PRELIMINARY
MX27C4000A
4M-BIT [512K x8] CMOS OTP ROM
FEATURES
•
•
•
•
•
•
512K x 8 organization
Single +5V power supply
+12.5V programming voltage
Fast access time: 90/100/120/150 ns
Totally static operation
Completely TTL compatible
•
Operating current: 40mA
•
Standby current: 100uA
•
Package type:
-
-
-
-
32 pin PDIP
32 pin PLCC
32 pin SOP
32 pin TSOP
GENERAL DESCRIPTION
The MX27C4000A is a 5V only, 4M-bit, One Time
Programmable Read Only Memory. It is organized as
512K words by 8 bits per word, operates from a single
+5 volt supply, has a static standby mode, and features
fast single address location programming. All program-
ming signals are TTL levels, requiring a single pulse. For
programming outside from the system, existing EPROM
programmers may be used. The MX27C4000A
supports a intelligent fast programming algorithm which
can result in programming time of less than two minutes.
This One Time Programmable Read Only Memory is
packaged in industry standard 32 pin dual-in-line plastic,
32 lead PLCC, 32 lead SOP, 32 lead TSOP packages.
PIN CONFIGURATIONS
32 PDIP/SOP
VPP
A16
A15
A12
A7
A6
A5
A4
A3
A2
A1
A0
Q0
Q1
Q2
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
VCC
A18
A17
A14
A13
A8
A9
A11
OE
A10
CE
Q7
Q6
Q5
Q4
Q3
32 PLCC
VCC
VPP
A12
A15
A16
A18
4
1
32
30
29
A17
A7
A6
A5
A4
A3
A2
A1
A0
Q0
5
A14
A13
A8
A9
MX27C4000A
9
MX27C4000A
25
A11
OE
A10
CE
13
14
17
21
20
Q7
Q1
Q2
GND
Q3
Q4
Q5
32 TSOP
A11
A9
A8
A13
A14
A17
A18
VCC
VPP
A16
A15
A12
A7
A6
A5
A4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
OE
A10
CE
Q7
Q6
Q5
Q4
Q3
GND
Q2
Q1
Q0
A0
A1
A2
A3
PIN DESCRIPTION
SYMBOL
A0~A18
Q0~Q7
CE
OE
VPP
VCC
GND
PIN NAME
Address Input
Data Input/Output
Chip Enable Input
Output Enable Input
Program Supply Voltage
Power Supply Pin (+5V)
Ground Pin
MX27C4000A
P/N: PM00694
1
Q6
REV. 1.6, JUL. 19, 2001
MX27C4000A
BLOCK DIAGRAM
CE
OE
CONTROL
LOGIC
OUTPUT
BUFFERS
Q0~Q7
PROGRAM INHIBIT MODE
Programming of multiple MX27C4000As in parallel with
different data is also easily accomplished by using the
Program Inhibit Mode. Except for CE and OE, all like
inputs of the parallel MX27C4000A may be common. A
TTL low-level program pulse applied to an
MX27C4000A CE input with VPP = 12.5
±
0.5 V and CE
LOW will program that MX27C4000A. A high-level CE
input inhibits the other MX27C4000As from being
programmed.
.
.
.
A0~A18
ADDRESS
INPUTS
.
.
.
.
.
VCC
VSS
Y-DECODER
.
.
.
.
.
.
.
.
Y-SELECT
4M BIT
CELL
MAXTRIX
X-DECODER
PROGRAM VERIFY MODE
Verification should be performed on the programmed
bits to determine that they were correctly programmed.
The verification should be performed with OE and CE at
VIL, and VPP at its programming voltage.
FUNCTIONAL DESCRIPTION
THE PROGRAMMING OF THE MX27C4000A
AUTO IDENTIFY MODE
When the MX27C4000A is delivered, or it is erased,
the chip has all 4M bits in the "ONE" or HIGH state.
"ZEROs" are loaded into the MX27C4000A through the
procedure of programming.
For programming, the data to be programmed is applied
with 8 bits in parallel to the data pins.
Vcc must be applied simultaneously or before Vpp, and
removed simultaneously or after Vpp. When
programming an MXIC OTP ROM, a 01uF capacitor is
required across Vpp and ground to suppress spurious
voltage transients which may damage the device.
The auto identify mode allows the reading out of a binary
code from an OTP ROM that will identify its
manufacturer and device type. This mode is intended for
use by programming equipment for the purpose of
automatically matching the device to be programmed
with its corresponding programming algorithm. This
mode is functional in the 25°C
±
5°C ambient
temperature range that is required when programming
the MX27C4000A.
To activate this mode, the programming equipment
must force 12.0
±
0.5 V on address line A9 of the device.
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 VIL during
auto identify mode.
Byte 0 ( A0 = VIL) represents the manufacturer code,
and byte 1 (A0 = VIH), the device identifier code. For the
MX27C4000A, these two identifier bytes are given in the
Mode Select Table. All identifiers for manufacturer and
device codes will possess odd parity, with the MSB (Q7)
defined as the parity bit.
