Logic - Latches

Category Introduction

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 enable signal is valid, as opposed to changing state only when the retained state has been fixed.

Product List

330 Items

Mfr Part #	Quantity Available	UnitPrice	Series	Packaging	Product Status	Logic Type	Circuit	Output Type	Voltage - Supply	Independent Circuits	Delay Time - Propagation	Current - Output High, Low	Operating Temperature	Mounting Type	Package / Case	Supplier Device Package
74HC573PW,118 IC LATCH OCTAL D 3STATE 20TSSOP Nexperia USA Inc.	891	$0.61	74HC	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	2V ~ 6V	1	14ns	7.8mA, 7.8mA	-40°C ~ 125°C	Surface Mount	20-TSSOP (0.173", 4.40mm Width)	20-TSSOP
74HC573PW,112 IC LATCH TRANSP OCT D 20TSSOP Nexperia USA Inc.	4,042	$0.15	74HC	Bulk	Obsolete	D-Type Transparent Latch	8:8	Tri-State	2V ~ 6V	1	14ns	7.8mA, 7.8mA	-40°C ~ 125°C	Surface Mount	20-TSSOP (0.173", 4.40mm Width)	20-TSSOP
74HC573D,653 IC LATCH OCTAL D 3STATE 20SOIC Nexperia USA Inc.	1,283	$0.67	74HC	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	2V ~ 6V	1	14ns	7.8mA, 7.8mA	-40°C ~ 125°C	Surface Mount	20-SOIC (0.295", 7.50mm Width)	20-SO
74HC573D,652 IC LATCH OCTAL D 3STATE 20SOIC Nexperia USA Inc.	1,347	$0.69	74HC	Tube	Obsolete	D-Type Transparent Latch	8:8	Tri-State	2V ~ 6V	1	14ns	7.8mA, 7.8mA	-40°C ~ 125°C	Surface Mount	20-SOIC (0.295", 7.50mm Width)	20-SO
SN74AHC373PW IC OCTAL TRANSP D LATCH 20-TSSOP Texas Instruments	234	$1.29	74AHC	Tube	Active	D-Type Transparent Latch	8:8	Tri-State	2V ~ 5.5V	1	1ns	8mA, 8mA	-40°C ~ 85°C	Surface Mount	20-TSSOP (0.173", 4.40mm Width)	20-TSSOP
SN74HCT573PWR IC LATCH OCT TRANSP D 20TSSOP Texas Instruments	311	$0.57	74HCT	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	4.5V ~ 5.5V	1	25ns	6mA, 6mA	-40°C ~ 85°C	Surface Mount	20-TSSOP (0.173", 4.40mm Width)	20-TSSOP
74HCT259D,653 IC ADDRESSABLE LATCH 8BIT 16SOIC Nexperia USA Inc.	440	$0.64	74HCT	Tape & Reel (TR)	Active	D-Type, Addressable	1:8	Standard	4.5V ~ 5.5V	1	20ns	4mA, 4mA	-40°C ~ 125°C	Surface Mount	16-SOIC (0.154", 3.90mm Width)	16-SO
74HCT259D,652 IC 8BIT ADDRESSABLE LATCH 16SOIC Nexperia USA Inc.	503	$0.60	74HCT	Tube	Obsolete	D-Type, Addressable	1:8	Standard	4.5V ~ 5.5V	1	20ns	4mA, 4mA	-40°C ~ 125°C	Surface Mount	16-SOIC (0.154", 3.90mm Width)	16-SO
HEF4043BT,653 IC R/S LATCH 3-STATE QUAD 16SOIC Nexperia USA Inc.	405	$0.60	4000B	Tape & Reel (TR)	Active	S-R Latch	1:1	Tri-State	3V ~ 15V	4	15ns	3mA, 3mA	-40°C ~ 85°C	Surface Mount	16-SOIC (0.154", 3.90mm Width)	16-SO
74HC573BQ,115 IC OCTAL D TRANSP LATCH 20DHVQFN Nexperia USA Inc.	1,444	$0.63	74HC	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	2V ~ 6V	1	14ns	7.8mA, 7.8mA	-40°C ~ 125°C	Surface Mount	20-VFQFN Exposed Pad	20-DHVQFN (4.5x2.5)
74HC373D,653 IC LATCH TRANSP OCT D 3ST 20SOIC Nexperia USA Inc.	483	$0.67	74HC	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	2V ~ 6V	1	12ns	7.8mA, 7.8mA	-40°C ~ 125°C	Surface Mount	20-SOIC (0.295", 7.50mm Width)	20-SO
CD74HCT259M96 IC 8BIT ADDRESSABLE LATCH 16SOIC Texas Instruments	1,431	$0.63	74HCT	Tape & Reel (TR)	Active	D-Type, Addressable	1:8	Standard	4.5V ~ 5.5V	1	16ns	4mA, 4mA	-55°C ~ 125°C	Surface Mount	16-SOIC (0.154", 3.90mm Width)	16-SOIC
MC74LCX573DTR2G IC LATCH OCT 3ST LV CMOS 20TSSOP onsemi	497	$0.87	74LCX	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	2V ~ 3.6V	1	1.5ns	24mA, 24mA	-55°C ~ 125°C	Surface Mount	20-TSSOP (0.173", 4.40mm Width)	20-TSSOP
SN74HC373NSR IC OCTAL TRANSP LATCH 20SO Texas Instruments	56	$0.77	74HC	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	2V ~ 6V	1	15ns	7.8mA, 7.8mA	-40°C ~ 85°C	Surface Mount	20-SOIC (0.209", 5.30mm Width)	20-SO
SN74HCT573NSR IC LATCH OCT TRANSP D 20SO Texas Instruments	1,130	$0.77	74HCT	Tape & Reel (TR)	Active	D-Type Transparent Latch	8:8	Tri-State	4.5V ~ 5.5V	1	25ns	6mA, 6mA	-40°C ~ 85°C	Surface Mount	20-SOIC (0.209", 5.30mm Width)	20-SO
74LVC16373ADGG,518 IC TRANSPARENT LATCH 16B 48TSSOP Nexperia USA Inc.	370	$0.00	74LVC	Tape & Reel (TR)	Obsolete	D-Type Transparent Latch	8:8	Tri-State	2.7V ~ 3.6V	2	1ns	24mA, 24mA	-40°C ~ 125°C	Surface Mount	48-TFSOP (0.240", 6.10mm Width)	48-TSSOP
74LVT16373ADGG,518 IC 16BIT TRANSP LATCH D 48TSSOP Nexperia USA Inc.	230	$0.00	74LVT	Tape & Reel (TR)	Obsolete	D-Type Transparent Latch	8:8	Tri-State	2.7V ~ 3.6V	2	2.1ns	32mA, 64mA	-40°C ~ 85°C	Surface Mount	48-TFSOP (0.240", 6.10mm Width)	48-TSSOP
74LVT16373ADGG,112 IC 16BIT TRANSP LATCH D 48TSSOP Nexperia USA Inc.	354	$0.00	74LVT	Tube	Obsolete	D-Type Transparent Latch	8:8	Tri-State	2.7V ~ 3.6V	2	2.1ns	32mA, 64mA	-40°C ~ 85°C	Surface Mount	48-TFSOP (0.240", 6.10mm Width)	48-TSSOP
74LVT16373ADGG,512 IC 16BIT TRANSP LATCH D 48TSSOP Nexperia USA Inc.	373	$0.00	74LVT	Tube	Obsolete	D-Type Transparent Latch	8:8	Tri-State	2.7V ~ 3.6V	2	2.1ns	32mA, 64mA	-40°C ~ 85°C	Surface Mount	48-TFSOP (0.240", 6.10mm Width)	48-TSSOP
CD4044BDW IC QUAD NAND R/S LATCH 16-SOIC Texas Instruments	321	$0.53	4000B	Tube	Active	S-R Latch	1:1	Tri-State	3V ~ 18V	4	50ns	6.8mA, 6.8mA	-55°C ~ 125°C	Surface Mount	16-SOIC (0.295", 7.50mm Width)	16-SOIC

