SKY77548数据手册RF/IF射频/中频RFID的射频前端（LNA+PA）规格书PDF

描述 Description

Please note: this product is being discontinued and is not recommended for new designs.

SKY77548 is a transmit and receive Front-End Module (FEM) with Integrated Power Amplifier Control(iPAC™) for Dual-band cellular handsets comprising GSM850/900 and DCS1800/PCS1900 operation.Designed in a low profile, compact form factor, the SKY77548 offers a complete Transmit VCO-to-Antenna and Antenna-to-Receive SAW filter solution. The FEM also supports Class 12 General PacketRadio Service (GPRS) multi-slot operation.

The module consists of a GSM850/900 PA block and a DCS1800/PCS1900 PA block, impedancematchingcircuitry for 50 ohm input and output impedances, Tx harmonics filtering, high linearity anda low insertion loss PHEMT RF switch, and a Power Amplifier Control (PAC) block with internal currentsense resistor. A custom BiCMOS integrated circuit provides the internal PAC function and decodercircuitry to control the RF switches. The two Heterojunction Bipolar Transistor (HBT) PA blocks arefabricated onto a single Gallium Arsenide (GaAs) die. One PA block supports the GSM850/900 bandsand the other PA block supports the DCS1800/PCS1900 bands. Both PA blocks share common powersupply pads to distribute current. The output of each PA block and the outputs to the four receivepads are connected to the antenna pad through a PHEMT RF switch. The GaAs die, PHEMT die, Silicon(Si) die and passive components are mounted on a multi-layer laminate substrate. The assembly isencapsulated with plastic overmold.

Band selection and control of transmit and receive are performed using four external control pads.Refer to the block diagram in Figure 1 below. The band select pads, BS1 and BS2, select GSM850,GSM900, DCS, and PCS modes of operation. Transmit enable Tx_EN controls receive or transmitmode of the RF switch (Tx = logic 1). Proper timing between transmit enable Tx_EN and AnalogPower Control VRAMP allows for high isolation between the antenna and Tx–VCO while the VCO isbeing tuned prior to the transmit burst.

The SKY77548 is compatible with logic levels from 1.2 V to VCC for BS1, BS2, and Tx_EN pads,depending on the level applied to the VLOGIC pad. This feature provides additional flexibility for thedesigner in the selection of FEM interface control logic.

特性 Features

• High efficiency 44% (GSM850/900) 42% (DCS1800/PCS1900)
• Low transmit supply current 1.30 A (GSM850/900)0.86 A (DCS1800/PCS1900)
• Internal ICC sense resistor for iPAC
• Closed loop iPAC
• 50 Ω matched Input/Output
• Tx–VCO-to-antenna and antenna-to-Rx-SAW filter RF interface
• PHEMT RF switch affords high linearity, low insertion loss, and less than 20 μA supply current in receive modes
• Small outline: 8 mm x 6 mm
• Low profile: 1.05 mm
• Compatible with multiple logic families
• Low APC current: 25 μA

简介

SKY77548属于RF/IF射频/中频RFID的射频前端（LNA+PA）。由制造生产的SKY77548射频前端（LNA + PA）本系列中的产品是各种集成电路，其中集成了射频 (RF) 信号链连接到系统天线的部分中常见的一种或多种功能，如低噪声放大器 (LNA) 和可编程放大器 (PA)。任何给定器件所含的实际功能各不相同，相比旨在提供更高应用灵活性的器件，针对相对较窄应用的器件通常集成更大一部分必要的信号链。