Linear 公司的LT3991 是静太电流仅为2.8uA的55V 1.2A降压稳压器,输入电压从4.3V到 55V,最大输出电流1.2A,可调整的开关频率从250kHz到2MHz,快速瞬态响应,关断电流仅为700nA,主要用作汽车电池调整,手提设备电源以及工业电源.
LT3991:55V, 1.2A Step-Down Regulator with 2.8μA Quiescent Current
The LT3991 is an adjustable frequency monolithic buck switching regulator that accepts a wide input voltage range up to 55V. Low quiescent current design consumes only 2.8μA of supply current while regulating with no load. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping the output ripple below 15mV in a typical application. An internally compensated current mode topology is used for fast transient response and good loop stability. A high efficiency 0.44Ω switch is included on the die along with a boost Schottky diode and the necessary oscillator, control and logic circuitry.
An accurate 1V threshold enable pin can be used to shut down the LT3991, reducing the input supply current to 700nA. A capacitor on the SS pin provides a controlled inrush current (soft-start). A power good flag signals when VOUT reaches 91% of the programmed output voltage.
The LT3991 is available in small 10-pin MSOP and 3mm × 3mm DFN packages with exposed pads for low thermal resistance.
LT3991主要特性:
Ultralow Quiescent Current:2.8μA IQ Regulating 12VIN to 3.3VOUT
Low Ripple Burst ModeR Operation:Output Ripple < 15mVP-P
Wide Input Voltage Range: 4.3V to 55V
1.2A Maximum Output Current
Adjustable Switching Frequency: 200kHz to 2MHz
Synchronizable Between 250kHz to 2MHz
Fast Transient Response
Accurate 1V Enable Pin Threshold
Low Shutdown Current: IQ = 700nA
Power Good Flag
Soft-Start Capability
Internal Compensation
Saturating Switch Design: 0.44Ω On-Resistance
Output Voltage: 1.19V to 30V
Small Thermally Enhanced 10-Pin MSOP Package and (3mm x 3mm) DFN Packages
LT3991应用:
Automotive Battery Regulation
Power for Portable Products
Industrial Supplies
