Philips BDL4640E Service Manual page 22

supply. An audio power amplifier with a maximum output of 10W (RL=8 ) 2ch can be configured with
one chip. YDA138 has a "Pure Pulse Direct Speaker Drive Circuit" which directly drives speakers
while reducing distortion of pulse output signal and reducing noise on the signal, and realizes the
highest standard low distortion rate characteristics and low noise characteristics as 10W-class of
output digital amplifier IC. In addition, circuit design with fewer external parts can be made depend on
the condition of use because corresponds to filter less. YDA138 provides Overcurrent protection
function for speaker output terminals, IC thermal protection function, POP noise reduction function,
and AM interference measures function as well as power-down function and output mute function.
9. Sipex SP3243 RS-232 transceiver
The SP3243 transceivers meet the EIA/TIA-232 and ITU-T V.28/V.24 communication protocols.
generate 5.5V RS-232 voltage levels from a single +3.0V to +5.5V power supply and operate at a data
rate of 120kbps fully loaded. The SP3243 devices feature circuitry automatically wakes up from . It
occurs after a RS-232 cable being disconnected. Under this condition, the internal charge pump and
the drivers will be shut down. Otherwise, the system automatically comes online.
10. Mitsumi MM1671 Low Supply Voltage 75 Ohm Driver
This IC is a 75 driver with a built-in LPF that can operate at low voltage. It supports 3V and 5V
operating power voltage, and is ideal for video signal output in devices ranging from portable digital
still cameras to stationary equipment such as DVD players. It incorporates a high performance
4-stage LPF, which is ideal for removing DAC sampling noise. In addition, ultra-low current
consumption has been achieved b of the batteries in portable devices. The built-in amp gain on this IC
is available in series: 6dB/9dB/12dB/16.5dB, thus enabling support for DAC and a variety of output
amplitudes. There is also a series with input clamp and one without, allowing support for a range of
video signals, not just composite signals.
11. EtronTech EM636165TS-5G SDRAM
The EM636165 SDRAM is a high-speed CMOS synchronous DRAM containing 16 Mbits. It is
internally configured as a dual 512K word x 16 DRAM with a synchronous interface (all signals are
registered on the positive edge of the clock signal, CLK). Each of the 512K x 16 bit banks is organized
as 2048 rows by 256 columns by 16 bits. Read and write accesses to the SDRAM are burst oriented;
accesses start at a selected location and continue for a programmed number of locations in a
programmed sequence. Accesses begin with the registration of a BankActivate command which is
then followed by a Read or Write command. The EM636165 provides for programmable Read or Write
burst lengths of 1, 2, 4, 8, or full page, with a burst termination option. An auto precharge function may
be enabled to provide a self-timed row precharge that is initiated at the end of the burst sequence. The
refresh functions, either Auto or Self Refresh are easy to use. By having a programmable mode
register, the system can choose the most suitable modes to maximize its performance. These devices
are well suited for applications requiring high memory bandwidth and particularly well suited to high
performance PC applications.
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