LTC554x mixers satisfy needs of WiMAX basestations
Linear Technologycontact supplier
LTC554x mixers are designed to satisfy the requirements of nascent fourth-generation LTE cellular and WiMAX basestations, as well as 3G CDMA, WCDMA, TD-SCDMA, UMTS and GSM/EDGE platforms.
The series of four high-dynamic-range downconverting mixers covering the 700MHz to 4GHz wireless infrastructure frequency range.
The LTC554x mixers offer IIP3 (input third-order intercept) of 26dBm, low noise figures of 9-10dB and high conversion gain of 8dB, enabling high dynamic range performance for main receivers and digital predistortion receivers.
The mixers maintain a low noise figure in the presence of strong blocking interferers, enhancing receiver sensitivity and robustness.
The LTC554x range operates on a single 3.3V supply without compromising performance, while reducing power consumption by 34 per cent compared with the closest competing solution - according to the company.
The mixers' robust performance is said to enhance other wireless systems such as point-to-point microwave systems, cellular repeaters, public safety radios and military communication systems.
The LTC554x mixers contain an integrated IF amplifier, LO buffer, LO switch and RF balun transformers.
Each mixer's RF input is single ended, 50ohm matched.
Two single-ended LO inputs with high isolation are provided for frequency-hopping applications.
Each LO input is also single ended and always 50ohm matched regardless of whether the mixer is active or powered down to avoid unlocking of the PLL (Phased-Lock Loop).
The LO input requires only 0dBm drive level.
The LTC554x mixers have identical pinouts, allowing designers to share PC board layouts across multiple platforms operating in different frequency bands.
This helps users reduce total ownership costs and speed time to market.
The mixers' pinouts are also similar to common industry footprints and pinouts, allowing ease of adoption while improving performance and reducing power consumption.
The LTC554x mixers operate on a single 3.3V supply, drawing a supply current of 200mA.
The devices have a power-down feature with turn-on and turn-off time of 2us and 3us, respectively.
When disabled, the ICs consume a maximum of 500uA.
The products are offered in a 20-lead, 5 x 5mm QFN surface-mount package.
The LT1070 five-terminal switching regulator from Linear Technology has been designed for ease of use and economy.
A tutorial on SAR type analogue-to-digital converters (ADCs), this application note from Linear Technology contains detailed information on several 12-bit circuits. Comparator, clocking and pre-amplifier designs are discussed. A final circuit gives a 12-bit conversion in 1.8µsec. Appended sections explain the basic SAR technique and explore digital-to-analogue considerations.
This application note from Linear Technology describes some of the unique IC design techniques incorporated into a fast, monolithic power buffer, the LT1010. Also, some application ideas are described such as capacitive load driving, boosting fast op amp output current and power supply circuits.
This application note from Linear Technology details 1.5V-powered circuits for complex linear functions. Designs include a V/F converter, a 10-bit analogue-to-digital converter, sample-hold amplifiers, a switching regulator and other circuits. Also included in the application note is a section presenting component considerations for 1.5V-powered linear circuits.
A variety of high-performance V/F circuits is presented in this application note from Linear Technology. Included are a 1Hz to 100MHz design, a quartz-stabilised type and a 0.0007 per cent linear unit. Other circuits feature 1.5V operation, sine wave output and non-linear transfer functions. A separate section examines the trade-offs and advantages of various approaches to V/F conversion.