General Purpose Amplifiers For Vhf To Microwave英文电子书.pdf

Chapter 7 General-Purpose Amplifiers for VHF to Microwave This chapter is devoted to typical IC amplifiers for use in wireless/RF circuits. The MAX2630 through 2633 are selected as examples. These ICs operate from a single 2.7-V to 5.5-V supply, and have a flat gain response to 900 MHz. Their low noise figure and low supply current make the ICs ideal for receiver, buffer, and transmitter IF applications, including cordless phones, cellular phones, TV tuners, set-top boxes, land-mobile radios, PCs (personal communicating systems), GPS (glob- al positioning systems), WLAN (wireless local area networks), and WLL (wireless local loops). 7.1 MAX2630 through 2633 Characteristics Figures 7.1, 7.2, 7.3, and 7.4 show a typical operating circuit, pin con- figurations, ratings and characteristics, and pin descriptions, respec- tively. The MAX2630/31 are biased internally, eliminating the need for external bias resistors or inductors. The MAX2632/33 have a user- selectable supply current, which can be adjusted by adding a single external resistor. This allows customized output power and gain, according to specific application requirements. The MAX2631/33 feature a shutdown pin that allows the ICs to be powered down to less than 1 A of supply current. Aside from a single bias resistor required for the MAX2632/33, the only external compo- nents needed for this family of IC amplifiers are input- and output- blocking capacitors and a VCC bypass capacitor. 117 118 Chapter Seven Figure 7.1 MAX2630 typical operat- ing circuit (Maxim, New Releases