MICROCHIP TC110501ECTTR

The TC110 is a step-up (Boost) switching controller that furnishes output currents of up to 300mA while delivering a typical efficiency of 84%. The TC110 normally operates in pulse width modulation mode (PWM), but automatically switches to pulse frequency modulation (PFM) at low output loads for greater efficiency. Supply current draw for the 100kHz version is typically only 50μA, and is reduced to less than 0.5μA when the SHDN input is brought low. Regulator operation is suspended during shutdown. The TC110 accepts input voltages from 2.0V to 10.0V, with a guaranteed start-up voltage of 0.9V. The TC110 is available in a small 5-Pin SOT-23A package, occupies minimum board space and uses small external components (the 300kHz version allows for less than 5mm surface-mount magnetics). The TC110 is a PFM/PWM step-up DC/DC controller for use in systems operating from two or more cells, or in low voltage, line-powered applications. It uses PWM as the primary modulation scheme, but automatically converts to PFM at output duty cycles less than approximately 25%. The conversion to PFM provides reduced supply current, and therefore higher operating efficiency at low loads. The TC110 uses an external switching transistor, allowing construction of switching regulators with maximum output currents of 300mA. The TC110 consumes only 70μA, typical, of supply current and can be placed in a 0.5μA shutdown mode by bringing the shutdown input (SHDN) low. The regulator remains disabled while in shutdown mode, and normal operation resumes when SHDN is brought high. Other features include start-up at VIN = 0.9V and an externally programmable soft start time.

• Assured Start-up at 0.9V
• 50μA (Typ) Supply Current (fOSC = 100kHz)
• 300mA Output Current @ VIN ≥ 2.7V
• 0.5μA Shutdown Mode
• 100kHz and 300kHz Switching Frequency Options
• Programmable Soft-Start
• 84% Typical Efficiency
• Small Package: 5-Pin SOT-23A

• Palmtops
• Battery-Operated Systems
• Positive LCD Bias Generators
• Portable Communicators