The CDCE925 and CDCEL925 are modular
PLL-based low-cost, high-performance, programmable clock synthesizers, multipliers,
and dividers. CDCE925 and CDCEL925 generate up to five output clocks from a single
input frequency. Each output can be programmed in-system for any clock frequency up
to 230MHz, using up to two independent configurable PLLs.
The CDCEx925 has a separate output
supply pin, VDDOUT, which is 1.8V for CDCEL925 and 2.5V to 3.3V for
CDCE925.
The input accepts an external crystal
or LVCMOS clock signal. In case of a crystal input, an on-chip load capacitor is
adequate for most applications. The value of the load capacitor is programmable from
0 to 20pF. Additionally, an on-chip VCXO is selectable which allows synchronization
of the output frequency to an external control signal, that is, PWM signal.
The deep M/N divider ratio allows the
generation of zero-ppm audio/video, networking (WLAN, Bluetooth, Ethernet, GPS), or
interface (USB, IEEE1394, memory stick) clocks from a 27MHz reference input
frequency, for example.
All PLLs support SSC (spread-spectrum
clocking). SSC can be center-spread or down-spread clocking, which is a common
technique to reduce electromagnetic interference (EMI).
Based on the PLL frequency and the
divider settings, the internal loop filter components are automatically adjusted to
achieve high stability and optimized jitter transfer characteristic of each PLL.
The device supports nonvolatile EEPROM programming for easy customization of the
device in the application. It is preset to a factory default configuration and can
be reprogrammed to a different application configuration before it goes onto the PCB
or reprogrammed by in-system programming. All device settings are programmable
through the SDA/SCL bus, a 2-wire serial interface.
Three,
free programmable control inputs, S0, S1, and S2, can be used to select different
frequencies, or change the SSC setting for lowering EMI, or other control features
like outputs disable to low, outputs in high-impedance state, power down, PLL
bypass, and so forth.
The
CDCx925 operates in a 1.8V environment and in a temperature range of –40°C to
85°C.
The CDCE925 and CDCEL925 are modular
PLL-based low-cost, high-performance, programmable clock synthesizers, multipliers,
and dividers. CDCE925 and CDCEL925 generate up to five output clocks from a single
input frequency. Each output can be programmed in-system for any clock frequency up
to 230MHz, using up to two independent configurable PLLs.
The CDCEx925 has a separate output
supply pin, VDDOUT, which is 1.8V for CDCEL925 and 2.5V to 3.3V for
CDCE925.
The input accepts an external crystal
or LVCMOS clock signal. In case of a crystal input, an on-chip load capacitor is
adequate for most applications. The value of the load capacitor is programmable from
0 to 20pF. Additionally, an on-chip VCXO is selectable which allows synchronization
of the output frequency to an external control signal, that is, PWM signal.
The deep M/N divider ratio allows the
generation of zero-ppm audio/video, networking (WLAN, Bluetooth, Ethernet, GPS), or
interface (USB, IEEE1394, memory stick) clocks from a 27MHz reference input
frequency, for example.
All PLLs support SSC (spread-spectrum
clocking). SSC can be center-spread or down-spread clocking, which is a common
technique to reduce electromagnetic interference (EMI).
Based on the PLL frequency and the
divider settings, the internal loop filter components are automatically adjusted to
achieve high stability and optimized jitter transfer characteristic of each PLL.
The device supports nonvolatile EEPROM programming for easy customization of the
device in the application. It is preset to a factory default configuration and can
be reprogrammed to a different application configuration before it goes onto the PCB
or reprogrammed by in-system programming. All device settings are programmable
through the SDA/SCL bus, a 2-wire serial interface.
Three,
free programmable control inputs, S0, S1, and S2, can be used to select different
frequencies, or change the SSC setting for lowering EMI, or other control features
like outputs disable to low, outputs in high-impedance state, power down, PLL
bypass, and so forth.
The
CDCx925 operates in a 1.8V environment and in a temperature range of –40°C to
85°C.