4 Mbit (256Kb x 16) Low Voltage UV EPROM and OTP EPROM
■ LOW VOLTAGEREAD OPERATION:
3V to 3.6V
■ FAST ACCESS TIME: 120ns
■ LOW POWERCONSUMPTION:
– Active Current15mA at 5MHz
– Standby Current 20µA
■ PROGRAMMING VOLTAGE: 12.75V ± 0.25V
■ PROGRAMMING TIME: 100µs/byte (typical)
■ ELECTRONIC SIGNATURE
– Manufacturer Code:20h
– Device Code: 8Dh
DESCRIPTION
The M27V402 is a low voltage, low power 4 Mbit
UV erasable and electrically programmable
EPROM, ideally suited for handheld and portable
microprocessor systems requiring large programs.
It is organized as 262,144 by16 bits.
The M27V402 operates in the read mode with a
supply voltage as low as 3V. The decrease in operating power allowseither a reduction of the size
of the battery or an increase in the time between
battery recharges.
The FDIP40W (window ceramic frit-seal package)
has a transparent lid which allows the user to expose thechip to ultraviolet light to erase the bit pattern. A new pattern can then be written to the
device by followingthe programming procedure.
40
1
FDIP40W (F)PDIP40 (B)
PLCC44 (K)TSOP40 (N)
Figure 1. Logic Diagram
V
18
A0-A17Q0-Q15
CC
40
V
PP
1
10 x 20 mm
16
Table 1. Signal Names
A0-A17Address Inputs
Q0-Q15Data Outputs
EChip Enable
GOutput Enable
V
A5
A4
A3
A2
A1
A0
G
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
V
SS
Warning: NC = Not Connected.
For applications wherethe content isprogrammed
only one time and erasure is not required, the
M27V256 is offered in PDIP40, PLCC44 and
TSOP40 (10 x 20 mm) packages.
DEVICE OPERATION
The operating modes of the M27V402 arelisted in
the OperatingModes table. A single power supply
is required in the read mode. All inputs are TTL
levels except for VPPand 12V on A9 forElectronic
Signature.
Read Mode
The M27V402 has two control functions, both of
which must be logically active in order to obtain
data at the outputs. Chip Enable (E) is the power
control and should be used for device selection.
Output Enable (G) is the output controland should
be used to gate data to the output pins,
independent of device selection. Assuming that
the addresses arestable, the address accesstime
(t
) is equal to the delay from E to output
AVQV
(t
). Data is availableattheoutput after a delay
ELQV
of t
from the falling edge of G, assuming that
GLQV
E has been low and the addresses have been
stable for at least t
AVQV-tGLQV
.
2/15
M27V402
Table 2. Absolute Maximum Ratings
(1)
SymbolParameterValueUnit
T
A
T
BIAS
T
STG
(2)
V
IO
V
CC
(2)
V
A9
V
PP
Note: 1. Except for the rating ”Operating Temperature Range”, stresses above those listed in the Table ”Absolute Maximum Ratings” may
cause permanent damage to the device. These are stress ratings onlyand operation of the device atthese or anyother conditions
above those indicated in the Operating sections of this specification is not implied. Exposure toAbsolute Maximum Rating conditions for extended periods may affect device reliability. Referalso to the STMicroelectronics SUREProgram andotherrelevant quality documents.
2. Minimum DC voltage on Input or Output is –0.5V with possible undershoot to –2.0V for a period less than 20ns. Maximum DC
voltage on Output is V
3. Depends on range.
Ambient Operating Temperature
Temperature Under Bias–50 to 125°C
Storage Temperature–65 to 150°C
Input or Output Voltage (except A9)–2 to 7V
Supply Voltage–2 to 7V
A9 Voltage–2 to 13.5V
Program Supply Voltage–2 to 14V
+0.5V with possible overshoot to VCC+2V for a period less than20ns.
CC
(3)
–40 to 125°C
Table 3. Operating Modes
ModeEGA9
Read
Output DisableV
Program
V
VerifyV
Program Inhibit
Standby
Electronic Signature
Note: X = VIHor VIL,VID= 12V ± 0.5V.
V
IL
IL
PulseV
IL
IH
V
IH
V
IH
V
IL
V
IL
V
IH
IH
V
IL
V
IH
X
XV
X
XVPPData Out
X
XX
V
IL
V
ID
V
PP
V
or V
CC
SS
or V
CC
SS
V
PP
V
PP
V
or V
CC
SS
V
CC
Q0-Q15
Data Out
Hi-Z
Data In
Hi-Z
Hi-Z
Codes
Table 4. Electronic Signature
IdentifierA0Q7Q6Q5Q4Q3Q2Q1Q0Hex Data
Manufacturer’s Code
Device Code
V
IL
V
IH
Standby Mode
The M27V402 has a standbymode which reduces
the supply current from 20mA to 20µA with low
voltage operationVCC≤ 3.6V, see Read Mode DC
00100000 20h
10001101 8Dh
Characteristics table for details. The M27V402 is
placed in the standby mode by applying a CMOS
high signal to the E input. When in the standby
mode, the outputs are in a high impedance state,
independent of the G input.