About Latches

What are Latches?

Latches

Latches are fundamental building blocks in digital electronics, serving as bistable devices that store one bit of data. They operate by maintaining a stable output state until an input signal prompts a change. Essentially, latches are memory elements that can hold a binary value (0 or 1) and are controlled by input signals, typically referred to as "set" and "reset". The basic operating principle of a latch involves feedback loops that ensure the output remains constant until explicitly altered by an input signal, making them crucial for temporary data storage and synchronization tasks in digital systems.

Types of Latches

SR Latch

The SR (Set-Reset) latch is the simplest form of a latch, constructed using two cross-coupled NOR or NAND gates. It has two inputs, labeled S (set) and R (reset), and two outputs, Q and Q'. The SR latch is used to store a single bit of data, where the set input stores a logic high (1) and the reset input stores a logic low (0). However, it has an undefined state when both inputs are high, which limits its applications.

D Latch

The D (Data or Delay) latch addresses the undefined state issue of the SR latch by ensuring that only one input is active at a time. It has a single data input and a clock input. The D latch captures the input value when the clock signal is active and holds it until the clock signal changes. This makes it ideal for data synchronization and temporary storage in digital circuits.

JK Latch

The JK latch is an enhancement of the SR latch, designed to eliminate the undefined state. It has two inputs, J and K, and operates similarly to the SR latch but with the added feature that when both inputs are high, the output toggles. This characteristic makes the JK latch versatile for applications requiring toggling operations.

T Latch

The T (Toggle) latch is a simplified version of the JK latch, with a single input that toggles the output state with each clock pulse. It is commonly used in counters and frequency dividers, where a consistent toggling action is required.

How to choose Latches?

When selecting a latch for your application, consider the following key parameters:

Type of Latch: Choose between SR, D, JK, or T latches based on the specific application requirements and desired functionality.
Speed: Evaluate the maximum operating frequency to ensure it meets the speed requirements of your system.
Power Consumption: Consider the power efficiency, especially for battery-operated devices.
Package Type: Ensure compatibility with your circuit board design and space constraints.
Temperature Range: Verify that the latch can operate within the environmental conditions of your application.

To evaluate product quality and reliability, review supplier datasheets, customer reviews, and industry certifications. Consider environmental factors such as temperature, humidity, and electromagnetic interference, and ensure proper installation to avoid signal integrity issues.

Applications of Latches

Computing and Data Storage

In the computing industry, latches are integral to memory devices, registers, and flip-flops, enabling data storage and retrieval. They help maintain data integrity and synchronization across various processing units.

Telecommunications

Latches are used in telecommunications for signal processing and data buffering. They ensure that data packets are correctly synchronized and transmitted without errors, enhancing communication reliability.

Consumer Electronics

In consumer electronics, latches play a role in controlling display screens, managing power states, and interfacing with user inputs. They contribute to the seamless operation of devices like smartphones and televisions.

Automotive Industry

The automotive sector utilizes latches in control systems for engine management, safety features, and infotainment systems. They ensure reliable data handling and processing in critical vehicle functions.

Industrial Automation

In industrial automation, latches are employed in control systems for machinery and robotics. They facilitate precise control and coordination of automated processes, enhancing efficiency and productivity.