900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




Maxim Integrated Semiconductor Electronic Components Datasheet

DS1270AB Datasheet

16M Nonvolatile SRAM

No Preview Available !

19-5615; Rev 11/10
www.maxim-ic.com
DS1270Y/AB
16M Nonvolatile SRAM
FEATURES
5 years minimum data retention in the
absence of external power
Data is automatically protected during power
loss
Unlimited write cycles
Low-power CMOS operation
Read and write access times of 70 ns
Lithium energy source is electrically
disconnected to retain freshness until power is
applied for the first time
Full ±10% VCC operating range (DS1270Y)
Optional ±5% VCC operating range
(DS1270AB)
Optional industrial temperature range of
-40°C to +85°C, designated IND
PIN ASSIGNMENT
NC
A20
A18
A16
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
36 VCC
35 A19
34 NC
33 A15
32 A17
31 WE
30 A13
29 A8
28 A9
27 A11
26 OE
25 A10
24 CE
23 DQ7
22 DQ6
21 DQ5
20 DQ4
19 DQ3
36-Pin ENCAPSULATED PACKAGE
740-mil EXTENDED
PIN DESCRIPTION
A0 – A20
- Address Inputs
DQ0 - DQ7
- Data In/Data Out
CE - Chip Enable
WE - Write Enable
OE - Output Enable
VCC
GND
- Power (+5V)
- Ground
NC - No Connect
DESCRIPTION
The DS1270 16M Nonvolatile SRAMs are 16,777,216-bit, fully static nonvolatile SRAMs organized as
2,097,152 words by 8 bits. Each NV SRAM has a self-contained lithium energy source and control
circuitry which constantly monitors VCC for an out-of-tolerance condition. When such a condition occurs,
the lithium energy source is automatically switched on and write protection is unconditionally enabled to
prevent data corruption. There is no limit on the number of write cycles which can be executed and no
additional support circuitry is required for microprocessor interfacing.
1 of 8


Maxim Integrated Semiconductor Electronic Components Datasheet

DS1270AB Datasheet

16M Nonvolatile SRAM

No Preview Available !

DS1270Y/AB
READ MODE
The DS1270 devices execute a read cycle whenever WE (Write Enable) is inactive (high) and CE (Chip
Enable) and OE (Output Enable) are active (low). The unique address specified by the 21 address inputs
(A0 - A20) defines which of the 2,097,152 bytes of data is accessed. Valid data will be available to the
eight data output drivers within tACC (Access Time) after the last address input signal is stable, providing
that CE and OE (Output Enable) access times are also satisfied. If OE and CE access times are not
satisfied, then data access must be measured from the later-occurring signal ( CE or OE ) and the limiting
parameter is either tCO for CE or tOE for OE rather than tACC.
WRITE MODE
The DS1270 devices execute a write cycle whenever WE and CE signals are active (low) after address
inputs are stable. The later-occurring falling edge of CE or WE will determine the start of the write cycle.
The write cycle is terminated by the earlier rising edge of CE or WE . All address inputs must be kept
valid throughout the write cycle. WE must return to the high state for a minimum recovery time (tWR)
before another cycle can be initiated. The OE control signal should be kept inactive (high) during write
cycles to avoid bus contention. However, if the output drivers are enabled ( CE and OE active) then WE
will disable the outputs in tODW from its falling edge.
DATA RETENTION MODE
The DS1270AB provides full-functional capability for VCC greater than 4.75 volts and write protects by
4.5 volts. The DS1270Y provides full-functional capability for VCC greater than 4.5 volts and write
protects by 4.25 volts. Data is maintained in the absence of VCC without any additional support circuitry.
The nonvolatile static RAMs constantly monitor VCC. Should the supply voltage decay, the NV SRAMs
automatically write protect themselves, all inputs become don’t care, and all outputs become high-
impedance. As VCC falls below approximately 3.0 volts, a power switching circuit connects the lithium
energy source to RAM to retain data. During power-up, when VCC rises above approximately 3.0 volts,
the power switching circuit connects external VCC to RAM and disconnects the lithium energy source.
Normal RAM operation can resume after VCC exceeds 4.75 volts for the DS1270AB and 4.5 volts for the
DS1270Y.
FRESHNESS SEAL
Each DS1270 device is shipped from Maxim with its lithium energy source disconnected, guaranteeing
full energy capacity. When VCC is first applied at a level greater than VTP, the lithium energy source is
enabled for battery backup operation.
2 of 8


Part Number DS1270AB
Description 16M Nonvolatile SRAM
Maker Maxim Integrated
PDF Download

DS1270AB Datasheet PDF






Similar Datasheet

1 DS1270AB 16M Nonvolatile SRAM
Maxim Integrated





Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z



Site map

Webmaste! click here

Contact us

Buy Components

Privacy Policy