function, the series can output a reset signal at any time.

Typical Application Circuit


DC/DC Block
Input Voltage Range 2.5V~5.5V
Output Voltage VOUT1=1.2V~4.0V/VOUT2=1.2V~4.0V(Accuracy ±2%)
Oscillation Frequency 1MHz(Accuracy±15%)
High Efficiency 95%(VIN=5V,VOUT=3.3V)
Output Current 800mA
Control Methods PWM
Protection Circuits Thermal Shut Down、Integral Latch(Over Current Limit)、Short Circuit Protection
Capacitor Low ESR Ceramic
VD Block
Detect Voltage Range 2.0~5.5V(Accuracy ±2%)
Delay Time 173ms(Cd=0.1μF is connected)
Output Configuration N-channel open drain



Quality Reports


QuestionWhat does the standby mode mean in the case of the multi channel IC?

It means the state where the entire IC has been turned off. For Torex products, it means that the pin voltages of EN1 and EN2 are both 0V.

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

QuestionHow does UVLO (under voltage lockout) work?

This circuit forcibly turns off the driver transistor when VIN drops below the UVLO voltage. If the input voltage recovers to the value which is equal to the specified value or more, UVLO will be released to resume the switching operation. It is resumed by the soft-start function. The paused state by UVLO is not the shutdown. The pulse output is stopped, but the internal circuit is operating.