Specifications
| Type | Description |
|---|---|
| Part Number | TCA9509 |
| Manufacturer | Texas Instruments |
| Product Type | Operational Amplifier |
| Category | Signal Chain |
| Package / Case | 8-pin VSSOP DGK 3.00 mm × 3.00 mm; 8-pin X2QFN RVH 1.60 mm × 1.60 mm |
| Interface function | Two-channel bidirectional buffer / repeater; I2C and SMBus compatible |
| A-side supply voltage | 0.9 to 5.5 V; recommended operating condition, VCCA |
| B-side supply voltage | 2.7 to 5.5 V; recommended operating condition, VCCB |
| Voltage-level translation range | 0.9 to 5.5 V and 2.7 to 5.5 V; A-side to B-side mixed-mode applications |
| Maximum I2C operating frequency | 400 kHz; Fast-mode I2C bus operation |
| B-side bus capacitance support | 400 pF; SDA and SCL buffered on I2C bus |
| Enable input | Active-high; repeater-enable input, EN pin |
| Driver enable threshold | VCCA > 0.8 V and VCCB > 2.5 V; drivers not enabled below these supply thresholds |
| A-side pull-up current source | 1 mA; A-side current sensing mechanism |
| A-side pull-down driver resistance | 200 Ω; A-side current sensing mechanism |
| A-side internal buffer low output | Approximately 0.2 V; output pull-down on A-side internal buffer LOW |
| B-side input low threshold | 0.3 × bus voltage level; B-side SMBus or I2C-bus input level |
| Absolute maximum VCCB | -0.5 to 6 V; supply voltage, over operating free-air temperature range |
| Absolute maximum VCCA | -0.5 to 6 V; supply voltage, over operating free-air temperature range |
| Absolute maximum enable input voltage | -0.5 to 6 V; VI, input current ratings observed |
| Absolute maximum I2C bus voltage | -0.5 to 6 V; VI/O, output current ratings observed |
| Maximum power dissipation | 100 mW; absolute maximum rating |
| Operating free-air temperature | -40 to 85 °C; recommended operating condition |
| Storage temperature | -65 to 150 °C; absolute maximum rating |
| Junction temperature | 125 °C max; absolute maximum rating |
| HBM ESD rating | ±2000 V; per ANSI/ESDA/JEDEC JS-001 |
| CDM ESD rating | ±1000 V; per JEDEC JESD22-C101 |
| High-level input voltage, A-side | 0.7 × VCCA to VCCA; SDAA, SCLA |
| High-level input voltage, B-side | 0.7 × VCCB to 5.5 V; SDAB, SCLB |
| High-level input voltage, EN | 0.7 × VCCA to 5.5 V; enable input |
| Low-level input voltage, A-side | -0.5 to 0.3 V; SDAA, SCLA |
| Low-level input voltage, B-side | -0.5 to 0.3 × VCCB V; SDAB, SCLB |
| Low-level input voltage, EN | -0.5 to 0.3 × VCCA V; enable input |
| Low-level output current, A-side | 10 µA max; SDAA, SCLA |
| Low-level output current, B-side | 6 mA max; SDAB, SCLB |
| Input clamp voltage | -1.5 to -0.5 V; II = -18 mA |
| A-side low-level output voltage | 0.18 typ, 0.25 V max; IOL = 10 µA, VILA = VILB = 0 V, VCCA = 0.9 to 1.2 V |
| A-side low-level output voltage | 0.2 typ, 0.3 V max; IOL = 20 µA, VILA = VILB = 0 V, 1.2 V < VCCA ≤ VCCB - 1 V |
| B-side low-level output voltage | 0.1 typ, 0.2 V max; SDAB, SCLB, IOL = 6 mA |
| A-side contention low input voltage | 110 typ, 150 mV max; SDAA, SCLA, VCCA ≥ 1.5 V and VCCB ≥ 3.15 V |
| A-side contention low input voltage | 50 typ, 100 mV max; SDAA, SCLA, VCCA < 1.5 V or VCCB < 3.15 V |
| Quiescent supply current for VCCA | 0.25 typ, 0.45 max, 0.9 mA; all port A static high |
| Quiescent supply current for VCCA | 1.25 mA; all port A static low |
| Quiescent supply current for VCCB | 0.2 typ, 0.5 max, 1.1 mA; all port B static high |
| A-side I/O capacitance | 6.5 typ, 7 pF max; SCLA, SDAA, VI = 0 V |
| B-side I/O capacitance | 5.5 typ, 6.2 pF max; SCLB, SDAB, VI = 0 V |
| EN setup time | 100 ns min; EN high before Start condition |
| EN hold time | 100 ns min; EN high after Stop condition |