FAST PROGRAMMING
The device is set up in the fast programming mode when
the programming voltage VPP = 12.75V is applied, with
VCC = 6.25 V and OE = VIH (Algorithm is shown in
Figure 1). The programming is achieved by applying a
single TTL low level 10us pulse to the CE input after
addresses and data line are stable. If the data is not
verified, an additional pulse is applied for a maximum of
25 pulses. This process is repeated while sequencing
through each address of the device. When the
programming mode is completed, the data in all address
is verified at VCC = VPP = 5V
±
10%.
READ MODE
The MX27C4000A has two control functions, both of
which must be logically satisfied in order to obtain data
P/N: PM00694
REV. 1.6, JUL. 19, 2001
2
MX27C4000A
at the outputs. Chip Enable (CE) is the power control
and should be used for device selection. Output Enable
(OE) is the output control and should be used to gate
data to the output pins, independent of device selection.
Assuming that addresses are stable, address access
time (tACC) is equal to the delay from CE to output (tCE).
Data is available at the outputs tOE after the falling edge
of OE's, assuming that CE has been LOW and
addresses have been stable for at least tACC - tOE.
2. Assurance that output bus contention will not
occur.
It is recommended that CE be decoded and used as the
primary device-selecting function, while OE be made a
common connection to all devices in the array and
connected to the READ line from the system control bus.
This assures that all deselected memory devices are in
their low-power standby mode and that the output pins
are only active when data is desired from a particular
memory device.
STANDBY MODE
The MX27C4000A has a CMOS standby mode which
reduces the maximum VCC current to 100 uA. It is
placed in CMOS standby when CE is at VCC
±
0.3 V.
The MX27C4000A also has a TTL-standby mode which
reduces the maximum VCC current to 1.5 mA. It is
placed in TTL-standby when CE is at VIH. When in
standby mode, the outputs are in a high-impedance
state, independent of the OE input.
SYSTEM CONSIDERATIONS
During the switch between active and standby
conditions, transient current peaks are produced on the
rising and falling edges of Chip Enable. The magnitude
of these transient current peaks is dependent on the
output capacitance loading of the device. At a minimum,
a 0.1 uF ceramic capacitor (high frequency, low inherent
inductance) should be used on each device between
VCC and GND to minimize transient effects. In addition,
to overcome the voltage drop caused by the inductive
effects of the printed circuit board traces on EPROM
arrays, a 4.7 uF bulk electrolytic capacitor should be
used between VCC and GND for each eight devices.
The location of the capacitor should be close to where
the power supply is connected to the array.
TWO-LINE OUTPUT CONTROL FUNCTION
To accommodate multiple memory connections, a two-
line control function is provided to allow for:
1. Low memory power dissipation,
MODE SELECT TABLE
PINS
MODE
Read
Output Disable
Standby (TTL)
Standby (CMOS)
Program
Program Verify
Program Inhibit
Manufacturer Code(3)
Device Code(3)
CE
VIL
VIL
VIH
VIL
VIH
VIH
VIL
VIL
OE
VIL
VIH
X
VIH
VIL
VIH
VIL
VIL
A0
X
X
X
X
X
X
X
VIL
VIH
A9
X
X
X
X
X
X
X
VH
VH
VPP
VCC
VCC
VCC
VCC
VPP
VPP
VPP
VCC
VCC
OUTPUTS
DOUT
High Z
High Z
High Z
DIN
DOUT
High Z
C2H
C0H
VCC±0.3V X
NOTES:
1. VH = 12.0 V
±
0.5 V
2. X = Either VIH or VIL
3. A1 - A8 = A10 - A18 = VIL(For auto select)
4. See DC Programming Characteristics for VPP voltage during programming.
P/N: PM00694
REV. 1.6, JUL. 19, 2001
3
MX27C4000A
FIGURE 1. FAST PROGRAMMING FLOWCHART
START
ADDRESS = FIRST LOCATION
VCC = 6.25V
VPP = 12.75V
X=0
PROGRAM ONE 10us PULSE
INTERACTIVE
SECTION
INCREMENT X
YES
X = 25?
NO
FAIL
VERIFY BYTE
?
PASS
NO
INCREMENT ADDRESS
LAST ADDRESS
FAIL
YES
VCC = VPP = 5.25V
VERIFY SECTION
VERIFY ALL BYTES
?
FAIL
DEVICE FAILED
PASS
DEVICE PASSED
P/N: PM00694
REV. 1.6, JUL. 19, 2001
4
MX27C4000A
SWITCHING TEST CIRCUITS
DEVICE
UNDER
TEST
1.8K ohm
+5V
CL
6.2K ohm
DIODES = IN3064
OR EQUIVALENT
CL = 100 pF including jig capacitance
SWITCHING TEST WAVEFORMS
2.0V
AC driving levels
2.0V
TEST POINTS
0.8V
OUTPUT
0.8V
INPUT
AC TESTING: (1) AC driving levels are 2.4V/0.4V.
(2) Input pulse rise and fall times are < 10ns.
P/N: PM00694
REV. 1.6, JUL. 19, 2001
5
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