STMICROELECTRONICS M48Z30Y

M48Z30
M48Z30Y
CMOS 32K x 8 ZEROPOWER SRAM
INTEGRATED LOW POWER SRAM,
POWER-FAIL CONTROL CIRCUIT and
BATTERY
CONVENTIONAL SRAM OPERATION;
UNLIMITED WRITE CYCLES
10 YEARS of DATA RETENTION in the
ABSENCE of POWER
PIN and FUNCTION COMPATIBLE with
JEDEC STANDARD 32K x 8 SRAMs
AUTOMATIC POWER-FAIL CHIP DESELECT
and WRITE PROTECTION
CHOICE of TWO WRITE PROTECT
VOLTAGES:
– M48Z30: 4.5V ≤ VPFD ≤ 4.75V
– M48Z30Y: 4.2V ≤ VPFD ≤ 4.50V
28
1
PMDIP28 (PM)
Module
Figure 1. Logic Diagram
BATTERY INTERNALLY ISOLATED UNTIL
POWER IS APPLIED
DESCRIPTION
The M48Z30/30Y 32K x 8 ZEROPOWER RAM is
a non-volatile 262,144 bit Static RAM organized as
32,768 words by 8 bits. The device combines an
internal lithium battery and a full CMOS SRAM in a
plastic 28 pin DIP Module. The ZEROPOWER
Table 1. Signal Names
A0 - A14
Address Inputs
DQ0 - DQ7
Data Inputs / Outputs
E
Chip Enable
G
Output Enable
W
Write Enable
VCC
Supply Voltage
VSS
Ground
July 1994
1/12
M48Z30, M48Z30Y
Table 2. Absolute Maximum Ratings
Symbol
Parameter
Value
Unit
TA
Ambient Operating Temperature
0 to 70
°C
TSTG
Storage Temperature (V CC Off)
–40 to 70
°C
TBIAS
Temperature Under Bias
–10 to 70
°C
TSLD
Lead Soldering Temperature for 10 seconds
VIO
VCC
260
°C
Input or Output Voltages
–0.3 to 7
V
Supply Voltage
–0.3 to 7
V
Note: Stresses greater than those listed under ”Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress
rating only and functional operation of the device at these or any other conditions above those indicated in the operational section of this
specification is not implied. Exposure to the absolute maximum ratings conditions for extended periods of time may affect reliability.
CAUTION: Negative undershoots below –0.3 volts are not allowed on any pin while in the Battery Back-up mode.
Table 3. Operating Modes
Mode
VCC
Deselect
4.75V to 5.5V
or
4.5V to 5.5V
Write
Read
Read
E
G
W
DQ0-DQ7
Power
VIH
X
X
High Z
Standby
VIL
X
VIL
DIN
Active
VIL
VIL
VIH
DOUT
Active
VIL
VIH
VIH
High Z
Active
Deselect
VSO to VPFD (min)
X
X
X
High Z
CMOS Standby
Deselect
≤ VSO
X
X
X
High Z
Battery Back-up Mode
Note: X = VIH or VIL
Figure 2. DIP Pin Connections
DESCRIPTION (cont’d)
RAM directly replaces industry standard SRAMs. It
also fits into many EPROM and EEPROM sockets,
providing the nonvolatility of PROMs without any
requirement for special write timing or limitations
on the number of writes that can be performed.
The M48Z30/30Y has its own Power-fail Detect
Circuit. The control circuitry constantly monitors the
single 5V supply for an out of tolerance condition.
When VCC is out of tolerance, the circuit write
protects the SRAM, providing a high degree of data
security in the midst of unpredictable system operations brought on by low VCC. As VCC falls below
approximately3V, the control circuitry connectsthe
battery which sustains data until valid power returns.
READ MODE
The M48Z30/30Y is in the Read Mode whenever
W (Write Enable) is high and E (Chip Enable) is low.
The device architecture allows ripple-through access of data from eight of 262,144 locations in the
static storage array. Thus, the unique address
2/12
M48Z30, M48Z30Y
Figure 3. Block Diagram
specified by the 15 Address Inputs defines which
one of the 32,768 bytes of data is to be accessed.
Valid data will be available at the Data I/O pins
within tAVQV (Address Access Time) after the last
address input signal is stable, providing that the E
and G (Output Enable) access times are also satisfied. If the E and G access times are not met, valid
data will be available after the later of Chip Enable
Access Time (tELQV) or Output Enable Access Time
(tGLQV).
The state of the eight three-state Data I/O signals
is controlled by E and G. If the outputs are activated
before tAVQV, the data lines will be driven to an
indeterminate state until t AVQV. If the Address Inputs are changed while E and G remain low, output
data will remain valid for tAXQX (Output Data Hold
Time) but will go indeterminate until the next Address Access.
