About irs2092s Quick Start PWM

Announcements

From sunburn to sun earn – we’ve got the power! Watch our #poweringgreen videos now.

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
lixia
Level 2
Level 2
25 sign-ins 10 replies posted First like received

Hello, using irs2092s design amplifier, I want to use the audio signal to control 2092, when there is audio 2092 working, no audio 2092 sleep, plan to control the Vcsd voltage of 2092 to make 2092 start quickly, shorten the Vcsd rise time (the purpose is that PWM starts slowly and causes audio loss). Are there any recommended solutions?

0 Likes
1 Solution
Pranava_YN
Moderator
Moderator
Moderator
100 likes received 500 replies posted 250 solutions authored

Hi,

Please refer to the following Application note (https://www.infineon.com/dgdl/an-1138.pdf?fileId=5546d462533600a40153559a077610d1) which describes in details the necessity of capacitor between VSS and CSD pins. It also explains how Ct value determines the Tsu and Treset timings as well. 

Best regards,
Pranava

View solution in original post

8 Replies
lixia
Level 2
Level 2
25 sign-ins 10 replies posted First like received

The boot time I can accept is about 100ms

0 Likes
Pranava_YN
Moderator
Moderator
Moderator
100 likes received 500 replies posted 250 solutions authored

Hi,

Please refer to the following Application note (https://www.infineon.com/dgdl/an-1138.pdf?fileId=5546d462533600a40153559a077610d1) which describes in details the necessity of capacitor between VSS and CSD pins. It also explains how Ct value determines the Tsu and Treset timings as well. 

Best regards,
Pranava

Hi, I calculated as follows:
VAA=+5V, VSS=-5V
VDD=VAA-VSS=10V?
Icsd = 100μA
The value of Ct is 10μF
The calculation formula is as follows

Treset = (10μF*10V)/(1.1*100μA) = 0.909S
Tsu = (10μF*10V)/(0.7*100μA) = 1.428S
Is there a problem with this calculation?

 

1.png2.png3.png

0 Likes
Pranava_YN
Moderator
Moderator
Moderator
100 likes received 500 replies posted 250 solutions authored

Hi,

 

Yes, your calculation is correct.

Best regards,
Pranava

1、What is the minimum startup time (Tsu) of irs2092s?
2、How can I control the irs2092 startup time to 100ms?

0 Likes
Pranava_YN
Moderator
Moderator
Moderator
100 likes received 500 replies posted 250 solutions authored

Hi,

As per the same Appnote,  it is recommended to have a Treset of atleast 0.1s. This again depends on the time required to avoid over heating of MOSFETs in OCP condition. 
Based on your calculation, you can reduce the Ct to get the Treset to 0.1s. This will automatically reduce the Tsu value as well. If you are confident about the MOSFET thermal management, then you can reduce it a little further.

Best regards,
Pranava

I get it, thank.
1. Using irs2092s, it is planned to output 50Vrms (THD+N <0.5%), how much power supply voltage is needed? How to calculate it?

0 Likes
Pranava_YN
Moderator
Moderator
Moderator
100 likes received 500 replies posted 250 solutions authored

Hi,

Sorry, I missed responding to this question. As you have specified output is 50Vrms. The peak output voltage is 50 x sqrt(2) = 70.5V  In a typical application the maximum linear modulation is up to 93% - 94%. Therefore 70.5/0.93 = 75.8V. The application requires +/- 75.8V at rated power.

Best regards,
Pranava
0 Likes