PCA9306USG - Dual I2C/SMBus Voltage-Level Translator | onsemi
Référence : PCA9306USG ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $0 | $0,00 |
| 10 | $0 | $0,00 |
| 100 | $0 | $0,00 |
| 500 | $0 | $0,00 |
| 1 000 | $0 | $0,00 |
PCA9306USG Présentation
A voltage-level translator is an interface IC that allows devices operating at different supply voltages - for example a 1.8 V microcontroller and a 5 V sensor - to share the same two-wire bus safely. Within the signal-chain hierarchy, level translators sit in the interface IC family alongside I2C multiplexers, buffers, and repeaters. The PCA9306 belongs to the switch-based (passive) translator class: it uses two N-channel pass transistors per channel rather than active output stages, so the bus is pulled up naturally by the resistors on each rail.
Key features include bidirectional voltage translation between 1.2 V and 5 V with no direction pin, support for Standard-mode (100 kbps), Fast-mode (400 kbps), and Fast-mode Plus (1 Mbps) I2C-bus plus SMBus operation, a very low 3.5 ohm ON-state connection that minimizes signal distortion, and an active-high EN input that isolates both buses when the translator is not needed. The 1.5 ns rise/fall propagation characteristic keeps bus timing margin intact even at Fast-mode Plus speeds.
The switch architecture means the PCA9306 introduces virtually no drive strength of its own - the 64 mA figure refers to the pass-transistor current handling capability. Because it is a passive switch, lock-up free operation is guaranteed even during bus contention or partial power-down, a known failure mode of active level-shifter designs. Both SDA and SCL channels are identical, so the device handles the full 2-bit I2C bus in a single package.
Typical applications include connecting 1.8 V to 3.3 V microcontrollers to 5 V I2C sensors and EEPROMs, level-shifting SMBus rails in server power supplies, battery-powered portable systems where two rail domains must communicate, and mixed-voltage industrial control modules.
Design consideration: the EN pin must be driven above the higher VREF2 rail to guarantee the pass gates turn fully on; always provide pull-up resistors on both sides of each channel sized for the respective rail.
This page synthesizes distributor cross-reference data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet. Pricing as of 2026-10-19.
Alternatives de remplacement direct pour PCA9306USG — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
NLA9306USG
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PCA9306DCUR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PCA9306DCUT
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PCA9306DC
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PCA9306USG Spécifications
| Fonction | Dual bidirectional I2C-bus and SMBus voltage-level translator |
| Canaux | 2 (SDA and SCL) |
| VREF1 Voltage Range | 1.2 V to 3.3 V |
| VREF2 Voltage Range | 1.8 V to 5.5 V |
| Voltage Range (all pins) | 0 V to 5.5 V |
| ON-State Resistance | 3.5 ohm |
| Propagation Delay | 1.5 ns (max rise/fall characteristic) |
| Output Drive Capability | 64 mA |
| I2C Bus Speeds | Standard-mode (100 kbps), Fast-mode (400 kbps), Fast-mode Plus (1 Mbps) |
| SMBus Support | Yes |
| Enable Input | EN (active-high) |
| Direction Pin | Not required (auto-direction sensing) |
| Boîtier | VSSOP-8 / US8 (8-VFSOP, 2.30 mm width) |
| Type de montage | Surface Mount |
| Statut RoHS | Compliant |
| Lead Free Status | Lead Free |
| Packaging | Tape & Reel |
Configuration des broches de PCA9306USG
| Broche 1 | A1 — Side-1 data I/O for channel 1 (connects to B1 through pass switch) |
| Broche 2 | A2 — Side-1 data I/O for channel 2 (connects to B2 through pass switch) |
| Broche 3 | GND — Ground |
| Broche 4 | EN — Enable input, active-high; drives pass-gate gates; pull low to isolate buses |
| Broche 5 | VREF2 — Side-2 reference supply, 1.8 V to 5.5 V |
| Broche 6 | B2 — Side-2 data I/O for channel 2 |
| Broche 7 | B1 — Side-2 data I/O for channel 1 |
| Broche 8 | VREF1 — Side-1 reference supply, 1.2 V to 3.3 V |
Applications typiques
PCA9306USG convient pour 6 applications: Mixed-Voltage I2C Sensor Interfacing, SMBus Power-Supply Management, Battery-Powered Portable Devices, Industrial Control Modules, Server and Datacenter Board Management, Medical and Diagnostic Equipment.
