My Inquiry
My Account
Texas Instruments SN74CBT3257D
- Part No.:
- SN74CBT3257D
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74CBT3257D.pdf
- Description:
- IC MUX/DEMUX 4 X 2:1 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,301
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74CBT3257D from Texas Instruments is a 4-bit 1-of-2 FET multiplexer/demultiplexer in SOIC-16 package, featuring 5 Ω on-state resistance, TTL-compatible control inputs (VIH = 2 V, VIL = 0.8 V), and operation across −40°C to 85°C. It routes bidirectional data between A-port and either B1 or B2 ports under select (S) and output-enable (OE) control, used in high-speed bus switching and level translation applications.
For engineers reviewing the SN74CBT3257D datasheet, SN74CBT3257D pinout, SN74CBT3257D application, or SN74CBT3257D equivalent, key selection criteria include on-resistance matching, propagation delay under 0.35 ns (VCC = 4 V), OE/S timing compatibility with TTL logic families, and thermal performance (θJA = 73°C/W) in industrial PCB layouts.
Technical Context
The SN74CBT3257D implements four independent bilateral analog switches using NMOS pass transistors with integrated charge pumps for rail-to-rail conduction. Each switch connects one A-line to either corresponding B1 or B2 line based on synchronous S and OE logic states.
Its TTL-compatible inputs drive internal buffers that control gate voltage of each FET switch, enabling low-voltage signal routing without level-shifting circuitry. The device operates with no DC bias requirement on signal paths, supporting AC-coupled or DC-coupled data transfer up to 100 MHz bandwidth.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| On-state resistance (ron) | 5 Ω typical at VCC = 4.5 V, enabling minimal voltage drop (<320 mV at 64 mA) and low insertion loss in signal paths. |
| Propagation delay (tpd) | 0.25 ns typical at VCC = 5 V, supporting sub-nanosecond timing integrity in high-speed digital interconnects. |
| Supply voltage range | 4 V to 5.5 V - compatible with standard 5-V TTL and mixed-voltage systems; absolute max 7 V prevents latch-up during transient overvoltage. |
| Input voltage range (VI) | −0.5 V to 7 V - supports hot-swap capability and negative undershoot tolerance without clamp diode conduction. |
| Channel current rating | 128 mA continuous - sufficient for driving 50-Ω transmission lines or fan-out to multiple CMOS inputs. |
| Off-state capacitance (Cio) | 4 pF - minimizes crosstalk and capacitive loading on inactive channels in dense multiplexed buses. |
| Operating temperature | −40°C to 85°C - qualified for industrial ambient environments without derating. |
Pinout & Package
SN74CBT3257D uses a 16-pin SOIC (D) package with 1.27 mm pitch, 7.4–8.2 mm body width, and 1.75 mm max height per JEDEC MS-012. Pin 1 index located at top-left corner with notch or bevel marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 11, 12, 13, 14, 15, 16 | A1–A4, B11–B41, B12–B42 | Four independent bidirectional signal channels: A-port connects to B1 or B2 port per channel under S/OE control. |
| 7 | GND | Power ground reference for internal logic and switch substrate; must be low-impedance connection to minimize noise coupling. |
| 8 | VCC | Positive supply (4–5.5 V); powers internal level translators and switch driver circuitry. |
| 9 | OE | Active-low output enable: drives all switches into high-impedance state when high, isolating A and B ports. |
| 10 | S | Select input: determines whether A-port connects to B1 (S = low) or B2 (S = high) for all four channels simultaneously. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional signal routing | Enables reuse of same device for mux and demux functions without direction control pins or external biasing. |
| TTL-compatible inputs | Accepts standard 5-V TTL logic thresholds (VIH ≥ 2 V, VIL ≤ 0.8 V), eliminating need for external level shifters in legacy systems. |
| Low on-capacitance (6.5 pF) | Maintains signal integrity above 100 MHz by limiting capacitive loading on active data lines. |
