1 of 12

111999

FEATURES

10 years minimum data retention in the
absence of external power

Data is automatically protected during power loss

Power supply monitor resets processor when
V

power loss occurs and holds processor in

reset during V

ramp-up

Battery monitor checks remaining capacity
daily

Read and write access times as fast as 70 ns

Unlimited write cycle endurance

Typical standby current 50

Upgrade for 128k x 8 SRAM, EEPROM or
Flash

Lithium battery is electrically disconnected to
retain freshness until power is applied for the
first time

Full

10% V

operating range (DS1345Y)

or optional

5% V

operating range

(DS1345AB)

Optional industrial temperature range of
-40

C to +85

C, designated IND

New 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 ASSIGNMENT

PIN DESCRIPTION

A0 - A16

- Address Inputs

DQ0 - DQ7

- Data In/Data Out

- Chip Enable

- Write Enable

- Output Enable

RST

- Reset Output

- Battery Warning Output

- Power (+5V)

GND -

Ground

- No Connect

DESCRIPTION

The DS1345 1024k Nonvolatile SRAMs are 1,048,576-bit, fully static, nonvolatile SRAMs organized as
131,072 words by 8 bits. Each NV SRAM has a self-contained lithium energy source and control circuitry
which constantly monitors V

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. Additionally, the DS1345 devices have dedicated circuitry for monitoring the
status of V

and the status of the internal lithium battery. DS1345 devices in the PowerCap Module

package are directly surface mountable and are normally paired with a DS9034PC PowerCap to form a
complete Nonvolatile SRAM module. The devices can be used in place of 128k x 8 SRAM, EEPROM or
Flash components.

DS1345Y/AB

1024k Nonvolatile SRAM

with Battery Monitor

www.dalsemi.com

A15

A16

RST

DQ7

DQ6

DQ5

DQ4

DQ3

DQ2

DQ1

DQ0

GND

A14

A13

A12

A11

A10

GND V

BAT

34-Pin POWERCAP MODULE (PCM)

(USES DS9034PC POWERCAP)

DS1345Y/AB

2 of 12

READ MODE

The DS1345 devices execute a read cycle whenever

(Write Enable) is inactive (high) and

(Chip

Enable) and

(Output Enable) are active (low). The unique address specified by the 17 address inputs

- A

) defines which of the 131,072 bytes of data is to be accessed. Valid data will be available to the

eight data output drivers within t

ACC

(Access Time) after the last address input signal is stable, providing

that

and

(Output Enable) access times are also satisfied. If

and

access times are not

satisfied, then data access must be measured from the later-occurring signal (

) and the limiting

parameter is either t

for

or t

for

rather than address access.

WRITE MODE

The DS1345 devices execute a write cycle whenever the

and

signals are in the active (low) state

after address inputs are stable. The later-occurring falling edge of

will determine the start of

the write cycle. The write cycle is terminated by the earlier rising edge of

. All address inputs

must be kept valid throughout the write cycle.

must return to the high state for a minimum recovery

time (t

) before another cycle can be initiated. The

control signal should be kept inactive (high)

during write cycles to avoid bus contention. However, if the output drivers are enabled (

and

active) then

will disable the outputs in t

ODW

from its falling edge.

DATA RETENTION MODE

The DS1345AB provides full functional capability for V

greater than 4.75 volts and write protects by

4.5 volts. The DS1345Y provides full functional capability for V

greater than 4.5 volts and write

protects by 4.25 volts. Data is maintained in the absence of V

without any additional support circuitry.

The nonvolatile static RAMs constantly monitor V

. 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 V

falls below approximately 2.7 volts, the power switching circuit connects the lithium

energy source to RAM to retain data. During power-up, when V

rises above approximately 2.7 volts,

the power switching circuit connects external V

to the RAM and disconnects the lithium energy source.

Normal RAM operation can resume after V

exceeds 4.75 volts for the DS1345AB and 4.5 volts for the

DS1345Y.

