XC9128/XC9129 Series ETR0411-013 1A Driver Transistor Built-In, Step-Up DC/DC Converters Green Operation Compatible GENERAL DESCRIPTION The XC9128/XC9129 series are synchronous step-up DC/DC converters with a 0.2 (TYP.) N-channel driver transistor and a synchronous 0.2 (TYP.) P-channel switching transistor built-in. A highly efficient and stable current can be supplied up to 1.0A by reducing ON resistance of the built-in transistors. With a high switching frequency of 1.2MHz, a small inductor is selectable making the series ideally suited for applications requiring low profile or space saving solutions. With the MODE pin, the series provides mode selection of PWM control or PFM/PWM automatic switching control. In the PWM/PFM automatic switching mode, the series switches from PWM to PFM to reduce switching loss when load current is small. When load current is large, the series switches automatically to the PWM mode so that high efficiency is achievable over a wide range of load conditions. The series also provides small output ripple from light to large loads by using the built-in circuit which enables the smooth transition between PWM and PFM. With a adaptor enable function of the XC9128 series, when a voltage higher than the input voltage is applied to the output, the input and the output become isolated making it possible for the IC to work in parallel with the likes of an AC adaptor. APPLICATIONS FEATURES Digital audio equipment High Efficiency, Large Current Step-Up Converter : 150mAVOUT=3.3V, VIN=0.9V Digital still cameras / Camcorders Output Current 500mAVOUT=3.3V, VIN=1.8V Computer Mouses Input Voltage Range : 0.8V ~ 6.0V Multi-function power supplies : 1.8V ~ 5.3V (Externally set) Output Voltage Setting Set up freely with a reference voltage Range supply of 0.45V (0.010V) & external components : 1.2MHz Oscillation Frequency (Fixed oscillation frequency accuracy 15%) Input Current : 1.0A Maximum Current Limit : 1.2A (MIN.), 2.0A (MAX.) : PWM, PWM/PFM control Control externally selectable High Speed :100mV VOUT=3.3V, Transient Response VIN=1.8V, IOUT=10mA100mA : Thermal shutdown Protection Circuits Integral latch method (Over current limit) Soft-Start Time : 5ms (TYP.) internally set Ceramic Capacitor Compatible Adaptor Enable Function (XC9128 series) Flag Output (XC9128 series) : Open-drain output Operating Ambient Temperature : - 40 ~ 85 Packages : MSOP-10, USP-10B Environmentally Friendly : EU RoHS Compliant, Pb Free TYPICAL PERFORMANCE TYPICAL APPLICATION CIRCUIT CHARACTERISTICS Efficiency vs. Output Current XC9128B45CD L=4.7H(LTF5022-LC),CL=30F(LMK212BJ106KG 3) V =3.3V,V =6V,V =OPEN,V =0V OUT EN FO AEN/ RFB1=270k,RFB2=43k,CFB=12pF,CIN=10F 100 CIN V OUT PGND VOUT 1 10 90 VIN MODE C R 2 Lx MODE 9 FB FB1 80 L C L (ceramic) 70 3 BAT FB 8 1.8V 3.0V EN 60 AGND EN 4 7 50 R FB2 FO 5 FO AEN/ 6 40 30 20 PWM/PFM (VMODE=0V) 10 PWM (V =V ) MODE OUT 0 0.1 1 10 100 1000 Output Current: I (mA) OUT 1/28 Efficiency: EFFI (%) XC9128/XC9129 Series BLOCK DIAGRAM XC9128 Series AGND VOUT Phase Current Sense, Compensation Limit, PFM Error Amp. PWM comparator FB Lx PWM/PFM Buffer Controller, Logic Driver PGND Vref with RAMP Wave AEN/ OSC Soft Start Generator MODE MODE EN, EN Thermal Shutdown FO Current Limit, Thermal, Soft Start, BAT EN XC9129 Series The XC9129 series does not have AEN/ pin and FO pin. 2/28