Upstream CATV Amplifier

The MAX3509 is a programmable power amplifier for use in CATV upstream applications. The device outputs up to 66dBmV QPSK through a 1:1 transformer. It features variable gain controlled by a 3-wire digital serial bus. Gain control is available in 1dB steps. The device operates over a 5MHz to 65MHz frequency range.

The MAX3509 offers a transmit-disable mode, which places the device in a high-isolation state for use between bursts in TDMA systems. In this mode, all analog functions are shut down, minimizing output noise and power consumption. When entering and leaving transmit-disable mode, transients are kept to 25mV nominal at full gain. In addition, supply current is reduced to 7.8mA.

An additional power-down mode is available. Shutdown mode disables all circuitry and reduces current consumption to less than 1µA.

The MAX3509 is available in a 20-pin TSSOP-EP package for the extended-industrial temperature range(-40°C to +85°C).

Applications

* Cable Modems * CATV Infrastructure * CATV Status Monitors * OPENCATV Set-Top Boxes * Telephony-Over-Cable

* Ultra-Low Power-Up/Down Transients, 25mV (typ) at 66dBmV Output

* Single-Supply Operation

* Output Level Ranges from <12dBmV to 67dBmV (QPSK)

* Gain Programmable in 1dB Steps

* Low Transmit Output Noise Floor: -41dBmV (160kHz BW)

* Low Transmit-Disable Output Noise: -70dBmV

* Shutdown Mode