LSF0108QPWRQ1 - Auto 8-Ch Bidirectional Level Shifter | TI
MPN: LSF0108QPWRQ1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.67 | $0.67 |
| 10 | $0.61 | $6.10 |
| 100 | $0.54 | $54.00 |
| 500 | $0.48 | $240.00 |
| 1,000 | $0.42 | $420.00 |
LSF0108QPWRQ1 Overview
A level translator, or voltage level shifter, is an interface IC that enables digital communication between circuits operating at different supply voltages. It sits between a low-voltage controller, such as a 1.8V MCU, and a higher-voltage peripheral, such as a 3.3V sensor, ensuring logic levels are interpreted correctly. Level translators belong to the broader interface IC family, and the LSF family uses a pass-gate (N-MOSFET) architecture with external pull-up resistors, allowing automatic bidirectional translation without direction control.
Key features include bidirectional operation with no direction pin, voltage support from 0.95V to 5V, and compatibility with both open-drain buses like I2C and push-pull signals. The device supports up to 100 MHz up-translation and greater than 100 MHz down-translation at <=30 pF load, and 40 MHz up/down translation at 50 pF load, per the TI datasheet (Rev. H).
Technically, each channel uses a single N-channel MOSFET with external pull-ups defining the high level on each side. When either side drives low, the MOSFET conducts and pulls the opposite side low through the resistor network, enabling automatic bidirectional shifting. This removes GPIO overhead for direction signaling and simplifies firmware in multi-voltage systems.
Typical applications include automotive body control modules, infotainment systems, MDIO management buses, and sensor interfaces where 1.8V, 2.5V, 3.3V, and 5V domains coexist, plus industrial automation mixed-voltage links.
Design tip: select pull-up resistor values according to bus capacitance and speed; lower values improve edge rates but raise current consumption, and VREF pins must be tied to the respective rails to set translation levels correctly.
Drop-in alternatives for LSF0108QPWRQ1 — 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 LSF0108QPWRQ1 (same form factor and footprint) — differing in Direction Control, Output Type, Operating Temperature, Package, Translator Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LSF0108PWR
✅ Drop-In✓ In Stock
$0.31 / Unit
View Datasheet →TXS0108EQPWRQ1
✅ Drop-In✓ In Stock
$0.39 / Unit
View Datasheet →TXB0108QPWRQ1
✅ Drop-In✓ In Stock
$0.68 / Unit
View Datasheet →TXS0108EPWR
✅ Drop-In✓ In Stock
$0.51 / Unit
View Datasheet →NTS0108PW
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LSF0108QPWRQ1 Specifications
| Translator Type | Voltage Level Translator |
| Channels | 8 bidirectional |
| Circuits | 1 |
| Voltage - VCCA (VREF_A) | 0.95 V to 4.5 V |
| Voltage - VCCB (VREF_B) | 1.65 V to 5.5 V |
| Translation Range | 0.95 V to 5 V |
| Direction Control | None (automatic bidirectional) |
| Output Type | Open-drain and push-pull compatible |
| Up Translation Speed | 100 MHz (<=30 pF load) |
| Down Translation Speed | >100 MHz (<=30 pF load) |
| Speed at 50 pF Load | 40 MHz up/down |
| Operating Temperature | -40C to +125C |
| Qualification | AEC-Q100 automotive |
| Package | 20-TSSOP (PW) |
| Mounting Type | Surface Mount |
| Features | Rise/fall time control via external pull-ups |
| RoHS Status | Compliant |
LSF0108QPWRQ1 Pin Configuration
| Pin 1 | A1 — Side A channel 1 |
| Pin 2 | A2 — Side A channel 2 |
| Pin 3 | A3 — Side A channel 3 |
| Pin 4 | A4 — Side A channel 4 |
| Pin 5 | A5 — Side A channel 5 |
| Pin 6 | A6 — Side A channel 6 |
| Pin 7 | A7 — Side A channel 7 |
| Pin 8 | A8 — Side A channel 8 |
| Pin 9 | GND — Ground |
| Pin 10 | EN — Enable input (high = active) |
| Pin 11 | VREF_B — Side B reference voltage (1.65 V to 5.5 V) |
| Pin 12 | B8 — Side B channel 8 |
| Pin 13 | B7 — Side B channel 7 |
| Pin 14 | B6 — Side B channel 6 |
| Pin 15 | B5 — Side B channel 5 |
| Pin 16 | B4 — Side B channel 4 |
| Pin 17 | B3 — Side B channel 3 |
| Pin 18 | B2 — Side B channel 2 |
| Pin 19 | B1 — Side B channel 1 |
| Pin 20 | VREF_A — Side A reference voltage (0.95 V to 4.5 V) |
Typical Applications
LSF0108QPWRQ1 is suitable for 6 applications: Automotive Body Control Modules, I2C Sensor Interface Level Translation, Automotive Infotainment Systems, MDIO Management Data Bus, Industrial Automation Mixed-Voltage Links, Battery-Powered Portable and IoT Devices.
Automotive Body Control Modules
The LSF0108QPWRQ1 fits body control modules where 1.8V, 3.3V, and 5V domains coexist between MCUs, sensors, and actuators. Its AEC-Q100 qualification and -40C to +125C rating meet automotive temperature requirements directly. As a bidirectional pass-gate translator, it bridges GPIO and sensor lines in both directions without firmware direction management. With 8 channels in one 20-TSSOP package, it consolidates discrete MOSFET shifter circuits, reducing BOM count and PCB area. External pull-ups let designers tune edge rates per channel for EMC compliance, a key automotive design constraint.