SYSTEM POWER MONITORING

DS1345 devices have the ability to monitor the external V

power supply. When an out-of-tolerance

power supply condition is detected, the NV SRAMs warn a processor-based system of impending power
failure by asserting

RST

. On power-up,

RST

is held active for 200 ms nominal to prevent system

operation during power-on transients and to allow t

REC

to elapse.

RST

has an open drain output driver.

BATTERY MONITORING

The DS1345 devices automatically perform periodic battery voltage monitoring on a 24-hour time
interval. Such monitoring begins within t

REC

after V

rises above V

and is suspended when power

failure occurs.

After each 24-hour period has elapsed, the battery is connected to an internal 1 M

=test resistor for one

second. During this one second, if battery voltage falls below the battery voltage trip point (2.6V), the
battery warning output

is asserted. Once asserted,

remains active until the module is replaced.

The battery is still retested after each V

power-up, however, even if

is active. If the battery voltage

is found to be higher than 2.6V during such testing,

is de-asserted and regular 24-hour testing

resumes.

has an open drain output driver.

DS1345Y/AB

3 of 12

FRESHNESS SEAL

Each DS1345 is shipped from Dallas Semiconductor with its lithium energy source disconnected,
guaranteeing full energy capacity. When V

is first applied at a level greater than V

, the lithium

energy source is enabled for battery backup operation.

PACKAGES

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 DS1345 PCM device to be surface mounted without subjecting its lithium backup battery to
destructive high-temperature reflow soldering. After a DS1345 PCM is reflow soldered, a DS9034PC is
snapped on top of the PCM to form a complete Nonvolatile SRAM module. The DS9034PC is keyed to
prevent improper attachment. DS1345 PowerCap Modules and DS9034PC PowerCaps are ordered
separately and shipped in separate containers. See the DS9034PC data sheet for further information.

DS1345Y/AB

4 of 12

ABSOLUTE MAXIMUM RATINGS*

Voltage on Any Pin Relative to Ground

-0.3V to +7.0V

Operating Temperature

0°C to 70°C, -40°C to +85°C for IND parts

Storage Temperature

-40°C to +70°C, -40°C to +85°C for IND parts

Soldering Temperature

260°C for 10 seconds

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 (t

: See Note 10)

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS NOTES

DS1345AB Power Supply Voltage

4.75

5.0

5.25

DS1345Y Power Supply Voltage

4.5

5.0

5.5

Logic 1

2.2

Logic 0

0.0

0.8

DC ELECTRICAL (V

=5V

5% for DS1345AB)

CHARACTERISTICS (t

: See Note 10) (V

=5V

10% for DS1345Y)

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS NOTES

Input Leakage Current

-1.0

+1.0

I/O Leakage Current

-1.0

+1.0

Output Current @ 2.4V

-1.0

Output Current @ 0.4V

2.0

Standby Current

=2.2V

CCS1

200

600

Standby Current

-0.5V

CCS2

150

Operating Current

CCO1

Write Protection Voltage (DS1345AB)

4.50

4.62

4.75

Write Protection Voltage (DS1345Y)

4.25

4.37

4.5

CAPACITANCE (t

=25

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS NOTES

Input Capacitance

Input/Output Capacitance

I/O

DS1345Y/AB

5 of 12

AC ELECTRICAL (V

=5V

5% for DS1345AB)

CHARACTERISTICS (t

: See Note 10) (V

=5V

10% for DS1345Y)

DS1345AB-70

DS1345Y-70

DS1345AB-100

DS1330Y-100

PARAMETER

SYMBOL

MIN

MAX

MIN

MAX

UNITS NOTES

Read Cycle Time

100

Access Time

ACC

100

to Output Valid

100

to Output Active

COE

Output High Z from Deselection

Output Hold from Address
Change

Write Cycle Time

100

Write Pulse Width

Address Setup Time

Write Recovery Time

WR1

WR2

12
13

Output High Z from

ODW

Output Active from

OEW

Data Setup Time

Data Hold Time

DH1

DH2

0
7

12
13

READ CYCLE

SEE NOTE 1

DS1345Y/AB

8 of 12

POWER-DOWN/POWER-UP TIMING (t

: See Note 10)

