74ACT843SC Fairchild Semiconductor, 74ACT843SC Datasheet - Page 2

• Manufacturer Part Number: 74ACT843SC
• Description: IC LATCH TRANSPARENT 9BIT 24SOIC
• Manufacturer: Fairchild Semiconductor
• Series: 74ACTr

Specifications of 74ACT843SC

• Logic Type: D-Type Transparent Latch
• Circuit: 9:9
• Output Type: Tri-State
• Voltage - Supply: 4.5 V ~ 5.5 V
• Independent Circuits: 1
• Delay Time - Propagation: 5.5ns
• Current - Output High, Low: 24mA, 24mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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Functional Description
The ACT843 consists of nine D-type latches with 3-STATE
outputs. The flip-flops appear transparent to the data when
Latch Enable (LE) is HIGH. This allows asynchronous
operation, as the output transition follows the data in transi-
tion. On the LE HIGH-to-LOW transition, the data that
meets the setup times is latched. Data appears on the bus
when the Output Enable (OE) is LOW. When OE is HIGH,
the bus output is in the high impedance state. In addition to
Function Tables
H
L
X
Z
NC
Logic Diagram
LOW Voltage Level
High Impedance
HIGH Voltage Level
Immaterial
No Change
CLR
H
H
H
H
H
H
H
H
L
L
L
PRE
H
H
H
H
H
H
H
H
L
L
L
Inputs
OE
H
H
H
H
H
L
L
L
L
L
L
LE
H
H
H
H
X
X
X
L
L
L
L
D
H
X
H
X
X
X
X
X
X
L
L
Internal
2
NC
NC
Q
H
H
H
H
H
L
L
L
L
the LE and OE pins, the ACT843 has a Clear (CLR) pin
and a Preset (PRE) pin. These pins are ideal for parity bus
interfacing in high performance systems. When CLR is
LOW, the outputs are LOW if OE is LOW. When CLR is
HIGH, data can be entered into the latch. When PRE is
LOW, the outputs are HIGH if OE is LOW. Preset overrides
CLR.
Outputs
NC
H
H
Z
Z
Z
L
L
Z
Z
O
H
High Z
High Z
Latched
Transparent
Transparent
Latched
Preset
Clear
Preset
Clear/High Z
Preset/High Z
Function