ucb1300 NXP Semiconductors, ucb1300 Datasheet - Page 7

• Manufacturer Part Number: ucb1300
• Description: Advanced Modem/audio Analog Front-end
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Product specification
Advanced modem/audio analog front-end
UCB1300
FUNCTIONAL DESCRIPTION
The UCB1300 consists of several analog and digital sub-circuits which can be programmed via the Serial Interface Bus
(SIB). This enables the user to set the UCB1300 functionality according to actual application requirements.
AUDIO CODEC
The audio codec contains an input channel, built up with a 64 times oversampling sigma delta analog to digital converter
(ADC) with digital decimation filters and a programmable gain microphone preamplifier. The programmable gain
microphone amplifier features a built-in offset cancellation stage, which reduces the distortion of this stage at high gain
settings, caused by the offset voltages of the internal amplifiers or leakage on the board. It can be deactivated (reg13,
bit 13) for improved performance at low gain settings. A general rule is that below a gain setting of 16 (24dB gain) the
offset cancellation circuit will reduce THD and signal bandwidth and should then be deactivated.
The output path consists of a digital up-sample filter, a 64 time oversampling 4-bit digital-to-analog converter (DAC)
circuit followed by a BTL speaker driver, capable of driving a 16
speaker. The output path features a digital
programmable attenuation and a mute function.
The audio codec also incorporates a loopback mode, in which codec output path and the input path are connected in
series.
2000 Jun 26
7