DLPC900ZPC datasheet(56/72 Pages) TI1

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MOSC

MOSCN

Crystal

RFB

CL1

CL2

DLPC900

DLPS037A – OCTOBER 2014 – REVISED AUGUST 2015

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CStray-MOSCN = Sum of package and PCB capacitance at the crystal pin associated with controller signal MOSCN. (3)

Figure 29. Crystal Oscillator Configuration

10.1.5 Spread Spectrum Clock Generator Support

DLPC900 supports limited, internally controlled, spread spectrum clock spreading on the DMD interface. The

purpose is to frequency-spread all signals on this high-speed external interface to reduce EMI emissions. Clock

spreading is limited to triangular waveforms. The DLPC900 provides modulation options of 0%, ±0.5%, and

±1.0% (center-spread modulation).

10.1.6 GPIO Interface

The DLPC900 provides 9 software-programmable, general-purpose I/O pins. Each GPIO pin is individually

configurable as either input or output. In addition, each GPIO output can be either configured as push-pull or

open-drain. Some GPIO have one or more alternative use modes, which are also software configurable. The

reset default for all GPIO is as an input signal. However, any alternative function connected to these GPIO pins,

with the exception of general-purpose clocks and PWM generation, will be reset. When configured as open-drain,

the outputs must be externally pulled-up (to the 3.3-V supply). External pullup or pulldown resistors may be

required to ensure stable operation before software can configure these ports.

10.1.7 General Handling Guidelines for Unused CMOS-Type Pins

To avoid potentially damaging current caused by floating CMOS input-only pins, it is recommended tying unused

controller input pins through a pullup resistor to its associated power supply or through a pulldown to ground

unless noted in the Pin Functions. For controller inputs with an internal pullup or pulldown resistor, it is

unnecessary to add an external pullup or pulldown unless specifically recommended. Internal pullup and

pulldown resistors are weak and should not be expected to drive the external line.

Unused output-only pins can be left open.

When possible, it is recommended to configure unused bidirectional I/O pins to their output state such that the

pin can be left open. If this control is not available and the pins may become an input, then they should be

pulled-up (or pulled-down) using an appropriate resistor unless noted in the Pin Functions.

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DLPC900ZPC Datasheet(PDF) 56 Page - Texas Instruments