STMICROELECTRONICS M27W256

M27W256
256 Kbit (32Kb x 8) Low Voltage UV EPROM and OTP EPROM
■
2.7V to 3.6V SUPPLY VOLTAGE in READ
OPERATION
■
ACCESS TIME:
– 70ns at VCC = 3.0V to 3.6V
– 80ns at VCC = 2.7V to 3.6V
28
28
■
PIN COMPATIBLE with M27C256B
■
LOW POWER CONSUMPTION:
1
1
– 15µA max Standby Current
FDIP28W (F)
PDIP28 (B)
– 15mA max Active Current at 5MHz
■
PROGRAMMING TIME 100µs/byte
■
HIGH RELIABILITY CMOS TECHNOLOGY
– 2,000V ESD Protection
– 200mA Latchup Protection Immunity
■
PLCC32 (K)
TSOP28 (N)
8 x 13.4mm
ELECTRONIC SIGNATURE
– Manufacturer Code: 20h
– Device Code: 3Dh
DESCRIPTION
The M27W256 is a low voltage 256 Kbit EPROM
offered in the two ranges UV (ultra violet erase)
and OTP (one time programmable). It is ideally
suited for microprocessor systems and is organized as 32,768 by 8 bits.
The M27W256 operates in the read mode with a
supply voltage as low as 3V. The decrease in operating power allows either a reduction of the size
of the battery or an increase in the time between
battery recharges.
The FDIP28W (window ceramic frit-seal package)
has a transparent lid which allows the user to expose the chip to ultraviolet light to erase the bit pattern. A new pattern can then be written to the
device by following the programming procedure.
For applications where the content is programmed
only one time and erasure is not required, the
M27W256 is offered in PDIP28, PLCC32 and
TSOP28 (8 x 13.4 mm) packages.
Figure 1. Logic Diagram
VCC
VPP
15
8
A0-A14
E
Q0-Q7
M27W256
G
VSS
AI03629
March 2000
1/15
M27W256
VCC
A14
A13
A8
A9
A11
G
A10
E
Q7
Q6
Q5
Q4
Q3
1
28
2
27
3
26
4
25
5
24
6
23
7
22
M27W256
8
21
9
20
10
19
11
18
12
17
13
16
14
15
1 32
A6
A5
A4
A3
A2
A1
A0
NC
Q0
9
M27W256
25
17
AI03627
AI03626
Figure 2C. TSOP Connections
G
A11
A9
A8
A13
A14
VCC
VPP
A12
A7
A6
A5
A4
A3
22
28
1
7
Table 1. Signal Names
21
M27W256
15
14
8
AI03628
2/15
A8
A9
A11
NC
G
A10
E
Q7
Q6
Q1
Q2
VSS
DU
Q3
Q4
Q5
VPP
A12
A7
A6
A5
A4
A3
A2
A1
A0
Q0
Q1
Q2
VSS
Figure 2B. LCC Connections
A7
A12
VPP
DU
VCC
A14
A13
Figure 2A. DIP Connections
A10
E
Q7
Q6
Q5
Q4
Q3
VSS
Q2
Q1
Q0
A0
A1
A2
A0-A14
Address Inputs
Q0-Q7
Data Outputs
E
Chip Enable
G
Output Enable
VPP
Program Supply
VCC
Supply Voltage
VSS
Ground
NC
Not Connected Internally
DU
Don’t Use
M27W256
Table 2. Absolute Maximum Ratings (1)
Symbol
Parameter
Value
Unit
Ambient Operating Temperature (3)
–40 to 125
°C
TBIAS
Temperature Under Bias
–50 to 125
°C
TSTG
Storage Temperature
–65 to 150
°C
VIO (2)
Input or Output Voltage (except A9)
–2 to 7
V
Supply Voltage
–2 to 7
V
–2 to 13.5
V
–2 to 14
V
TA
VCC
VA9 (2)
A9 Voltage
Program Supply Voltage
VPP
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 only and operation of the device at these or any other conditions
above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant 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 VCC +0.5V with possible overshoot to VCC +2V for a period less than 20ns.
3. Depends on range.
Table 3. Operating Modes
E
G
A9
VPP
Q7-Q0
Read
V IL
VIL
X
VCC
Data Out
Output Disable
V IL
VIH
X
VCC
Hi-Z
VIL Pulse
VIH
X
VPP
Data In
Verify
VIH
VIL
X
VPP
Data Out
Program Inhibit
VIH
VIH
X
VPP
Hi-Z
Standby
VIH
X
X
VCC
Hi-Z
Electronic Signature
V IL
VIL
VID
VCC
Codes
Mode
Program
Note: X = VIH or VIL, VID = 12V ± 0.5V.
