Toshiba 29VH27E, Service Manual

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14.2.27W401
14.2.1.Description
The M27W401 is a low voltage 4 Mbit EPROM offered in the two ranges UV (ultra violet erase) and
OTP (one time programmable). It is ideally suited for microprocessor systems requiring large data or
program storage and is organized as 524,288 by 8 bits. The M27W401 operates in the read mode with
a supply voltage as low as 2.7V at –40 to 8??C temperature range. The decrease in operating power
allows either a reduction of the size of the battery or an increase in the time between battery re-
charges.
The FDIP32W (window ceramic frit-seal package) has a transparent lid, which allows the user to ex-
pose the chip to ultraviolet light to erase the bit pat -tern. A new pattern can then be written to the device
by following the programming procedure. For application where the content is programmed only one
time and erasure is not required, the M27W401 is offered in PDIP32, PLCC32 and TSOP32 (8x20 mm)
packages.
14.2.2.Features
2.7V to 3.6v Low voltage in Read Operation
Access time:
–70ns at V
CC
= 3.0V to 3.6V
–80ns at V
CC
= 2.7V to 3.6V
Pin Compatible with M27C4001
Low Power Consumption:
–1?mA max Standby Current
– 15mA max Active Current at 5MHz
Programming Time 10?
ms/byte
High Reliability CMOS Technology
– 2,000V ESD Protection
– 200mA Latchup Protection Immunity
Electronic Signature
– Manufacturer Code: 20h
– Device Code: 41h
14.2.3.Connections
DIP connections LCC Connections TSOP Connections