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LM3668是一个同步升降压DC/DC变换器,用于优化单节锂电池输出的低压电路和2.5V--5.5V输入电压电路。It has the capability to support up to 1 A output current over the output voltage range. The LM3668 regulates the output voltage over the complete input voltage range by automatically switching between buck or boost modes depending on the input voltage.The LM3668 has 2 N-channel MOSFETS and 2 P-channel MOSFETS arranged in a topology that provides continuous operation through the buck and boost operating modes. There is a MODE pin that allows the user to choose between an intelligent automatic PFM一PWM mode operation and forcedPWM operation. During PWM mode, a fixed-frequency 2.2MHz (typ.) is used. PWM mode drives load up to 1A. Hysteretic PFM mode extends the battery life through reduction of the quiescent current to 45pA (typ.) at light loads during system standby.Internal synchronous rectification provides high efficiency. In shutdown mode (Enable pin pulled low)the device turns off and reduces battery consumption to 0.01 uA (typ.).The LM3668 is available in a 12-pin WSON package.A high switching frequency of 2.2MHz (typ.) allows the use of tiny surface-mount components including a 2.2pH inductor, a 10pF input capacitor, and a 22pF output capacitor.产品特性
- 45trA Typical Quiescent Current
- For 2.8V/3.3V and 3.0/3.4V Versions:
一1A Maximum Load Current for VIN=2.8V to 5.5V 一800mA Maximum Load Current for VIN=2.7V 一600mA Maximum Load Current for VIN=2.5V
一1A Maximum Load Current for VIN=3.9V to 5.5V 一800mA Maximum Load Current for VIN=3.4V to 3.8V 一700mA Maximum Load Current for VIN=3.0V to 3.3V 一600mA Maximum Load Current for VIN=2.7V to 2.9V
- 2.2MHz PWM Fixed Switching Frequency (typ.)
- Automatic PFM-PWM Mode or Forced PWM Mode
- Wide Input Voltage Range: 2.5V to 5.5V
- Internal Synchronous Rectification for High Efficiency
- Internal Soft Start: 600trs Maximum Startup Time After VIN Settled
- O.O1trA Typical Shutdown Current
- Current Overload and Thermal ShutdownProtection
- Frequency Sync Pin: 1.6MHz to 2.7MHz
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发表于 2013-7-29 08:48:33
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