描述 Description

The PGA870 is a wideband programmable-gain amplifier (PGA) for high-speed signal chain and data acquisition systems. The PGA870 has been optimized to provide high bandwidth, low distortion, and low noise, making it ideally suited as a 14-bit analog-to-digital converter (ADC) driver for wireless base station signal chain applications. The wide gain range of –11.5 dB to +20 dB can be adjusted in 0.5-dB gain steps through a 6-bit control word applied to the parallel interface. The gain control interface may be configured as a level-triggered latch or an edge-triggered latch, or it may be placed in an unlatched (transparent) mode. In addition to the 6-bit gain control, the PGA870 contains a power-down pin (PD) that can be used to put the device into a low-current, power-down mode. In this mode, the quiescent current drops to 2 mA, but the gain control circuitry remains active, allowing the gain of the PGA870 to be set before device power-up. The PGA870 is offered in a QFN-28 PowerPAD? package.

特性 Features

? Wideband +5-V Operation: 650-MHz Bandwidth
? Low Impedance, Voltage Mode Output
? Wide Gain Range: –11.5 dB to +20 dB
? Precise 0.5-dB Gain Steps Step-to-Step Gain Error = ±0.03 dB
? HD2: –93 dBc at 100 MHz
? HD3: –88 dBc at 100 MHz
? IMD3: –98 dBc at 100 MHz, –95 dBc at 200 MHz
? OIP3: +47 dBm at 100 MHz; Exceeds +45 dBm for Frequencies to 300 MHz
? Flexible Gain Control Interface:
? Supports latched and unlatched options
? Gain may be set in power-down state
? Fast setup and hold times: 2.5 ns

? Low Disable Current: 2 mA
? Pb-Free (RoHS-Compliant) and Green Package
? APPLICATIONS

? Programmable Gain IF Amplifier:
? Differential signal chains
? Single-ended to differential conversion

? Fast Gain Control Loops for:
? Test/measurement
? Digital radio signal chains

? ADC Driver for Wireless Base Station Signal Chains: GSM, WCDMA, MC-GSM
? Radar/Ranging Systems
PowerPAD is a trademark of Texas Instruments. All other trademarks are the property of their respective owners.