Häufig gestellte Fragen (FAQ) |ROHM Semiconductor

In the top row of the electrical characteristics table, does the condition 'unless stated otherwise…' apply to all parameters?
- The conditions listed in the upper row of the electrical characteristics table are measurement conditions common to each parameter. If separate measurement conditions are applicable they will be listed. Please check the datasheet.

What are the features of bipolar and CMOS products?
- Bipolar linear regulators are characterized by high withstand voltage and large current, while CMOS types feature low voltage operation and low current consumption. We are also utilizing Bi-CDMOS processes that combine low current with high withstand voltage.
  Related Link：Technical Document

What are the differences and features between standard regulators and LDOs?
- Standard regulators are also called 3-pin regulators, with the BA178/178M series considered industry-standard products. LDO is short for 'Low Drop Out', and is characterized by a smaller input/output voltage difference vs standard regulators, making it possible to suppress power loss. In recent years, the use of LDOs that support ceramic capacitors is increasing, and models featuring low current consumption, low voltage operation, high withstand voltage, and increased miniaturization are being developed.
  Related Link：Technical Document

Is there anything to be aware of besides the electrical characteristics when replacing products in the same series but in a different output voltage/package or with characteristics-equivalent products?
- When replacing with a different output voltage the amount of amp feedback will change, making it necessary to re-confirm the stability of the output capacitor, load, temperature range, and supply voltage range. When changing packages the permissible loss and thermal resistance will change, requiring verification of heat loss under usage conditions and thermal design of the final set. In the case of replacing with characteristics-equivalent models the ESR conditions of the output capacitor may differ depending on the product, so please check the stable operating range in the datasheet.
  Related Link：Technical Document

How do you calculate power loss?
- The power loss P_d=(Vin-Vo)×Io+Vin×Icc, where Vin is the supply voltage, Vo is the output voltage, Io the output current, and Icc the circuit (bias) current.
  Related Link：Technical Document

How do you improve power loss (permissible)?
- It can be effective to change to the same product or one with similar characteristics in a larger package with higher power loss. Or if the package cannot be changed, the permissible loss can be increased by making the area of the copper foil connected to the backside heat radiating pad as large as possible, increasing the thickness of the copper foil, or using copper foil for the inner layer of the multilayer substrate. There is also a method for improving the heat sink in screw stop package products. Refer to the technical materials for details on backside heat dissipation and heat sink.

Although permissible loss is listed in the absolute maximum ratings, is there an absolute maximum rating for transient loss?
- The permissible loss listed under the maximum ratings is the value at steady state. For the transient thermal resistance against transient loss, contact ROHM using the online inquiry form [Home/Technical Information/Inquiry Form]