Mixed-Voltage I2C Sensor Interfacing
The most common use of the PCA9306USG is bridging a low-voltage microcontroller I2C port (1.8 V or 3.3 V) to sensors, EEPROMs, or RTCs running on a 5 V rail. Its switch-based topology with only 3.5 ohm ON resistance adds negligible series impedance, while the 1.5 ns propagation delay is invisible even at Fast-mode Plus 1 Mbps timing. Both SDA and SCL are translated in one US8 package, and the EN pin lets firmware isolate the 5 V bus during boot or fault conditions. Pull-up resistors on each side source the bus current, so no external drivers are needed.
Recommandé
SMBus Power-Supply Management
Server, telecom, and industrial power supplies frequently use SMBus (PMBus-style) telemetry at 5 V while the supervising microcontroller operates at 3.3 V or lower. The PCA9306USG supports SMBus directly per the onsemi datasheet, and its 64 mA channel capability comfortably handles the stronger SMBus pull-up currents. Because the device is lock-up free, it cannot wedge the management bus during brownout events - a critical reliability attribute in redundant power systems. The EN pin enables hot-plug isolation of a live 5 V SMBus segment from an unpowered controller rail.
Recommandé
Battery-Powered Portable Devices
Smartphones, wearables, and portable instruments commonly mix a 1.2 V to 1.8 V processor domain with 3.3 V peripherals. The PCA9306USG is one of the few translators whose low rail extends down to 1.2 V on VREF1 while reaching 5.5 V on VREF2, covering the full portable-design span in a single 2.3 mm-width VSSOP-8. Its passive switch draws no static drive current of its own, which preserves battery budget. The 1.5 ns delay and 3.5 ohm ON resistance keep the 400 kbps Fast-mode touch-controller and sensor buses within timing and voltage-margin budgets even with significant bus capacitance.
Recommandé
Industrial Control Modules
Factory automation and process-control boards routinely mix legacy 5 V I2C peripherals with modern 3.3 V MCUs. The PCA9306USG tolerates 0 V to 5.5 V on all pins, surviving 5 V bus transients during partial power-down without latch-up. Its lock-up free operation guarantees the bus recovers automatically after a fault, minimizing field-service interventions. The EN pin supports bus segmentation for multiplexed sensor banks, allowing one controller I2C port to serve isolated 5 V segments. The VSSOP-8 footprint fits dense DIN-rail module layouts, and the RoHS-compliant, lead-free construction meets industrial environmental requirements.
Recommandé
Server and Datacenter Board Management
Datacenter baseboards, NICs, and storage backplanes run multiple I2C/SMBus rail domains: 1.8 V for the BMC-side EEPROM and fan controllers and 3.3 V or 5 V for hot-swap controllers and power supplies. The PCA9306USG's wide 1.2 V to 5.5 V span and 2-channel configuration map directly onto these bus trees. Fast-mode Plus support at 1 Mbps suits high-throughput telemetry polling by the BMC. The EN input enables isolation during blade hot-insertion so inrush and bus contention do not corrupt ongoing transactions on the live segment. Its small 2.3 mm-width package suits dense server PCB real estate.
