What checks are done in Electrical rule check (ERC)
What is ERC?
The electrical integrity of a layout in a circuit design is checked using an electrical rule check (ERC), a design rule check (DRC). An ERC verifies that the design is electrically sound and will operate as intended by comparing the layout to a set of rules. Some of the investigations that ERC frequently conducts include
The following Checks are Done in ERC
- Any floating N-Well in Layout.
- Any floating Substrate in the Layout.
- Is N-Well Connected to VDD
- Is P-Well(P-substrate) connected to VSS
- Substrate without Tap connection(Bulk)
- N-Well without Tap connection(Bulk)
What is Bulk Connection in CMOS?
The bulk connection is used in CMOS (complementary metal-oxide semiconductor) devices to connect the substrate (bulk) region to a reference voltage, usually ground. The bulk connection is important because it aids in regulating the device’s threshold voltage, which establishes the voltage at which the gadget starts to conduct. #
The kind and concentration of doping in the substrate region, as well as the applied voltage on the bulk connection, all have an impact on the threshold voltage of CMOS devices. The substrate region is maintained at a constant voltage by connecting the bulk to the ground, which aids in stabilizing the device’s threshold voltage.
Why We are using Bulk(Tap) Connection in CMOS?
To provide the ohmic contact with the substrate, we are using a Bulk(Tap) connection in CMOS. It is the fourth terminal of the MOSFET.#
