Step-Up DC/DC Converter MM1331 MITSUMI Step-Up DC/DC Converter (VFF) Monolithic IC MM1331 Outline This is a converter IC which steps up the DC input voltage to output a fixed voltage level. Utilizing technology for low-voltage operation, which is a feature of Mitsumi semiconductor processes, operation is possible beginning at 0.85V, making this device ideal for the power supply circuits of portable equipment driven by a single battery. Under small load currents oscillation is stopped and the charge stored in an externally mounted capacitor is output in an intermittent oscillation design, to improve the efficiency of operation under light loads. Features 1. 2. 3. 4. Low-voltage operation possible, 0.85V (no-load) Internal oscillation circuit Intermittent oscillation design for improved light-load efficiency Numerous output voltages available (seven ranks) Package SOT-25 Output Voltage Rank Rank A B C D E G H Voltage (V) 5.0 3.2 3.5 3.0 2.5 2.2 2.7 Applications 1. Pagers 2. Separate vibrators 3. Other portable equipment Pin Assignment 5 1 4 2 SOT-25 3 1 GND 2 SUB 3 VL 4 VOUT 5 VIN *Pin 2 is the SUB pin, and should be connected to GND. Step-Up DC/DC Converter MM1331 MITSUMI Block Diagram Note: Pin 2 is the SUB pin, and should be connected to GND. Absolute Maximum Ratings Item Symbol Ratings Units Storage temperature TSTG -40~+125 °C Operating temperature TOPR -20~+75 °C Voltage applied to VIN pin -0.3~+10 V Voltage applied to VOUT pin -0.3~+10 V Voltage applied to VL pin -0.3~+10 V 150 mW Allowable loss Pd Recommended Operating Conditions Item Symbol Ratings Units Operating temperature Top -20~+75 °C Operating voltage Vop +0.85~VOUT V Step-Up DC/DC Converter MM1331 MITSUMI Electrical Characteristics (Except where noted otherwise, VIN=1.5V, IO=1mA) Item Measurement conditions Operating voltage No-load Min. Typ. Max. Units 0.85 VOUT Output voltage rank A 4.80 5.0 5.20 rank B 3.07 3.2 3.33 rank C 3.36 3.5 3.64 2.88 3.0 3.12 rank E 2.40 2.5 2.60 rank G 2.11 2.2 2.29 rank H 2.59 2.7 2.81 VIN=1.5V, Io=1mA rank D Output voltage temperature coefficient Ta=-20~75°C VIN=1.1 Input fluctuations 1.7V, Io=1mA VIN=1.5V, Io=0 Load fluctuations ±100 7mA V V PPM/°C 3 %/°C 1 %/mA VIN pin consumption current VIN=1.5V, VOUT=VOUT max.+0.05 3 4.5 µA VOUT pin consumption current VOUT=VOUT max.+0.05 5 7.5 µA VL pin leakage current VL=10V 1 µA Output ripple voltage VIN=1.5V, Io=1mA 60 120 mV Oscillation frequency VIN=1.5V 115 185 kHz 70 Note: Electrical characteristics assume use of the following externally mounted components. Coil Mitsumi model C5-R L=120µH Capacitor tantalum electrolytic C=33µF SBD Rohm model RB451F Application Circuits Note: Coil: L = 120µH (Mitsumi model C5-R) Capacitor : C=33µF (tantalum electrolytic capacitor) Schottky barrier diode (Rohm model RB451F) Step-Up DC/DC Converter MM1331 MITSUMI Characteristics Tek Stop : 100kS/S 402 Acqs Conditions ;VIN=1.5V, Io=1mA L=120µH (C5-R) CIN=COUT=33µF (tantalum) SBD ; RB451F 1 VOUT pin waveform 50mV/div 500µS/div VL pin waveform 1V/div 2 Ch1 50.0mV Ch2 100V M 500µS Ch2 2.66V VOUT Output voltage (V) 4 3 IO=100mA 2 IO=1mA IO=5mA 1 0 0.5 1.0 1.5 VIN Input voltage (V) *The above characteristics are representative, and are not guaranteed values.