TXB0108PWR - 8-Bit Bidirectional Level Shifter 100Mbps | TI
MPN: TXB0108PWR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.42 | $0.42 |
| 10 | $0.38 | $3.80 |
| 100 | $0.34 | $34.00 |
| 500 | $0.3 | $150.00 |
| 1,000 | $0.26 | $260.00 |
TXB0108PWR Overview
A voltage-level translator is a logic IC that enables communication between devices operating at different supply voltages, such as a 1.8V microcontroller and a 3.3V or 5V peripheral. It sits in the hierarchy of logic ICs under level shifters (translators), which are essential in multi-voltage digital systems alongside buffers and bus transceivers. The TXB0108PWR uses auto-direction sensing, eliminating the need for a direction control pin and reducing firmware complexity.
Key features include auto-direction sensing, +/-15-kV ESD protection (HBM), a 100 Mbps maximum data rate, and a VCC isolation feature: if either VCC input is at GND, all outputs enter the high-impedance state, enabling partial-power-down operation with Ioff support. The device operates from -40C to +85C.
Technically, the TXB0108 uses a one-shot architecture that accelerates low-to-high transitions to achieve 100 Mbps. It is designed for push-pull (totem-pole) CMOS drivers only; for open-drain buses such as I2C, TI recommends the TXS0108E. Output drive is intentionally weak (internal 4 kOhm series resistors), so heavy capacitive loads above ~70 pF reduce achievable speed.
Typical applications include 1.8V-to-3.3V microcontroller-to-sensor interfaces, SD card level shifting, UART/SPI signal translation, and FPGA configuration buses. The 100 Mbps capability suits high-speed SPI and UART links.
Design tip: ensure VCCA <= VCCB, drive all eight channels push-pull, and place 0.1uF decoupling capacitors close to both VCCA and VCCB pins with short traces for signal integrity.
Drop-in alternatives for TXB0108PWR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TXB0108PWR (same form factor and footprint) — differing in Operating Temperature, Direction Control, Output Type, Translator Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TXB0108QPWRQ1
✅ Drop-In✓ In Stock
$0.68 / Unit
View Datasheet →TXB0108PWRG4
✅ Drop-In📋 Reference alternative (not in catalog)
TXS0108EQPWRQ1
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$0.39 / Unit
View Datasheet →NXB0108PW
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
TXB0108PWR Maximum Ratings & Electrical Characteristics
| Bits per Channel | 8 |
| Channels | 8 |
| Translator Type | Bidirectional voltage-level translator, auto-direction sensing |
| A Port Voltage Range | 1.2 V to 3.6 V |
| B Port Voltage Range | 1.65 V to 5.5 V |
| Max Data Rate | 100 Mbps |
| ESD Protection | +/-15 kV (HBM) |
| Output Type | Push-pull, 3-state |
| VCC Isolation | Yes - outputs high-impedance if either VCC at GND |
| Operating Temperature | -40C to +85C |
| Package | TSSOP-20 (PW) |
| Mounting Type | Surface Mount |
| Internal Series Resistance | 4 kOhm |
| Latch-Up Performance | Exceeds 100 mA per JESD 78, Class II |
| Driver Type | Push-pull (totem-pole) CMOS only; not for open-drain buses |
| RoHS Status | Compliant |
TXB0108PWR Pin Configuration
| Pin 1 | VCCA — A-port supply, 1.2V to 3.6V |
| Pin 2 | A1 — A-port data I/O 1 |
| Pin 3 | A2 — A-port data I/O 2 |
| Pin 4 | A3 — A-port data I/O 3 |
| Pin 5 | A4 — A-port data I/O 4 |
| Pin 6 | GND — Ground |
| Pin 7 | B4 — B-port data I/O 4 |
| Pin 8 | B3 — B-port data I/O 3 |
| Pin 9 | B2 — B-port data I/O 2 |
| Pin 10 | B1 — B-port data I/O 1 |
| Pin 11 | NC — No connect |
| Pin 12 | NC — No connect |
| Pin 13 | NC — No connect |
| Pin 14 | B5 — B-port data I/O 5 |
| Pin 15 | B6 — B-port data I/O 6 |
| Pin 16 | B7 — B-port data I/O 7 |
| Pin 17 | B8 — B-port data I/O 8 |
| Pin 18 | A8 — A-port data I/O 8 |
| Pin 19 | A7 — A-port data I/O 7 |
| Pin 20 | NC — No connect |
Typical Applications
TXB0108PWR is suitable for 6 applications: MCU-to-Sensor Level Shifting (1.8V to 3.3V), SD Card Interface Level Translation, UART Signal Translation, FPGA Configuration and I/O Bank Translation, Mixed-Voltage Industrial Control Boards, Portable and Battery-Powered Devices.
MCU-to-Sensor Level Shifting (1.8V to 3.3V)
The TXB0108PWR fits 1.8V microcontroller-to-3.3V sensor interfaces because its A port accepts 1.2V-3.6V and its B port 1.65V-5.5V, matching common logic levels exactly. Auto-direction sensing means no firmware-managed DIR pin on point-to-point links such as SPI or sensor data lines. Place the device between the 1.8V MCU and 3.3V sensor rails with 0.1uF decoupling on both VCCA and VCCB; its 100 Mbps rating comfortably covers typical SPI clocks of 10-50 MHz, though keep trace lengths short due to the internal 4 kOhm series resistors.
