NXP Semiconductors
74HC595; 74HCT595
8-bit serial-in, serial or parallel-out shift register with output latches;
3-state
6.2 Pin description
Table 2.
Symbol
Q1
Q2
Q3
Q4
Q5
Q6
Q7
GND
Q7S
MR
SHCP
STCP
OE
DS
Q0
V
CC
Pin description
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Description
parallel data output 1
parallel data output 2
parallel data output 3
parallel data output 4
parallel data output 5
parallel data output 6
parallel data output 7
ground (0 V)
serial data output
master reset (active LOW)
shift register clock input
storage register clock input
output enable input (active LOW)
serial data input
parallel data output 0
supply voltage
7. Functional description
Table 3.
Control
SHCP STCP OE
X
X
X
X
X
X
L
L
H
L
MR
L
L
L
H
Function table
Input
DS
X
X
X
H
Output
Q7S
L
L
L
Q6S
Qn
NC
L
Z
NC
a LOW-level on MR only affects the shift registers
empty shift register loaded into storage register
shift register clear; parallel outputs in high-impedance OFF-state
logic HIGH-level shifted into shift register stage 0. Contents of all
shift register stages shifted through, e.g. previous state of stage 6
(internal Q6S) appears on the serial output (Q7S).
contents of shift register stages (internal QnS) are transferred to
the storage register and parallel output stages
contents of shift register shifted through; previous contents of the
shift register is transferred to the storage register and the parallel
output stages
Function
X
L
L
H
H
X
X
NC
Q6S
QnS
QnS
[1]
H = HIGH voltage state;
L = LOW voltage state;
= LOW-to-HIGH transition;
X = don’t care;
NC = no change;
Z = high-impedance OFF-state.
74HC_HCT595
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© NXP B.V. 2011. All rights reserved.
Product data sheet
Rev. 6 — 12 December 2011
5 of 24
PHILIPS [ NXP SEMICONDUCTORS ]
