SPECIAL CONTROLLERS AND PSUs
Millimetrica designs controllers and integrated linear power supply for sophisticated and delicate RF devices, such GaAs FETs, power GaAs FETs, PINs, requiring precise voltage/current control and protection for safety use.
Power GaAs Fets and PINs Power Supply protection
Power GaAs FETs are generally quite delicate in term of voltages handling such the drain current and gain are directly depending from the negative gate voltage variations. If the negative voltage is missing the drain current goes to its max limit and the device can be destroyed in a few nS.
Millimetrica has developed a special protection circuit, based on single or dual MosFets switch applicable to any power supply with the funtion to shut down the positive voltage in case of negative voltage lost. The circuit is also able to delay the positive voltage when the power device is switched on and to delay the the negative when switched off.
This circuit can be used with high power RF PIN switch requiring dual voltges, to prevent failures when the RF pattern is applied.
Picture 1 shows how the circuits controls a PIN diode switch requiring -28/+5 VDC (-28V-Yellow traces/ +5 -blue traces) and the delay time. The positive voltage cannot rise if the negative is missed. If the negative slow down, the positive will be shut immediately, after a min .treshold.
Picture 1 A (1 S./div.)
Picture 1 B (200 mS/div.)
Picture 2 shows and advanced version of this circuit using two MosFets cascaded, to achieve more delay and more isolation and safety.
|All type of circuits can be customized on different voltage ranges. Please contact Millimetrica for more information.|
|Special Power Supply|
|Today the market offers a wide range of power supply for any kind of applications, however sometime it's not possible to find what one is looking for, if the power supply must handle special devices requiring precise voltage sequences, protections and advanced embedded controls. In this cases a special design need.
Millimetrica can design power supplies including dedicated control interfaces and circuits able to protect delicated devices.
|We develop embedded controllers for advanced RF devices handling, based on PICs or dsPICs technology programmed with machine language, featuring "robust" routines, avoiding traditional PC issues.
For eg. we have solution for HPAs or TWTAs control or radar sequencing functions.