TMS27C256 32768 BY 8BIT UV ERASABLE

TMS27PC256 32768 BY 8BIT

PROGRAMMABLE READONLY MEMORIES

SMLS256H− SEPTEMBER 1984 − REVISED NOVEMBER 1997

2

POST OFFICE BOX 1443

description (continued)

These devices are fabricated using power-saving CMOS technology for high speed and simple interface with

MOS and bipolar circuits. All inputs (including program data inputs) can be driven by Series 74 TTL circuits

without the use of external pull-up resistors. Each output can drive one Series 74 TTL circuit without external

resistors.

The data outputs are 3-state for connecting multiple devices to a common bus. The TMS27C256 and the

TMS27PC256 are pin compatible with 28-pin 256K MOS ROMs, PROMs, and EPROMs.

The TMS27C256 EPROM is offered in a dual-in-line ceramic package (J suffix) designed for insertion in

mounting-hole rows on 15,2-mm (600-mil) centers. The TMS27PC256 OTP PROM is supplied in a 32-lead

plastic leaded chip-carrier package using 1,25-mm (50-mil) lead spacing (FM suffix).

The TMS27C256 and TMS27PC256 are offered with two choices of temperature ranges of 0

°C to 70°C (JL and

FML suffixes) and − 40

°C to 85°C (JE and FME suffixes). See Table 1.

All package styles conform to JEDEC standards.

Table 1. Temperature Range Suffixes

EPROM

AND

SUFFIX FOR OPERATING

FREE-AIR TEMPERATURE RANGES

AND

OTP PROM

0

°C TO 70°C

−40

°C TO 85°C

TMS27C512-xxx

JL

JE

TMS27PC512-xxx

FML

FME

These EPROMs and OTP PROMs operate from a single 5-V supply (in the read mode), thus are ideal for use

in microprocessor-based systems. One other 13-V supply is needed for programming . All programming signals

are TTL level. These devices are programmable by the SNAP! Pulse programming algorithm. The SNAP! Pulse

For programming outside the system, existing EPROM programmers can be used. Locations can be

programmed singly, in blocks, or at random.