Note: The following assumes that the 'overheating IC' is the PWM (i.e. the IR2110) -- If not, please advise...

I'm bound to say it would have come as no surprise had you reported overheating MOSFETs -- A 'toasty' PWM driver, however, is a bit of a 'twist'

FWIW -- At 'first blush' incorrect connection, a malfunctioning or misapplied PS, oscillatory PWM condition, a damaged (or otherwise defective) PWM or even a shorted/leaky MOSFET gate seem probable etiologies...

Please note that while I am quite dubious regarding establishment of a common load and logic ground (cip Vss to COM connection) and, frankly, appalled at the use of an lm555 circuit as a logic inverter (Re: IC2) neither of these potential missteps are likely cause of your present difficulty and, hence, will be 'given a miss' for the nonce...

So....

Please preform the following procedure then report the results...

1) Does the PWM overheat with the VCC (15v) supply disconnected?
If 'no' please skip steps 2 & 3...

-- Reconnect VCC ---
2) Adjust IC1 for minimum duty cycle --- Does the PWM overheat?
3) Adjust IC1 for maximum duty cycle --- Does the PWM overheat?

Additionally, please measure the period (or frequency) of the exciting signal at the output of IC1 --- Note: A 'scope' is preferred! If, however, you will be using a frequency counter, be advised that best results will be obtained via setting IC1 for a 50% d/c (i.e. the 100k Pot. at approximately mid-range)... Also please verify IC2's output...

Again, please report your findings
Best regards
HP

Hi,

I tested the completed circuit as shown in my first PDF.
the voltage measurements across IC1 output is 14.99V(max) and 0.272V(min)
IC2 output is 0.141V(min) and 14.78V(max) with the supply voltage of 15V.
The problem now I have is I'm not getting H0 Output from IR2110 IC but L0 output is available and it is about 14.53V.
The thing is I'm getting L0 when HIN signal is available and also L0 only when LIN signal is available which is not expected as per circuit design.
Pls tel me what can be the problem.
What is the dead time and how it is gonna effect circuit?
How can I correct my circuit so it can work as variable DC-DC converter..

 

Hi,

I tested the completed circuit as shown in my first PDF.
the voltage measurements across IC1 output is 14.99V(max) and 0.272V(min)
IC2 output is 0.141V(min) and 14.78V(max) with the supply voltage of 15V.
The problem now I have is I'm not getting H0 Output from IR2110 IC but L0 output is available and it is about 14.53V.
The thing is I'm getting L0 when HIN signal is available and also L0 only when LIN signal is available which is not expected as per circuit design.
Pls tel me what can be the problem.
What is the dead time and how it is gonna effect circuit?
How can I correct my circuit so it can work as variable DC-DC converter..

DMM measurement of dynamic signals are, in this instance, less than meaningless! --- Please observe Hin, Lin vs. Ho, Lo with a multichannel TDO --- Should a suitable 'scope' be unavailable, you may 'statically' test the PWM as follows:
1) Make certain the point shown shown as 'VO' is open (Inasmuch as Xl=zero at DC this step is necessary to prevent damage to Q[high]...)
2) Disconnect Hin and Lin from IC1 & IC2 respectively.
3) Manually tie Hin & Lin to each of the four possible 'combinations' [i.e. 00b -11b] while verifying correct output response.

Notes:
-Please be advised that, IIRC, the '2110 employs internal pulldown resistors at Hin & Lin
-Meaningful readings at Ho require that Vb remains tied high (via the 'bootstrap' diode) and that the 1K resistor remains as shown (to act as a pull-down for Vs) --- Similar considerations
apply to Vcc and COM as regards Lo.
-Again, dynamic examination (via O'scope or logic analyzer) is far preferable --- That said, the static test will, in most cases, identify gross malfunction...

Good luck and best regards!
HP