View CYM1946_313126.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

fax id: 2045
CYM1946
512K x 32 Static RAM Module
Features
* High-density 16-megabit SRAM module * 32-bit Standard Footprint supports densities from 16K x 32 through 1M x 32 * High-speed SRAMs -- Access time of 35 ns * Low active power -- 7.3W (max.) at 35ns * Compatible with CYM1821, CYM1831, CYM1836, CYM1841, and CYM1851 JDEC Modules constructed from 16 128K x 8 SRAMs in SOJ packages mounted on an epoxy laminate substrate. Four chip selects are used to independently enable the four bytes. Reading or writing can be executed on individual bytes or any combination of multiple bytes through proper use of selects. The CYM1946 is designed for use with standard 72-pin SIMM sockets. The pinout is downward compatible with the 64-pin JEDEC ZIP/SIMM module family (CYM1821, CYM1831, CYM1836, and CYM1841). Thus, a single motherboard design can be used to accommodate memory depth ranging from 16K words (CYM1821) to 1,024K words (CYM1851). Presence detect pins (PD0-PD3) are used to identify module memory density in applications where modules with alternate word depths can be interchanged.
Functional Description
The CYM1946 is a high-performance 16-megabit static RAM module organized as 512K words by 32 bits. This module is
Logic Block Diagram
17
PD0 PD1 PD2 PD3 -
OPEN OPEN GND OPEN
Pin Configuration
ZIP/SIMM Top View
NC PD3 PD0 I/O0 I/O1 I/O2 I/O3 VCC A7 A8 A9 I/O4 I/O5 I/O6 I/O7 WE A14 CS1 CS3 A16 GND I/O16 I/O17 I/O18 I/O19 A10 A11 A12 A13 I/O20 I/O21 I/O22 I/O23 GND NC NC
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71
A0 - A16 OE WE CS1 A17 A18 A0 - A16
128Kx8 SRAM
1-4 Decoder 17
128Kx8 SRAM
128Kx8 SRAM
128Kx8 SRAM
8
I/O0 - I/O7
128Kx8 SRAM CS2 A17 A18 A0 - A16
1-4 Decoder 17
128Kx8 SRAM
128Kx8 SRAM
128Kx8 SRAM
8
I/O8 - I/O15
NC PD2 GND PD1 I/O8 I/O9 I/O10 I/O11 A0 A1 A2 I/O12 I/O13 I/O14 I/O15 GND A15 CS2 CS4 A17 OE I/O24 I/O25 I/O26 I/O27 A3 A4 A5 VCC A6 I/O28 I/O29 I/O30 I/O31 A18 NC
1946-2
128Kx8 SRAM CS3 A17 A18 A0 - A16
128Kx8 SRAM
128Kx8 SRAM
128Kx8 SRAM
8
I/O16 I/O23 -
1-4 Decoder 17
128Kx8 SRAM CS4 A17 A18
1-4 Decoder
128Kx8 SRAM
128Kx8 SRAM
128Kx8 SRAM
8
I/O24 I/O31 -
1946-1
Cypress Semiconductor Corporation
*
3901 North First Street
*
San Jose
*
CA 95134
* 408-943-2600 December 2, 1997
CYM1946
Selection Guide
1946-35 Maximum Access Time (ns) Maximum Operating Current (mA) Maximum Standby Current (mA) 35 1100 585 1946-45 45 1100 585 1946-55 55 1100 585
Maximum Ratings
(Above which the useful life may be impaired. For user guidelines, not tested.) Storage Temperature ................................. -55C to +125C Ambient Temperature with Power Applied ............................................... -10C to +85C Supply Voltage to Ground Potential ............... -0.5V to +7.0V
DC Voltage Applied to Outputs in High Z State.................................................-0.5V to +VCC DC Input Voltage ............................................-0.5V to +7.0V
Operating Range
Range Commercial Ambient Temperature 0C to +70C VCC 5V 10%
Electrical Characteristics Over the Operating Range
Parameter VOH VOL VIH VIL IIX IOZ ICC ISB1 ISB2 Description Output HIGH Voltage Output LOW Voltage Input HIGH Voltage Input LOW Voltage Input Load Current Output Leakage Current VCC Operating Supply Current Automatic CS Power-Down Current[1] Automatic CS Power-Down Current[1] GND < VI < VCC GND < VO < VCC, Output Disabled VCC = Max., IOUT = 0 mA, -35, -45, -55 CSN < VIL Max. VCC, CS > VIH, Min. Duty Cycle = 100% Max. VCC, CS > VCC - 0.2V, VIN > VCC - 0.2V, or VIN < 0.2V -35, -45, -55 Test Conditions VCC = Min., IOH = -4.0 mA VCC = Min., IOL = 8.0 mA 2.2 -0.3 -32 -20 Min. 2.4 0.4 VCC + 0.3 0.8 +32 +20 1100 585 200 Max. Unit V V V V A A mA mA mA
Capacitance[2]
Parameter CINA CINB COUT CINA17-18 Description Input Capacitance (WE, OE, A0-16) Input Capacitance (CS) Output Capacitance Input Capacitance A17-18 Test Conditions TA = 25C, f = 1 MHz, VCC = 5.0V Max. 175 10 45 45 Unit pF pF pF pF
