The Ricoh’s R1525 is a 200 mA voltage regulator with special features such as a wide operating voltage range and ultra-low current consumption. The significant advantage of this product is that it has excellent EMC noise immunity and is used in particular applications that have severe electromagnetic noise requirements in order to provide a reliable operation.
EMC Noise Immunity:
Our internal car environment is nowadays equipped with numerous applications using wireless communication, such as:
- Aftermarket accessories: Bluetooth, NFC and Wi-Fi communication
- ADAS car safety systems: Adaptive Cruise Control, Collision Avoidance System, Tire Pressure Monitoring, Keyless Entry
In addition, the future scheduled connected car systems (Vehicle to Everything) will extensively make use of wireless communication. As a result, the total EMC noise level caused by such systems increases the risk that the proper operation of other on-board systems may be affected by this. It becomes evident to take counter measures in the circuit design to prevent this and select components, which contribute to a reliable operation of the application.
The new R1525 is especially tailored for this purpose and has the capability to resist EMC noise in the high-frequency band from 10 MHz to 1 GHz, providing a stable output voltage. Compared to predecessor generation products the transient response speed has been significantly improved; only minor and short peaks will occur at the output voltage because of input or load transients.
Wide Operating Voltage Range:
The new CMOS-based R1525 is robust enough to survive in harsh conditions; it operates up to 42 V and has a maximum rating of 50 V. It even tolerates load dump surge peak inrush voltages of 60 V with a duration of less than 200 ms. The minimum operating voltage starts at 3.5 V, which makes the R1525 suitable to use even at severe cranking conditions. The product will be available in a version targeted for the consumer, industrial and automotive application market and has customized operating temperature ranges for each purpose, respectively –40 to 105 °C, –50 to 125 °C and –40 to 125 °C. As for the automotive version, it is scheduled to become AEC-Q100 compliant by July 2019.
The output voltage is internally set and one has a choice to select from 14 output voltage versions in the range from 1.8 to 9.0 V.
Low Current Consumption:
Another important feature is to minimize current consumption for specific (automotive) applications that are continuously active, extending the operational lifetime of the battery. The R1525 contributes to reduce the total current consumption of the application with only 2.2 µA in On-mode and 0.1 µA in Off-mode.
The R1525 has an excellent output voltage accuracy of 0.6% and low temperature drift coefficient of only 60 ppm/°C, making the product suitable as a solid power source with high reliability.
Transient Response:
The R1525 has a stable operation by using a ceramic output capacitor with a minimum value of 0.1 μF. When the output voltage does not meet the system’s requirements due to input voltage and load current fluctuation, it is recommended to use a ceramic capacitor of 10 μF or larger to minimize the output voltage variation significantly.
Safety Circuits:
The R1525 has an array of safety features, protecting the voltage regulator and other parts of the application from possible damage and failure.
- Over-current protection, reducing the output current when overloaded.
- Short protection, an embedded fold back short current limit circuit detects a short circuit and decreases the output current to a safe level of 80 mA, after removing the short the regulator resumes to normal operation automatically.
- Protected pin lay-out, a special lay-out was arranged for the R1525S in HSOP-8E package preventing a failure when adjacent pins are shorted. All four regulator terminals are isolated with not connected adjacent pins.
- Thermal protection is incorporated and will turn off the regulator when an over-temperature of 160 °C is detected and will resume to normal operation again as soon a temperature of 135 °C is reached.
To be used in:
Target applications for this regulator are for example automotive applications with a direct battery connection or for use in ECUs, Infotainment, Security, Dashboard, Remote Keyless Entry, Immobilizer, Gateway systems etc. The R1525 is available in four different packages: SOT-23-5, SOT-89-5, HSOP-6J and HSOP-8E.
The new R1525 is a voltage regulator intended for use in a wide variety of applications that require a long battery lifetime. It has a remarkable current consumption of only 2.2 µA, good transient response performance and has a high immunity for electromagnetic noise. This makes the R1525 a reliable voltage source for use in noise critical devices.
