1. Overview

️· Device: C9716J - A clock generator designed for mobile applications (likely a processor companion chip).
️· Functionality: Generates multiple clock signals (CPU, 48MHz, PCI, PCI_F, Ref) derived from a primary input. Provides SSCG (Spread Spectrum Clock Generation) for EMI reduction.
️· Key Features:
- Multiple output clocks
- SSCG capability
- Power down modes for low power operation
- Focus on precise timing and minimal jitter.

2. Power Management

️· Power Down Modes: The device has multiple power-down modes, critical for battery-powered devices.
- I2.5PD: 200 μA (Power Down Mode, VDDC = 2.5V)
- I3.3PD: 100 μA (Power Down Mode, VDD = 3.3V)
️· Voltage Requirements: Operates with several voltage rails (VDD, VDDF, VDDP, VDDR, VDDC) generally around 3.3V, with VDDC being 2.5V. These voltages support different internal functions. Tolerance of ±5% is specified.

3. Timing Characteristics (Most Important for Understanding the Device)

️· CPU to PCI Offset (tOFF): Crucial timing parameter. CPU clock must lead the PCI clock. Range is 1-4 nanoseconds.
️· Output Duty Cycle: Output signals have a duty cycle around 50%. This is an important characteristic for downstream circuits to function correctly.
️· AC Skew Requirements:
- CPU Skew: 175 pS
- 48 MHz Skew: Not specified, but expected to be low.
- PCI/PCI_F Skew: 500 pS
- Ref Skew: Not specified, but expected to be low.
️· Jitter: Maximum jitter is specified.
- CPU: +/- 250 pS
- 48 MHz: +/- 500 pS
- PCI/PCI_F: +/- 500 pS
️· ∆Period (Cycle-to-Cycle Jitter): Limits on cycle-to-cycle variation in period. (e.g., CPU: +/- 250 pS, PCI: +/- 500 pS).

4. Electrical Characteristics

️· Input Requirements: Not explicitly detailed (but implies a reference clock input).
️· Output Driver Characteristics:
- CPU Outputs: Driven with both pull-up and pull-down resistors. Specifies rise/fall times, pull-up currents (IOHmin, IOHmax) and pull-down currents (IOLmin, IOLmax).
- 48 MHz, PCI, PCI_F, Ref outputs: Driven with output buffers; characteristics (rise/fall times, drive strength) would be similar to the CPU outputs but aren’t listed explicitly.
️· Power Consumption: Includes static and dynamic consumption figures for various operating modes (VDD = 3.3V, VDDC = 2.5V).
️· Operating Temperature Range: 0°C to +70°C.

Key Considerations & Implications

️· Design Constraints: The timing parameters (tOFF, skew, jitter) are *critical* to meet in the overall system design. Downstream circuits that use the clocks will have performance limits dictated by these characteristics.
️· Power Management: The power-down modes allow for significant power savings, essential in mobile devices.
️· SSCG: The spread spectrum clock generator will reduce EMI which might otherwise be problematic.