LT1144 Datasheet | Linear Technology

LTC1144 Switched-Capacitor Wide Input Range Voltage Converter with Shutdown Features s s s s s s DESCRIPTIO s s Wide Operating Supply Voltage Range: 2V to 18V Boost Pin (Pin 1) for Higher Switching Frequency Simple Conversion of 15V to - 15V Supply Low Output Resistance: 120Ω Maximum Power Shutdown to 8µA with SHDN Pin Open Circuit Voltage Conversion Efficiency: 99.9% Typical Power Conversion Efficiency: 93% Typical Easy to Use The LTC1144 is a monolithic CMOS switched-capacitor voltage converter. It performs supply voltage conversion from positive to negative from an input range of 2V to 18V, resulting in plementary output voltages of - 2V to - 18V. Only two noncritical external capacitors are needed for the charge pump and charge reservoir functions. The converter has an internal oscillator that can be overdriven by an external clock or slowed down when connected to a capacitor. The oscillator runs at a 10k Hz frequency when unloaded. A higher frequency outside the audio band can also be obtained if the Boost Pin is tied to V +. The SHDN pin reduces supply current to 8µA and can be used to save power when the converter is not in use. The LTC1144 contains an internal oscillator, divide-bytwo, voltage level shifter, and four power MOSFETs. A special logic circuit will prevent the power N-channel switch substrate from turning on. APPLICATI s s s s s s s Conversion of 15V to ±15V Supplies Inexpensive Negative Supplies Data Acquisition Systems High Voltage Upgrade to LTC1044 or 7660 Voltage Division and Multiplications Automotive Applications Battery Systems with Wall Adapter/Charger TYPICAL APPLICATI LTC1144 1 Generating - 15V from 15V 8 BOOST V+ 2 7 CAP+ OSC 3 6 GND SHDN 4 5 CAP- VOUT Output Voltage vs Load Current, V + = 15V - 15 ROUT = 56Ω TA = 25°C - 14 OUTPUT VOLTAGE (V) 15V INPUT 10µF + - 15V OUTPUT 10µF 1144 TA01 - 13 - 12 - 11 - 10 0 10 30 40 20 LOAD CURRENT (m A) 50 1144...