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FEATURES
10 years minimum data retention in the
absence of external power
Data is automatically protected during power
loss
Replaces 32k x 8 volatile static RAM,
EEPROM or Flash memory
Unlimited write cycles
Low-power CMOS
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 (DS1230Y)
Optional ±5% VCC operating range
(DS1230AB)
Optional industrial temperature range of
-40°C to +85°C, designated IND
JEDEC standard 28-pin DIP package
PowerCap Module (PCM) package
- Directly surface-mountable module
- Replaceable snap-on PowerCap provides
lithium backup battery
- Standardized pinout for all nonvolatile
SRAM products
- Detachment feature on PowerCap allows
easy removal using a regular screwdriver
PIN ASSIG N MENT
PIN DESCRIPTION
A0 - A14 - Address Inputs
DQ0 - DQ7 - Data In/Data Out
CE - Chip Enable
WE - Write Enable
OE - Output Enable
VCC - Power (+5V)
GND - Ground
NC - No Connect
DS1230Y/AB
256k Nonvolatile S RAM
www.maxim-ic.com
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27
28-Pin Encapsulated Package
740-mil Extended
A14
A7
A5
A4
A3
A2
A1
A0
DQ1
DQ0
VCC
28
26
25
24
23
22
21
20
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18
17
15
16
A12
A6
DQ2
GND
1
NC
2
3
NC
NC
NC
VCC
WE
OE
CE
DQ7
DQ6
DQ5
DQ4
DQ3
DQ2
DQ1
DQ0
GND
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NC
A14
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A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
34
NC
GND
VBAT
34-Pin PowerCap Module (PCM)
(Uses DS9034PC+ or DS9034PCI+ PowerCap)
19-5635; Rev 11/10
DS1230Y/AB
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DESCRIPTION
The DS1230 256k Nonvolatile SRAMs are 262,144-bit, fully static, nonvolatile SRAMs organized as
32,768 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. DIP-package DS1230 devices can be used in place of existing 32k x 8 static
RAMs directly conforming to the popular bytewide 28-pin DIP sta ndard. The DIP devices also match the
pinout of 28256 EEPROMs, allowing direct substitution while enhancing performance. DS1230 devices
in the Low Profile Module package are specifically designed for surface-mount applications. There is no
limit on the number of write cycles that can be executed and no additional support circuitry is required for
microprocessor interfacing.
READ MODE
The DS1230 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 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 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 address access.
WRITE MODE
The DS1230 devices execute a write cycle whenever the
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 RETENTIO N M ODE
The DS1230AB provides full functional capability for VCC greater than 4.75 volts and write protects by
4.5 volts. The DS1230Y 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 DS1230AB and 4.5 volts for the
DS1230Y.
FRESHNESS SEAL
Each DS1230 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 4.25 volts, the lithium energy source
is enabled for battery back-up operation.
DS1230Y/AB
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PACKAGES
The DS1230 devices are available in two packages: 28-pin DIP and 34-pin PowerCap Module (PCM).
The 28-pin DIP integrates a lithium battery, an SRAM memory and a nonvolatile control function into a
single package with a JEDEC-standard, 600-mil DIP pinout. The 34-pin PowerCap Module integrates
SRAM memory and nonvolatile control along with contacts for connection to the lithium battery in the
DS9034PC PowerCap. The PowerCap Module package design allows a DS1230 PCM device to be
surface mounted without subjecting its lithium backup battery to destructive high-temperature reflow
soldering. After a DS1230 PCM is reflow soldered, a DS9034PC PowerCap is snapped on top of the
PCM to form a complete Nonvolatile SRAM module. The DS9034PC is keyed to prevent improper
attachment. DS1230 PowerCap Modules and DS9034PC PowerCaps are ordered separately and shipped
in separate containers. See the DS9034PC data sheet for further information.
