MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Order Number: MPC9315/D
Rev 2, 02/2002
2.5V and 3.3V CMOS PLL
Clock Generator and Driver
The MPC9315 is a 2.5V and 3.3V compatible, PLL based clock
generator designed for low-skew clock distribution in low-voltage
mid-range to high-performance telecom, networking and computing
applications. The MPC9315 offers 8 low-skew outputs and 2 selectable
inputs for clock redundancy. The outputs are configurable and support
1:1, 2:1, 4:1, 1:2 and 1:4 output to input frequency ratios. In addition, a
selectable output 180° phase control supports advanced clocking
schemes with inverted clock signals. The MPC9315 is specified for the
extended temperature range of –40 to +85°C.
MPC9315
LOW VOLTAGE
2.5V AND 3.3V PLL
CLOCK GENERATOR
•
Configurable 8 outputs LVCMOS PLL clock generator
•
Compatible to various microprocessor such as PowerQuicc I and II
•
Wide range output clock frequency of 18.75 to 160 MHz
•
2.5V and 3.3V CMOS compatible
•
Designed for mid-range to high-performance telecom, networking and
computer applications
Features
•
Fully integrated PLL supports spread spectrum clocking
•
Supports applications requiring clock redundancy
•
Max. output skew of 120 ps (80 ps within one bank)
•
Selectable output configurations (1:1, 2:1, 4:1, 1:2, 1:4 frequency ratios)
•
2 selectable LVCMOS clock inputs
•
External PLL feedback path and selectable feedback configuration
•
Tristable outputs
•
32 ld LQFP package
•
Ambient operating temperature range of –40 to +85°C
Functional Description
The MPC9315 utilizes PLL technology to frequency and phase lock its outputs onto an input reference clock. Normal operation
requires a connection of one of the device outputs to the selected feedback (FB0 or FB1) input to close the PLL feedback path.
The reference clock frequency and the output divider for the feedback path determine the VCO frequency. Both must be selected
to match the VCO frequency range. With available output dividers of divide-by-1, divide-by-2 and divide-by-4 the internal VCO of
the MPC9315 is running at either 1x, 2x or 4x of the reference clock frequency. The frequency of the QA, QB, QC output groups is
either the equal, one half or one fourth of the selected VCO frequency and can be configured for each output bank using the
FSELA, FSELB and FSELC pins, respectively. The available output to input frequency ratios are 4:1, 2:1, 1:1, 1:2 and 1:4. The
REF_SEL pin selects one of the two available LVCMOS compatible reference input (CLK0 and CLK1) supporting clock
redundant applications. The selectable feedback input pin allows the user to select different feedback configurations and input to
output frequency ratios. The MPC9315 also provides a static test mode when the PLL supply pin (VCCA) is pulled to logic low
state (GND). In test mode, the selected input reference clock is routed directly to the output dividers bypassing the PLL. The test
mode is intended for system diagnostics, test and debug purpose. This test mode is fully static and the minimum clock frequency
specification does not apply. The outputs can be disabled by deasserting the OE pin (logic high state). In PLL mode, deasserting
OE causes the PLL to lose lock due to no feedback signal presence at FB0 or FB1. Asserting OE will enable the outputs and
close the phase locked loop, also enabling the PLL to recover to normal operation. The MPC9315 is fully 2.5V and 3.3V
compatible and requires no external loop filter components. All inputs accept LVCMOS signals while the outputs provide
LVCMOS compatible levels with the capability to drive terminated 50
Ω
transmission lines. For series terminated transmission
lines, each of the MPC9315 outputs can drive one or two traces giving the devices an effective fanout of 1:18. The device is
packaged in a 7x7 mm2 32-lead LQFP package.
The fully integrated PLL of the MPC9315 allows the low skew outputs to lock onto a clock input and distribute it with essentially
zero propagation delay to multiple components on the board. In zero-delay buffer mode, the PLL minimizes phase offset between
the outputs and the reference signal.
FA SUFFIX
LQFP PACKAGE
CASE 873A–02
©
Motorola, Inc. 2002
1
MOTOROLA [ MOTOROLA, INC ]