Table 4. Electronic Signature
Identifier
A0
Q7
Q6
Q5
Q4
Q3
Q2
Q1
Q0
Hex Data
Manufacturer’s Code
VIL
0
0
1
0
0
0
0
0
20h
Device Code
VIH
1
0
0
0
1
1
0
1
8Dh
3/15
M27W256
Table 5. AC Measurement Conditions
High Speed
Standard
Input Rise and Fall Times
≤ 10ns
≤ 20ns
Input Pulse Voltages
0 to 3V
0.4V to 2.4V
1.5V
0.8V and 2V
Input and Output Timing Ref. Voltages
Figure 3. AC Testing Input Output Waveform
Figure 4. AC Testing Load Circuit
1.3V
High Speed
1N914
3V
1.5V
3.3kΩ
0V
DEVICE
UNDER
TEST
Standard
2.4V
OUT
CL
2.0V
0.8V
0.4V
AI01822
CL = 30pF for High Speed
CL = 100pF for Standard
CL includes JIG capacitance
AI01823B
Table 6. Capacitance (1) (TA = 25 °C, f = 1 MHz)
Symbol
C IN
COUT
Parameter
Input Capacitance
Output Capacitance
Test Condit ion
Min
Max
Unit
VIN = 0V
6
pF
VOUT = 0V
12
pF
Note: 1. Sampled only, not 100% tested.
DEVICE OPERATION
The modes of operation of the M27W256 are listed
in the Operating Modes. A single power supply is
required in the read mode. All inputs are TTL levels except for VPP and 12V on A9 for Electronic
Signature.
Read Mode
The M27W256 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 control and should
be used to gate data to the output pins, indepen-
4/15
dent of device selection. Assuming that the addresses are stable, the address access time
(tAVQV) is equal to the delay from E to output
(tELQV). Data is available at the output after delay
of t GLQV from the falling edge of G, assuming that
E has been low and the addresses have been stable for at least tAVQV-tGLQV.
Standby Mode
The M27W256 has a standby mode which reduces the supply current from 10mA to 10µA with low
voltage operation VCC ≤ 3.6V, see Read Mode DC
Characteristics table for details. The M27W256 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.
M27W256
Table 7. Read Mode DC Characteristics (1)
(TA = –40 to 85°C; VCC = 2.7V to 3.6V; VPP = VCC)
Symbol
Parameter
ILI
Input Leakage Current
ILO
Output Leakage Current
ICC
Supply Current
Test Condition
Min
Max
Unit
0V ≤ VIN ≤ V CC
±10
µA
0V ≤ VOUT ≤ VCC
±10
µA
E = VIL, G = VIL,
IOUT = 0mA, f = 5MHz,
15
mA
E = VIH
1
mA
E > VCC – 0.2V,
VCC ≤ 3.6V
15
µA
VPP = VCC
100
µA
VCC ≤ 3.6V
ICC1
Supply Current (Standby) TTL
ICC2
Supply Current (Standby) CMOS
IPP
Program Current
VIL
Input Low Voltage
–0.6
0.2 VCC
V
VIH (2)
Input High Voltage
0.7 VCC
VCC + 0.5
V
VOL
Output Low Voltage
0.4
V
VOH
Output High Voltage TTL
IOL = 2.1mA
IOH = –400µA
2.4
V
Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after V PP.
2. Maximum DC voltage on Output is VCC +0.5V.
Table 8. Read Mode AC Characteristics (1)
(TA = –40 to 85°C; VCC = 2.7V to 3.6V; VPP = VCC)
M27W256
Symbol
Alt
Parameter
-100
(-120/-150/-200)
-80 (3)
Test
Condition
Unit
VCC = 3.0V to 3.6V VCC = 2.7V to 3.6V VCC = 2.7V to 3.6V
Min
Max
Min
Max
Min
Max
tAVQV
tACC
Address Valid to
Output Valid
E = VIL,
G = VIL
70
80
100
ns
tELQV
tCE
Chip Enable Low to
Output Valid
G = VIL
70
80
100
ns
tGLQV
tOE
Output Enable Low
to Output Valid
E = VIL
40
50
60
ns
tEHQZ (2)
tDF
Chip Enable High
to Output Hi-Z
G = VIL
0
40
0
50
0
60
ns
tGHQZ (2)
tDF
Output Enable High
to Output Hi-Z
E = VIL
0
40
0
50
0
60
ns
tAXQX
tOH
Address Transition
to Output Transition
E = VIL,
G = VIL
0
0
0
ns
Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after V PP.
