MXIC MX27C4000AMC-10, MX27C4000AMC-12, MX27C4000AMC-15, MX27C4000AMC-90, MX27C4000AMI-10 Datasheet

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FEATURES

PRELIMINARY

MX27C4000A

4M-BIT [512K x8] CMOS OTP ROM

• 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

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 programming signals are TTL levels, requiring a single pulse. For programming outside from the system, existing EPROM

PIN CONFIGURATIONS 32 PDIP/SOP

VPP

A16 A15 A12

GND

A7 A6 A5 A4 A3 A2 A1 A0 Q0 Q1 Q2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

MX27C4000A

VCC

A18

A17

A14

A13

A11

A10

• Operating current: 40mA

• Standby current: 100uA

• Package type:

- 32 pin PDIP

- 32 pin PLCC

- 32 pin SOP

- 32 pin TSOP

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.

32 PLCC

A12

A15

A16

VPP

VCC

A18

A17

A7 A6 A5 A4

A3 A2 A1 A0

14 17 20

MX27C4000A

GND

A14

A13 A8 A9 A11

OE A10 CE Q7

32 TSOP

A11

A13 A14 A17 A18

VCC

VPP

A16 A15 A12

P/N: PM00694

1 2

4 5 6 7 8 9 10 11 12 13

MX27C4000A

PIN DESCRIPTION

A10

GND

SYMBOL PIN NAME

A0~A18 Address Input Q0~Q7 Data Input/Output CE Chip Enable Input OE Output Enable Input VPP Program Supply Voltage VCC Power Supply Pin (+5V) GND Ground Pin

REV. 1.6, JUL. 19, 2001

MX27C4000A

BLOCK DIAGRAM

A0~A18

ADDRESS

INPUTS

VCC VSS

. . . . . . . .

CONTROL

LOGIC

Y -DECODER

X-DECODER

OUTPUT

BUFFERS

Y -SELECT

. . .

4M BIT

. . . .

CELL

MAXTRIX

Q0~Q7

FUNCTIONAL DESCRIPTION

THE PROGRAMMING OF THE MX27C4000A

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.

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%.

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.

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.

AUTO IDENTIFY MODE

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.

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

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.

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.

TWO-LINE OUTPUT CONTROL FUNCTION

To accommodate multiple memory connections, a twoline control function is provided to allow for:

1. Low memory power dissipation,

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.

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.

MODE SELECT TABLE

PINS

MODE CE OE A0 A9 VPP OUTPUTS

Read VIL VIL X X VCC DOUT Output Disable VIL VIH X X VCC High Z Standby (TTL) VIH X X X VCC High Z Standby (CMOS) VCC±0.3V X X X VCC High Z Program VIL VIH X X VPP DIN Program Verify VIH VIL X X VPP DOUT Program Inhibit VIH VIH X X VPP High Z Manufacturer Code(3) VIL VIL VIL VH VCC C2H Device Code(3) VIL VIL VIH VH VCC C0H

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

FIGURE 1. FAST PROGRAMMING FLOWCHART

MX27C4000A

ST AR T

ADDRESS = FIRST LOCATION

VCC = 6.25V VPP = 12.75V

X = 0

PROGRAM ONE 10us PULSE

INTERACTIVE SECTION

VERIFY SECTION

INCREMENT ADDRESS

FAIL

VCC = VPP = 5.25V

VERIFY ALL BYTES

INCREMENT X

X = 25?

VERIFY BYTE

PASS

LAST ADDRESS

YES

PASS

DEVICE PASSED

YES

FAIL

DEVICE FAILED

P/N: PM00694

REV. 1.6, JUL. 19, 2001

SWITCHING TEST CIRCUITS

MX27C4000A

DEVICE UNDER

TEST

CL = 100 pF including jig capacitance

SWITCHING TEST WAVEFORMS

AC driving levels

AC TESTING: (1) AC driving levels are 2.4V/0.4V.

6.2K ohm

2.0V TEST POINTS

0.8V

INPUT

(2) Input pulse rise and fall times are < 10ns.

1.8K ohm +5V

DIODES = IN3064 OR EQUIVALENT

2.0V

0.8V OUTPUT

P/N: PM00694

REV. 1.6, JUL. 19, 2001

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