ICS8431-11

Supply Voltage................................4.6V
Inputs ............................ -0.5V to V_DD + 0.5V
Outputs  .......................... -0.5V to V_DDO + 0.5V
Ambient Operating Temperature ..................0°C to 85°C
Storage Temperature ......................-65°C to 150°C

Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only and functional operation of product at these condition or any conditions beyond those listed in the DC Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability.

The ICS8431-11 is a general purpose clock frequency synthesizer for IA64/32 application and a member of the HiPerClockS™ family of High Performance Clock Solutions from ICS. The VCO operates at a frequency range of 190MHz to 510MHz providing an output frequency range of 95MHz to 255MHz. The output frequency can be programmed using the parallel interface, M0 thru M8, to the configuration logic. Spread spectrum clocking is programmed via the control inputs SSC_CTL0 and SSC_CTL1.

Programmable features of the ICS8431-11 support four operational modes. The four modes are spread spectrum clocking (SSC), non-spread spectrum clock and two test modes which are controlled by the SSC_CTL[1:0] pins. Unlike other synthesizers, the ICS8431-11 can immediately change spread-spectrum operation without having to reset the device.

In SSC mode, the output clock of the ICS8431-11 is modulated in order to achieve a reduction in EMI. In one of the PLL bypass test modes, the PLL is disconnected as the source to the differential output allowing an external source to be connnected to the TEST_I/O pin. This is useful for incircuit testing and allows the differential output to be driven at a lower frequency throughout the system clock tree. In the other PLL bypass mode, the oscillator divider is used as the source to both the M and the Fout divide by 2. This is useful for characterizing the oscillator and internal dividers.