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS NOTES

Fail Detect to

and

Inactive

1.5

slew from V

to 0V

150

Fail Detect to

RST

Active

RPD

slew from 0V to V

150

Valid to

and

Inactive

Valid to End of Write Protection

REC

125

Valid to

RST

Inactive

RPU

150

200

350

Valid to

Valid

BPU

BATTERY WARNING TIMING (t

: See Note 10)

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS NOTES

Battery Test Cycle

BTC

Battery Test Pulse Width

BTPW

Battery Test to

Active

=25

PARAMETER

SYMBOL

MIN

TYP

MAX

UNITS NOTES

Expected Data Retention Time

years

WARNING:

Under no circumstance are negative undershoots, of any amplitude, allowed when device is in battery
backup mode.

NOTES:

is high for a Read Cycle.

= V

or V

. If

= V

during write cycle, the output buffers remain in a high-impedance state.

is specified as the logical AND of

and

. t

is measured from the latter of

going low to the earlier of

going high.

is measured from the earlier of

going high.

These parameters are sampled with a 5 pF load and are not 100% tested.

If the

low transition occurs simultaneously with or latter than the

low transition, the output

buffers remain in a high-impedance state during this period.

If the

high transition occurs prior to or simultaneously with the

high transition, the output

buffers remain in high-impedance state during this period.

is low or the

low transition occurs prior to or simultaneously with the

low transition,

the output buffers remain in a high impedance state during this period.

DS1345Y/AB

9 of 12

Each DS1345Y has a built-in switch that disconnects the lithium source until V

is first applied by

the user. The expected t

is defined as accumulative time in the absence of V

starting from the

time power is first applied by the user.

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

11.

In a power-down condition the voltage on any pin may not exceed the voltage on V

12.

WR1

and t

DH1

are measured from

going high.

13.

WR2

and t

DH2

are measured from

going high.

14.

RST

and

are open-drain outputs and cannot source current. External pullup resistors should be

connected to these pins for proper operation. Both pins will sink 10 mA.

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

ORDERING INFORMATION

DS1345 TTP - SSS - III

Operating Temperature Range
blank: 0

to 70

IND: -40

to +85

Access Speed
70:

70 ns

100:

100 ns

Package Type
P:

34-pin PowerCap Module

Tolerance

AB:

10%

DS1345Y/AB

11 of 12

DS1345Y/AB NONVOLATILE SRAM, 34-PIN POWERCAP MODULE WITH
POWERCAP

INCHES

PKG

DIM

MIN

NOM

MAX

0.920

0.925

0.930

0.955

0.960

0.965

0.240

0.245

0.250

0.052

0.055

0.058

0.048

0.050

0.052

0.015

0.020

0.025

0.020

0.025

0.030

ASSEMBLY AND USE

Reflow soldering
Dallas Semiconductor recommends that PowerCap Module bases experience one pass through solder
reflow oriented label-side up (live-bug).

Hand soldering and touch-up
Do not touch soldering iron to leads for more than 3 seconds. To solder, apply flux to the pad, heat the
lead frame pad and apply solder. To remove part, apply flux, heat pad until solder reflows, and use a
solder wick.

LPM replacement in a socket
To replace a Low Profile Module in a 68-pin PLCC socket, attach a DS9034PC PowerCap to a module
base then insert the complete module into the socket one row of leads at a time, pushing only on the
corners of the cap. Never apply force to the center of the device. To remove from a socket, use a PLCC
extraction tool and ensure that it does not hit or damage any of the module IC components. Do not use
any other tool for extraction.

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: DS1345YP-70-IND

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: DS1345YP-70-IND