Texas Instruments SN74CBTLV3245DBR

Overview

SN74CBTLV3245DBR from Texas Instruments is a low-voltage octal FET bus switch in a 20-pin SSOP (DB) package, featuring 5-Ω on-state resistance, –40°C to 85°C operating range, and isolation under power-off conditions. It implements an 8-bit bidirectional switch with standard '245 pinout, used for high-speed data path control in voltage-level-flexible digital systems.

For engineers reviewing the SN74CBTLV3245DBR datasheet, SN74CBTLV3245DBR pinout, SN74CBTLV3245DBR application, or SN74CBTLV3245DBR equivalent, key selection criteria include on-resistance stability across 2.3–3.6 V supply, OE-controlled high-impedance isolation, ESD robustness (>2000 V HBM), and compatibility with legacy '245-based board layouts.

Technical Context

This device uses NMOS FET transmission gates per channel, enabling bidirectional signal flow with minimal propagation delay (<0.25 ns typical at 3.3 V). Its OE input controls all eight switches simultaneously in positive logic: low enables A↔B conduction; high forces high-Z isolation between ports.

Designed for low-voltage operation, it supports mixed-voltage interfacing (e.g., 3.3-V logic driving 2.5-V loads) without level-shifting circuitry. The internal architecture ensures power-off isolation-no current leakage between A and B when VCC = 0-and requires OE pull-up to VCC during power sequencing to guarantee safe startup behavior.

Key Specifications

Pinout & Package

SN74CBTLV3245DBR is housed in a 20-pin Shrink Small-Outline Package (SSOP, DB), 7.2 mm × 5.3 mm body, 0.65 mm pitch, with exposed pad not present. Pin 1 marked by beveled corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal FET bus switch applications.

Compared with SN74CBTLV3245DBR, SN74CBT3245DBR offers wider voltage tolerance at the cost of higher on-resistance and reduced low-voltage margin, while 74LVC245ADB provides active direction control but introduces timing skew and layout incompatibility due to non-'245 pin mapping.

Availability

SN74CBTLV3245DBR is available at Aetrix Electronics and suitable for PCI Express interposers, DDR memory bus isolation, FPGA I/O translation, and legacy ISA bus extension requiring stable component supply and long-term industrial availability.

Supply support for SN74CBTLV3245DBR 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 global semiconductor leader specializing in analog, embedded processing, and logic solutions, with decades of expertise in high-reliability interface and signal-path components.

The SN74CBTLV family was designed specifically for low-voltage, high-speed digital bus switching in space-constrained industrial and communications equipment, emphasizing minimal propagation delay and power-off safety.

FAQ

What is the recommended OE pull-up resistor value for SN74CBTLV3245DBR?

The minimum OE pull-up resistor value depends on the current-sinking capability of the driving signal source. For standard CMOS drivers capable of sinking ≥20 µA at 0.8 V, a 10-kΩ resistor to VCC is sufficient. TI recommends verifying pull-up strength using the formula R_PULLUP ≤ (V_CC − V_IL) / I_OL, where V_IL = 0.8 V max and I_OL is the driver's low-level output current. This ensures reliable high-impedance state activation during power-up for SN74CBTLV3245DBR.

Can SN74CBTLV3245DBR operate at 2.3 V continuously?

Yes, SN74CBTLV3245DBR is fully characterized and guaranteed to operate across the full recommended range of 2.3 V to 3.6 V. At 2.3 V, on-state resistance increases to 7 Ω max, propagation delay remains <0.3 ns, and I_off stays below 30 µA. All AC and DC parameters in the datasheet SCDS034F are validated at 2.3 V, making SN74CBTLV3245DBR suitable for battery-powered or low-power 2.5-V systems where supply headroom is constrained.

Does SN74CBTLV3245DBR support hot-swap applications?

Yes, SN74CBTLV3245DBR supports hot-swap operation due to its power-off isolation feature: when VCC = 0, I_off is limited to 30 µA maximum between A and B ports, preventing back-powering or latch-up in live-backplane environments. Combined with >2000 V HBM ESD rating and rail-to-rail input tolerance (–0.5 V to 4.6 V), SN74CBTLV3245DBR safely handles insertion/removal in powered systems-provided OE is held high during insertion to maintain isolation until VCC stabilizes.

Is SN74CBTLV3245DBR pin-compatible with older 74ACT245 devices?

No, SN74CBTLV3245DBR is not pin-compatible with 74ACT245. While both share the standard '245 functional block diagram and 20-pin DIP/SOIC pinout numbering, SN74CBTLV3245DBR uses a 20-pin SSOP (DB) package with 0.65 mm pitch, whereas 74ACT245 typically uses 20-pin SOIC (DW) with 1.27 mm pitch. More critically, SN74CBTLV3245DBR has no direction (DIR) pin-it is a bidirectional switch controlled solely by OE-unlike the 74ACT245's dual-control (DIR + OE) architecture. Thus, SN74CBTLV3245DBR cannot replace 74ACT245 without PCB redesign.

What is the thermal performance of SN74CBTLV3245DBR in the DB package?

The DB package (SSOP) for SN74CBTLV3245DBR has a junction-to-ambient thermal impedance (θ_JA) of 115°C/W under JEDEC-standard PCB conditions (2-layer board, 1-in² copper). With a maximum continuous channel current of 128 mA per switch and typical power dissipation of <1 mW per channel at 3.3 V, junction temperature rise remains below 15°C above ambient under full 8-bit load-well within the –40°C to 85°C operating range. No heatsink is required for SN74CBTLV3245DBR in standard industrial airflow environments.