Product Info

VTech proprietary and confidential
VTech Communications LTD.
R&D Department
The document is VTech’s proprietary information, Please do not disclose to third party without VTech’s consent
Ref. No.: 20191009 Version: 01 Date: 09 Oct, 2019 Page 11 of 33
The terminals are open-drain outputs, so the LED must be connected from a positive supply rail to the pad in
series with a current-limiting resistor.
Figure 6-1 LED equivalent circuit
From Figure 6-1 it is possible to derive Equation 6-1 to calculate ILED. If a known value of current is
required through the LED to give a specific luminous intensity, then the value of RLED is calculated.
ILED =(VDD-VF)/(RLED+RPAD)
NOTE The supply domain for LED [2:0], must remain powered for LED functions to operate.
7 Audio interface
The audio interface circuit consists of the following components:
• Dual analog audio inputs
• Dual analog audio outputs
• 1 digital microphone input
• 2 configurable I²S interfaces
• Configurable SPDIF input interface
Figure 7-1 shows the functional blocks of the audio interface. The codec supports stereo/dual-mono playback
and recording of audio signals at multiple sample rates with a 16-bit resolution. The ADC and the DAC of the
codec each contain two independent high-quality channels. Each ADC or DAC channel runs at its own