2. Sampled only, not 100% tested.
3. Speed obtained with High Speed AC measurement conditions.
5/15
M27W256
Figure 5. Read Mode AC Waveforms
A0-A14
VALID
tAVQV
VALID
tAXQX
E
tGLQV
tEHQZ
G
tELQV
Q0-Q7
tGHQZ
Hi-Z
AI00758B
Two Line Output Control
Because EPROMs are usually used in larger
memory arrays, this product features a 2 line control function which accommodates 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.
For the most efficient use of these two control
lines, E should be decoded and used as the 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 devices are in their low power standby
mode and hat the output pins are only active when
data is desired from a particular memory device.
6/15
System Considerations
The power switching characteristics of Advance
CMOS EPROMs require careful decoupling of the
devices. The supply current, I CC, 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 falling and rising edges of E. The magnitude of
this transient current peaks is dependent on the
capacitive and inductive loading of the device at
the output. 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 VCC
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 VCC and VSS for every eight devices. The bulk capacitor should be located near the
power supply connection point. The purpose of the
bulk capacitor is to overcome the voltage drop
caused by the inductive effects of PCB traces.
M27W256
Table 9. Programming Mode DC Characteristics (1)
(TA = 25 °C; VCC = 6.25V ± 0.25V; VPP = 12.75V ± 0.25V)
Symbol
Parameter
Test Condition
ILI
Input Leakage Current
VIL ≤ VIN ≤ VIH
ICC
Supply Current
IPP
Program Current
VIL
Input Low Voltage
VIH
Input High Voltage
VOL
Output Low Voltage
IOL = 2.1mA
VOH
Output High Voltage TTL
IOH = –1mA
VID
A9 Voltage
Min
Max
Unit
±10
µA
50
mA
50
mA
–0.3
0.8
V
2
VCC + 0.5
V
0.4
V
E = VIL
3.6
11.5
V
12.5
V
Note: VCC must be applied simultaneously with or before V PP and removed simultaneously or after VPP.
Table 10. Programming Mode AC Characteristics (1)
(TA = 25 °C; VCC = 6.25V ± 0.25V; VPP = 12.75V ± 0.25V
Symbol
Alt
Parameter
Min
Max
tAVEL
tAS
Address Valid to Chip Enable Low
2
µs
tQVEL
tDS
Input Valid to Chip Enable Low
2
µs
tVPHEL
tVPS
VPP High to Chip Enable Low
2
µs
tVCHEL
tVCS
VCC High to Chip Enable Low
2
µs
tELEH
tPW
Chip Enable Program Pulse Width
95
t EHQX
tDH
Chip Enable High to Input Transition
2
µs
tQXGL
tOES
Input Transition to Output Enable Low
2
µs
tGLQV
tOE
Output Enable Low to Output Valid
tGHQZ
tDFP
Output Enable High to Output Hi-Z
0
t GHAX
tAH
Output Enable High to Address Transition
0
105
Unit
µs
100
ns
130
ns
ns
Note: VCC must be applied simultaneously with or before V PP and removed simultaneously or after VPP.
Programming
The M27W256 has been designed to be fully compatible with the M27C256B and has the same
electronic signature. As a result the M27W256 can
be programmed as the M27C256B on the same
programming equipments applying 12.75V on VPP
and 6.25V on VCC by the use of the same PRESTO II algorithm. When delivered (and after each
erasure for UV EPROM), all bits of the M27W256
are in the ’1’ state. Data is introduced by selectively programming ’0’s into the desired bit locations.
Although only ’0’s will be programmed, 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 M27W256 is in
the programming mode when VPP input is at
12.75V, G is at VIH and E is pulsed to VIL. The data
to be programmed is applied to 8 bits in parallel to
the data output pins. The levels required for the
address and data inputs are TTL. VCC is specified
to be 6.25 V ± 0.25 V.
7/15
M27W256
Figure 6. Programming and Verify Modes AC Waveforms
VALID
A0-A14
tAVEL
Q0-Q7
DATA IN
tQVEL
DATA OUT
tEHQX
VPP
tGLQV
tVPHEL
tGHQZ
VCC
tVCHEL
tGHAX
E
tELEH
tQXGL
G
PROGRAM
VERIFY
AI00759
Figure 7. Programming Flowchart
VCC = 6.25V, VPP = 12.75V
n=0
P = 100µs Pulse
NO
++n
= 25
YES
FAIL
NO
VERIFY
++ Addr
YES
Last
Addr
NO
YES
CHECK ALL WORDS
1st: VCC = 5V
2nd: VCC = 2.7V
AI00707D
8/15
PRESTO II Programming Algorithm
PRESTO II Programming Algorithm allows to program the whole array with a guaranteed margin, in
a typical time of 3.5 seconds. Programming with
PRESTO II involves the application of a sequence
of 100µs program pulses to each byte until a correct verify occurs (see Figure 7). During programming and verify operation, a MARGIN MODE
circuit is automatically activated in order to guarantee that each cell is programmed with enough
margin. No overprogram pulse is applied since the
verify in MARGIN MODE at VCC much higher than
3.6V provides necessary margin to each programmed cell.
