ROHM Introduces 4ch System Power Supply IC For CCD Camera Modules
ROHM Co., Ltd. has recently announced the development of the BD8676KN, a 4ch system power supply featuring an efficiency of 80% even during all-channel (4) driving. It was designed specifically to drive CCD camera modules in a variety of devices, including in-vehicle rear monitors, digital AV equipment, surveillance cameras and PC peripheral equipment.
According to ROHM, the number of devices equipped with cameras is increasing rapidly, driving the need for camera modules. Two types of technologies are currently in use: CMOS and CCD, each with advantages and disadvantages. CCD systems enjoy high sensitivity and an excellent S/N ratio, and are primarily used in digital cameras and camcorders. According to the company, until now, CMOS sensors consumed less power and were easier to configure, making them the ideal choice for low power applications such as web cameras.
CCD sensors require a positive and negative power supply, as well as a specialized driver circuit for controlling the startup sequence of the power supply. This results in a relatively complex configuration, requiring at least 3 power supply ICs and 2 reset ICs for timing control. Integrating all of these vital components into a power supply circuit configuration has been extremely difficult due to problems related to voltage resistance and heat generation.
ROHM states that its BD8676KN solves these problems by integrating 4 channels into a single chip– a 2ch step-down switching regulator for DSP/video driver along with a 1ch step-up/-down voltage power supply and 1ch inverted power supply for the CCD sensor and analog front end/driver. A sequence circuit is also built in for startup control of all power supplies, rendering reset ICs – required in conventional circuits – unnecessary. This is said to not only reduce costs, but to simplify design as well. Additional features include internal FETs and LDO regulators for low noise and synchronous operation between the inverter charge pump and step-down switching regulator circuits that increase efficiency to greater than 80% during full-ON driving while ensuring 0µA current consumption during standby.
The units are priced at 1000 yen/unit in OEM quantities.
