Technical support / CGD1200HB2P-BM2

Lexos69

Hi everyone,

I am writing to report a small problem with the CGD1200HB2P-BM2 driver board that I acquired on DigitKey.

The 2 pictures below represent what I am trying to achieve with the assembly's electric circuit. The first image shows the working capacitor being charged by a DC power supply; ''CHARGING MODE''. The second image illustrates that same capacitor discharging on the load, a Laser; ''FIRING MODE''.

CHARGING MODE

FIRING MODE

Now, we did multiple tests.

In the first test, everything works as expected in the setting. The laser flashes by being supplied with 30 Volts coming from a DC-DC step up booster power supply. At each flash, the laser turns on for 200 microseconds and stays off for 200 milliseconds. Hence, we have a 0.1% duty cycle at 5 Hz.

However, on the second test and others, we see that the CGD1200HB2P-BM2 board stops working when trying to operate the Laser with 40 Volts using the same duty cycle and frequency. The DT6 indicator lights up red.

We have tried other duty cycles as well. No matter the pulse width or frequency setup, The same thing keeps on happening for any voltage above 30 Volts.

What is interrupting the system ?

Am I missing something ?

Sincerely,

Forum_Moderator

Thank you for your post, it has been approved and we will respond as soon as possible.

Lexos69

Adding info:

Here are 2 pictures of my setup.

As you can see, I only connected the power feeds as well as the High-side and low-side signal feeds (Pins 1, 2, 3, 4, 5 & 6). All of them, are coming from the output of the CGD12HB00D transceiver board.

Below, is the code that I am using in my microcontroller to generate the desired pulse signal:

void setup() {

pinMode(2, OUTPUT); ———> Pin# 3 of the CGD1200HB2P-BM2
pinMode(4, OUTPUT); ———> Pin# 5 of the CGD1200HB2P-BM2

}

HIGH SIDE CHARGING MODE
void loop() {
digitalWrite(2, HIGH); ———> Pin# 3 of the CGD1200HB2P-BM2
delay(0100);
digitalWrite(2, LOW); ———> Pin# 3 of the CGD1200HB2P-BM2
delay(0050);

LOW SIDE FIRING MODE
digitalWrite(4, HIGH); ———> Pin# 5 of the CGD1200HB2P-BM2
delayMicroseconds(0200);
digitalWrite(4, LOW); ———> Pin# 5 of the CGD1200HB2P-BM2
delay(0050);

}

Again, the CGD1200HB2P-BM2 board is unable to pulse currents above 30 Volts at any duty cycle. No matter the delays I choose, the indicator DT6 lights up red every time I try to pulse a current above 30 Volts through the CAS120M12BM2 module. I read somewhere on this forum that, when DT6 goes red, it is an issue of the positive side of the module with the high-side terminals of the gate driver board.

How do I fix the issue ?

Please, help

JHayes

Hello,

What is the impedance of the load and/or the pulsed current you are expecting?

LED DT6 indicates a low-side fault - most likely an overcurrent event. More information can be found in the datasheet for that driver.

Thanks,

Jonathan

Lexos69

Hi Jonathan,

The load is this CO2 Laser.

On a continuous mode, we can feed it a maximum of 20 Volts, 50 Amps. Lasers are around 50% efficient, so, the 500 Watts is the average optical output on continuous mode.

Now, when I pulse the current with a duty cycle of 0.1%, I expect the average power to be much lower than 500 Watts. That is the reason I am increasing the voltage that is being pulsed.

My goal is to eventually pulse 1000 Volts with a width of 1 microsecond and a repetition rate of 5 Hz. According to my calculations, that should give me an average power of 125 Watts.

Lexos69

@JHayes I responded to your question. Is my setup missing something for it to work as intended ?

Lexos69

@JHayes

Update:

I am going to try by switching low with the components instead of switching high.

See the 2 pictures below.

CHARGING MODE

FIRING MODE

AAnders

Hello Paulin,

Unfortunately we need to terminate this support request over safety concerns. I will follow up with you over email.

Thanks for your understanding.

-Adam