| Break-before-make switching | Guaranteed non-overlapping conduction between B1 and B2 paths prevents short-circuit faults during S transitions. |
| Hot-swap tolerant I/O | Withstands −0.5 V to 7 V input voltages independent of VCC, allowing safe insertion/removal in live backplanes. |
Applications
| PCI Bus Switching | Memory Address Multiplexing |
|---|---|
|
Use Scenario: Isolating two PCI peripheral slots sharing a common address/data bus while maintaining signal integrity and timing compliance. IC Role / Device Role / Timing Role: Bidirectional 4-bit mux/demux routing address strobes and command signals between host and selected peripheral under S/OE arbitration. Use Value: 5 Ω Ron and 0.25 ns tpd preserve PCI timing margins; TTL-compatible inputs interface directly with PCI controller outputs without level conversion. |
Use Scenario: Reducing pin count on microcontroller units by time-multiplexing address lines to multiple SRAM or flash devices. IC Role / Device Role / Timing Role: Selectively connecting MCU address bus (A0–A3) to one of two memory banks via B1/B2 ports controlled by bank-select logic. Use Value: Low off-capacitance (4 pF) prevents address skew across banks; break-before-make ensures no address bus contention during bank switching. |
| Test Equipment Signal Routing | Digital Audio Data Switching |
|
Use Scenario: Configurable signal path selection in automated test equipment where DUT interfaces require reconfigurable analog/digital I/O mapping. IC Role / Device Role / Timing Role: High-fidelity analog switch for routing calibration references or stimulus signals to DUT pins under software-controlled S/OE sequencing. Use Value: Rail-to-rail conduction and <1% THD support accurate DC/AC signal transfer; hot-swap tolerance allows field-reconfigurable probe connections. |
Use Scenario: Dynamic selection between two I²S audio sources (e.g., Bluetooth receiver and USB DAC) feeding a single codec or amplifier. IC Role / Device Role / Timing Role: Bidirectional 4-bit data lane switch handling I²S WS, SCK, SDIN, and MCLK lines with simultaneous channel alignment. Use Value: Matched propagation delay across all four channels (<0.1 ns skew) preserves I²S timing relationships; low Ron avoids signal attenuation in differential pairs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FET multiplexer/demultiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CBTD3384D | 8-bit configuration with 3-state outputs and higher Ron (7 Ω typical); includes power-down mode. | Supports wider data buses but requires additional control logic for independent channel enable. | Choose when expanding to 8-bit paths or requiring individual channel disable capability beyond global OE. |
| 74LVC1G3157DBVR | Single-channel variant in SOT-23-6; Ron = 6 Ω, VCC = 1.65–5.5 V; lacks S input (fixed 1-of-2). | Used for point-to-point signal routing rather than synchronized 4-bit bus switching. | Choose for space-constrained designs needing only one switched path with broader voltage support. |
Compared with SN74CBT3257D, SN74CBTD3384D offers greater channel count but higher on-resistance and added complexity, while 74LVC1G3157DBVR reduces footprint and voltage range flexibility at the cost of parallel bus functionality and select control.
Availability
SN74CBT3257D is available at Aetrix Electronics and suitable for industrial bus switching, memory interface design, and test instrumentation requiring stable component supply and long-term obsolescence management.
Supply support for SN74CBT3257D 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
Texas Instruments is a U.S.-based semiconductor company founded in 1930, specializing in analog and embedded processing technologies with broad manufacturing scale and automotive/industrial qualification infrastructure.
The SN74CBT3257D belongs to TI's CBT (Crossbar Bus Transceiver) family, designed specifically for high-speed, low-distortion signal routing in 5-V TTL and mixed-signal systems where minimal propagation delay and precise on-resistance matching are critical.
FAQ
What is the maximum operating frequency supported by the SN74CBT3257D?
