1.0A Inductor Built-in Step-Down “micro DC/DC” Converters
The XCL219 series is a synchronous step-down micro DC/DC converter which integrates an inductor and a control IC in one tiny package (2.0mm×2.5mm, h=1.0mm). An internal coil simplifies the circuit and enables minimization of noise and other operational trouble due to the circuit wiring. A wide operating voltage range of 2.5V to 5.5V enables support for applications that require an internally fixed output voltage (0.8V to 3.6V). The XCL219 series uses synchronous rectification at an operating frequency of 3.0MHz. The XCL219 series uses HiSAT-COT(*) synchronous rectification.
The series have a high speed soft-start as fast as 0.3ms in typical for quick turn-on. With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage becomes 2.0V or lower. When CE=Low, the integrated CL discharge function which enables the electric charge at the output capacitor CL to be discharged via the internal discharge switch located between the LX and VSS pins. The power consumption will be less than 1.0μA.
(*) HiSAT-COT is an original Torex term for High Speed Transient Response
|Jul 1, 2015||
|Smallest size in the world! Step-down "micro DC/DC" converters with1.0A output current and integrated coil|
Typical Application Circuit
|Input Voltage Range||2.5V～5.5V|
|Control Methods||HiSAT-COT Control
100% Duty cycle
|Protection Circuits||Thermal Shut Down
Current Limit Circuit (Drop)
Short Circuit Protection
|Capacitor||Low ESR Ceramic|
|Operating Ambient Temperature||-40℃～+105℃|
|Environmentally Friendly||EU RoHS compliant, Pb free|
|Package||CL-2025-02||Number of Pins||6|
|Pcs/Reel||3,000||Package Size(mm)||2.0 x 2.5 x 1.04|
What is the soft-start function?
The function to soften the rise to prevent the inrush current.
How does the CL discharge function work?
The function rapidly releases the charge remained in the CL capacitor to make the VOUT pin voltage zero. The VOUT pin voltage does not reach zero immediately after being turned off by the CE function due to the charge remained in the connected CL capacitor. While the charge in the CL capacitor is gradually reaching zero, the LSI continues operating and does not work with the CE pin signal, which may cause a malfunction. This is why the discharge is required when turning off the CE pin. A larger capacitance of the capacitor needs longer time to be discharged.
What does CL mean?
Load capacitor. Other companies often refer to it as COUT.
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
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.