The TLV320AD13A is a high-speed coder/decoder (codec) for remote terminal (RT)-side modems that supports ADSL over integrated services digital network (ISDN) solution. The TLV320AD13A is a low-power device composed of five major functional groups for transmit (TX), receive (RX), clock, reference, and host interface. It is designed to work with the Texas Instruments (TITM) TNETD2022D central office (CO)-side codec for ISDN. The TX channel consists of a 138-kHz to 276-kHz digital bandpass filter, a 14-bit high-speed digital-to-analog converter (DAC), a 276-kHz analog low-pass filter (LPF), a TX attenuator, and an echo-cancellation (EC) channel. The RX channel consists of a 1.104-MHz digital LPF, a 1.104-MHz analog LPF, a frequency equalizer, and a programmable-gain amplifier (PGA). The clock circuit divides a 35.328-MHz frequency from an external voltage-controlled oscillator (VCXO) down to the necessary frequencies used throughout the device. The frequency of the external VCXO is controlled by a 12-bit onboard voltage-output DAC. An onboard reference circuit generates a 1.5-V reference for the converters. The device has a parallel port for data transfer and a serial port for control. The parallel port is 16 bits wide and is reserved for moving data between the codec and a host transceiver such as the TI C6x DSP. Configuration is done via a serial port. The device can be powered down via a dedicated pin, or through software control, to reduce heat dissipation. Additionally, there is a general-purpose (GP) port consisting of eight output terminals for control of external circuitry. The TLV320AD13A codec is characterized for operation in the temperature range of 40C to 85C and is available in a 100-pin PQFP (PZ) package.