Microchip’s MCP1640 | Super-Effective Battery Power

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Super-effective battery power

Designers working on line-powered systems are in luck; whilst wasting power is always bad, a few mA of waste don’t really matter. When working on battery powered systems, every bit of energy helps – an efficient switching regulator can be helpful in various ways.

First of all, the holy grail of battery powered systems is connecting your electronics directly to the battery. Controllers with a wide input range can “float” around the battery voltage, thereby eliminating switching losses completely. Sadly, this is not always possible – LCD modules and various other elements demand fixed voltages or tight voltage ranges.

In this case, a highly efficient voltage regulator can be valuable. Microchip’s MCP1640 boasts with a 96% conversion rate, and furthermore it comes with a power-saving shutdown mode as shown in figure A.

The MCP1640's external circuitry looks similar to other switching regulators

The MCP1640’s external circuitry looks similar to other switching regulators

Due to the high switching frequency – the PWM modules work at 500KhZ – the inductors required are small; their weight is comparable with that of SMD resistors, thereby ensuring “minimal grief” when used in surface-mount form factors.

Focus on the family…

Microchip provides designers with a set of power-gating methods which are designated by the letter after the part number. On the B series, the EN pin completely disconnects the output from the power supply – this yields a loss current of less than 1 microampere.

The C and D family, instead, use output bypass. This means that the battery voltage is “passed through” via the FET when the EN pin is used to switch off the regulator – especially useful in cases where the load can also run in a lower-voltage hibernation mode.

Let this table be your guide to the world of the MCP1640

Another, albeit more “esoteric”, difference involves the switching mode used when currents are very low; in principle, Microchip provides a trade-off between higher efficiency and lower ripple.


In Conclusion

This product can, for example, be used to isolate OLED modules and their driver circuitry from low-power parts of the system. As always, let OEMSecrets find the best price for you!