| In recent years, portable devices such as smartphone have been widespread. MITT issued the license of TD-LTE and FDD-LTE at the end of 2013 and in February 2015 respectively, indicating the era of fully commercial 4G is arrival. Power amplifier module(PAM), as a core component and one of the most energy-consuming module of smartphone, its performance is becoming a critical factor restricting the user experience. Multi-mode multi-band(MMMB) PAM will gradually replace multiple single-mode chip solution with higher level of integration.First, the communication standards and corresponding air interface are reviewed, the needs of PA for different transmitter are analyzed, and the requirements of PA controller with different transimitters, control interfaces, switch and logic interfaces are discussed.Then, the PA control systems for GPIO and MIPI interface, voltage and current control, Qualcomm and MTK platform, pHEMT and SOI switch is proposed respectively. The implement for bandgap reference, low dropout regulator, current clamp, over-voltage protection and other module of PA controller is given and verified with simulation results. The error of the voltage outputed by bandgap reference and low dropout regulator are analyzed deeply. A noval structure reusing the error amplifier and compensation capacitor is ultized for reducing the chip size and retaining the independence of individual output.Finally, a MMMB PA controller for Qualcomm platform which ultizing voltage control and GPIO interface is fabricated in TSMC 0.25μm CMOS process. The simulation and test results show that, the mean, standard deviation, temperature coefficient of the output voltage for 3G PA is 2.894V,17mV,-370ppm/℃ respectively. While the respond and recovery time of over-voltage protection is less than 0.9μs and 7.05μs of the controller for 2G PA respectively. An I/O interface circuit with an enhanced output buffer is proposed for compatible with GPIO and MIPI. The simulation results show that it meets the requirement of GPIO and MIPI interface with different wire bonding schemes. |
