National Semiconductor Launches DVGA Supporting High-Performance Base Station Wireless Architecture
Dual/Quad DVGA integrates high channel count and excellent high-frequency linearity.

August 11, 2011 – National Semiconductor Korea (CEO: Choi Chung-won) announced today the launch of Quad and Dual Digital Variable Gain Amplifiers (DVGA) that enable the manufacturing of higher-performance broadband wireless systems.

The quad LMH6522 and dual LMH6521 DVGA provide excellent linearity over a wide frequency range, making them suitable solutions for demanding multi-channel broadband wireless systems. Target applications include broadband direct conversion radio used in multi-carrier GSM, TD-SCDMA, W-CDMA, and LTE base stations, including Intermediate Frequency (IF) sampling receivers and I/Q Digital Pre-Distortion (DPD) signal paths.

Wireless designers must produce cost-effective Anti-Alias Filters (AAFs) that meet a wider range of wireless bandwidths. AAF design is simplified and performance and manufacturability are improved by offering flexible selection across various filter impedance levels, as well as low impedances of around 50 Ohms. National's DVGA is optimized for driving across a wide load impedance range. It provides smooth signal fidelity through low Z-output drive and supports the additional power required when driving low-impedance filters.

The LMH6522 and LMH6521 are suitable for driving high-speed ADCs, including National's ADC16DV160 dual 16-bit, 160 MSPS converter. In addition, the LMH6521 is also ideal for driving National's ultra-fast ADC12D500/800RF 12-bit, 500 MSPS/800 MSPS direct RF sampling ADCs. A complete signal path can be constructed by adding the LMX2541 frequency synthesizer and one of National's LMK04800 or LMK04000 clock jitter cleaner families.

Key Features of the LMH6522 Quad DVGA
• OIP3: 49 dBm at an input frequency of 200 MHz
• Precise 1 dB gain intervals over a wide range of 31 dB
• 8.5 dB of noise at maximum gain
• Available in a 54-pin LLP® package

Key Features of LMH6521 Dual DVGA
• OIP3: 48.5 dBm at an input frequency of 200 MHz
• +/- 0.04 dB / +/- 0.45 degrees channel gain/phase alignment
• Precise 0.5 dB gain intervals over a wide range of 31.5 dB
• 7.3 dB of noise at maximum gain
• Provided in a 32-pin LLP package

Price and commercial viability
They are currently available for purchase, with the LMH6522 selling for $9.85 and the LMH6521 for $6.15 in units of 1,000. For additional information on the LMH6522 Quad DVGA or to order samples and evaluation boards, please refer to http://www.national.com/pf/LM/LMH6522.html . If you need more information about the LMH6521 Dual DVGA, visit http://www.national.com/pf/LM/LMH6521.html .