LTC3445 - I²C Controllable Buck Regulator with Two LDOs in a 4mm × 4mm QFN

The buck regulator has a 6-bit programmable output range of 0.85V to 1.55V. Also, the buck regulator uses either a constant (1.5MHz) or a spread spectrum switching frequency. Using the spread spectrum option allows for a lower noise regulated output as well as low noise at the input. In addition, the regulated output voltage slew rate is programmable via the I2C interface.

The LTC3445 contains two LDO voltage regulators. The regulator output voltages are externally resistor programmable. Each LDO is capable of delivering up to 50mA.

The LTC3445 contains control circuitry (PowerPath) for automatic back-up battery selection. VBACKUP is typically a coin cell.

Typical supply current during operation is only 360µA and drops to 27µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3445 ideal for single Li-Ion battery-powered applications. Automatic Burst Mode® operation increases efficiency at light loads, further extending battery life.

Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, Spread Spectrum patent pending.

特点

Buck Regulator
High Efficiency: Up to 93%
600mA Output Current (VCC1 = 3V, VOUT = 1.3V)
Programmable Output Voltage: 0.85V to 1.55V
2.5V to 5.5V Input Voltage Range
1.5MHz Constant Frequency or Spread Spectrum Option
Soft-Start
LDOs
Two LDO Regulators: 0.3V Dropout at 50mA
PowerPath Controller
Dynamically Regulates VCC BATT
I2C
Standard (100kHz) or Fast Mode (400kHz)
24-Lead (4mm × 4mm) QFN Package

典型应用

应用

Intel’s Microprocessor Supply (PXA27X)
Portable Instruments

封装信息

**Order Information 订购型号**
器件型号	封装	温度	价格 (以 1 ~ 99 片为批量)	价格 (以 1000 片为批量) *
LTC3445EUF#PBF	4x4 QFN-24	E	$3.50	$2.45
LTC3445EUF#TRPBF	4x4 QFN-24	E		$2.51

演示电路板


器件型号	描述	价格
DC698A	LTC3445EUF Demo Board \| I2C-Controllable Buck Plus Dual LDO & PowerPath, 2.5V ≤ VIN ≤ 5.5V, Vout1 = 0.85 to 1.55 @ 0.6A, Vout2 = 1.3V @ 50mA, Vout3 = 1.1V @ 50mA	联系凌力尔特