This Product Selection Guide contains information to help select products in the Latches category on DigiKey.com
Latches are elementary digital memory devices similar to flip-flops, but different in that the retained logic state can change at any time a latch enable (or similarly named) signal is in a valid logic state. Latches described as “transparent” further allow the device outputs to reflect the current state of the inputs while the latch enables the signal to be valid, as opposed to changing the state only when the retained state has been fixed.
SelectionCharacteristics
Logic Type: Describes the logic functions used within the circuit.
Circuit: Describes the input to output ratio latch function(s).
Output Type: Indicates the type of electrical signal the device provides, such as complimentary, differential, or non-inverted.
Voltage - Supply: Typically represented by a range, this indicates the low and high voltage limits which one can expect standard operation. Voltages outside this range may damage the device and other system components.
Independent Circuits: Indicates the number of identical functional elements that are incorporated into a device. While the inputs and outputs of each element are addressable separately, all elements typically share a common power supply connection.
Delay Time - Propagation: Characterizes the time delay between the assertion of device input and the appearance of the resulting change in device output, subject to the indicated supply voltage and load capacitance conditions.
Current - Output High, Low: The maximum recommended current flow through a device’s output pin. Multiple values reflect ratings that differ depending on the direction of the current flow.
Operating Temperature: Recommended operating temperature, typically given in a range or as a maximum. Exceeding these temperatures may affect performance or damage the device and other system components.
Mounting Type: Indicates how the device is attached.
Package / Case: Indicates the type of protective case used on an electronic component to allow easy handling, installation, and protection. This selection was determined to be the closest industry standard applicable to the suppliers device packaging. Typically it is best to check the actual dimensions from the datasheet rather than depend on this terminology when designing your circuit.
Supplier Device Package: This is what the manufacturer calls the package of this device. They are manufacturer specific. It is typically best to use the actual dimensions from the datasheets rather than to go by this terminology when designing your circuit.
ProductExamples
20-VFQFN Exposed Pad D-Type Transparent Latch
| MFR PART # | 74AHC573BQ,115 |
|---|---|
| DIGI-KEY PART # | 1727-4471-2-ND - Tape & Reel (TR) |
| MANUFACTURER | Nexperia USA Inc. |
| DESCRIPTION | D-Type Transparent Latch 1 Channel 8:8 IC Tri-State 20-DHVQFN (4.5x2.5) |
| DATASHEET | Click Here |
20-SOIC D-Type Transparent Latch
| MFR PART # | SN74AHC573DWR |
|---|---|
| DIGI-KEY PART # | 296-4612-2-ND - Tape & Reel (TR) |
| MANUFACTURER | Texas Instruments |
| DESCRIPTION | D-Type Transparent Latch 1 Channel 8:8 IC Tri-State 20-SOIC |
| DATASHEET | Click Here |
MediaLinks
Blogs
Understanding Standard Character LCD Communication Protocol
How to Add More Digital GPIO Pins to Arduino Projects using Shift Registers