DS1217A-64K-25 ,Nonvolatile Read/Write Cartridgeapplications requiring a rugged and durable pack- that have JEDEC 28-pin bytewide memory sites.age. ..
DS1218 ,Nonvolatile ControllerPIN DESCRIPTIONV - Input +5 Volt SupplyCCIV - RAM Power (V ) SupplyCCO CCCEI - Chip Enable InputNC ..
DS1218S ,Nonvolatile ControllerPIN DESCRIPTIONV - Input +5 Volt SupplyCCIV - RAM Power (V ) SupplyCCO CCCEI - Chip Enable InputNC ..
DS1220AB ,16k Nonvolatile SRAMPIN DESCRIPTION Optional ±5% V operating rangeCCA0-A10 - Address Inputs(DS1220AB)DQ0-DQ7 - Data In ..
DS1220AB-100 ,2k x 8 CMOS nonvolatile SRAM, 100nsFEATURES PIN ASSIGNMENT 10 years minimum data retention in theA7VCC1 24absence of external power A ..
DS1220AB-100+ ,16k Nonvolatile SRAMFEATURES PIN ASSIGNMENT 10 years minimum data retention in theA7VCC1 24absence of external power A ..
DTA114WUA , -100mA / -50V Digital transistors (with built-in resistors)
DTA114YCA ,Conductor Holdings Limited - Digital Transistor
DTA114YE ,Bias Resistor Transistor PNP Silicon Surface Mount Transistor with Monolithic Bias Resistor NetworkMaximum ratings applied to the device are individual stress limit values (notnormal operating condi ..
DTA114YET1 ,Bias Resistor TransistorFeaturesBASE(INPUT)• Pb−Free Packages are Available* R2• Simplifies Circuit DesignPIN 2• Reduces Bo ..
DTA114YM , -100mA / -50V Digital transistors (with built-in resistors)
DTA114YS , DTA/DTC SERIES
DS1217A-64K-25
Nonvolatile Read/Write Cartridge
DS1217ANonvolatile Read/Write Cartridge
DS1217A
030598 1/8
FEATURESUser-insertableCapacity up to 32K x 8Standard bytewide pinout facilitates connection to
JEDEC 28-pin DIP socket via ribbon cableData retention greater than 10 yearsAutomatic write protection circuitry safeguards
against data lossManual switch unconditionally protects dataCompact size and shapeRugged and durableWide operating temperature range of 0°C to 70°C
PIN ASSIGNMENTGround
+5 Volts
Write Enable
Address 13
Address 8
Address 9
Address 11
Output Enable
Address 10
Cartridge Enable
Data I/O 7
Data I/O 6
Data I/O 5
Data I/O 4
Data I/O 3
No Connect
Address 14
Address 12
Address 7
Address 6
Address 5
Address 4
Address 3
Address 2
Address 1
Address 0
Data I/O 0
Data I/O 1
Data I/O 2
Ground
Name
PositionNameOFF – ON
See Mech. Drawings Section
DESCRIPTIONThe DS1217A is a nonvolatile RAM designed for porta-
ble applications requiring a rugged and durable pack-
age. The nonvolatile cartridge is available in densities
ranging from 2K x 8 to 32K x 8 in 8K byte increments. A
card edge connector is required for connection to a host
system. A standard 30-pin connector can be used for di-
rect mount to a printed circuit board. Alternatively, re-
mote mounting can be accomplished with a 28-conduc-
tor ribbon cable terminated with a 28-pin DIP plug. The
remote method can be used to retrofit existing systems
that have JEDEC 28-pin bytewide memory sites.
The DS1217A cartridge has a lifetime energy source to
retain data and circuitry needed to automatically protect
memory contents. Reading and writing the memory lo-
cations is the same as using conventional static RAM. If
the user wants to convert from read/write memory to
read-only memory, a manual switch is provided to un-
conditionally protect memory contents.
DS1217A
030598 2/8
READ MODEThe DS1217A executes a read cycle whenever WE
(write enable) is inactive (high) and CE (cartridge en-
able) is active (low). The unique address specified by
the 15 address inputs (A0-A14) defines which of the
32,768 bytes of data is to be accessed. Valid data will be
available to the eight data I/O pins within tACC (access
time) after the last address input signal is stable, provid-
ing that CE and OE (output enable) access times are
also satisfied. If OE and CE times are not satisfied , then
data access must be measured from the latter occurring
signal (CE or OE); the limiting parameter is either tCO for
CE or tOE for OE rather than address access. Read
cycles can only occur when VCC is greater than 4.5
volts. When VCC is less than 4.5 volts, the memory is
inhibited and all accesses are ignored.
