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

The LTC®3445 contains a high efficiency monolithic synchronous current mode buck regulator, two LDO regulators, a PowerPathTM controller and an I2CTM interface.

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

产品特点 Features
  • 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
应用
  • Intel’s Microprocessor Supply (PXA27X)
  • Portable Instruments
典型应用图
LTC3445 典型应用
参数
LTC3445 参数
LTC3445 订购信息和价格参考Package Variations and Pricing
器件型号 封装 引脚 温度 价格 (以 1 ~ 99 片为批量) 价格 (以 1000 片为批量) *
LTC3445EUF QFN 24 E $3.50  $2.45 
LTC3445EUF#PBF QFN 24 E $2.51 
LTC3445EUF#TR QFN 24 E $3.50  $2.45 
LTC3445EUF#TRPBF QFN 24 E $2.51 
LTC3445 数据手册及相关资料下载
  1. 数据手册(英文) : LTC3445 - I2C Controllable Buck Regulator with Two LDOs in a 4mm × 4mm QFN.PDF
  2. 设计要点 (英文) : Design Solutions 10 - Active Voltage Positioning Reduces Output Capacitors.PDF
  3. 可靠性数据 : R415 Reliability Data .PDF