Program Inhibit
Programming of multiple M27W256s in parallel
with different data is also easily accomplished. Except for E, all like inputs including G of the parallel
M27W256 may be common. A TTL low level pulse
applied to a M27W256’s E input, with VPP at 12.75
V, will program that M27W256. A high level E input
inhibits the other M27W256s from being programmed.
Program Verify
A verify (read) should be performed on the programmed bits to determine that they were correctly programmed. The verify is accomplished with G
at VIL, E at VIH, VPP at 12.75V and VCC at 6.25V.
M27W256
On-Board Programming
The M27W256 can be directly programmed in the
application circuit. See the relevant Application
Note AN620.
Electronic Signature
The Electronic Signature (ES) mode allows the
reading out of a binary code from an EPROM that
will identify its manufacturer and type. This mode
is intended for use by programming equipment to
automatically match the device to be programmed
with its corresponding programming algorithm.
The ES mode is functional in the 25°C ± 5°C ambient temperature range that is required when programming the M27W256. To activate the ES
mode, the programming equipment must force
11.5V to 12.5V on address line A9 of the
M27W256, with VCC = VPP = 5V. Two identifier
bytes may then be sequenced from the device outputs by toggling address line A0 from VIL to VIH. All
other address lines must be held at V IL during
Electronic Signature mode. Byte 0 (A0 = VIL) represents the manufacturer code and byte 1 (A0 =
VIH) the device identifier code. For the
STMicroelectronics M27W256, these two identifier
bytes are given in Table 4 and can be read-out on
outputs Q7 to Q0. Note that the M27W256 and
M27C256B have the same identifier bytes.
ERASURE OPERATION (applies for UV EPROM)
The erasure characteristics of the M27W256 is
such that erasure begins when the cells are exposed to light with wavelengths shorter than approximately 4000 Å. It should be noted that
sunlight and some type of fluorescent lamps have
wavelengths in the 3000-4000 Å range. Research
shows that constant exposure to room level fluorescent lighting could erase a typical M27W256 in
about 3 years, while it would take approximately 1
week to cause erasure when exposed to direct
sunlight. If the M27W256 is to be exposed to these
types of lighting conditions for extended periods of
time, it is suggested that opaque labels be put over
the M27W256 window to prevent unintentional
erasure. The recommended erasure procedure for
the M27W256 is exposure to short wave ultraviolet
light which has wavelength 2537Å. The integrated
dose (i.e. UV intensity x exposure time) for erasure
should be a minimum of 15 W-sec/cm2. The erasure time with this dosage is approximately 15 to
20 minutes using an ultraviolet lamp with 12000
µW/cm2 power rating. The M27W256 should be
placed within 2.5 cm (1 inch) of the lamp tubes
during the erasure. Some lamps have a filter on
their tubes which should be removed before erasure.
9/15
M27W256
Table 11. Ordering Information Scheme
Example:
M27W256
-80 K
6
TR
Device Type
M27
Supply Voltage
W = 2.7V to 3.6V
Device Function
256 = 256 Kbit (32Kb x 8)
Speed
-80 (1,2) = 80 ns
-100 = 100 ns
Not For New Design (3)
-120 = 120 ns
-150 = 150 ns
-200 = 200 ns
Package
F = FDIP28W (4)
B = PDIP28
K = PLCC32
N = TSOP28: 8 x 13.4 mm (4)
Temperature Range
6 = –40 to 85 °C
Optio ns
TR = Tape & Reel Packing
Note: 1.
2.
3.
4.
High Speed, see AC Characteristics section for further information.
This speed also guarantees 70ns access time at VCC = 3.0V to 3.6V.
These speeds are replaced by the 100ns.
Packages option available on request. Please contact STMicroelectronics local Sales Office.
For a list of available options (Speed, Package, etc...) or for further information on any aspect of this device, please contact the STMicroelectronics Sales Office nearest to you.