AC MEASUREMENT CONDITIONS
Input Rise and Fall Times
≤ 5ns
Input Pulse Voltages
0 to 3V
Input and Output Timing Ref. Voltages
1.5V
Note that Output Hi-Z is defined as the point where data
is no longer driven.
Figure 4. AC Testing Load Circuit
WRITE MODE
The M48Z30/30Yis in the Write Mode whenever W
and E are active. The start of a write is referenced
from the latter occurring falling edge of W or E.
3/12
M48Z30, M48Z30Y
Table 4. Capacitance (1, 2) (TA = 25 °C, f = 1 MHz )
Symbol
C IN
CIO
(3)
Parameter
Test Condition
Max
Unit
VIN = 0V
10
pF
VOUT = 0V
10
pF
Input Capacitance
Input / Output Capacitance
Min
Notes: 1. Effective capacitance measured with power supply at 5V.
2. Sampled only, not 100% tested.
3. Outputs deselected
Table 5. DC Characteristics (TA = 0 to 70°C; VCC = 4.75V to 5.5V or 4.5V to 5.5V)
Symbol
Parameter
ILI
(1)
Input Leakage Current
ILO
(1)
Output Leakage Current
Test Condition
Min
Max
Unit
0V ≤ VIN ≤ VCC
±1
µA
0V ≤ VOUT ≤ VCC
±1
µA
E = VIL, Outputs open
85
mA
E = VIH
7
mA
E ≥ VCC – 0.2V
4
mA
ICC
Supply Current
ICC1
Supply Current (Standby) TTL
ICC2
Supply Current (Standby) CMOS
VIL
Input Low Voltage
–0.3
0.8
V
VIH
Input High Voltage
2.2
VCC + 0.3
V
VOL
Output Low Voltage
IOL = 2.1mA
0.4
V
VOH
Output High Voltage
IOH = –1mA
2.4
V
Note: 1. Outputs deselected.
Table 6. Power Down/Up Trip Points DC Characteristics (1) (TA = 0 to 70°C)
Symbol
Parameter
Typ
Max
Unit
VPFD
Power-fail Deselect Voltage (M48Z30)
4.5
4.6
4.75
V
VPFD
Power-fail Deselect Voltage (M48Z30Y)
4.2
4.3
4.5
V
VSO
Battery Back-up Switchover Voltage
tDR
(2)
Data Retention Time
Notes: 1. All voltages referenced to VSS.
2. @ 25°C
4/12
Min
3
10
V
YEARS
M48Z30, M48Z30Y
Table 7. Power Down/Up Mode AC Characteristics (TA = 0 to 70°C)
Symbol
(1)
Parameter
Min
Max
Unit
VPFD (max) to VPFD (min) VCC Fall Time
300
µs
VPFD (min) to VSO VCC Fall Time
10
µs
Write Protect Time from VCC = VPFD
40
tR
VSO to VPFD (max) VCC Rise Time
0
tER
E Recovery Time
40
tF
tFB
(2)
tWP
150
µs
µs
120
ms
Notes: 1. VPFD (max) to VPFD (min) fall time of less than tF may result in deselection/write protection not occurring until 200 µs after
VCC passes VPFD (min).
2. VPFD (min) to VSO fall time of less than tFB may cause corruption of RAM data.
Figure 5. Power Down/Up Mode AC Waveforms
5/12
M48Z30, M48Z30Y
Table 8. Read Mode AC Characteristics (TA = 0 to 70°C; VCC = 4.75V to 5.5V or 4.5V to 5.5V)
M48Z30 / 30Y
Symbol
Parameter
-85
Min
tAVAV
tAVQV
(1)
tELQV (1)
tGLQV
(1)
tELQX (2)
tGLQX
(2)
tEHQZ (2)
Read Cycle Time
Unit
-100
Max
85
Min
Max
100
ns
Address Valid to Output Valid
85
100
ns
Chip Enable Low to Output Valid
85
100
ns
Output Enable Low to Output Valid
45
50
ns
Chip Enable Low to Output Transition
5
5
ns
Output Enable Low to Output Transition
5
5
ns
Chip Enable High to Output Hi-Z
40
40
ns
tGHQZ
(2)
Output Enable High to Output Hi-Z
35
35
ns
tAXQX
(1)
Address Transition to Output Transition
Notes: 1. CL = 100pF (see Figure 4).
2. CL = 5pF (see Figure 4)
Figure 6. Address Controlled, Read Mode AC Waveforms
Note: E = Low, G = Low, W = High.
6/12
10
10
ns
M48Z30, M48Z30Y
Figure 7. Chip Enable or Output Enable Controlled, Read Mode AC Waveforms
Note: W = High.
