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Details, datasheet, quote on part number:74HCT646
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| Part: | 74HCT646 |
| Category: | Logic => Transceivers => Registered transceivers |
| Description: | 74HC/HCT646; Octal Bus Transceiver/register; 3-state;; Package: SOT101-1 (DIP24), SOT137 (SO24), SOT340-1 (SSOP24) |
| Company: | Philips Semiconductors |
| Datasheet: | Download 74HCT646 datasheet File size : 90 kB |
| Request For quote: | Find where to buy 74HCT646
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Datasheet text preview:
INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
· The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications · The IC06 74HC/HCT/HCU/HCMOS Logic Package Information · The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT646 Octal bus transceiver/register; 3-state
Product specification File under Integrated Circuits, IC06 September 1993
Philips Semiconductors
Product specification
Octal bus transceiver/register; 3-state
FEATURES · Independent register for A and B buses · Multiplexed real-time and stored data · Output capability: bus driver · ICC category: MSI GENERAL DESCRIPTION The 74HC/HCT646 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 74HC/HCT646 consist of bus transceiver circuits with 3-state outputs, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the internal registers. Data on the "A" or "B" bus will be QUICK REFERENCE DATA GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns
74HC/HCT646
clocked into the registers as the appropriate clock (CPAB and CPBA) goes to a HIGH logic level. Output enable (OE) and direction (DIR) inputs are provided to control the transceiver function. In the transceiver mode, data present at the high-impedance port may be stored in either the "A" or "B" register, or in both. The select source inputs (SAB and SBA) can multiplex stored and real-time (transparent mode) data. The direction (DIR) input determines which bus will receive data when OE is active (LOW). In the isolation mode (OE = HIGH), "A" data may be stored in the "B" register and/or "B" data may be stored in the "A" register. When an output function is disabled, the input function is still enabled and may be used to store and transmit data. Only one of the two buses, A or B, may be driven at a time. The "646" is functionally identical to the "648", but has non-inverting data paths.
TYPICAL SYMBOL tPHL/ tPLH fmax CI CPD Notes 1. CPD is used to determine the dynamic power dissipation (PD in µW): PD = CPD × VCC2 × fi + (CL × VCC2 × fo) where: fi = input frequency in MHz fo = output frequency in MHz (CL × VCC2 × fo) = sum of outputs CL = output load capacitance in pF VCC = supply voltage in V 2. For HC the condition is VI = GND to VCC For HCT the condition is VI = GND to VCC - 1.5 V ORDERING INFORMATION See "74HC/HCT/HCU/HCMOS Logic Package Information". PARAMETER propagation delay input capacitance power dissipation capacitance per channel notes 1 and 2 An, Bn to Bn, An CONDITIONS HC CL = 15 pF; VCC = 5 V 11 69 3.5 30 maximum clock frequency HCT 13 85 3.5 33 ns MHz pF pF UNIT
September 1993
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Philips Semiconductors
Product specification
Octal bus transceiver/register; 3-state
PIN DESCRIPTION PIN NO. 1 2 3 4, 5, 6, 7, 8, 9, 10, 11 12 20, 19, 18, 17, 16, 15, 14, 13 21 22 23 24 SYMBOL CPAB SAB DIR A0 to A7 GND B0 to B7 OE SBA CPBA VCC NAME AND FUNCTION
74HC/HCT646
A to B clock input (LOW-to-HIGH, edge-triggered) select A to B source input direction control input A data inputs/outputs ground (0 V) B data inputs/outputs output enable input (active LOW) select B to A source input B to A clock input (LOW-to-HIGH, edge-triggered) positive supply voltage
Fig.1 Pin configuration.
Fig.2 Logic symbol.
Fig.3 IEC logic symbol.
September 1993
3
Philips Semiconductors
Product specification
Octal bus transceiver/register; 3-state
74HC/HCT646
Fig.4 Functional diagram.
FUNCTION TABLE INPUTS (1) OE H H L L L L Notes 1. H L X = HIGH voltage level = LOW voltage level = don't care = LOW-to-HIGH level transition DIR X X L L H H CPAB H or L X X X H or L CPBA H or L X H or L X X X X X X L H SAB X X L H X X SBA DATA I/O (2) FUNCTION A0 to A7 input output input B0 to B7 input input output isolation store A and B data real-time B data to A bus stored B data to A bus real-time A data to B bus stored A data to B bus
2. The data output functions may be enabled or disabled by various signals at the OE and DIR inputs. Data input functions are always enabled, i.e., data at the bus inputs will be stored on every LOW-to-HIGH transition on the clock inputs.
September 1993
4
Philips Semiconductors
Product specification
Octal bus transceiver/register; 3-state
74HC/HCT646
Fig.5 Logic diagram.
September 1993
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