DS1230Y/AB
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ABSOLUTE MAXI M UM RATINGS
Voltage on Any Pin Relative to Ground -0.3V to +6.0V
Operating Temperature Range
Commercial: 0°C to +70°C
Industrial: -40°C to +85°C
Storage Temperature Range
EDIP -40°C to +85°C
PowerCap -55°C to +125°C
Lead Temperature (soldering, 10s) +260°C
Note: EDIP is wave or hand soldered only.
Soldering Temperature (reflow, PowerCap) +260°C
This 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 (TA: See Note 10)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
DS1230AB Power Supply Voltage VCC 4.75 5.0 5.25 V
DS1230Y Power Supply Voltage VCC 4.5 5.0 5.5 V
Logic 1 VIH 2.2 VCC V
Logic 0 VIL 0.0 0.8 V
DC ELECTRICAL CHARACTERISTICS (VCC = 5V ±5% for DS1230AB)
(TA: See Note 10) (VCC = 5V ±10% for DS1230Y)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Input Leakage Current IIL -1.0 +1.0 µA
I/O Leakage Current
CE
≥ VIH ≤ VCC IIO -1.0 +1.0 µA
Output Current @ 2.4V IOH -1.0 mA
Output Current @ 0.4V IOL 2.0 mA
Standby Current CE =2.2V ICCS1 200 600 µA
Standby Current
CE
=VCC-0.5V ICCS2 50 150 µA
Operating Current ICCO1 85 mA
Write Protection Voltage (DS1230AB) VTP 4.50 4.62 4.75 V
Write Protection Voltage (DS1230Y) VTP 4.25 4.37 4.5 V
CAPACITANCE (TA = +25°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Input Capacitance CIN 5 10 pF
Input/Output Capacitance CI/O 5 10 pF
DS1230Y/AB
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AC ELECTRICAL CHARACTERISTICS (VCC = 5V ±5% for DS1230AB)
(TA: See Note 10) (VCC = 5V ±10% for DS1230Y)
PARAMETER SYMBOL DS1230AB-70
DS1230Y-70 UNITS NOTES
MIN MAX
Read Cycle Time tRC 70 ns
Access Time tACC 70 ns
OE to Output Valid tOE 35 ns
CE to Output Valid tCO 70 ns
OE or CE to Output Active tCOE 5 ns 5
Output High-Z from
Deselection tOD 25 ns 5
Output Hold from Address
Change tOH 5 ns
Write Cycle Time tWC 70 ns
Write Pulse Width tWP 55 ns 3
Address Setup Time tAW 0 ns
Write Recovery Time tWR1
tWR2
5
15 ns 12
13
Output High-Z from WE tODW 25 ns 5
Output Active from WE tOEW 5 ns 5
Data Setup Time tDS 30 ns 4
Data Hold Time tDH1
tDH2
0
10 ns 12
13
DS1230Y/AB
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READ CYCLE
SEE NOTE 1
WRITE CYCLE 1
SEE NOTES 2, 3, 4, 6, 7, 8, and 12
DS1230Y/AB
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WRITE CYCLE 2
SEE NOTES 2, 3, 4, 6, 7, 8, and 13
POWER-DOWN/POWER-UP CONDITI ON
SEE NOTE 11
POWER-DOWN/POWER-UP TIMING (TA: See Note 10)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
VCC Fail Detect to CE and WE Inactive tPD 1.5 µs 11
VCC slew from VTP to 0V tF 150 µs
VCC slew from 0V to VTP tR 150 µs
VCC Valid to CE and
WE
Inactive tPU 2 ms
VCC Valid to End of Write Protection tREC 125 ms
DS1230Y/AB
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(TA = +25°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Expected Data Retention Time tDR 10 years 9
WARNING:
Under no circumstance are negative undershoots, of any amplitude, allowed when device is in battery
backup mode.
NOTES:
1.
WE
is high for a Read Cycle.
2.
OE
= VIH or VIL. If OE = VIH during write cycle, the output buffers remain in a high-impedance state.
