Output voltage fixed products (Vout products) and output voltage externally adjusted products (FB products) show the output voltage setting method for DC/DC and voltage regulators.
An output voltage fixed product (Vout product) is a product in which the output voltage is fixed inside the IC, and an output voltage externally adjusted product (FB product) is a product that can adjust the output voltage using an externally connected resistance, etc.
(a) Output voltage fixed products (Vout products)
An output voltage fixed product has a high-accuracy feedback resistance for adjusting the output voltage built into the IC. An externally connected resistance to adjust the output voltage is not required, making miniaturization and component reduction possible.
In addition, since the feedback resistance is built into the IC, the product is resistant to external noise and a higher feedback resistance value than with output voltage externally adjusted products can be used.
This makes it possible to hold down the quiescent current consumed by the feedback resistance, making it optimal for low consumption applications.
(b) Output voltage externally adjusted products (FB products)
An output voltage externally adjusted product requires the feedback resistance for adjusting the output voltage to be external to the IC. Since the output voltage can be changed by just changing the externally connected resistance, this type of product can be used to build multiple power supply lines using the same IC, which is advantageous for components control and inventory control.
A disadvantage is that an externally connected feedback resistance and a phase compensation capacitor are required, so there is a greater number of components compared to an output voltage fixed product.
In addition, since there is a feedback resistance external to the IC, the product is more easily affected by external noise, and if the feedback resistance value is too high, the IC could malfunction, so caution is required.