Philips Semiconductors Linear Products

Product specification

NE590/591

Addressable peripheral drivers

August 31, 1994

519

PIN DESIGNATION

590

PIN NO.

591

PIN NO.

SYMBOL

NAME & FUNCTION

1-3

2-4

A 3-bit binary address on these pins defines which of the 8 output latches is to receive the data.

4-7,

9-12

5-8,

11-14

The 8 device outputs. The NE590 has open-collector Darlington outputs. The NE591 has open emit-

ter-follower outputs.

13

15

D

The data input. When the chip is enabled, this data bit is transferred to the defined output such that:

“1” turns output switch “ON”

“0” turns output switch “OFF”

Thus in logic terms, the NE590 inverts data to the relevant output. The NE591 retains true data at the

output.

14

16

CE

The chip enable. When this input is low, the output latches will accept data. When CE goes high, all

outputs will retain their existing state regardless of address or data input conditions.

15

17

CLR

The clear input. When CLR goes low all output switches are turned “OFF”. On the NE590, a high

data input will override the clear function on the addressed latch. On the NE591, CLR low will over-

ride any other condition.

-

1

CS

The chip select input provides for an additional level of address decoding.

-

10

BLOCK DIAGRAM

LATCH

LATCH

LATCH

LATCH

LATCH

LATCH

LATCH

LATCH

CLR

CE

A0

A1

A2

D

1–OF–8

DECODER

COMTROL

GATE

VCC

NE590

Q0

Q1

Q2

Q3

Q4

Q5

Q6

Q7

cs

(NE51 ONLY)

INPUT STAGE

NE591

OUTPUT STAGE