MDT7727 Step-up DC/DC Converter 4. Pin Function Description 1.General Description MDT7727ST MDT7727 is a step-up DC/DC converter . It has low start-up voltage and a high output voltage accuracy with low ripple. 1 VSS 2. Features ● ● ● 2 3 VOUT LX MDT7727ST23 VOUT High output voltage accuracy：+/- 2.5% Low start-up voltage: 0.75V (Typ.) High efficiency: 85% (Typ.) 3 1 2 VSS LX 3. Applications ● ● ● ● ● Cellular phones, pagers, mcu Power failure detection Portable / Battery-Powered Equipment Palmtops RF Keyboard / Mouse Pin Name I/O VSS Function Ground LX VOUT Open Switching pin Drain Input Output voltage monitor, IC internal power supply ORDERING INFORMATION Device Package MDT7727ST SOT89 MDT7727ST23 SOT23 This specification are subject to be changed without notice. Any latest information please preview P.1 2006/11 http;//www.mdtic.com.tw Ver 1.1 MDT7727 Step-up DC/DC Converter 5. Electrical Characteristics Parameter Output Voltage Output Ripple Vin Vstart Vhold Iin Supply Current IDD1 Supply Current IDD2 Shutdown Current LX Leakage Current Maximum Oscillator Frequency Oscillator Duty Cycle Test Conditions Min. ---------------2.6325 ------------------------------Iout=1mA Iout=30mA Iout=1mA 0.7 Iout=30mA 1 Without loading VIN=VOUT × 0.95 Measured at VOUT pin without external component VIN=VOUT+0.5V Measured at VOUT pin without external component VCE=0 , VIN=VOUT×0.95 VIN=6V VIN=VOUT0.95 Measured at ETR pin 70 VIN=VOUT_0.95 Measured at ETR pin L , SD , CL etc. connected Typ. 2.7 ±2.5 0.75 1.1 Max. 2.7675 ±3 6 0.8 1.2 20 45 25 52 Unit V % V V V V V uA uA 8 12 uA 200 0.5 1 230 uA uA kHz 75 80 % 85 Efficiency +2.7V Output Type VIN=VOUT×0.6 ; IOUT=30mA ; Ta=25℃ (Unless otherwise specified) % Note: " Supply current 1 " is the supply current while the oscillator is continuously oscillating. In actual operation the oscillator periodically operates. The current actually provided by an external VIN source from VOUT pin. " Supply current 2 " is the supply current while the oscillator stop oscillating. In actual operation the oscillator periodically operates. The current actually provided by an external VIN source from VOUT pin This specification are subject to be changed without notice. Any latest information please preview P.2 2006/11 http;//www.mdtic.com.tw Ver 1.1 MDT7727 Step-up DC/DC Converter 6.Application Circuit & Block Diagram EXTERNAL COMPONENT : Cin=100uF ; CL=100uF ; Cb=0.1uF L=100uH This specification are subject to be changed without notice. Any latest information please preview P.3 2006/11 http;//www.mdtic.com.tw Ver 1.1 MDT7727 Step-up DC/DC Converter 7.TYPICAL PERFOMACE OF EFFICIENCY % EFFICIENCY 100 90 80 70 60 50 40 30 20 10 0 2.0V 1.8V 1.5V 1.2V 0.9V 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 mA 8. OUTPUT VOLTAGE V.S LOADING LOADING v.s OUTPUT VOLTAGE 3.1 2.6 2.0V 2.1 1.8V V 1.5 1.2V 1.6 0.9V 1.1 0.6 10 20 30 40 50 60 70 80 90 100 mA This specification are subject to be changed without notice. Any latest information please preview P.4 2006/11 http;//www.mdtic.com.tw Ver 1.1