For Consumer / IoT
Power Management ICs Meeting Industrial Needs
Needs for high-voltage power management products have been increasing in the industrial equipment field.
The DC 24 V power sources generally used in industrial equipment have a safety extra low voltage (SELV) circuit as a functional safety circuit in order the voltage not to exceed the safety level at both normal operation and single fault conditions. The SELV circuit sets DC 60 V as the maximum safe voltage. Therefore, the SELV circuit itself and input and output parts of systems must have high voltage resistance of over 60 V.
For example, high resistance is required for the SELV circuit and power source circuit inside equipment such as programmable logic controllers, motion controllers processing factory automation, servo amplifiers, safety devices like safety relays and safety light curtains, etc.
In some cases, power source wires of the controlling unit become long due to the locational conditions of the whole equipment. As the wiring gets longer, the probability of unpredicted voltage surge caused by parasitic inductance increases. In order to protect systems from damage caused by surge voltages, there must be a voltage margin for the transient overvoltage. In the case of 24 V power source systems, components must have more than twice as large a voltage margin as the source voltage of the systems, such as 48 V or 60 V.
These days, in order to make power loss of systems with long cables as low as possible, high-voltage systems connectable directly with the primary power supply such as a 48 V battery, are under development. As a matter of course, power management ICs, one of the components of those systems, are also required to correspond to the 48 V input.
Ricoh Electronic Devices has a lineup of reset ICs and LDO regulators with maximum operating voltage of 60 V and maximum rating voltage of 80 V, suitable for those high voltage systems.
The R3160 is a high-voltage reset IC directly connectable to a 48 V battery without any voltage divider. It enables reducing external components, mounting area, and supply current.
The R3160 is usable for early warning systems by directly monitoring the battery voltage. Detector threshold accuracy is also high: ±1.0% (Ta=25°C).
The R1560/R1561 are LDO regulators both of which can receive a source voltage directly from a 48 V battery. The regulators require no resistor divider, which contributes to reducing the number of external components, mounting space, and supply current.
The R1560, with its low operating current of typically 0.3 µA and standby current of typically 0.1 µA, reduces supply current at the system shutdown.
The R1561, characterized by its good transient response, achieves a stable operation even in applications with large ripples and heavy load.