Texas Instruments SN74CBTLV3857DGVR

Overview

SN74CBTLV3857DGVR from Texas Instruments is a 10-bit FET bus switch designed for 3-V to 3.6-V operation with SSTL_2-compatible enable input, 7–13 Ω on-state resistance, rail-to-rail switching, and integrated 10-kΩ B-port pulldowns-optimized for DDR SDRAM data-path termination in high-speed memory interfaces.

For engineers reviewing the SN74CBTLV3857DGVR datasheet, SN74CBTLV3857DGVR pinout, SN74CBTLV3857DGVR application, or SN74CBTLV3857DGVR equivalent, key selection criteria include on-resistance matching for SSTL_2 series termination replacement, Ioff-enabled partial-power-down isolation, flow-through PCB layout compatibility, and TVSOP-24 thermal performance (θJA = 86°C/W).

Technical Context

This device implements a 10-channel bidirectional FET switch array with independent OE control, where each channel exhibits low and symmetric on-resistance (7–13 Ω at VCC = 3 V) and sub-nanosecond propagation delay (0.25 ns typical). The internal 10-kΩ pulldown resistors on all B-port pins and 50-kΩ pullup on OE support SSTL_2 logic level compliance without external biasing.

It supports rail-to-rail signal switching across A/B ports, features Ioff protection for backflow current suppression during partial power-down, and meets JESD 78 Class II latch-up immunity (>100 mA). Its flow-through pinout minimizes trace skew and layer transitions in DDR memory routing.

Key Specifications

Pinout & Package

SN74CBTLV3857DGVR is housed in a 24-pin TVSOP (Thin Very Small Outline Package) with 0.4 mm lead pitch and exposed pad-less construction, optimized for high-density DDR memory subsystem layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTLV3857DGVR, SN74CBT3857PWR requires higher supply voltage and lacks SSTL_2 support, while PI3CHD3857LEX offers better Ron and ESD rating but shifts B-port bias responsibility to external components-making SN74CBTLV3857DGVR optimal for drop-in DDR SDRAM termination in 3.3-V industrial systems.

Availability

SN74CBTLV3857DGVR is available at Aetrix Electronics and suitable for DDR SDRAM memory interface design, industrial embedded controller interconnects, and high-speed test access multiplexing requiring stable component supply, long-term lifecycle assurance, and consistent TVSOP-24 packaging.

Supply support for SN74CBTLV3857DGVR 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 connectivity technologies, with over 90 years of innovation in high-reliability industrial and automotive electronics.

SN74CBTLV3857DGVR belongs to TI's CBTLV (Crossbar TTL) family of low-voltage FET bus switches, engineered specifically for DDR memory subsystems requiring precise impedance matching, fast switching, and robust power-domain isolation.

FAQ

What is the function of the VREF pin on the SN74CBTLV3857DGVR?

The VREF pin on the SN74CBTLV3857DGVR sets the reference voltage for SSTL_2-compatible input thresholds (VIH = VREF + 350 mV, VIL = VREF − 350 mV). It is internally derived as 0.38 × VCC but may be externally driven to fine-tune noise margins. This pin ensures accurate enable-level detection in DDR memory interfaces without external level-shifting circuitry, and its use is mandatory for compliant SN74CBTLV3857DGVR operation in SSTL_2 systems.

Does the SN74CBTLV3857DGVR support partial-power-down operation?

Yes, the SN74CBTLV3857DGVR supports partial-power-down via its Ioff feature. When VCC is powered down, the switch isolates A and B ports to prevent backflow current, protecting upstream and downstream circuitry. This behavior is verified per JESD 78 Class II latch-up testing and is essential for hot-swap and low-power sleep modes in industrial DDR memory systems using SN74CBTLV3857DGVR.

What is the maximum data rate supported by the SN74CBTLV3857DGVR?

The SN74CBTLV3857DGVR is explicitly designed for 200 Mbit/s double-data-rate (DDR) SDRAM applications, with a maximum propagation delay of 0.25 ns and low on-state resistance (7–13 Ω) that preserves signal integrity at this rate. Its 5-pF OFF-capacitance and rail-to-rail switching further support clean eye diagrams in real-world DDR layouts using SN74CBTLV3857DGVR as a bus switch.

Are the B-port pins of the SN74CBTLV3857DGVR internally pulled down?

Yes, the SN74CBTLV3857DGVR includes internal 10-kΩ pulldown resistors on all B1–B10 pins. This ensures a defined logic-low state when the DDR SDRAM device is unpowered or in high-impedance mode, preventing floating inputs and improving system reliability. These resistors are factory-integrated and require no external components-confirming their presence in every SN74CBTLV3857DGVR unit shipped.

What package type is used for the SN74CBTLV3857DGVR?

The SN74CBTLV3857DGVR uses a 24-pin TVSOP (Thin Very Small Outline Package) with 0.4 mm lead pitch and no exposed thermal pad. This package provides compact footprint and excellent high-frequency performance (θJA = 86°C/W), making it ideal for space-constrained DDR memory modules. The TVSOP-24 pinout matches the flow-through architecture documented in the official SN74CBTLV3857DGVR datasheet.