3/15
M27V402
Table 5. AC Measurement Conditions
High SpeedStandard
Input Rise and Fall Times≤ 10ns≤ 20ns
Input Pulse Voltages0 to3V0.4V to 2.4V
Input and Output Timing Ref. Voltages1.5V0.8V and 2V
Figure 3. AC Testing Input OutputWaveform
High Speed
3V
1.5V
0V
Standard
2.4V
0.4V
Table 6. Capacitance
(1)
(TA=25°C, f = 1 MHz)
2.0V
0.8V
AI01822
Figure 4. AC Testing Load Circuit
1.3V
1N914
3.3kΩ
DEVICE
UNDER
TEST
C
L
CL= 30pF for HighSpeed
CL= 100pF for Standard
CLincludes JIG capacitance
OUT
AI01823B
SymbolParameterTest ConditionMinMaxUnit
V
C
IN
C
OUT
Note: Sampled only, not 100% tested.
Input Capacitance
Output CapacitanceV
=0V
IN
=0V12pF
OUT
6pF
Two Line Output Control
Because EPROMs are usually used in larger
memory arrays, the product features a 2 line control function whichaccommodates the use of multiple memory connection. The two line control
function allows:
a. the lowest possible memory power dissipation,
b. complete assurance that output bus contention
will not occur.
4/15
For the most efficient use of these two control
lines, E should bedecodedand used asthe primary device selecting function, while G should be
made a common connection to all devices in the
array and connected to the READ line from the
system control bus. This ensures that all deselected memory devicesare intheir lowpower standby
mode and that the output pins are only active
when data is required from a particular memory
device.
M27V402
Table 7. Read Mode DC Characteristics
(1)
(TA = 0to 70°C, –20 to 70°C, –20 to 85°C or –40 to 85°C; VCC= 3.3V ± 10%; VPP=VCC)
SymbolParameterTestConditionMinMaxUnit
I
I
I
CC
I
CC1
I
CC2
I
V
V
IH
V
V
Note: 1. VCCmust be applied simultaneously with or before VPPand removed simultaneously or after VPP.
Input Leakage Current
LI
Output Leakage Current
LO
Supply Current
Supply Current (Standby) TTL
Supply Current (Standby) CMOS
Program Current
PP
Input Low Voltage–0.30.8V
IL
(2)
Input High Voltage2
Output Low Voltage
OL
Output High Voltage TTL
OH
Output High Voltage CMOS
2. Maximum DC voltage on Output is V
CC
+0.5V.
E=V
IL
f = 5MHz, V
E>V
0V ≤ V
0V ≤ V
,G=VIL,I
CC
I
OH
I
OH
≤ V
IN
CC
≤ V
OUT
CC
= 0mA,
OUT
= 3.6V
CC
E=V
IH
– 0.2V, VCC= 3.6V
V
PP=VCC
I
= 2.1mA
OL
= –400µA
= –100µAV
2.4V
–0.7V
CC
±10µA
±10µA
20mA
1mA
20µA
10µA
V
+1
CC
0.4V
V
V
System Considerations
The power switching characteristics of Advanced
CMOS EPROMs requirecareful decoupling of the
devices. The supply current, ICC, has three segments that are of interest to the system designer:
the standby current level, the active current level,
and transient current peaks that are produced by
the fallingand rising edgesof E. The magnitudeof
the transient current peaks is dependent on the
output capacitive and inductive loading of the device.
The associated transient voltage peaks can be
suppressed by complying with the two line output
control and by properly selected decoupling capacitors. It is recommended that a 0.1µF ceramic
capacitor be used on every device between V
CC
and VSS. This should be a high frequency capacitor of low inherent inductance and should be
placed as close to the device as possible. In addition, a 4.7µF bulk electrolytic capacitor should be
used between VCCand VSSfor every eight devices. The bulk capacitor should be located near the
power supply connection point.Thepurpose of the
bulk capacitor is to overcome the voltage drop
caused bythe inductive effects of PCB traces.
Programming
When delivered (and after each erasure for UV
EPROM), all bits of the M27V402 are in the ’1’
state. Data is introduced by selectively programming ’0’s into the desired bit locations. Although
only ’0’s will beprogrammed, both ’1’s and ’0’s can
be present in the data word. The only way to
change a ’0’ to a’1’is by die exposure to ultraviolet
light (UV EPROM). The M27V402 is in the programming modewhen VPPinput is at12.75V, Gia
at VIHand E is pulsed to VIL. The data to be programmedis applied to16 bitsin paralleltothe data
output pins.
The levels required for the address and data inputs are TTL. VCCis specified to be 6.25V ±
0.25V.
5/15
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