Philips Semiconductors
Product specification
Advanced modem/audio analog front-end
FUNCTIONAL DESCRIPTION
UCB1200
The UCB1200 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 UCB1200 functionality according to actual application requirements.
AUDIO CODEC
The audio codec contains an input channel, built up with an 64 times oversampling sigma delta analog to digital converter
(ADC) with digital decimation filters and a programmable gain microphone preamplifier.
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
Ω
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.
AUD_GAIN[4,3]
AUD_OFF_CAN
AUD_LOOP
AUD_GAIN[2..0]
1bit ADC
MICP
DIGITAL
DECIMATION
FILTER
12
MICGND
AUD_IN_ENA
AUD_OUT_ENA
VCCSPKR
SPKRP
4bit DAC
SPKRN
DIGITAL
ATTENUATOR
DIGITAL
NOISE
SHAPER
12
VSSSPKR
AUD_MUTE
AUD_ATT[2..0]
AUD_ATT[4,3]
Fig.3 Audio codec block diagram.
1998 Jul 22
7
PHILIPS [ NXP SEMICONDUCTORS ]
