1.General Description 4. Pin Function Description MDT7733 is a step-up DC/DC converter . It has low start-up voltage and a high output voltage accuracy with low ripple. MDT7733 1 2. Features VSS ● High output voltage accuracy：+/- 2.5% Low start-up voltage: 0.75V (Typ.) ● High efficiency: 85% (Typ.) ● Pin Name 2 3 VOUT LX I/O Function Ground ● ● Drain Cellular phones, pagers, mcu Power failure detection ● Portable / Battery-Powered Equipment Palmtops ● RF Keyboard / Mouse ● Open Switching pin LX 3. Applications VOUT Input Output voltage monitor, IC internal power supply ORDERING INFORMATION 1 of 4 Device Package MDT7733ST SOT89 2005/10/18 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. ---------------3.225 ------------------------------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. 3.3 ±2.5 0.75 1.1 Max. 3.375 ±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 +3.3V 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 2 of 4 2005/10/18 6.Application Circuit EXTERNAL COMPONENT : Cin=100uF ; CL=100uF ; Cb=0.1uF L=100uH 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 3 of 4 2005/10/18