Broadband Modem Mixed-Signal Front End AD9867 FEATURES FUNCTIONAL BLOCK DIAGRAM OSCIN XTAL CLKOUT1 CLKOUT2 Low cost, 3.3 V CMOS MxFE for broadband modems AD9867 10-bit digital-to-analog converter (DAC) M 2 CLK CLK TX PWDN TX DISABLE MULTIPLIER SYN/DIST DELAY PWR DWN 2/4 interpolation filter TXEN/TXSYNC DCTCXO 250 MSPS DAC update rate IOUT P+ TXCLK/TXQUIET TxDAC 2/4 10 10-bit, 75 MSPS ADC IOUT P ADIO 9:5 / Tx 4:0 0 TO 7.5dB Low noise RxPGA THIRD-ORDER LPF f = 33MHz 3dB Dual channel muxed input ADIO 4:0 / Rx 4:0 RX2+ 10 6 dB input overload attenuator ADC 2-POLE 1-POLE LPF LPF 80MSPS RXCLK RX2 RXEN/RXSYNC 12 dB to +48 dB (without attenuator) 0dB TO 6dB 6dB TO +18dB 6dB TO +24dB 5 AGC 4:0 = 1dB = 6dB = 6dB Third-order programmable low-pass filter 4 REGISTER RX1+ SPORT CONTROL Flexible digital datapath interface 1 RXSELECT RX1 1 Half-duplex and full-duplex operation ATTEN/RXQUIET Programmable delay Tx driver disable signal Figure 1. Various power-down/reduction modes Internal clock multiplier (PLL) 2 auxiliary programmable clock outputs 64-lead LFCSP APPLICATIONS Power-line networking GENERAL DESCRIPTION The AD9867 is a mixed-signal front-end (MxFE) IC for The receive path consists of a programmable amplifier transceiver applications requiring Tx and Rx path functionality (RxPGA), a tunable low-pass filter (LPF), and a 10-bit analog- with data rates up to 75 MSPS. Its flexible digital interface, to-digital converter (ADC). The low noise RxPGA has a power-saving modes, and high Tx-to-Rx isolation make the programmable gain range of 12 dB to +48 dB in 1 dB steps. part well suited for half-duplex and full-duplex applications. Its input referred noise is less than 3.6 nV/Hz for gain settings The digital interface is extremely flexible allowing simple beyond 36 dB. An optional attenuator provides an additional interfaces to digital back ends. Power-saving modes can reduce 6 dB (or more) of attenuation (when combined with external power consumption of individual functional blocks or can series resistors). The receive path LPF cutoff frequency can power down unused blocks in half-duplex applications. A serial either be set over a 22 MHz to 38 MHz range or simply port interface (SPI) allows software programming of the bypassed. The 10-bit ADC achieves excellent dynamic performance over a 5 MSPS to 75 MSPS span. Both the RxPGA various functional blocks. An on-chip PLL clock multiplier and synthesizer provide all the required internal clocks, as well as and the ADC offer scalable power consumption allowing two external clocks from a single crystal or clock source. power/performance optimization. The Tx signal path consists of a bypassable 2/4 low-pass The AD9867 provides a highly integrated solution for interpolation filter and a 10-bit, 250 MSPS TxDAC. The broadband modems. It is available in a space-saving, 64-lead transmit path signal bandwidth can be as high as 33.6 MHz at LFCSP and is specified over the commercial (40C to +85C) an input data rate of 75 MSPS. The TxDAC provides temperature range. differential current outputs that can be steered directly to a For more information on the AD9867, contact Analog Devices, differential or single-ended external load. Tx power can be Inc. at email MxFE Support analog.com. digitally controlled over a 7.5 dB range in 0.5 dB steps. Rev. SpB Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. Tel: 781.329.4700 www.analog.com No license is granted by implication or otherwise under any patent or patent rights of Analog Fax: 781.461.3113 20072020 Analog Devices, Inc. All rights reserved. Devices. Trademarks and registered trademarks are the property of their respective owners. 06203-001AD9867 NOTES 20072020 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06203F-11/20(SpB) Rev. SpB Page 2 of 2