SII Launches World's First Zero-power Photo Detect IC

– Innovative “S-5470” Series ICs Combined with Photovoltaic Device Achieve World’s First² Zero-power&sup1 Consumption Light/Dark Detection Switch –

CHIBA, Japan — July 23, 2012 — Seiko Instruments Inc. (SII) announced the new “S-5470” series photo detect ICs&sup3 that enable design of light/dark detection switch circuits with zero-power consumption (nW class) when combined with a photo diode, LED, or other photovoltaic devices.

Due to the photo voltaic effect, photodiodes and LEDs generate tiny electrical current when exposed to light. Conventional ICs require amplifiers to sense the minute current, and consume significant power to operate. In contrast, SII’s new “S-5470” series ICs detect the same minute current without the need for amplifiers using SII’s unique low power CMOS technology. This approach has achieved zero-power consumption (nW class) circuit designs. It also enables the design of shading detection switches based on illumination differences between two photo voltaic devices.

Typical applications include auto power-off functionality detecting light/dark conditions, automatic lighting during darkness, and non-contact switching when the device is covered by a hand. Some examples would be a wireless mouse that turns itself on when the user grasps it for use; smartphones that activate when their covers are opened; clocks that inactivate chimes during periods of darkness; equipment that operates when its box is opened, and the like.

The “S-5470” series ICs feature super-low power consumption: 0.1 nA (typ.) at a 5.5V supply voltage; can be used with a number of different photovoltaic devices including photo diodes, LEDs, solar batteries, etc.; wide operating voltage range: 0.9V-5.5V; and small SOT-23-5 package (2.9×2.8×1.3 mm).

“S-5470” Series Main Features – Zero-power: below 1nW (Typ.) The current consumption is 0.1nA (Typ.) at the supply voltage 5.5V. Thereby, the power consumption becomes below 1nW (Typ.).

– Monofunctional photo detect and illuminance difference detection are possible. The light/dark detection system using one photovoltaic device, and the shading detection system detecting the illuminance difference using two photovoltaic device.

– It is possible to combine with various photovoltaic devices. Because this IC can use external photovoltaic devices which are small power generation, it is possible to combine with various photovoltaic devices such as a solar battery, a photo-diode and a LED.

– Wide operating voltage range 0.9V-5.5V It can operate on the wide range voltage from the low voltage (0.9V) of one dry cell to the high voltage of 5.5V.

– Package SOT-23-5 (2.9×2.8×1.3mm)

Application – Auto power-off of various portable devices – Wireless equipment, such as a mouse, a keyboard, and a remote controller – A smart phone, a tablet PC – Automatic lighting – Non-contact switch

Detailed information:

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&sup1 According to international standard IEC 62301 for measuring standby power consumption, electricity usage of less than 5 mW can be considered “zero”. This product power consumption is nW class and corresponds to one 5 millionth of this regulation. Therefore we call this product “Zero-power”. “nW” is one billionth of 1W. It is a very minute electric power unit corresponding to one hundred billionth of the power consumption (100W) of a common LED television. &sup2 Our investigation &sup3 Here, we means the IC which can detect light/dark and shading by combining with a photovoltaic device as a external photo detector.

About Seiko Instruments Inc. (SII) Seiko Instruments Inc. is a subsidiary of Seiko Holdings Corporation (TSE:8050). The company develops, manufactures and sells watches, precision components and machine tools, electronic components, communication products and solutions, printers, and analysis instruments. Please visit:

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