74HC194D: 4-bit bidirectional universal shift register

The 74HC/HCT194 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A.

The functional characteristics of the 74HC/HCT194 4-bit bidirectional universal shift registers are indicated in the logic diagram and function table. The registers are fully synchronous.

The '194' design has special features which increase the range of application. The synchronous operation of the device is determined by the mode select inputs (S0, S1).

As shown in the mode select table, data can be entered and shifted from left to right (Q0→ Q1→ Q2, etc.) or, right to left (Q3→ Q2→ Q1, etc.) or parallel data can be entered, loading all 4 bits of the register simultaneously. When both S0 and S1 are LOW, existing data is retained in a hold ('do nothing') mode. The first and last stages provide D-type serial data inputs (DSR, DSL) to allow multistage shift right or shift left data transfers without interfering with parallel load operation.

Mode select and data inputs are edge-triggered, responding only to the LOW-to-HIGH transition of the clock (CP). Therefore, the only timing restriction is that the mode control and selected data inputs must be stable one set-up time prior to the positive transition of the clock pulse.

The four parallel data inputs (D0 to D3) are D-type inputs. Data appearing on the D0 to D3 inputs, when S0 and S1 are HIGH, is transferred to the Q0 to Q3 outputs respectively, following the next LOW-to-HIGH transition of the clock. When LOW, the asynchronous master reset (MR) overrides all other input conditions and forces the Q outputs LOW.

The '194' is similar in operation to the '195' universal shift register, with added features of shift-left without external connections and hold ('do nothing') modes of operation.

sot109-1_3d
Data Sheets (1)
Name/DescriptionModified Date
4-bit bidirectional universal shift register (REV 1.0) PDF (76.0 kB) 74HC_HCT194_CNV [English]01 Dec 1990
Application Notes (2)
Name/DescriptionModified Date
Live Insertion Aspects of Philips Logic Families (REV 1.0) PDF (73.0 kB) AN252 [English]13 Mar 2013
Pin FMEA 74HC/74HCT family (REV 1.0) PDF (51.0 kB) AN11044 [English]16 Mar 2011
Users Guides (1)
Name/DescriptionModified Date
HC/T User Guide (REV 1.0) PDF (508.0 kB) HCT_USER_GUIDE [English]01 Nov 1997
Package Information (1)
Name/DescriptionModified Date
plastic small outline package; 16 leads; body width 3.9 mm (REV 1.0) PDF (192.0 kB) SOT109-1 [English]08 Feb 2016
Supporting Information (2)
Name/DescriptionModified Date
Footprint for reflow soldering (REV 1.0) PDF (9.0 kB) SO-SOJ-REFLOW [English]08 Oct 2009
Footprint for wave soldering (REV 1.0) PDF (8.0 kB) SO-SOJ-WAVE [English]08 Oct 2009
Ordering Information
ProductStatusFamilyVCC (V)FunctionDescriptionLogic switching levelsOutput drive capability (mA)Package versiontpd (ns)fmax (MHz)No of bitsPower dissipation considerationsTamb (Cel)Rth(j-a) (K/W)Ψth(j-top) (K/W)Rth(j-c) (K/W)Package nameNo of pins
74HC194DActiveHC(T)2.0 - 6.0Shift registers4-bit bidirectional parallel or serial-in/parallel-out shift registerCMOS+/- 5.2SOT109-1141024low-40~125783.236SO1616
Package Information
Product IDPackage DescriptionOutline VersionReflow/Wave SolderingPackingProduct StatusPart NumberOrdering code(12NC)MarkingChemical ContentRoHS / Pb Free / RHFLeadFree Conversion DateEFRIFR(FIT)MTBF(hour)MSLMSL LF
74HC194DSOT109-1SO-SOJ-REFLOW SO-SOJ-WAVE
SO-SOJ-REFLOW SO-SOJ-WAVE
Reel 13" Q1/T1 CECCActive74HC194D,653 (9337 140 90653)74HC194D74HC194Dweek 6, 200484.96.621.51E811
Bulk Pack, CECCActive74HC194D,652 (9337 140 90652)74HC194D74HC194Dweek 6, 200484.96.621.51E811
4-bit bidirectional universal shift register 74HC194DB
Live Insertion Aspects of Philips Logic Families 74HC_T_245_Q100
Pin FMEA 74HC/74HCT family 74HC_T_597_Q100
HC/T User Guide 74HCU04PW
plastic small outline package; 16 leads; body width 3.9 mm NPIC6C596A_Q100
Footprint for reflow soldering NPIC6C596A_Q100
Footprint for wave soldering NPIC6C596A_Q100
SA614A