Electronic Components Datasheet Search |
|
CY7C1648KV18 Datasheet(PDF) 18 Page - Cypress Semiconductor |
|
CY7C1648KV18 Datasheet(HTML) 18 Page - Cypress Semiconductor |
18 / 29 page Document Number: 001-44061 Rev. *L Page 18 of 29 CY7C1648KV18 CY7C1650KV18 Power Up Sequence in DDR II+ SRAM DDR II+ SRAMs must be powered up and initialized in a predefined manner to prevent undefined operations. Power Up Sequence ■ Apply power and drive DOFF either high or low (all other inputs can be high or low). ❐ Apply VDD before VDDQ. ❐ Apply VDDQ before VREF or at the same time as VREF. ❐ Drive DOFF high. ■ Provide stable DOFF (high), power and clock (K, K) for 20 s to lock the PLL PLL Constraints ■ PLL uses K clock as its synchronizing input. The input must have low phase jitter, which is specified as tKC Var. ■ The PLL functions at frequencies down to 120 MHz. ■ If the input clock is unstable and the PLL is enabled, then the PLL may lock onto an incorrect frequency, causing unstable SRAM behavior. To avoid this, provide 20 s of stable clock to relock to the desired clock frequency. Figure 4. Power Up Waveforms > 20μs Stable clock Start Normal Operation DOFF Stable (< +/- 0.1V DC per 50ns ) Fix HIGH (or tie to VDDQ) K K DDQ DD V V / DDQ DD V V / Clock Start (Clock Starts after Stable) DDQ DD V V / Unstable Clock |
Similar Part No. - CY7C1648KV18 |
|
Similar Description - CY7C1648KV18 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |