My Inquiry
My Account
onsemi DM74ALS652WMX
- Part No.:
- DM74ALS652WMX
- Manufacturer:
- onsemi
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
DM74ALS652WMX.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 24SOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,668
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
DM74ALS652WMX from Fairchild Semiconductor is an octal 3-STATE bus transceiver with integrated edge-triggered D-type registers for bidirectional data routing between two 8-bit buses (A and B). It supports real-time or stored data transfer, features totem-pole 3-STATE outputs capable of driving capacitive bus loads up to 50 pF, operates at VCC = 4.5–5.5 V, and delivers clock frequency up to 40 MHz - used in legacy industrial control backplanes and buffered I/O port interfaces.
For engineers reviewing the DM74ALS652WMX datasheet, pinout, applications, or equivalent options, key selection criteria include independent A/B register clocking (CAB/CBA), make-before-break select logic (SAB/SBA), dual-directional 3-STATE enable control (GAB/GBA), and guaranteed switching performance over 0°C to +70°C.
Technical Context
The DM74ALS652WMX implements two independent 8-bit D-type flip-flop registers clocked on the positive edge of CAB (for A-side) or CBA (for B-side), enabling synchronous storage of bus data. Its multiplexed output path uses SAB/SBA select inputs with "make before break" timing to prevent glitches during real-time ↔ stored data transitions.
Four functional modes are controlled via GAB and GBA enables: real-time A→B or B→A transfer, simultaneous A/B → internal register store, or internal register → A/B bus output. All I/O pins support TTL-compatible voltage thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and drive ±24 mA (IOL/IOH) under VCC = 5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5 V to 5.5 V - ensures compatibility with standard 5 V TTL systems without level-shifting. |
| Max Clock Frequency | 40 MHz - supports high-speed bus handshaking in legacy microprocessor peripheral interfaces. |
| Propagation Delay | 5–30 ns (tPLH/tPHL) - guarantees sub-35 ns worst-case path timing for 50 pF bus loads. |
| IOL / IOH | 24 mA / −15 mA - drives standard TTL fan-out (up to 20 loads) directly without external buffers. |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade industrial control and instrumentation environments. |
| Input Clamp Voltage | −1.2 V - protects against negative transient spikes on control or I/O lines. |
| Output Disable Time | 1–16 ns (tPHZ/tPLZ) - enables fast bus arbitration and multi-master contention resolution. |
Pinout & Package
DM74ALS652WMX is housed in a 24-lead SOIC package (JEDEC MS-013, 0.300" wide, Package Number M24B), with 1.27 mm lead pitch and body dimensions 15.4 mm × 7.5 mm × 2.3 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1–A8 | Bus A Data I/O | 8-bit bidirectional data port connected to System Bus A; functions as input (store) or output (drive) depending on GAB/SAB state. |
| B1–B8 | Bus B Data I/O | 8-bit bidirectional data port connected to System Bus B; mirrors A-side functionality with independent control. |
| CAB | Register A Clock | Positive-edge-triggered clock input controlling storage of A-bus data into A register. |
| CBA | Register B Clock | Positive-edge-triggered clock input controlling storage of B-bus data into B register. |
| SAB | Select A-to-B Path | HIGH selects stored A-register data for output to B bus; LOW passes real-time A-bus data. |
| SBA | Select B-to-A Path | HIGH selects stored B-register data for output to A bus; LOW passes real-time B-bus data. |
| GAB | Enable A→B Transfer | Active-low control enabling output drivers from A to B; disables A-side outputs when HIGH. |
| GBA | Enable B→A Transfer | Active-low control enabling output drivers from B to A; disables B-side outputs when HIGH. |
| VCC | Power Supply | +5 V supply pin; decoupling required within 1 cm due to fast switching currents. |
| GND | Ground Reference | Signal and power ground reference for all logic and I/O operations. |
Key Features
| Feature | Design Value |
|---|---|
| Edge-triggered dual registers | Independent CAB/CBA clocks allow asynchronous capture of A- and B-bus data without cross-talk or race conditions. |
| Make-before-break select logic | SAB/SBA transition eliminates output glitches during real-time ↔ stored data mode switching - critical for glitch-free bus arbitration. |
