FullFlex - Power sequencing for the Fullflex

Question: How is Power Sequencing done for the Fullflex Dual Ports?

 

Answer:


There is no power on sequence requirements for the Fullflex dual ports. For the 1.5V/1.8V devices, there is one pin (VC_SEL) to select the external core power between 1.5V and 1.8V. The default value for the pin is LOW which selects 1.8V core supply. Devices without the VC_SEL pin have the core voltage to be equal to 1.2V.

                       

 

Table 1 shows the power supply requirement details and table 2 shows external power supply values for the Fullflex dual ports.

 

Table 1: Power supply requirements

                                                                                                 
   

                                              POWER SUPPLY REQUIREMENTS

  
   

     Voltage Ramp Rate

  
   

     External power supply will be expected to have a ramp rate from GND to [nominal] that can be any rate between 100nS/volt to 100mS/volt.

   

      

  
   

     Monotonicity

   

      

  
   

     External power supply will be expected to offer no guarantee of

   

     monotonicity during application of power.

   

      

  
   

     Supply Order

   

      

  
   

     External power supplies can be applied in any order with any duration between supply activation.

   

      

  
   

     Low frequency ripple

   

      

  
   

     Supply variations of ?2% at frequencies up to 400KHz

   

      

  
   

     High Frequency noise

   

      

  
   

     Supply variations of ?2% at frequencies between 1MHz and 250MHz

   

      

  
   

     Hot-Plug considerations

   

      

  
   

     NA

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 2: External Power Supply Values.

 

 

 

                                                                                                                                                                                                               
   

     VC_SEL

  
   

     VCORE

  
   

     IO STD

  
   

     VDDIO

  
   

     VTTL

  
   

     VREF

  
   

     Unit

  
     
   

     Min

  
   

     Typ

  
   

     Max

  
   

     Min

  
   

     Typ

  
   

     Max

  
   

     Min

  
   

     Typ

  
   

     Max

  
   

     Min

  
   

     Typ

  
   

     Max

  
     
   

     L

  
   

     1.7

  
   

     1.8

  
   

     1.9

  
   

     LVTTL

  
   

     3.0

  
   

     3.3

  
   

     3.6

  
   

     2.3

   

     3.0

  
   

      2.5

   

     3.3

  
   

      2.7

   

     3.6

  
   

     NA

  
   

     NA

  
   

     NA

  
   

     V

  
     
   

     2.5CMOS

  
   

     2.3

  
   

     2.5

  
   

     2.7

  
   

     NA

  
   

     NA

  
   

     NA