Philips 298P4QJEB/00 Service Manual page 105

3.18.4 Audio Amplifier
The amplifier shall provide two channels of audio up to 2.0 Watts per channel from 100
Hz to 20 kHz, based upon an audio signal input of 1.0V RMS per channel.
3.18.5 Volume Control
For monitors with a manual volume control, the direction (at the bottom) of the bezel
volume control is "-" key for Minimum volume and "+" key for Maximum volume. The
default shipping position of the Volume Control shall be approximately 90%.
3.18.6 Speaker Sensitivity
The speakers shall support a minimum sensitivity of 75 dB +/- 3 dB at 2W/1m at 1 kHz.
3.18.7 Maximum Audio Card Output
The monitor audio amplifier shall accept a maximum input voltage of 1.5 Vrms and meet
the following requirements at the maximum monitor volume setting:
1. The ratings of the audio amplifier may not be exceeded.
2. The ratings of the speakers may not be exceeded.
3. There must not be any clipping of the audio amplifier output signal.
Voltage dividers may be used to reduce the input signal level.
3.18.8 Monitor Audio Amplifier Input Impedance
The monitor audio amplifier shall have minimum 10K Ohm AC input impedance
3.19 USB HUB 2.0 support
Connect the HUB port of the monitor to host PC's USB port via USB cable,
Then attach external device to the downstream port of the monitor.
Check if the device can work properly.
3.20 POWER SENSOR
UNCTIONAL Requirements for the front detection
For the presence sensor functionality, the following requirements are defined:
Two IRs be used for user present detections, one IR is for transmission signals, the other one is for
receiving reflection IR signals
User must be detected in the following range:
40 up to 100 cm (+ 20cm).
Detection angle:
Meridian 3 105