Document
74AHCT594
8-BIT SHIFT REGISTER WITH 8-BIT OUTPUT REGISTER
Description
The 74AHCT594 is an advanced high speed CMOS device that is designed to be pin compatable with 74LS low power Schottky types.
An eight bit shift register accepts data from the serial input (DS) on each positive transition of the shift register clock (SHCP). When asserted low the shift register reset function (SHR) sets all shift register values to zero and is independent of all clocks. Also when asserted low, the storage register reset function (STR) sets all shift register values to zero and is independent of all clocks.
Data from the input serial shift register is placed in the output register with a rising pulse on the storages resister clock (STCP). The storage resister includes output Q7S which is used for cascading information between devices. As the information moves into the storage register, it is asserted on the push-pull outputs Q0-Q7.
All registers capture data on rising edge and change output on the falling edge. If both clocks are connected together, the input shift register is always one clock cycle ahead of the output register.
Pin Assignments
Q1 Q2 Q3 Q4 Q5 Q6 Q7 GND
( Top View )
1 16 2 15 3 14 4 13 5 12 6 11 7 10 89
Vcc Q0 DS
STR STCP SHCP SHR Q7S
SO-16 / TSSOP-16
Features
Wide Supply Voltage Range from 4.5V to 5.5V Sinks or sources 8mA at VCC = 4.5V CMOS low power consumption Schmitt Trigger Action at All Inputs Inputs accept up to 6.0V ESD Protection Tested per JESD 22
Exceeds 200-V Machine Model (A115-A) Exceeds 2000-V Human Body Model (A114-A) Exceeds 1000-V Charged Device Model (C101C) Latch-Up Exceeds 250mA per JESD 78, Class II Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3)
Applications
General Purpose Logic Serial to Parallel Data conversion Capture and hold data for extended periods of time. Allow simple serial bit streams from a microcontroller to control as
many peripheral lines as needed. Wide array of products such as:
Computer Peripherals Appliances Industrial control
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free. 3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
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74AHCT594
Document number: DS35485 Rev. 2 - 2
1 of 10 www.diodes.com
June 2013
© Diodes Incorporated
Pin Descriptions
Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Pin Name Q1 Q2 Q3 Q4 Q5 Q6 Q7 GND Q7S SHR
SHCP STCP STR
DS Q0 Vcc
Description Parallel Data Output 1 Parallel Data Output 2 Parallel Data Output 3 Parallel Data Output 4 Parallel Data Output 5 Para.