The SN74CBT3257D does not specify a hard maximum operating frequency in its datasheet, but its 0.25 ns typical propagation delay and 4 pF off-state capacitance support reliable operation up to 100 MHz in well-terminated 50-Ω environments. Signal integrity depends on PCB layout, load capacitance, and drive strength - actual usable bandwidth must be validated per application with eye diagram testing.
Does the SN74CBT3257D support hot-swap or live-insertion operation?
Yes, the SN74CBT3257D supports hot-swap operation: its absolute maximum input voltage range (−0.5 V to 7 V) exceeds VCC, and it tolerates input undershoot and overshoot without damage or latch-up. This enables safe insertion into powered backplanes or live test fixtures, provided current limits (128 mA per channel) and thermal dissipation (θJA = 73°C/W) are respected.
Can the SN74CBT3257D be used for analog signal switching, such as audio or sensor signals?
Yes, the SN74CBT3257D is suitable for analog signal switching including audio and sensor signals due to its bidirectional, rail-to-rail conduction, low on-resistance (5 Ω), and low THD. Its 4 pF off-capacitance and absence of DC bias requirements allow clean AC coupling. However, it is not specified for precision op-amp-grade offset or leakage - verify signal fidelity against system SNR and dynamic range requirements.
Is the SN74CBT3257D pin-compatible with other members of the SN74CBT3257 family?
Yes, all SN74CBT3257 variants - including SN74CBT3257DBQR (SSOP), SN74CBT3257DR (SOIC tape), and SN74CBT3257PW (TSSOP) - share identical 16-pin functional pinouts and logic behavior. Mechanical differences exist in package dimensions and thermal characteristics (e.g., θJA = 73°C/W for D vs. 90°C/W for DBQ), but PCB footprints are not interchangeable without layout revision.
What is the recommended decoupling strategy for the SN74CBT3257D?
TI recommends placing a 0.1 μF ceramic capacitor between VCC and GND as close as possible to pin 8, supplemented by a bulk 4.7 μF tantalum or ceramic capacitor near the power entry point. This mitigates high-frequency switching noise generated during channel transitions and maintains stable VCC under dynamic load, especially critical when routing fast edges across multiple channels simultaneously in the SN74CBT3257D.
SN74CBT3257D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74CBT
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Type:
- Multiplexer/Demultiplexer
- Circuit:
- 4 x 2:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- -
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SN74CBT3257D FAQ
1.How can I place an order for SN74CBT3257D through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74CBT3257D 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 SN74CBT3257D reliable?
The price and inventory of SN74CBT3257D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74CBT3257D is usually 5 days.
3.What payment methods are accepted for SN74CBT3257D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74CBT3257D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74CBT3257D?
SN74CBT3257D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74CBT3257D 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 SN74CBT3257D?
For technical support, including SN74CBT3257D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74CBT3257D requirements.
6.How does Aetrix verify that SN74CBT3257D is sourced from the original manufacturer or authorized distributors?
All SN74CBT3257D 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 SN74CBT3257D meets industry standards.
7.What is the process for return or replacement of SN74CBT3257D?
All SN74CBT3257D units undergo pre-shipment inspection (PSI). If there is an issue with SN74CBT3257D, 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 SN74CBT3257D part is unused and in its original packaging.
Return procedure for SN74CBT3257D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74CBT3257D Tags
-
SN74HC138DR
Texas Instruments
-
TC7SB3157CFU,LF(CT
Toshiba Semiconductor and Storage
-
74CBTLV3257PW,118
Nexperia USA Inc.
-
SN74CBTLV3257PWR
Texas Instruments
-
74CBTLV3257GUX
Nexperia USA Inc.
-
74HC154BQ,118
Nexperia USA Inc.
-
P3S0200GMX
NXP USA Inc.
-
SN74CB3Q3245PWR
Texas Instruments
-
SN74CB3Q3257RGYR
Texas Instruments
-
TCA9543APWR
Texas Instruments
-
TCA9546APWR
Texas Instruments
-
SN74HC138N
Texas Instruments
Tech Hub
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