3. tWP is specified as the logical AND of CE and WE . tWP is measured from the latter of
CE
or
WE
going low to the earlier of CE or WE going high.
4. tDH, tDS are measured from the earlier of
CE
or
WE
going high.
5. These parameters are sampled with a 5 pF load and are not 100% tested.
6. If the CE low transition occurs simultaneously with or latter than the
WE
low transition, the output
buffers remain in a high-impedance state during this period.
7. If the
CE
high transition occurs prior to or simultaneously with the
WE
high transition, the output
buffers remain in high-impedance state during this period.
8. If WE is low or the WE low transition occurs prior to or simultaneously with the
CE
low transition,
the output buffers remain in a high-impedance state during this period.
9. Each DS1230 has a built-in switch that disconnects the lithium source until the user first applies VCC.
The expected tDR is defined as accumulative time in the absence of VCC starting from the time power
is first applied by the user. This parameter is assured by component selection, process control, and
design. It is not measured directly during production testing.
10. All AC and DC electrical characteristics are valid over the full operating temperature range. For
commercial products, this range is 0°C to 70°C. For industrial products (IND), this range is -40°C to
+85°C.
11. In a power-down condition the voltage on any pin may not exceed the voltage on VCC.
12. tWR1 and tDH1 are measured from
WE
going high.
13. tWR2 and tDH2 are measured from
CE
going high.
14. DS1230 modules are recognized by Underwriters Laboratories (UL) under file E99151.
DC TEST CONDITIONS AC TEST CONDITIONS
Outputs Open Output Load: 100 pF + 1TTL Gate
Cycle = 200 ns for operating current Input Pulse Levels: 0 - 3.0V
All voltages are referenced to ground Timing Measurement Reference Levels
Input: 1.5V
Output: 1.5V
Input pulse Rise and Fall Times: 5 ns
DS1230Y/AB
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ORDERING INFO RM ATION
PART TEMP RANGE
SUPPLY
TOLERANCE
PIN-PACKAGE
SPEED GRADE
(ns)
DS1230AB-70+
0°C to +70°C
5V
±
5%
28 740 EDIP
70
DS1230ABP-70+
0°C to +70°C
5V
±
5%
34 PowerCap*
70
DS1230AB-70IND+
-40°C to +85°C
5V ± 5%
28 740 EDIP
70
DS1230ABP-70IND+
-40°C to +85°C
5V ± 5%
34 PowerCap*
70
DS1230Y-70+
0°C to +70°C
5V
±
10%
28 740 EDIP
70
DS1230YP-70+
0°C to +70°C
5V
±
10%
34 PowerCap*
70
DS1230Y-70IND+
-40°C to +85°C
5V
±
10%
28 740 EDIP
70
DS1230YP-70IND+
-40°C to +85°C
5V ± 10%
34 PowerCap*
70
+Denotes a lead(Pb)-free/RoHS-compliant package.
*DS9034PC+ or DS9034P C I+ (PowerCap) required. M us t be ordered separately.
PACKAGE INFORMATION
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix
character, bu t the drawing pertains to the package regardless of RoHS status.
PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
28 EDIP MDT28+3 —
21-0245
34 PCAP PC2+4 —
21-0246
DS1230Y/AB
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REVISION HISTORY
REVISION
DATE
DESCRIPTION
PAGES
CHANGED
121907
Added package information table; removed the DIP module
package drawing and dimension table
9, 10
11/10
Updated the storage information, soldering temperature, and
lead temperatu re inf o rm ation in the Absolute Maximum Ratings
section; removed the -85, -100, -120, -150, and -200
MIN/MAX information from the AC Electrical Characteristics
table; updated the Ordering Information table (removed -85,
-100, -120, -150, and -200 parts and leaded -70 parts); removed
the PowerCap module drawings and updated the Package
Information table
1, 4, 5, 9