Texas Instruments SN74CBTK16245DGVR

Overview

SN74CBTK16245DGVR from Texas Instruments is a 16-bit FET bus switch with active-clamp undershoot protection, designed for high-speed TTL-compatible bidirectional data routing in memory and I/O expansion interfaces. It features 5-Ω on-state resistance, I_off partial-power-down support, and clamps I/O undershoots to –2 V. Used in hot-swap-capable backplane interfaces and level-translating peripheral buses.

For engineers reviewing the SN74CBTK16245DGVR datasheet, SN74CBTK16245DGVR pinout, SN74CBTK16245DGVR application, or SN74CBTK16245DGVR equivalent, key selection criteria include its 48-pin TVSOP package, dual 8-bit independent OE control, active undershoot clamp circuitry, and guaranteed operation from –40°C to 85°C with 4–5.5 V supply.

Technical Context

This device implements two independent 8-bit low-impedance FET switches, each controlled by a dedicated output-enable (OE) input. The switch architecture uses transmission-gate topology with integrated active-clamp circuitry that sources current from V_CC to limit I/O undershoot to –2 V during transient events.

It supports partial-power-down via I_off circuitry that disables outputs when V_CC = 0 V, preventing backflow current up to ±50 mA per I/O. Input levels are TTL-compatible (V_IL ≤ 0.8 V, V_IH ≥ 2 V), and propagation delay is specified at 0.25 ns (V_CC = 5 V).

Key Specifications

Pinout & Package

SN74CBTK16245DGVR is housed in a 48-pin Thin Very Small Outline Package (TVSOP), JEDEC MO-153 compliant, with 0.4 mm lead pitch and 7.1 mm × 4.4 mm body dimensions. Pin 1 located at top-left corner (Q1 quadrant), marked "CP245" on top-side.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTK16245DGVR, SN74CBT16245DGVR lacks active undershoot protection and has higher r_on, reducing robustness in dynamic systems; SN74LVC16245ADGVR introduces direction control overhead and cannot replace passive bidirectional switching in existing '16245-pinout designs.

Availability

SN74CBTK16245DGVR is available at Aetrix Electronics and suitable for memory expansion interfaces, hot-swap backplane buses, level-translating peripheral buses, and test access port multiplexers requiring stable component supply and long-term industrial availability.

Supply support for SN74CBTK16245DGVR 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 delivering analog, embedded processing, and logic solutions with emphasis on reliability, integration, and system-level performance.

SN74CBTK16245DGVR belongs to TI's Widebus™ family of high-speed logic devices, engineered specifically for low-latency, low-distortion bidirectional data routing in demanding digital interconnect applications.

FAQ

What is the maximum undershoot voltage the SN74CBTK16245DGVR can safely clamp?

The SN74CBTK16245DGVR features an active-clamp undershoot-protection circuit that safely limits I/O transients to –2 V, as verified under JESD22-A114-A test conditions. This clamping occurs without external components and applies to all 32 I/O pins (A and B ports). The circuit draws current from V_CC to maintain the –2 V threshold, ensuring signal integrity during hot-swap events or noisy bus transitions. SN74CBTK16245DGVR maintains this specification across its full operating temperature range (–40°C to +85°C).

Does the SN74CBTK16245DGVR support partial-power-down operation?

Yes, the SN74CBTK16245DGVR fully supports partial-power-down via its I_off circuitry, which disables outputs and limits leakage to 20 µA maximum when V_CC = 0 V. This feature prevents damaging back-current flow through the device during power sequencing or hot insertion, making SN74CBTK16245DGVR suitable for modular systems with staggered power-up/down. The I_off behavior is specified across the full –40°C to +85°C temperature range and does not require external biasing.

What is the on-state resistance (r_on) of the SN74CBTK16245DGVR and how does it affect signal integrity?

The SN74CBTK16245DGVR has a typical on-state resistance of 5 Ω at V_CC = 4.5 V and 30 mA, with a maximum of 7 Ω. This low r_on minimizes voltage drop and RC delay across the A–B path, preserving signal rise/fall times and timing margins in high-speed buses. Measured at the lower of the A or B terminal voltages, this value ensures consistent performance regardless of signal direction. SN74CBTK16245DGVR's 5-Ω r_on contributes directly to its 0.25 ns propagation delay at 5 V, enabling reliable operation above 1 GHz.

Can the SN74CBTK16245DGVR be used in 3.3-V systems?

No, the SN74CBTK16245DGVR is not rated for 3.3-V operation. Its recommended supply voltage range is 4 V to 5.5 V, and absolute maximum V_CC is 7 V. Operating below 4 V risks unreliable switching, increased r_on, and failure to meet TTL input thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2 V). For 3.3-V systems, TI recommends alternatives like SN74LVC16245A; SN74CBTK16245DGVR must be powered from a stable 5-V rail to ensure correct function and undershoot-clamp performance.

How many independent enable controls does the SN74CBTK16245DGVR provide?

The SN74CBTK16245DGVR provides two independent active-low output-enable (OE) inputs: 1OE controls the first 8-bit switch bank (1A ↔ 1B), and 2OE controls the second (2A ↔ 2B). This dual-OE architecture allows granular control-e.g., enabling memory address lines while isolating data lines during refresh cycles. Each OE input drives its respective 8-bit path with identical timing (t_en = 4.9 ns, t_dis = 7.5 ns at V_CC = 5 V). SN74CBTK16245DGVR's pinout matches standard '16245 devices, simplifying drop-in replacement in existing layouts.