Recommended
I2C Sensor Interface Level Translation
For I2C buses connecting a 1.8V or 2.5V controller to 3.3V or 5V sensors, the LSF0108QPWRQ1's open-drain pass-gate architecture is ideal: SDA/SCL remain fully bidirectional with no direction pin, and external pull-ups set the high level on each side. With >100 MHz down-translation capability, it far exceeds I2C Fast-mode Plus (1 MHz) needs. TI application notes specifically cover LSF family I2C use. Typical pull-ups of 1-10 kOhm balance edge rate against current draw, and VREF pins tie directly to each bus rail for clean, automatic translation.
Recommended
Automotive Infotainment Systems
Infotainment head units mix 1.8V application processors with 3.3V/5V peripherals such as touch controllers, EEPROMs, and audio codecs. The LSF0108QPWRQ1 provides eight bidirectional channels on one footprint for control and management signals, including MDIO management bus lines, at rates up to 100 MHz (<=30 pF). Its AEC-Q100 rating addresses the automotive cabin environment, while the small TSSOP-20 saves board space behind display assemblies. External pull-up control allows per-rail tuning to balance signal integrity and power in EMI-sensitive audio and display regions.
Recommended
MDIO Management Data Bus
MDIO management buses in Ethernet PHY and switch systems run between 1.8V/2.5V MACs and 3.3V PHYs. TI explicitly cites MDIO as a supported interface for the LSF family's 100 MHz up / >100 MHz down translation capability at <=30 pF load, providing ample margin for 2.5 MHz MDIO clocking with fast edge rates. The LSF0108QPWRQ1's automatic bidirectionality handles MDIO's turnaround periods without a direction-control GPIO, and its eight channels also cover MDC and control lines on the same die in the compact 20-TSSOP package.
Recommended
Industrial Automation Mixed-Voltage Links
Factory automation systems combine legacy 5V logic with modern 1.8V/3.3V controllers and sensors. The LSF0108QPWRQ1 bridges these domains bidirectionally on up to eight lines without direction signaling, simplifying firmware in PLC I/O cards. Its 0.95V floor supports advanced low-voltage FPGAs and MCUs, while 5V VCCB handles industrial sensor outputs. The 100 MHz capability covers high-speed parallel signaling and SPI at 30 pF loads. Robust pull-up-based architecture tolerates industrial ground offsets better than push-pull auto-direction designs, and the -40C rating suits unheated cabinets.
Recommended
Battery-Powered Portable and IoT Devices
Portable designs translating between 1.8V sensor/MCU domains and 3.3V peripherals benefit from the LSF's pass-gate efficiency: with no internal pull-down path on idle channels, static current is set only by pull-up resistors, preserving battery life. The 20-TSSOP fits space-constrained boards, and the single-device 8-channel integration replaces multiple discrete MOSFET shifters. Push-pull signals such as SPI, UART, and GPIO translate cleanly at rates up to 100 MHz. External pull-ups let designers trade speed versus current per channel, and the enable pin gates all channels for power saving.
Recommended
Recommended Products Summary
Engineering reference data for LSF0108QPWRQ1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LSF0108PWR | TXS0108EQPWRQ1 | TXB0108QPWRQ1 | NTS0108PW |
|---|---|---|---|---|---|
| Package | 20-TSSOP (PW) | 20-TSSOP (PW) - same | 20-TSSOP (PW) - same | 20-TSSOP (PW) - same | 20-TSSOP (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi |
| Channels | 8 bidirectional | 8 bidirectional | 8 bidirectional | 8 bidirectional | 8 bidirectional |
| Voltage Range | 0.95 V to 5 V | 0.95 V to 5 V | 1.2 V to 3.6 V / 1.65 V to 5.5 V | 1.2 V to 3.6 V / 1.65 V to 5.5 V | 1.2 V to 3.6 V / 1.65 V to 5.5 V |
| Architecture | Pass-gate N-MOSFET, external pull-ups | Pass-gate, external pull-ups | Auto-direction, internal pull-ups | Auto-direction push-pull | Auto-direction |
| Open-Drain (I2C) Support | Yes (native) | Yes (native) | Limited (load capacitance constraints) | No (push-pull only) | Limited |
Key Differentiators
- Native open-drain/I2C support with automatic bidirectionality (vs TXB0108QPWRQ1)
- Automotive qualification at comparable cost (vs LSF0108PWR)
- Lower capacitive loading and wider low-voltage floor (vs TXS0108EQPWRQ1)
Design Notes
Tie VREF_A (pin 20) and VREF_B (pin 11) directly to the respective supply rails - these set the translation levels for the pass-gate channels. Place 0.1 uF decoupling capacitors at both VREF pins and keep traces short. Unused channels can be left floating but pull-up resistors must still be present on all used channels on both A and B sides; without pull-ups the channel high level is undefined.
Edge rate is determined entirely by pull-up resistance and total node capacitance (device capacitance plus trace plus load). For 100 MHz operation keep load capacitance <=30 pF per TI datasheet Rev. H. Calculate rise time as t_r ~= 0.85 x R_pu x C_total; choose R_pu so rise time is under one-third of the bit period. Lower pull-ups speed edges but increase sink current when driving low.
Use the EN pin (pin 10) to tri-state all channels during power-up sequencing or for low-power standby, preventing back-powering of the lower rail through the pass gates. Ensure VREF_B is within 1.65 V to 5.5 V and VREF_A within 0.95 V to 4.5 V before asserting EN. Observe that VREF_B - VREF_A should be >=0.7 V per LSF family usage notes for reliable gate drive.
Compliance Information
AEC-Q100 qualified per TI product page (-Q1 automotive suffix). RoHS status compliant per DigiKey/TI listings; other compliance fields not stated in provided data.