Recommended
SD Card Interface Level Translation
SD cards in SDIO mode traditionally use 2.7-3.6V signaling while newer low-voltage MCUs run at 1.8V; the TXB0108PWR bridges this with its 1.2V-3.6V A port and 1.65V-5.5V B port. Its 100 Mbps capability supports the 50 MHz default SDIO clock (parallel data across 8 channels covers CMD plus 4 data lines plus spares). Designers should keep SDIO traces matched and short since the one-shot edge accelerators lose speed above roughly 70 pF of trace and pin capacitance, and VCCA must not exceed VCCB.
Recommended
UART Signal Translation
UART links between a 1.8V/2.5V processor and a 3.3V or 5V peripheral are a classic TXB0108PWR use case: each of the 8 channels is bidirectional with auto-direction sensing, so RX/TX pairs map directly without control logic. UART rates of 115.2 kbps to 4 Mbps are far below the 100 Mbps ceiling, leaving generous margin even with moderate load capacitance. Because both sides are push-pull CMOS, the TXB's 4 kOhm internal series resistors pose no issue; avoid adding pull-ups for this application and reserve TXS0108E for open-drain variants.
Recommended
FPGA Configuration and I/O Bank Translation
FPGA banks operating at 1.8V frequently need to talk to 3.3V flash, configuration PROMs, or legacy peripherals; the TXB0108PWR's 8-bit width and VCC isolation make it a natural fit. If either rail powers down, outputs go high-impedance, enabling partial-power-down designs with Ioff support so floating buses do not back-power the FPGA. SPI configuration clocks of 10-50 MHz fall well within the 100 Mbps limit. Tie OE low during power-up sequencing to keep the bus tri-stated until both supplies stabilize.
Recommended
Mixed-Voltage Industrial Control Boards
Industrial controllers often mix 5V legacy I/O with modern 1.8V/3.3V processors. The TXB0108PWR translates between these domains with +/-15-kV HBM ESD robustness, valuable in factory environments with handling and cable discharge events. Its -40C to +85C industrial temperature range and latch-up performance exceeding 100 mA per JESD 78 Class II suit harsh conditions. Designers should enforce VCCA <= VCCB in power sequencing and use the OE pin for clean power-up; the TSSOP-20 footprint enables compact, dense control-board layouts.
Recommended
Portable and Battery-Powered Devices
Battery-powered products routinely combine a low-voltage (1.8V) low-power MCU with 3.3V displays, memory cards, and radios. The TXB0108PWR supports partial-power-down via its VCC isolation feature: when either rail collapses, all 8 outputs enter high-impedance, preventing leakage into the sleeping domain. Quiescent current is low enough for portable designs, and the small TSSOP-20 body fits compact layouts. Keep capacitive loading on each channel under ~70 pF to preserve signal edges, and drive channels push-pull CMOS for best speed.
Recommended
Recommended Products Summary
Engineering reference data for TXB0108PWR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TXB0108QPWRQ1 | TXB0108PWRG4 | TXS0108EQPWRQ1 | NXB0108PW |
|---|---|---|---|---|---|
| Package | TSSOP-20 (PW) | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | NXP Semiconductors |
| Bits / Channels | 8 | 8 | 8 | 8 | 8 |
| A Port Range | 1.2V to 3.6V | 1.2V to 3.6V | 1.2V to 3.6V | 1.2V to 3.6V | 1.2V to 3.6V |
| B Port Range | 1.65V to 5.5V | 1.65V to 5.5V | 1.65V to 5.5V | 1.65V to 5.5V | 1.65V to 5.5V |
Key Differentiators
- Auto-direction sensing eliminates a DIR pin (vs SN74LVC8T245)
- 100 Mbps speed via one-shot edge accelerators (vs TXS0108EQPWRQ1)
- VCC isolation with Ioff support (vs NXB0108PW)
Design Notes
Place 0.1uF ceramic decoupling capacitors as close as possible to both VCCA (pin 1) and VCCB pins with short, low-inductance returns to GND. The one-shot edge-rate accelerators draw fast transient currents during transitions; inadequate decoupling causes ground bounce and false direction switching. Keep all eight channel traces short and matched-length for parallel buses like SDIO, since trace and pin capacitance above roughly 70 pF per channel degrades the achievable data rate due to the internal 4 kOhm series resistors.
The most common design error is using the TXB0108 on open-drain buses such as I2C. The auto-direction sensing and 4 kOhm series resistors produce contention with pull-up-based signaling; TI explicitly recommends the TXS0108E for open-drain applications. Also enforce VCCA <= VCCB at all times including power sequencing - tie OE low until both rails stabilize to keep outputs in high-impedance during startup, then release OE to enable translation.
Load each channel with a pure push-pull CMOS receiver and minimize capacitive loading. Avoid connecting multiple receivers in a multi-drop arrangement - the weak 4 kOhm internal drivers are designed for point-to-point links only. For longer buses or heavy loads, use the SN74LVC8T245 family instead, which offers strong output drive and a controlled direction pin. The +/-15-kV HBM ESD rating helps during assembly and handling but does not replace system-level TVS protection on external connectors.
Compliance Information
RoHS compliant per TI product page; the PWR suffix indicates lead-free finish. Automotive AEC-Q100 variant is TXB0108QPWRQ1. Other compliance values not stated in provided data.
