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74HC(T)194: 4-bit bidirectional universal shift register (Based on PIP 74HC_HCT194_CNV)

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.

74HC_T_194: Product Block Diagram

Outline 3d SOT338-1

Data Sheets (1)

Application Notes (2)

Users Guides (1)

Package Information (2)

Supporting Information (4)

Ordering Information

Package Information

Product ID	Package Description	Outline Version	Reflow/Wave Soldering	Packing	Product Status	Part NumberOrdering code(12NC)	Marking	Chemical Content	RoHS / Pb Free / RHF	LeadFree Conversion Date	EFR	IFR(FIT)	MTBF(hour)	MSL	MSL LF
74HC194DB		SOT338-1	SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE	Reel 13" Q1/T1	Active	74HC194DB,118 (9351 897 40118)	HC194	74HC194DB		week 12, 2005	84.9	6.62	1.51E8	1	1
				Bulk Pack	Active	74HC194DB,112 (9351 897 40112)	HC194	74HC194DB		week 12, 2005	84.9	6.62	1.51E8	1	1
74HC194D		SOT109-1	SO-SOJ-REFLOW SO-SOJ-WAVE SO-SOJ-REFLOW SO-SOJ-WAVE	Reel 13" Q1/T1 CECC	Active	74HC194D,653 (9337 140 90653)	74HC194D	74HC194D		week 6, 2004	84.9	6.62	1.51E8	1	1
				Bulk Pack, CECC	Active	74HC194D,652 (9337 140 90652)	74HC194D	74HC194D		week 6, 2004	84.9	6.62	1.51E8	1	1