Hi, I need to switch between 28V and 12V supplies controlled by a LVTTL signal. I am using ADG5234 device. But the IC seems to blow up as soon as it is powered. VSS pin is grounded in the board. Is there anything which I am doing wrong or needs changes?VDD to the device is 28V.
What current is being drawn through the switch from the 28V and 12V power supplies?
The continuous current rating of the ADG5234 is in the tens of mA range so if there is a large amount of current passing through the switch that could cause damage to the device.
I am using ADG5234 output to drive the gate of IRF5803 PMOS whose source is connected to 28V and drain to a 10ohm load. I am using an LVTTL signal of 100us pulse width and 10% duty to switch 28V and 12V. I have added no external circuitry to the switch. Kindly suggest me the circuit to be added otherwise and the condition of VSS pin. I am feeding 28V and 12V on the Sx pins and driving the PMOS through the Dx pin.
Could you please share your schematic so I see what all the device pin are connected to? Are you using the LFCSP or TSSOP version of the device?
Having the VSS of the device connected to ground is normal if you are using the device with a single supply.
Hi, I have attached the schematic where I have used ADG5234 device.
I am using the LFCSP_WQ package.
Pin 1 is taken as an output pin which is connected to the gate of IRF5803 MOSFET.
Pin 2 is connected to 12V supply.
Pin 3,4 and 18 are connected to GND.
Pin 19 is connected to LVTTL pulse.
Pin 20 is connected to 28V supply line.
Application of this circuit is to switch between 28V and 12V based on the LVTTL control.
Sorry about the delay replying.
How you checked the sequencing of the power up? If the +28V or +12V is present on the S1A/S1B before the +28V is present on VDD then that could cause issues.