NEC Barracuda, Service Manual

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Barracuda PDA Maintenance
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1.2.2.4 Touch Screen Controller Chip with ADC: Philips semiconductors UCB1300
General Description
The UCB1300 is a single chip, integrated mixed signal audio and telecom codec. The single channel audio codec
is designed for direct connection of a microphone and a speaker. The built-in telecom codec can directly be connected
to a DAA and supports high speed modem protocols. The incorporated analog-to-digital converter and the touch
screen interface provides complete control and read-out of an 4 wire resistive touch screen. The 10 general purpose
I/O pins provide programmable inputs and/or outputs to the system.
The UCB1300 has a serial interface bus (SIB) intended to communicate to the system controller. Both the codec
input data and codec output data and the control register data are multiplexed on this SIB interface.
Features
48 pin LQFP (SOT313-2) small body SMD package and low external component count results in minimal PCB
space
12-bit sigma delta audio codec with programmable sample rate, input and output voltage levels, capable of
connecting directly to speaker and microphone, including digitally controlled mute, loopback and clip
detection functions
14-bit sigma delta telecom codec with programmable sample rate, including digitally controlled input voltage
level, mute, loopback and clip detection functions. The telecom codec can be directly connected to a Data
Access Arrangement (DAA) and includes a built in sidetone suppression circuit.
Complete 4 wire resistive touch screen interface circuit supporting position, pressure and plate resistance
Measurements
10-bit successive approximation ADC with internal track and hold circuit and analog multiplexer for touch
screen read-out and monitoring of four external high voltage (7.5V) analog voltages
High speed, 4 wire serial interface data bus (SIB) for communication to the system controller