| Four-mode operation via GAB/GBA | Enables isolated bus hold, bidirectional real-time transfer, parallel store, and registered broadcast - reducing external logic count by ≥3 gates per function. |
| Totem-pole 3-STATE outputs | Direct bus-line drive capability (24 mA sink / 15 mA source) eliminates need for pull-up resistors or interface buffers in 5 V TTL systems. |
| Guaranteed AC specs at 50 pF | Switching parameters validated at realistic load capacitance - ensures timing predictability in actual PCB trace environments. |
Applications
| Industrial Backplane Interface | Microprocessor I/O Port Expansion |
|---|---|
Use Scenario: Interfacing multiple 8-bit peripheral modules (ADCs, DACs, GPIO) to a shared CPU bus in programmable logic controllers. IC Role / Device Role / Timing Role: Bidirectional registered buffer isolating CPU address/data bus from peripheral response timing variations. Use Value: Enables deterministic read/write cycles using stored register values while allowing real-time monitoring via SAB/SBA toggle - eliminating wait-state insertion. | Use Scenario: Expanding Z80 or 8085-based system I/O with synchronized handshake signals and local data staging. IC Role / Device Role / Timing Role: Dual-function I/O port: stores CPU writes in A register for peripheral consumption, captures peripheral reads in B register for CPU fetch. Use Value: Eliminates need for separate latch + transceiver ICs - reduces component count and board area by 2× in space-constrained embedded designs. |
| Legacy Test Equipment Bus Controller | Digital Signal Acquisition Buffer |
Use Scenario: Managing signal routing between DMM front-end digitizers, calibration references, and GPIB controller in automated test systems. IC Role / Device Role / Timing Role: Registered bus switch synchronizing analog-to-digital conversion triggers with digital control bus updates. Use Value: Prevents metastability during trigger propagation by capturing conversion-ready flags in CBA-clocked B register before GPIB transmission. | Use Scenario: Capturing parallel-output sensor data (e.g., 8-bit optical encoders) and forwarding to FPGA-based processing pipeline with precise timing alignment. IC Role / Device Role / Timing Role: Input register (B-side) latches raw sensor samples on CBA edge; output transceiver (A-side) forwards to FPGA on demand via GAB control. Use Value: Decouples sensor sampling rate (up to 40 MHz) from FPGA processing latency - avoids sample loss during burst transfers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal registered transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ALS652N | Same logic function and pinout; PDIP package (N24C), higher θJA (44.5°C/W), no tape-and-reel option without suffix. | Preferred for through-hole prototyping or legacy rework where SOIC reflow is unavailable. | Select SN74ALS652N only when manual soldering or socket-based testing is required. |
| 74F652PC | Fast TTL variant: faster tPLH/tPHL (3–12 ns), higher ICC (95 mA typ), narrower VCC range (4.75–5.25 V), no make-before-break select logic. | Suitable for speed-critical paths but requires tighter supply regulation and lacks glitch-free mode switching. | Choose 74F652PC only when propagation delay <12 ns is mandatory and bus arbitration glitches are mitigated externally. |
Compared with SN74ALS652N and 74F652PC, DM74ALS652WMX offers optimal balance of SOIC manufacturability, guaranteed 50 pF timing, and intrinsic glitch suppression - making it the preferred choice for new production of industrial backplane and I/O expansion designs requiring long-term supply stability.
Availability
DM74ALS652WMX is available at Aetrix Electronics and suitable for industrial backplane interfaces, microprocessor I/O port expansion, legacy test equipment bus controllers, and digital signal acquisition buffers requiring stable component supply across extended product lifecycles.
Supply support for DM74ALS652WMX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in analog and mixed-signal ICs, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed in industrial and automotive systems.
The DM74ALS652WMX belongs to Fairchild's advanced Schottky TTL (ALS) logic family, designed specifically for high-speed, low-power registered bus interfacing in noise-immune industrial control and instrumentation applications.
FAQ
What is the primary function of the DM74ALS652WMX in a digital system?
