600kHZ PWM/PFM STEP-DOWN DC-DC CONTROLLER
DESCRIPTION
The UTC UC3750 is a high frequency, micropower, voltage mode
step-down DC-DC controller IC and is designed for battery operated
hand-held electronic products. It can provide up to 2.0A loading
current with conversion efficiency by connection of appropriate
external P-type MOSFET. It also can be applied to operate for voltage
regulation with minimum external components and board space.
The UTC UC3750 can operate in the constant -frequency PWM
(Pulse Width Modulation) mode that provide low output ripple noise in
the normal operation and will automatically switch to PFM(Pulse
Frequency Modulation) mode at low output loads for higher efficiency.
Moreover, it is ideal for portable applications profited from Chip
Enable (CE) to reduce IC off-stage current and integrated feedback resistor network.
The UTC UC3750 is suitable for applications, such as PDA,
camcorders and digital still camera, hand-held instrument, distributed
power system, computer peripheral, conversion from four NiMH or
NiCd or one Lithium-ion cells to 3.3V/1.8V.
FEATURES
* High efficiency: 92% (Typ.)
* Low quiescent bias current :50μA
* Low shutdown current:0.3μA (Typ.)
* Output voltage:1.8V~3.3V ±2.0%
* Low output voltage ripple:50mV (Typ.)
* Built-in soft-start (SS)
* Pulse Width Modulation (PWM)switching frequency:600kHz
* Automatic PWM/PFM switchover under light load condition
* Very low dropout operation, 100% max. duty cycle
* Chip enable(CE) pin with on-chip 150nA pull-up current source
* Input voltage：2.45V- 5.5V
* Internal under-voltage lockout (UVLO) protection
* Low profile and minimum external components
* Halogen free |
