Targets low-power sensors, consumer products, portable medical devices and industrial systems

By Brian Santo, contributing writer

Cymbet Corp.
offers a rechargeable battery back-up IC called the EnerChip. But how does the
company make it more useful in a wider variety of applications? The answer: marry
it with a real-time clock (RTC) with battery management capabilities. By
leveraging the company’s EnerChip solid-state rechargeable micro-battery, Cymbet
developed a standalone IC that combines an ultra-low-power RTC with power
management functions, supporting power switching and battery management.

The new
power management with RTC (PMRTC) product will work with a variety of backup
power sources, whether its own
EnerChip micro-battery, a supercapacitor, or a rechargeable coin battery. The
company plans to follow-up with new chips that integrate the RTC and power
management circuitry of the PMRTC directly with the EnerChip in a single
package.

The EnerChip devices are designed for
battery backup for any number of devices, including remote sensors, consumer
products, portable medical devices, and industrial systems. If the main power is lost, momentarily or
even up to several weeks, the EnerChip can keep the device alive. If the device
is equipped with an RTC (including the company’s own PMRTC), the EnerChip backup
battery will similarly keep the RTC powered until the main power can be
restored, at which point the EnerChip can be recharged.

The PMRTC, available in several
versions, has several unique features. Among them is that the RTC element
consumes less power than any similar device on the market, Jeff Sather, Cymbet
VP of technology told Electronic Products.

Most devices
on the market consume somewhere in the range of about 100 nanoamps to several
microamps of current, Sather noted.

The PMRTC
has dual operating modes. The higher precision mode relies on a crystal oscillator
and draws about 50 nanoamps, Sather said. There is also mode that does not
require a crystal oscillator, and though less precise, it draws even less
current – about 20 nanoamps, he continued.

If, for
example, you’re powering a chip that might need to only wake up every few days,
you don’t need a lot of clock precision, he added.

As for the power
management, Sather said a rare feature is the ability to handle multiple
voltages – 4.1 V is common, but supercapacitors and rechargeable coin batteries
tend to operate at 3.1 V or 3.2 V. He said the company also will offer a power
output pin that can be used to provide a limited amount of power to an outside
component.

Another uncommon
feature will be a pin that allows the user to disconnect external components
from the main power rail, Sather said. For example, if you have a device that
tends to draw a lot of power (a microcontroller or accelerometer), the power
management system will allow the user to disconnect it.

“That might
be useful for remote sensors when you don’t need access to the microcontroller or
the accelerometer all the time,” he said.

Additionally,
the part will support both the I2C and SPI interfaces. Another rare, if not
unique feature, is an integrated temperature sensor.

Sampling of
the standalone PMRTC will begin in the second quarter of 2018, with a product
family containing an integrated EnerChip to follow in late 2018, the company
said.

Pricing is
not set yet, but Sather said a preliminary cost estimate is roughly $0.60 in
volume in the U.S. for the PMRTC. Versions integrated with the Enerchip battery
will probably range from $0.80 to $1.20 in volume, depending on the
configuration.

The company also announced that it is
now shipping the EnerChip micro-batteries in volume.