PWM/PFM Step-Up DC/DC Controllers
- XC9120 PWM Only
- XC9121 PWM/PFM (Auto Switching Control)
- XC9122B091MR-G PWM/PFM (Manual Switching Control)
The XC9120/9121/9122 Series are PWM, PWM/PFM auto/external switching controlled step-up DC/DC converter controller ICs. Since maximum duty ratio is as large as 93%, the series is optimised for applications used as high step-up ratios, such as the LCD panels and OLEDs. Even with a high step-up ratio, a stable output voltage at high efficiency can be obtained. With 0.9V (±2.0%) of reference voltage supply internal, and using external resistors, (RFB1 and 2),output voltage can be set up freely within a range of 1.5V to 30V.
Control automatically switches from PWM to PFM during light loads with the XC9121 series and the XC9122B091MR-G series can switch the control from PWM to PFM using external signals depending on the circuit conditions.During stand-by (when the CE pin is low), all circuits are shutdown to reduce current consumption to as low as 1.0μA or less.
A current limiter circuit is built in to the IC (except with the 500kHz version) and monitors the ripple voltage on the FB pin. Operation is shut down when the ripple voltage is more than 250mV. The operations of the IC can be returned to normal with a toggle of the CE pin or by turning the power supply back on.
Features:
- Input Voltage Range : 0.9V ~ 6V
- Operating Voltage Range: 1.8V ~ 6V
- Output Voltage Range : 1.5V ~ 30V
- Set up freely with a standard voltage supplyof 0.9V(±2.0%) & external components
- Oscillation Frequency : 100kHz (±15%)
- Output Current : more than 80mA(VIN=3.6V, VOUT=15V)
- Controls : PWM (XC9120)PWM/PFM auto-switching (XC9121)PWM/PFM manual switching (XC9122)
- High Efficiency : 85% (TYP.)
- Stand-by Current : ISTB=1.0μA (MAX.)
- Load Capacitors : Low ESR capacitors compatible
- Current Limiter Function :Operates when ripple voltage=250mV