Notes: 1. A pull-up resistor to VCC on the CS input is required to keep the device deselected during VCC power-up, otherwise ISB will exceed values given. 2. Tested on a sample basis.
2
CYM1946
AC Test Loads and Waveforms
R1 481 5V OUTPUT 30 pF INCLUDING JIG AND SCOPE R2 255 5V OUTPUT 5 pF INCLUDING JIG AND SCOPE R2 255 R1 481 3.0V 90% GND < 5 ns
1946-3
ALL INPUT PULSES 90% 10% < 5 ns
10%
(a)
(b)
1946-4
Equivalent to: OUTPUT
THEVENIN 167
EQUIVALENT 1.73V
Switching Characteristics Over the Operating Range[3]
1946-35 Parameter READ CYCLE tRC tAA tOHA tACS tDOE tLZOE tHZOE tLZCS tHZCS tPD WRITE CYCLE tWC tSCS tAW tHA tSA tPWE tSD tHD tLZWE tHZWE Read Cycle Time Address to Data Valid Data Hold from Address Change CS LOW to Data Valid OE LOW to Data Valid OE LOW to Low Z OE HIGH to High Z CS LOW to Low Z
[4]
1946-45 Min. 45 Max.
1946-55 Min. 55 Max. Unit ns 55 5 55 22 0 22 10 27 55 55 50 50 5 2 45 35 7 5 ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns 15 ns
Description
Min. 35
Max.
35 5 35 15 0 12 10 17 35 35 30 30 5 2 30 20 7 5 15 45 40 40 5 2 35 25 7 5 10 0 5
45 45 17 17 22 45
CS HIGH to High Z[4, 5] CS HIGH to Power-Down
[6]
Write Cycle Time CS LOW to Write End Address Set-Up to Write End Address Hold from Write End Address Set-Up to Write Start WE Pulse Width Data Set-Up to Write End Data Hold from Write End WE HIGH to Low Z WE LOW to High Z[5]
15
Notes: 3. Test conditions assume signal transition times of 5 ns or less, timing reference levels of 1.5V, input pulse levels of 0 to 3.0V, and output loading of the specified IOL/I OH and 30-pF load capacitance. 4. At any given temperature and voltage condition, tHZCS is less than tLZCS for any given device. These parameters are guaranteed and not 100% tested. 5. tHZCS and t HZWE are specified with CL = 5 pF as in part (b) of AC Test Loads and Waveforms. Transition is measured 500 mV from steady-state voltage. 6. The internal write time of the memory is defined by the overlap of CS LOW and WE LOW. Both signals must be LOW to initiate a write and either signal can terminate a write by going HIGH. The data input set-up and hold timing should be referenced to the rising edge of the signal that terminates the write.
3
CYM1946
Switching Waveforms
Read Cycle No. 1 [7,8]
t RC ADDRESS tAA tOHA DATA OUT PREVIOUS DATA VALID DATA VALID
1851-5
Read Cycle No. 2 [7,9]
t RC CS tACS OE tDOE tLZOE HIGH IMPEDANCE DATA OUT tLZCS tPU V CC SUPPLY CURRENT 50% DATA VALID tPD ICC 50% ISB
1851-6
tHZOE tHZCS HIGH IMPEDANCE
Write Cycle No. 1 (WE Controlled)
[6]
tWC ADDRESS tSCS CS tAW tSA WE tSD DATA IN DATA VALID tHZWE DATA OUT DATA UNDEFINED
1851-7
tHA tPWE
tHD
tLZWE HIGH IMPEDANCE
Notes: 7. WE is HIGH for read cycle. 8. Device is continuously selected, CS = VIL, and OE= VIL. 9. Address valid prior to or coincident with CS transition LOW.
4
CYM1946
Switching Waveforms (continued)
Write Cycle No. 2 (CS Controlled)
[6,10]
tWC ADDRESS tSA CS tAW tPWE WE tSD DATA IN DATA VALID tHZWE DATA OUT HIGH IMPEDANCE DATA UNDEFINED
1840-8
tSCS
tHA
tHD
Note: 10. If CS goes HIGH simultaneously with WE HIGH, the output remains in a high-impedance state.
Truth Table
CS H L L L WE X H L H OE X L X H Inputs/Output High Z Data Out Data In High Z Read Write Deselect Mode Deselect/Power-Down
Ordering Information
Speed (ns) 35 45 55 Ordering Code CYM1946PM-35C CYM1946PM-45C CYM1946PM-55C Package Type PM47 PM47 PM47 Package Type 72-Pin Plastic SIMM Module 72-Pin Plastic SIMM Module 72-Pin Plastic SIMM Module Operating Range Commercial Commercial Commercial
Document #: 38-M-00084
5
PRELIMINARY
Package Diagram
72-Pin Plastic SIMM Module PM47
CYM1946
(c) Cypress Semiconductor Corporation, 1997. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.

▲Up To Search▲

Price & Availability of CYM1946

	To Download CYM1946 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .