Ultra Small PLL Clock Generator from Torex

4th September 2008

ES Admin

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Datasheet

Torex Semiconductor has introduced the XC25BS8 Series of PLL clock generator ICs with built-in crystal oscillator circuit, divider circuit and multiplier PLL circuit. Suitable for low voltage and battery-powered applications of between 2.5V and 5.5V, the devices can generate a high frequency output from an input as low as 8kHz by multiplying the input up to 4095 times.

Available in either the small SOT-26W or ultra-small USP-6C (1.8mm x 2.0mm x 0.6mm) package, it is possible to configure a fully operational circuit with a few external components like one low-pass filter capacitor. The XC25BS8 Series features improved synchronous characteristics over conventional PLLs, such as Torex’s XC25BS3 and XC25BS5 devices, and offers a much wider frequency range.

Laser trimming gives the option of being able to select from input divider ratios (M) of 1 to 2047 and output divider ratios (N) of 1 to 4095, where the output frequency (fQ0) is equal to input clock frequency (fCLKin) multiplied by N/M. Accordingly, it is possible to choose virtually any frequency multiplication factor within the 8kHz to 36MHz input and 1MHz to 100MHz output frequency ranges, with N/M not necessarily set as an integer.

Devices in the XC25BS8 Series incorporate a CE function enabling designers to reduce current consumption down to a maximum of 10µA in standby mode. When the IC is in standby mode, the output becomes high impedance and the IC stops operation. It is possible to change the main clock frequency supplied to another chip by controlling the CE signal with the output configured as wired or using two or more ICs.