AD7011ARS

The AD7011ARS from Analog Devices is a complete, low-power CMOS modulator designed for the baseband conversion of I and Q transmit waveforms, compliant with the American Digital Cellular Telephone system (TIA IS-54). It features an on-chip π/4 Differential Quadrature Phase Shift Keying (DQPSK) digital modulator, including root raised cosine filters, which generate I and Q data from the transmit data stream.

This device operates from a single +5V power supply and includes two 10-bit D/A converters with 4th order reconstruction filters for smooth analog outputs. It also provides differential analog outputs for both I and Q signals. The AD7011ARS incorporates on-chip ramp control envelope logic for shaping output waveforms during transmit bursts and offers power-down options for reduced consumption. It is housed in a 24-pin SSOP package.

Key features include a single +5V supply, on-chip π/4 DQPSK modulator, root-raised cosine Tx filters with α = 0.35, two 10-bit D/A converters, and 4th order reconstruction filters. It also has differential analog outputs, on-chip ramp up/down power control, and on-chip Tx offset calibration. The device supports dual mode operation (analog and digital) and has very low power dissipation, typically 30 mW, with a power-down mode consuming less than 10 mA. An on-chip voltage reference is also included.