DESCRIPTION
UTC UD05123 is a 2.25MHz constant frequency current mode
PWM step-down converter. It is ideal for portable equipment
requiring very high current up to 1.8A from single-cell Lithium-ion
batteries while still achieving over 90% efficiency during peak load
conditions. The 2.5V to 5.5V input voltage range makes UTC
UD05123 ideally suited for single Li-Ion, two to four AA
battery-powered applications. 100% duty cycle provides low
dropout operation, extending battery life in portable systems. Pulse
skipping mode operation provides very low output ripple voltage for
noise sensitive applications. Switching frequency is internally set at
2.25MHz, allowing the use of small surface mount inductors and
capacitors. The internal synchronous switch increases efficiency
and decreases need of an external Schottky diode. Low output
voltages are easily supported with the 0.6V feedback reference
voltage.
FEATURES
* Input Voltage Range :2.5V~5.5V
* Output Voltage: from 0.6V to VIN
* High Efficiency: Up to 92%
* Constant Frequency Operation: 2.25MHz
* Output Current:1.2A
* Quiescent Current: 50uA (input < 4.2V)
* No Schottky Diode Required
* 100% Duty Cycle in Dropout
* 0.6V Reference Allows Low Output Voltages
* Current Mode Operation for Excellent Line and Load
Transient Response
* Current limit, Enable function
* Short Circuit Protect (SCP)
* ≤1μA Shutdown Current