LM3290 RF Power Envelope Modulator for Power Amplifiers
【产品特性】• Supports Envelope Tracking - dynamically adjustable output power
• Integrated boost
• Extremely low receive band (RxBN) noise:
• Provides maximum PA efficiency for even longer battery life and reduced heat
• Maximizes efficiency at all output powers with no dropped signals
• Flexible implementation with various 3G/4G platforms
• Reliable, established supplier and product with the ability to meet high volumes
【产品应用】• Handset: Smartphone
• 3G/LTE data cards and wireless modems
• Tablet: Multimedia
【文字介绍】The LM3290 operates in two active modes:
For low TX output power, LM3290 may operate in Average Power Tracking (APT) mode, providing a static, but programmable, output voltage to supply the PA.
At light load and in APT mode, the LM3290 enters into Pulse Frequency Mode (PFM) operation automatically and operates with reduced switching frequency. In PFM mode, the quiescent current is reduced, which extends the battery life. In ET mode, the LM3290 with LM3291 efficiently provides a dynamic, high-bandwidth supply voltage for the PA to maximize total EM + PA efficiency.
The envelope modulator follows the envelope reference input signal delivered by the RFIC to the LM3291 via a differential analog input. The output is a single-ended power supply signal to the PA.
The LM3290 and LM3291 support 3G, as well as LTE operation up to 20-MHz signal bandwidth.
The LM3290 controls the LM3291 companion-IC through direct control signals, and no additional controls are needed from the system. Shutdown, standby, and idle modes turn the EM off and reduce battery current consumption.