XC9505 Series

2ch. Step-Down / Inverting DC/DC Controller

XC9505 series are PWM controled, PWM/PFM automatic switching, 2 channel (step-down and inverting) DC/DC controller ICs. With 0.9V of standard voltage supply internal, and using externally connected components, the output 1 voltage (step-down DC/DC controller) can be set freely within a range of 0.9V to 6.0V. Since the output 2 (inverting DC/DC controller) has a built-in 0.9V reference voltage (±2.0%), negative voltage can be set with the external components.

With a 180kHz frequency, the size of the external components can be reduced. Switching frequencies of 300kHz and 500kHz frequency are also available as custom designed products.

The control of the XC9505 series can be switched between PWM control and PWM/PFM automatic switching control using external signals. Control switches from PWM to PFM during light loads when automatic switching is selected and the series is highly efficient from light loads through to large output currents. Noise is easily reduced with PWM control since the frequency is fixed.

The series gives freedom of control selection so that control suited to the application can be selected. Soft-start time is internally set to 10ms (output1) which offers protection against rush currents and voltage overshoot when the power is switched on.

Typical Application Circuit


2chDC/DC Controller Output1 : Step-down DC/DC Controller
Output2 : Inverting DC/DC Controller
Soft-Start Internally Set-Up
Output Voltage Range Output 1: 0.9V~6.0V ,Can be set freely with 0.9V (±2.0%) of reference voltage supply and external components
Output2 : -30.0V~0V ,Can be set freely with 0.9V (±2.0%) of reference voltage supply and external components
Output Current Output1 :more than 1000mA (VIN=5.0V, VOUT=3.3V),Output2 :more than -100mA (VIN=5.0V, VOUT= -3.3V)
Stand-by Current 3.0μA(MAX)
Power Supply Voltage Range 2.0V~10V
Oscillation Frequency 180kHz±15%, 300kHz、500kHz are available as custom



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.

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.