LTC1757A-1 Single/Dual Band RF Power Controllers

The LTC®1757A-2 is a dual band RF power controller for RF power amplifiers operating in the 850MHz to 2GHz range. The LTC1757A is pin compatible with the LTC1757 but has improved RF detection range. The input voltage range is optimized for operation from a single lithium-ion cell or 3x NiMH. Several functions required for RF power control and protection are integrated in one small 10-pin MSOP package, thereby minimizing PCB area.

The LTC1757A-1 is a single output RF power controller that is identical in performance to the LTC1757A-2 except that one output (VPCA) is provided. The LTC1757A-1 can be used to drive a single RF channel or dual channel module with integral multiplexer. This part is available in an 8-pin MSOP package.

RF power is controlled by driving the RF amplifier power control pins and sensing the resultant RF output power via a directional coupler. The RF sense voltage is peak detected using an on-chip Schottky diode. This detected voltage is compared to the DAC voltage at the PCTL pin to control the output power. The RF power amplifier is protected against high supply voltage and current and high power control pin voltages.

Internal and external offsets are cancelled over temperature by an autozero control loop, allowing accurate low power programming. The shutdown feature disables the part and reduces the supply current to <1µA

产品特点 Features

Dual Band RF Power Amplifier Control (LTC1757A-2)
Improved Internal Schottky Diode Detector
Wide Input Frequency Range: 850MHz to 2GHz
Autozero Cancels Initial Offsets and Temperature Dependent Offset Errors
Wide VIN Range of 2.7V to 6V Allows Direct Connection to Battery
RF Output Power Set by External DAC
Fast Acquire After Transmit Enable
Internal Frequency Compensation
Rail-to-Rail Power Control Outputs
RF PA Supply Current Limiting
Battery Overvoltage Protection
Power Control Signal Overvoltage Protection
Low Operating Current: 1mA
Very Low Shutdown Current: <1µA
Available in a 8-Pin MSOP Package (LTC1757A-1) and 10-Pin MSOP (LTC1757A-2)

应用

Single and Dual Band GSM Cellular Telephones
PCS Devices
Wireless Data Modems
TDMA Cellular Telephones

典型应用图

参数

LTC1757A-1 订购信息和价格参考Package Variations and Pricing

器件型号	封装	引脚	温度	价格 (以 1 ~ 99 片为批量)	价格 (以 1000 片为批量) *
LTC1757A-1EMS8	MSOP	8	E	$2.00	$1.75
LTC1757A-1EMS8#PBF	MSOP	8	E	$2.00	$1.75
LTC1757A-1EMS8#TR	MSOP	8	E		$1.81
LTC1757A-1EMS8#TRPBF	MSOP	8	E		$1.81
LTC1757A-2EMS	MSOP	10	E	$2.10	$1.90
LTC1757A-2EMS#PBF	MSOP	10	E	$2.10	$1.90
LTC1757A-2EMS#TR	MSOP	10	E		$1.96
LTC1757A-2EMS#TRPBF	MSOP	10	E		$1.96

LTC1757A-1 数据手册及相关资料下载

数据手册 (英文) : LTC1757A-1/LTC1757A-2 - Single/Dual Band RF Power Controllers.PDF
应用指南 (英文) : AN91 - Low Cost Coupling Methods for RF Power Detectors Replace Directional Couplers.PDF
可靠性数据 : R421 Reliability Data .PDF