TC105

Features:

• 57µA (Typ) Supply Current
• 1A Output Current
• 0.5µA Shutdown Mode
• 300kHz Switching Frequency for Small Inductor Size
• Programmable Soft-Start
• 92% Typical Efficiency
• Small Package: 5-Pin SOT-23A




Application

• Palmtops
• Battery-Operated Systems
• Portable Instruments
• Positive LCD Bias Generators
• Portable Communicators
• Hand-Held Scanners
• 5V to 3V Down Converters




Pinout






Specifications

Parameter NameValueDevice DescriptionStep-down DC/DC ControllerSW Reg OutputFixedTypical Active Supply (A)67Switching Frequency (kHz)300Output Current (mA)1000Output Voltage (V)3.0, 3.3, 5.0Input Voltage Range (V)2.2 to 10

Parameter Name	Value
Device Description	Step-down DC/DC Controller
SW Reg Output	Fixed
Typical Active Supply (A)	67
Switching Frequency (kHz)	300
Output Current (mA)	1000
Output Voltage (V)	3.0, 3.3, 5.0
Input Voltage Range (V)	2.2 to 10

Voltage on V_DD...................................... -0.3V to +12V
EXTOutput Current .......................................±100mA
Voltage on V_OUT, EXT,
SHDN Pins .....................................-0.3V to V_DD +0.3V
Power Dissipation............................................150mW
Operating Temperature Range.............-40 to +85
Storage Temperature Range ..............-40to +125

*Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These
are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability.

Description

The TC105 is a step-down (Buck) switching controller that furnishes output currents of up to 1A (max) while
delivering a typical efficiency of 92%. The TC105 normally operates in pulse width modulation mode (PWM), but automatically switches to pulse frequency modulation (PFM) at low output loads for greater efficiency. Oscillator frequency is 300kHz, allowing use of small (22µH) inductors. Supply current draw is only 102µA (max), and is reduced to less than 0.5µA when the SHDN input is brought low. Regulator operation is suspended during shutdown. The TC105 accepts a maximum input voltage of 10V.

The TC105 is available in a small 5-Pin SOT-23A package, occupies minimum board space and is ideal for a wide range of applications.