LTC3405A-1.5/LTC3405A-1.8
1.5V, 1.8V, 1.5MHz, 300mA Synchronous Step-Down Regulators in ThinSOT
U U
FEATURES
■ High Ef...
LTC3405A-1.5/LTC3405A-1.8
1.5V, 1.8V, 1.5MHz, 300mA Synchronous Step-Down
Regulators in ThinSOT
U U
FEATURES
■ High Efficiency: Up to 93% ■ Very Low Quiescent Current: Only 20µA
During Operation ■ 300mA Output Current at VIN = 3V ■ 2.5V to 5.5V Input Voltage Range ■ 1.5MHz Constant Frequency Operation ■ No
Schottky Diode Required ■ Low Dropout Operation: 100% Duty Cycle ■ Stable with Ceramic Capacitors ■ Shutdown Mode Draws < 1µA Supply Current ■ ±3% Output Voltage Accuracy ■ Current Mode Operation for Excellent Line and
Load Transient Response ■ Overtemperature Protected ■ Low Profile (1mm) ThinSOTTM Package
U APPLICATIO S
■ Cellular Telephones ■ Personal Information Appliances ■ Wireless and DSL Modems ■ Digital Still Cameras ■ MP3 Players ■ Portable Instruments
TYPICAL APPLICATIO
VIN 2.7V
TO 5.5V
CIN** 4.7µF
CER
4 VIN
3 4.7µH* SW
LTC3405A-1.8
1 RUN
6
5
MODE VOUT
GND 2
3405A1518 F01
*MURATA LQH3C4R7M34 **TAIYO YUDEN JMK212BJ475MG
VOUT 1.8V
300mA COUT** 4.7µF CER
Figure 1a. High Efficiency Step-Down Converter
DESCRIPTIO
The LTC®3405A-1.5/LTC3405A-1.8 are high efficiency monolithic synchronous buck
regulators using a constant frequency, current mode architecture. Supply current during operation is only 20µA and drops to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3405A-1.5/LTC3405A-1.8 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable syste...