10/15
M27W256
Table 12. FDIP28W - 28 pin Ceramic Frit-seal DIP, with window, Package Mechanical Data
mm
Symb
Typ
inches
Min
Max
A
Typ
Min
5.72
Max
0.225
A1
0.51
1.40
0.020
0.055
A2
3.91
4.57
0.154
0.180
A3
3.89
4.50
0.153
0.177
B
0.41
0.56
0.016
0.022
B1
–
–
–
–
C
1.45
0.23
0.30
0.009
0.012
D
36.50
37.34
1.437
1.470
–
–
1.300
–
–
0.600
D2
33.02
E
15.24
E1
0.057
–
–
13.06
13.36
–
–
0.514
0.526
e
2.54
–
–
0.100
–
–
eA
14.99
–
–
0.590
–
–
eB
16.18
18.03
0.637
0.710
L
3.18
4.10
0.125
0.161
S
1.52
2.49
0.060
0.098
–
–
–
–
α
4°
11°
4°
11°
N
28
∅
7.11
0.280
28
Figure 8. FDIP28W - 28 pin Ceramic Frit-seal DIP, with window, Package Outline
A2
A3
A1
B1
B
A
L
e
α
eA
D2
C
eB
D
S
N
∅
E1
E
1
FDIPW-a
Drawing is not to scale.
11/15
M27W256
Table 13. PDIP28 - 28 pin Plastic DIP, 600 mils width, Package Mechanical Data
mm
inches
Symb
Typ
Min
Max
A
–
A1
Min
Max
5.08
–
0.200
0.38
–
0.015
–
A2
3.56
4.06
0.140
0.160
B
0.38
0.51
0.015
0.020
–
–
–
–
C
0.20
0.30
0.008
0.012
D
36.83
37.34
1.450
1.470
B1
1.52
Typ
0.060
D2
33.02
–
–
1.300
–
–
E
15.24
–
–
0.600
–
–
13.59
13.84
0.535
0.545
E1
e1
2.54
–
–
0.100
–
–
eA
14.99
–
–
0.590
–
–
eB
15.24
17.78
0.600
0.700
L
3.18
3.43
0.125
0.135
S
1.78
2.08
0.070
0.082
α
0°
10°
0°
10°
N
28
28
Figure 9. PDIP28 - 28 pin Plastic DIP, 600 mils width, Package Outline
A2
A1
B1
B
A
L
e1
α
eA
D2
C
eB
D
S
N
E1
E
1
PDIP
Drawing is not to scale.
12/15
M27W256
Table 14. PLCC32 - 32 lead Plastic Leaded Chip Carrier, Package Mechanical Data
mm
Symb
Typ
inches
Min
Max
A
2.54
A1
Min
Max
3.56
0.100
0.140
1.52
2.41
0.060
0.095
A2
–
0.38
–
0.015
B
0.33
0.53
0.013
0.021
B1
0.66
0.81
0.026
0.032
D
12.32
12.57
0.485
0.495
D1
11.35
11.56
0.447
0.455
D2
9.91
10.92
0.390
0.430
E
14.86
15.11
0.585
0.595
E1
13.89
14.10
0.547
0.555
E2
12.45
13.46
0.490
0.530
–
–
–
–
0.00
0.25
0.000
0.010
–
–
–
–
e
1.27
F
R
0.89
Typ
0.050
0.035
N
32
32
Nd
7
7
Ne
9
9
CP
0.10
0.004
Figure 10. PLCC32 - 32 lead Plastic Leaded Chip Carrier, Package Outline
D
D1
A1
A2
1 N
B1
E1 E
Ne
e
D2/E2
F
B
0.51 (.020)
1.14 (.045)
A
Nd
R
CP
PLCC
Drawing is not to scale.
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M27W256
Table 15. TSOP28 - 28 lead Plastic Thin Small Outline, 8 x 13.4 mm, Package Mechanical Data
mm
inch
Symbol
Typ
Min
Max
Typ
Min
A
1.250
0.0492
A1
0.200
0.0079
A2
0.950
1.150
0.0374
0.0453
B
0.170
0.270
0.0067
0.0106
C
0.100
0.210
0.0039
0.0083
D
13.200
13.600
0.5197
0.5354
D1
11.700
11.900
0.4606
0.4685
–
–
–
–
E
7.900
8.100
0.3110
0.3189
L
0.500
0.700
0.0197
0.0276
α
0°
5°
0°
5°
e
0.550
CP
0.0217
0.100
N
0.0039
28
28
Figure 11. TSOP28 - 28 lead Plastic Thin Small Outline, 8 x 13.4 mm, Package Outline
A2
22
21
e
28
1
E
B
7
8
D1
A
CP
D
DIE
C
TSOP-c
Drawing is not to scale
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Max
A1
α
L
M27W256
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