3A Step-Down DC/DC Converter with 16V input
The XCM526 series is a multi-module IC which includes a step-down DC/DC controller IC and P-channel power MOSFET. The IC enables a high efficiency, stable power supply with an output current up to 3A. Low ESR electrolytic capacitors such as an OS-CON aluminum solid capacitor, a tantalum Neo capacitor can be used as an output capacitor. In case of using a ceramic capacitor, RSENSE is needed to be placed on.
The XCM526 series has a 0.9V (±1.5%) reference voltage, and using externally connected resistors, the output voltage can be set freely. With an internal switching frequency of 500kHz and 1.0MHz, small external components can also be used. The XCM526A has a fixed PWM control for low output voltage ripple, and the XCM526B has a PWM/PFM control, which automatically switches from PWM to PFM during light loads and high efficiencies can be achieved over a wide range of load conditions. As for the soft-start time, there are two types, one is internally set to 4ms and the other can be externally set-up. With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage becomes 2.3V (TYP.) or lower.
Typical Application Circuit
|Power Supply Voltage Range||4.0V～16.0V|
|Output VoltageExternally Set Renge||1.2V～(0.9V±1.5%)|
|Control Methods||PWM control(XCM526A)
PWM/PFM automatic switching(XCM526B)
|Soft-Start||4ms internally fixed and externally set|
|Protection Circuits||Short Circuit Protection|
|Environmentally Friendly||EU RoHS compliant, Pb free|
|Package||USP-12B01||Number of Pins||12|
|Pcs/Reel||3,000||Package Size(mm)||2.3 x 2.8 x 0.6|
How 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.
What is the soft-start function?
The function to soften the rise to prevent the inrush current.
Tell me about XCL205/XCL206/XCL207 Series.
They are coil-integrated step-down DC/DC converters that achieves both a reduction of the mounting area and good characteristics by means of a simple structure whereby the coil is placed on top of the complete DC/DC converter IC. The only components that are needed to output the output current (maximum of 600 mA) are two capacitors, enabling miniaturization when mounting on the board . The simple structure allows existing mass production pieces to be used without degrading the characteristics of the IC, a major advantage.
To limit the height of the combined coil and DC/DC converter to 1 mm, we developed a new ultra-flat package (USP-6EL) with a height of 0.4 mm for the DC/DC converter.
How 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.
What 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