Differential amplifiers launched by Analog Devices

The ADL5561 and ADL5562 differential amplifiers drive high-speed, high-IF sampling ADCs (analogue-to-digital convertors) required by today's advanced communications systems.

The ADL5561 and ADL5562 are capable of maintaining performance while driving ADCs up to 500 MHz.

On-chip, user-selectable gain-setting resistors enable ADI to provide detailed specifications at common IF frequencies (70MHz, 100MHz, 140MHz, and 250MHz) and common gain settings (6dB, 12dB, 15.5dB).

This degree of specified performance simplifies and expedites the design process, provides flexibility, and allows the designer to exploit the amplifier's performance at multiple gain settings and IF frequencies.

Additionally, the pin-compatible ADL5561 and ADL5562 allow the user to select power consumption and performance to meet the requirements for a given application.

The ADL5561 and ADL5562 amplifiers drive 12- to 16-bit ADCs at the highest practical IF frequencies for use in next-generation communications systems, such as 3G LTE (long-term evolution) and NGMN (next-generation mobile networks).

In today's demanding advanced-communications applications, lowering the distortion level of the ADC driver improves system performance at higher frequencies by helping to maximise the receive channel's SFDR (spurious free dynamic range) and minimise its SNR (signal-to-noise-ratio).

This improvement minimises the number of IF frequencies within the radio design, resulting in lower power, cost, component count, and board area, and advancing system-level performance in applications such as cellular and cable communications, medical, instrumentation, military radios and satellite communications.

ADL5561 and ADL5562 provide good performance and low power within a small footprint package.

The 2GHz ADL5561 ultra-low-distortion differential amplifier consumes 40mA, making it suited for use in sub-140 MHz IF applications.

The ADL5561 achieves distortion levels of -86dBc HD2, -88dBc HD3, and -95dBc IMD3 at 100MHz.

The 2.6GHz ADL5562 ultra-low distortion differential amplifier consumes 80mA.

The ADL5562 achieves distortion levels of -95dBc HD2, -86dBc HD3, and -96dBc IMD3 at 140MHz.

Both the ADL5561 and ADL5562 operate on a 3V power supply and are available in a space-saving 3 x 3 mm LFCSP.

Furthermore, unlike conventional GaAs differential amplifiers, which often require the use of a transformer to perform the single-ended to differential conversion, the ADL5561 and ADL5562 can operate in fully differential circuits or provide the single-ended to differential conversion.

The ADL5561 and ADL5562 samples are available now.

Production quantities will be available in April 2009.