Cypress CY7C1518KV18 manual Power Up Sequence in DDR-II Sram, PLL Constraints, VDD/ Vddq Doff, Ddq

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CY7C1516KV18, CY7C1527KV18 CY7C1518KV18, CY7C1520KV18

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.

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 μs of stable clock to relock to the desired clock frequency.

■Provide stable DOFF (HIGH), power and clock (K, K) for 20 μs to lock the PLL.

K

K

VDD/ VDDQ

DOFF

Figure 3. Power Up Waveforms

~ ~

 

~ ~

 

Unstable Clock

> 20Πs Stable clock

Start Normal

 

 

Operation

Clock Start (Clock Starts after VDD/ V DDQ Stable)

VDD/ V DDQ Stable (< +/- 0.1V DC per 50ns )

Fix HIGH (or tie to V )

DDQ

Document Number: 001-00437 Rev. *E

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Contents Cypress Semiconductor Corporation 198 Champion Court FeaturesConfigurations Functional DescriptionCLK Logic Block Diagram CY7C1516KV18Logic Block Diagram CY7C1527KV18 DoffLogic Block Diagram CY7C1520KV18 Logic Block Diagram CY7C1518KV18BWS CY7C1527KV18 8M x Pin ConfigurationBall Fbga 13 x 15 x 1.4 mm Pinout CY7C1516KV18 8M xCY7C1520KV18 2M x CY7C1518KV18 4M xPin Name Pin Description Pin DefinitionsSynchronous Read or Write Input. When TDO for Jtag Power supply Inputs to the Core of the DevicePower Supply Inputs for the Outputs of the Device Referenced with Respect toFunctional Overview SRAM#1 ZQ Application ExampleProgrammable Impedance Echo ClocksComments Write Cycle DescriptionsOperation First Address External Second Address InternalBWS0 Ieee 1149.1 Serial Boundary Scan Jtag Idcode TAP Controller State Diagram TAP Electrical Characteristics TAP Controller Block DiagramTAP Timing and Test Conditions TAP AC Switching CharacteristicsRegister Name Bit Size Identification Register DefinitionsScan Register Sizes Instruction CodesBit # Bump ID Boundary Scan OrderVDD/ Vddq Doff Power Up Sequence in DDR-II SramPower Up Sequence PLL ConstraintsOperating Range Electrical CharacteristicsDC Electrical Characteristics Maximum RatingsAC Electrical Characteristics Parameter Description Test Conditions Fbga Unit CapacitanceThermal Resistance Parameter Description Test Conditions Max UnitParameter Min Max Switching CharacteristicsPLL Timing Parameter Min Max Output TimesCare Undefined Switching WaveformsOrdering Information 250 167 Ball Fbga 13 x 15 x 1.4 mm Package DiagramWorldwide Sales and Design Support Products PSoC Solutions Sales, Solutions, and Legal InformationDocument History

CY7C1516KV18, CY7C1520KV18, CY7C1527KV18, CY7C1518KV18 specifications

The Cypress CY7C1516KV18, CY7C1520KV18, CY7C1527KV18, and CY7C1518KV18 are a series of high-performance asynchronous static random-access memory (SRAM) devices designed for a variety of applications requiring fast data access and reliable operation. These SRAM chips feature density options ranging from 1Mbit to 4Mbit, catering to a broad spectrum of consumer electronics, telecommunications, networking, and industrial applications.

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Data integrity is another critical characteristic of these SRAM devices. They are designed with features such as byte-write capability and asynchronous read/write operations, ensuring that users can manage data efficiently and reliably. The robust architecture also allows for simple interfacing with most processors and microcontrollers, facilitating easy integration into various systems.

The packages of these SRAM chips are available in several form factors, including 44-pin and 48-pin configurations, allowing for flexibility in board design and layout. Their compatibility with standard interface protocols ensures seamless communication with other components of electronic designs.

These Cypress SRAM devices support a range of temperature specifications, making them suitable for both commercial and industrial-grade applications. Enhanced reliability during various operating conditions assures designers that these memory chips will maintain performance in diverse environments.

In summary, the Cypress CY7C1516KV18, CY7C1520KV18, CY7C1527KV18, and CY7C1518KV18 SRAM devices offer high speed, low power consumption, and flexibility in integration. With their advanced technology and robust features, these memory solutions continue to play a vital role in modern electronics, driving innovation across multiple sectors.
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