Материал: 271001

VERY FAST ACCESS TIME: 45ns

COMPATIBLE with HIGH SPEED MICROPROCESSORS, ZERO WAIT STATE

LOW POWER ºCMOSº CONSUMPTION:

±Active Current 30mA

±Standby Current 100μA PROGRAMMING VOLTAGE: 12.75V

ELECTRONIC SIGNATURE for AUTOMATED PROGRAMMING

PROGRAMMING TIMES of AROUND 12sec. (PRESTO II ALGORITHM)

DESCRIPTION

The M27C1001 is a high speed 1 Megabit UV erasable and electrically programmable memory EPROM ideally suited for microprocessor systems requiring large programs. It is organized as 131,072 by 8 bits.

The 32 pin Window Ceramic Frit-Seal Dual-in-Line and Leadless Chip Carrier packages have transparent lids which allow 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 M27C1001 is offered in both Plastic Dual-in-Line, Plastic Leaded Chip Carrier and Plastic Thin Small Outline packages.

Table 1. Signal Names

28

1

Figure 1. Logic Diagram

P M27C1001

E

G

VSS

AI00710B

M27C1001

Figure 2A. DIP Pin Connections

Warning: NC = Not Connected.

Figure 2C. TSOP Pin Connections

Warning: NC = Not Connected.

DEVICE OPERATION

The modes of operationof the M27C1001 are listed in the Operating Modes table. A single 5V power supply is required in the read mode. All inputs are TTL levels except for VPP and 12V on A9 for Electronic Signature.

Figure 2B. LCC Pin Connections

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Warning: NC = Not Connected.

Read Mode

The M27C1001 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, independent 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 a delay of tGLQV 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 M27C1001 has a standby mode which reduces the active current from 30mA to 100μA. The M27C1001 is placed in the standby mode by applying a CMOS high signal to the E input. When in the standbymode, the outputs are in a high impedance state, independent of the G input.

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.

DEVICE OPERATION (cont'd)

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 that the output pins are only active when data is required from a particular memory device.

System Considerations

The power switching characteristics of Advanced CMOS EPROMs require careful 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 falling and rising edges of E. The magnitude of the transient current peaks is dependent on the capacitive and inductiveloading of the device at the output.

M27C1001

AC MEASUREMENT CONDITIONS

Note that Output Hi-Z is defined as the point where data is no longer driven.

Figure 3. AC Testing Input Output Waveforms

2.4V

2.0V

0.8V

0.4V

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Figure 4. AC Testing Load Circuit

1.3V

1N914

3.3kΩ

DEVICE

UNDER OUT TEST

CL = 100pF

CL includes JIG capacitance

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