YDA136

18

■

Digital Amplifier Function

YDA136 has a 2-channel differential analog signal input digital amplifier controller.

This digital amplifier controller consists of High-Side and Low-Side PowerMOSFET drivers and a PWM circuit.

By combining the two sets of Pch/Nch PowerMOSFET in each channel, a digital amplifier (60W to 100W) can be

configured.

To each PowerMOSFET driver, it is possible to set up an off-time individually, and it can be set as the optimal driver

according to PowerMOSFET to be used.

AM intermodulation can be performed with AM reception interference reduction function.

Moreover, it can be optimized to the digital amplifier which has a lower distortion by adding a filter element to a PWM

circuit.

●Gain Setup Method

The gain of digital amplifier can be set up by external resistance (RE1 to RE4).

The gain of digital amplifier can be calculated with the following formula.

()

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

+

⋅

⋅

+

⋅

+

⋅

⋅

=

Ω

400

4

2

3

1

3

2

2

1

log

20

)

(

RE

RE

RE

RE

RE

RE

RE

RE

dB

Av

●Characteristic Improvement by External Filter Element Connection

Although it is possible to realize high performance digital amplifier by the PWM circuit, by adding resistor and a capacitor

between DBPL(FBPR) and ITPL (ITPR), and between FBML (FBMR) and ITML (ITMR), it is possible to optimize a

circuit further and to improve distortion rate.