Recommandé
Medical and Diagnostic Equipment
Medical devices frequently combine low-voltage digital cores with 5 V isolation-barrier-side peripherals for sensors such as pressure and temperature modules. The PCA9306USG's passive, latch-up-free switch architecture is well suited to safety-conscious designs: the bus cannot be driven into a stuck state, and failure of the translator degrades gracefully to an open circuit rather than clamping a rail. The 1.2 V VREF1 floor supports modern low-voltage SoCs, while the 5.5 V VREF2 ceiling accommodates legacy 5 V sensors. RoHS and lead-free compliance align with medical-device environmental directives, and the US8 package supports compact handheld diagnostic layouts.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour PCA9306USG — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | NLA9306USG | PCA9306DCUR | PCA9306DCUT | PCA9306DC |
|---|---|---|---|---|---|
| Package | VSSOP-8 (US8), 2.30 mm width | VSSOP-8 (US8) - same | VSSOP-8 (DCU) - same 2.3 mm-width 8-pin body | VSSOP-8 (DCU) - same | VSSOP-8 (DCU) - same |
| Brand | onsemi | onsemi | Texas Instruments | Texas Instruments | Texas Instruments |
| VREF1 Range | 1.2 V to 3.3 V | 1.2 V to 3.3 V | 1.2 V to 3.3 V | 1.2 V to 3.3 V | 1.2 V to 3.3 V |
| VREF2 Range | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| ON-State Resistance | 3.5 ohm | 3.5 ohm | 3.5 ohm | 3.5 ohm | 3.5 ohm |
| Propagation Delay | 1.5 ns | 1.5 ns | 1.5 ns | 1.5 ns | 1.5 ns |
| Enable Input | Yes (EN, active-high) | Yes (EN, active-high) | Yes (EN, active-high) | Yes (EN, active-high) | Yes (EN, active-high) |
| Supported Bus Speeds | Standard / Fast / Fast-mode Plus (1 Mbps) + SMBus | Standard / Fast / Fast-mode Plus + SMBus | Standard / Fast / Fast-mode Plus + SMBus | Standard / Fast / Fast-mode Plus + SMBus | Standard / Fast / Fast-mode Plus + SMBus |
| RoHS / Lead Free | RoHS compliant, lead free | RoHS compliant, lead free (Pb-free designation) | RoHS compliant, lead free | RoHS compliant, lead free | RoHS compliant, lead free |
Principaux différenciateurs
- Native onsemi US8-package pedigree (vs PCA9306DCUR)
- 1.2 V low-rail floor covers newest process nodes (vs PCA9306DC)
- EN-pin bus isolation in a low-pin-count package (vs NLA9306USG)
Notes de conception
Pull-up resistors are mandatory on both sides of every channel: connect the A-side I/Os to VREF1 and the B-side I/Os to VREF2 through separate resistors. The PCA9306USG is a passive switch and sources no drive current itself - without pull-ups the bus will not operate. Typical values: 4.7 kohm on 3.3 V rails, 2.2-4.7 kohm on 5 V SMBus rails; lower values trade standby current for edge rate at Fast-mode Plus speeds. Place pull-ups close to the bus master/load rather than at the translator.
Drive the EN pin to at least VREF2 (not merely VIH of a 1.8 V rail) to guarantee the N-channel pass gates turn fully on and keep the 3.5 ohm ON resistance specification. If EN is driven from a rail below VREF2, the effective ON resistance rises and bus edges degrade. During system power-up, keep EN low until both VREF1 and VREF2 are stable to prevent undefined bus states; the device is lock-up free, but transactions initiated mid-ramp can NACK.
Decouple VREF1 and VREF2 each with a 100 nF ceramic capacitor placed within 2 mm of pins 8 and 5 respectively. Keep the SDA/SCL traces short (under 10 cm when possible) and match SDA and SCL trace lengths to minimize skew. Because the device sits between two voltage domains, avoid routing the A-side traces adjacent to the B-side traces for long runs; crosstalk between domains can couple transients into the passive switches during partial power-down events.
Informations de conformité
Lead Free and RoHS Compliant status confirmed per chipdig/Mouser specification records. REACH, halogen-free, and conflict-minerals status not stated in provided data.
