Are there any power-up sequence requirements for National\s Channel-link transmitters?
Yes, use the following power-up sequence for the DS90CR217 and DS90CR287: Apply power while holding the powerdown (PD) pin LOW → Apply clock→ assert PD pin HIGH. In this sequence the PLL is held off until a valid clock is applied. OR Apply clock → Apply power. In this sequence, the part starts up with a valid clock at the PLL input. DO NOT Apply power → PD Pin = HIGH (device enabled) → (after a delay) Apply clock. This can cause a miss start and corrupt the LVDS output clock and data. AND DO NOT Apply PLLVcc before Vcc and LVDSVcc. The three Vcc”s can power up at the same time. For the DS90CR485, use the following power-up sequence: Apply all Vccs at the same time and then apply Clock.