WRITE MODEThe DS1217A is in the write mode whenever both the
WE and CE signals are in the active (low) state after ad-
dress inputs are stable. The last falling edge to occur of
either CE or WE will determine the start of the write
cycle. The write cycle is terminated by the first rising
edge of either 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 bus has
been enabled (CE and OE active) then WE will disable
the outputs in tODW from its falling edge. Write cycles
can only occur when VCC is greater than 4.5 volts.
When VCC is less than 4.5 volts, the memory is write
protected.
DATA RETENTION MODEThe Nonvolatile Cartridge provides full functional capa-
bility for VCC greater than 4.5 volts and guarantees write
protection for VCC less than 4.5 volts. Data is main-
tained in the absence of VCC without any additional sup-
port circuitry. The DS1217A constantly monitors VCC.
Should the supply voltage decay, the RAM is automati-
cally write protected below 4.5 volts. As VCC falls below
approximately 3.0 volts, the power switching circuit con-
nects a lithium energy source to RAM. To retain data
during power-up, when VCC rises above approximately
3.0 volts, the power switching circuit connects the exter-
nal VCC to the RAM and disconnects the lithium energy
source. Normal RAM operation can resume after VCC
exceeds 4.5 volts.
The DS1217A checks battery status to warn of potential
data loss. Each time that VCC power is restored to the
cartridge, the battery voltage is checked with a precision
comparator. If the battery supply is less than 2.0 volts,
the second memory cycle is inhibited. Battery status
can, therefore, be determined by performing a read
cycle after power-up to any location in memory, record-
ing that memory location content. A subsequent write
cycle can then be executed to the same memory loca-
tion, altering data. If the next read cycle fails to verify the
written data, the contents of the memory are question-
able.
In many applications, data integrity is paramount. For
this reason, the cartridge provides battery redundancy.
The DS1217A features an internal isolation switch that
provides for the connection of two batteries. During bat-
tery backup time, the battery with the highest voltage is
selected for use. If one battery fails, the other will auto-
matically take over. The switch between batteries is
transparent to the user. A battery status warning will oc-
cur if both batteries are less than 2.0 volts.
REMOTE CONNECTION VIA A RIBBON
CABLEExisting systems that contain 28-pin bytewide sockets
can be retrofitted using a 28-pin DIP plug. The DIP plug,
AMP Part Number 746616-2, can be inserted into the
28-pin site after the memory is removed. Connection to
the cartridge is accomplished via a 28-pin ribbon cable
connected to a 30-contact card edge connector, AMP
Part Number 499188-4. The 28-pin ribbon cable must
be right-justified such that positions A1 and B1 are left
disconnected. For applications where the cartridge is
installed or removed with power applied, both ground
contacts (A1 and B15) on the card edge connector
should be grounded to further enhance data integrity.
Access time push-out may occur as the distance be-
tween the cartridge and driving circuitry is increased.
DS1217A
030598 3/8
CARTRIDGE NUMBERING Table 1*Unused address inputs must be held low (VIL).
DS1217A
030598 4/8
ABSOLUTE MAXIMUM RATINGS* Voltage on Any Connection Relative to Ground-0.3V to +7.0V
Operating Temperature 0°C to 70°C
Storage Temperature-40°C to +70°CThis is a stress rating only and functional operation of the device at these or any other conditions above those
indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods of time may affect reliability.
RECOMMENDED DC OPERATING CONDITIONS(0°C to 70°C)
DC ELECTRICAL CHARACTERISTICS(0°C to 70°C; VCC=5V ± 10%)
CAPACITANCE(tA = 25°C)
DS1217A
030598 5/8
AC ELECTRICAL CHARACTERISTICS (0°C to 70°C; VCC=5V ± 10%)
DS1217A
030598 6/8
ADDRESSES
DOUT
READ CYCLE (1)ADDRESSES
DOUT
DIN
VIL
VIL
WRITE CYCLE 1 (2), (6), (7)ADDRESSES
WRITE CYCLE 2 (2), (8)DOUT
DIN
tWR
VIL
VIH
VIL