WRITE MODE (cont’d)
A write is terminated by the earlier rising edge of W
or E. The addresses must be held valid throughout
the cycle. E or W must return high for minimum of
tEHAX from E or tWHAX from W prior to the initiation
of another read or write cycle. Data-in must be valid
tDVWH prior to the end of write and remain valid for
tWHDX or tEHDX afterward. G should be kept high
during write cycles to avoid bus contention; although, if the output bus has been activated by a
low on E and G, a low on W will disable the outputs
tWLQZ after W falls.
DATA RETENTION MODE
With valid VCC applied, the M48Z30/30Y operates
as a conventional BYTEWIDETM static RAM.
Should the supply voltage decay, the RAM will
automatically power-fail deselect, write protecting
itself tWP after VCC falls below VPFD. All outputs
become high impedance, and all inputs are treated
as ”don’t care.”
If power fail detection occurs during a valid access,
the memory cycle continues to completion. If the
memory cycle fails to terminate within the time tWP ,
write protection takes place. When Vcc drops below VSO, the control circuit switches power to the
internal energy source which preserves data.
The internal coin cell will maintain data in the
M48Z30/30Y after the initial application of VCC for
an accumulated period of at least 10 years when
VCC is less than VSO. As system power returns and
Vcc rises above VSO, the battery is disconnected,
and the power supply is switched to external Vcc.
Write protectioncontinues for tER after VCC reaches
VPFD to allow for processor stabilization. After t ER,
normal RAM operation can resume.
7/12
M48Z30, M48Z30Y
Table 9. Write Mode AC Characteristics (TA = 0 to 70°C; VCC = 4.75V to 5.5V or 4.5V to 5.5V)
M48Z30 / 30Y
Symbol
Parameter
-85
Min
Unit
-100
Max
Min
Max
tAVAV
Write Cycle Time
85
100
ns
tAVWL
Address Valid to Write Enable Low
0
0
ns
tAVEL
Address Valid to Chip Enable Low
0
0
ns
tWLWH
Write Enable Pulse Width
65
75
ns
tELEH
Chip Enable Low to Chip Enable High
75
90
ns
tWHAX
Write Enable High to Address Transition
5
5
ns
tEHAX
Chip Enable High to Address Transition
15
15
ns
tDVWH
Input Valid to Write Enable High
35
40
ns
tDVEH
Input Valid to Chip Enable High
35
40
ns
tWHDX
Write Enable High to Input Transition
0
0
ns
tEHDX
Chip Enable High to Input Transition
15
15
ns
tWLQZ
(1,2)
Write Enable Low to Output Hi-Z
35
35
tAVWH
Address Valid to Write Enable High
75
80
ns
tAVEH
Address Valid to Chip Enable High
75
80
ns
Write Enable High to Output Transition
5
5
ns
tWHQX
(1,2)
Notes: 1. CL = 5pF (see Figure 4).
2. If E goes low simultaneously with W going low after W going low, the outputs remain in the high-impedance state.
8/12
ns
M48Z30, M48Z30Y
Figure 8. Write Enable Controlled, Write AC Waveforms
Note: G = High.
Figure 9. Chip Enable Controlled, Write AC Waveforms
Note: G = High.
9/12
M48Z30, M48Z30Y
ORDERING INFORMATION SCHEME
Example:
M48Z30Y
30Y
VCC = 4.75V to 5.5V
VPFD = 4.5V to 4.75V
PM
1
Speed
Supply Voltage and Write
Protect Voltage
30
-85
-85
85ns
-100
100ns
Package
PM
PMDIP28
Temp. Range
1
0 to 70°C
VCC = 4.5V to 5.5V
VPFD = 4.2V to 4.5V
For a list of available options (Package and Speed) refer to the current Memory Shortform catalogue.
For further information or any aspect of this device, please contact the SGS-THOMSON Sales Office
nearest to you.
10/12
M48Z30, M48Z30Y
PMDIP28 - 28 pin Plastic DIP Module
mm
Symb
Typ
inches
Min
Max
A
9.27
A1
Typ
Min
Max
9.52
0.365
0.375
0.38
–
0.015
–
B
0.43
0.59
0.017
0.023
C
0.20
0.33
0.008
0.013
D
37.34
38.10
1.470
1.500
E
18.03
18.80
0.710
0.740
e1
2.29
2.79
0.090
0.110
e3
29.72
36.32
1.170
1.430
eA
14.99
16.00
0.590
0.630
L
3.05
3.81
0.120
0.150
S
1.91
2.79
0.075
0.110
N
28
28
PMDIP28
A
A1
S
B
L
C
eA
e1
e3
D
N
E
1
PMDIP
Drawing is not to scale
11/12
M48Z30, M48Z30Y
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express
written approval of SGS-THOMSON Microelectronics.
 1994 SGS-THOMSON Microelectronics - All Rights Reserved
 ZEROPOWER is a registered trademark of SGS-THOMSON Microelectronics
 BYTEWIDE is a trademark of SGS-THOMSON Microelectronics
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12/12