The DM74ALS652WMX serves as an octal 3-STATE bus transceiver with integrated edge-triggered D-type registers, enabling bidirectional data flow between two 8-bit buses (A and B) with selectable real-time or stored data routing. Its dual-register architecture allows independent capture and synchronized release of bus data, making DM74ALS652WMX ideal for buffered I/O ports, bus isolation, and timing-critical peripheral interfaces in legacy 5 V TTL systems.
Does the DM74ALS652WMX support simultaneous clocking of both A and B registers?
Yes - the DM74ALS652WMX supports simultaneous clocking of both registers only when SAB and SBA are LOW (real-time mode); however, when SAB and SBA are HIGH (stored-data mode), clocks must be staggered to avoid metastability, as specified in Note 2 of the function table. This behavior is inherent to DM74ALS652WMX's internal multiplexer timing and must be observed in synchronous design implementations.
What package type is used for the DM74ALS652WMX, and is it RoHS-compliant?
The DM74ALS652WMX is supplied in a 24-lead SOIC package (JEDEC MS-013, 0.300" wide, Package Number M24B). As a legacy device manufactured prior to 2006, DM74ALS652WMX is not RoHS-compliant and contains lead in solder and die attach; however, it remains available under exemption for industrial repair and legacy system continuity per EU Directive 2011/65/EU Annex III.
How does the "make before break" feature of the DM74ALS652WMX improve system reliability?
The "make before break" configuration of the SAB and SBA select controls ensures that the new data path is established before the old one is disabled - preventing momentary bus floating or undefined states during mode transitions. This eliminates output glitches that could corrupt data or trigger false interrupts in systems relying on clean bus handshaking, a key reliability advantage built into DM74ALS652WMX's internal logic design.
Can the DM74ALS652WMX operate with a 3.3 V supply?
No - the DM74ALS652WMX is specified only for VCC = 4.5 V to 5.5 V and is incompatible with 3.3 V logic families. Its input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and output drive strength (24 mA sink) are optimized for 5 V TTL signaling. Attempting to power DM74ALS652WMX at 3.3 V will result in non-functional outputs, excessive ICC, or permanent damage due to internal biasing constraints.
DM74ALS652WMX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74ALS
- Package/Case:
- 24-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Transceiver, Non-Inverting
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 15mA, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SOP
DM74ALS652WMX FAQ
1.How can I place an order for DM74ALS652WMX through Aetrix?
Please submit a Request for Quotation (RFQ) for DM74ALS652WMX on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for DM74ALS652WMX reliable?
The price and inventory of DM74ALS652WMX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DM74ALS652WMX is usually 5 days.
3.What payment methods are accepted for DM74ALS652WMX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DM74ALS652WMX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DM74ALS652WMX?
DM74ALS652WMX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DM74ALS652WMX order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for DM74ALS652WMX?
For technical support, including DM74ALS652WMX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DM74ALS652WMX requirements.
6.How does Aetrix verify that DM74ALS652WMX is sourced from the original manufacturer or authorized distributors?
All DM74ALS652WMX products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that DM74ALS652WMX meets industry standards.
7.What is the process for return or replacement of DM74ALS652WMX?
All DM74ALS652WMX units undergo pre-shipment inspection (PSI). If there is an issue with DM74ALS652WMX, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The DM74ALS652WMX part is unused and in its original packaging.
Return procedure for DM74ALS652WMX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
DM74ALS652WMX Tags
-
SN74LVC1G17DBVR
Texas Instruments
-
SN74LVC1G07DCKR
Texas Instruments
-
SN74LVC1G17DCKR
Texas Instruments
-
SN74LVC1G07DBVR
Texas Instruments
-
SN74LVC1G125DCKR
Texas Instruments
-
SN74AHCT1G126DBVR
Texas Instruments
-
SN74LVC1G125DBVR
Texas Instruments
-
SN74AHCT1G125DBVR
Texas Instruments
-
SN74LVC2G17DBVR
Texas Instruments
-
SN74LVC2G07DCKR
Texas Instruments
-
SN74LVC1G34DCKR
Texas Instruments
-
SN74LVC2G17DCKR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
