Difference between HV CMOS and BCDMOS

[asicpark]

high voltage cmos vs. bcdmos

Hi, I'm working on the project for the class-d amp.
Actually the supply needs about 30~40 due to the output power.
So I'm looking for the proper process, but I'm so confused between
the HV CMOS and BCDMOS process for what is cons and pros.
Anyone who have exprience ?

Thanks in advance.

 

[rfsystem]

BCDMOS have a bipolar but the difference for your project is the DMOS versus HVCMOS.

You can make high voltage MOS by using either an NWELL instead of N+ to have a high voltage drain for the NMOS or using additional implants for a

differential diffused MOS = DMOS

where there a one further degree of freedom to make the drain high voltage capable.

Typical the R[Ohm]*sqmm is by a factor lower than in poor man HVCMOS

If the drivers are outside HVCMOS is then still an option.

 

[forkschgrad]

BCDMOS have a bipolar but the difference for your project is the DMOS versus HVCMOS.

You can make high voltage MOS by using either an NWELL instead of N+ to have a high voltage drain for the NMOS or using additional implants for a

differential diffused MOS = DMOS

where there a one further degree of freedom to make the drain high voltage capable.

Typical the R[Ohm]*sqmm is by a factor lower than in poor man HVCMOS

If the drivers are outside HVCMOS is then still an option.

isn't is the double diffused MOS?

 

[kumard35b]

DMOS is Double Diffused Metal oxide Semiconductor.

The cross section of a VDMOS (see figure 1) shows the "verticality" of the device: It can be seen that the source electrode is placed over the drain, resulting in a current mainly vertical when the transistor is in the on-state. The "diffusion" in VDMOS refers to the manufacturing process: the P wells (see figure 1) are obtained by a diffusion process (actually a double diffusion process to get the P and N+ regions, hence the name double diffused).

BCDMOS has

Very high voltage, yet small, transistors provide up to 250V Breakdown


Low on-resistance - just 0.6 ohm-mm*2 at 80V - allows integration of multiple low resistivity power FETs


Double metal layer supports currents up to 10A


Thin film and poly-poly caps are combined in silicon to integrate high-performance analog functions such as high-accuracy references, along with high-power devices.