| Propagation delay A to B, high-to-low | 123.1 min, 127.2 typ, 132.8 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Propagation delay B to A, high-to-low | 88.1 min, 88.8 typ, 89.8 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Propagation delay A to B, low-to-high | 122.6 min, 125.7 typ, 131.7 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Propagation delay B to A, low-to-high | 123 min, 124.1 typ, 126.9 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Transition rise time, port A | 40.1 min, 40.9 typ, 41.9 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Transition rise time, port B | 57.3 min, 57.5 typ, 58.4 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Transition fall time, port A | 14.5 min, 16.4 typ, 17.9 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Transition fall time, port B | 18.7 min, 19.4 typ, 20.2 ns max; VCCA = 1.9 V, VCCB = 5 V, EN high |
| Propagation delay A to B, PLH2 | 176 min, 177.3 typ, 178 ns max; 50% of initial low on port A to 1.5 V on port B, VCCA = 1.9 V, VCCB = 5 V |
| Datasheet Status | request_only |
Product Overview
The Texas Instruments TCA9509 is an I2C and SMBus compatible two-channel bidirectional buffer and repeater. It is intended for mixed-voltage bus connections, with the A side operating from 0.9 to 5.5 V and the B side operating from 2.7 to 5.5 V. Fast-mode I2C operation is supported up to 400 kHz.
The device buffers SDA and SCL lines and supports up to 400 pF bus capacitance on the B side. The EN pin is active high, with 100 ns minimum setup time before a Start condition and 100 ns minimum hold time after a Stop condition. Drivers are not enabled until VCCA is above 0.8 V and VCCB is above 2.5 V.
Electrical characteristics include A-side current sensing with a 1 mA pull-up current source, 200 Ω pull-down driver resistance, and approximately 0.2 V A-side internal buffer low output. Package options are 8-pin VSSOP DGK 3.00 mm × 3.00 mm and 8-pin X2QFN RVH 1.60 mm × 1.60 mm for compact I2C or SMBus signal-chain assemblies.
Key Features
- Two-channel bidirectional buffer and repeater for I2C and SMBus
- A-side supply range from 0.9 to 5.5 V
- B-side supply range from 2.7 to 5.5 V
- Supports mixed-mode voltage translation between A and B sides
- Fast-mode I2C operation up to 400 kHz
- B-side SDA and SCL bus capacitance support to 400 pF
- Active-high EN input controls repeater operation
- Drivers enable above VCCA 0.8 V and VCCB 2.5 V
- A-side current sensing uses 1 mA pull-up source
- Specified operation across -40 to 85 °C free-air temperature
Typical Applications
- I2C bus buffering
- SMBus bus repeaters
- Mixed-voltage I2C connections
- A-side to B-side level translation
- 400 pF B-side bus segments
- Fast-mode 400 kHz I2C buses
- Enable-controlled bus isolation
- Compact signal-chain assemblies
Procurement Notes
When requesting a quote for TCA9509, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.
If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.
For analog and signal-chain sourcing, supply voltage, bandwidth, accuracy, noise level, package, temperature grade, input/output configuration and qualification requirements should be verified before approval.
FAQ
What type of interface function does the TCA9509 provide?
The TCA9509 provides a two-channel bidirectional buffer and repeater function for I2C and SMBus compatible buses. It buffers SDA and SCL lines and supports mixed-mode operation between lower-voltage A-side and higher-voltage B-side bus domains.
What supply voltage ranges are supported on each side?
The A-side VCCA recommended operating range is 0.9 to 5.5 V. The B-side VCCB recommended operating range is 2.7 to 5.5 V, supporting A-side to B-side mixed-mode voltage translation applications.
What is the maximum I2C operating frequency?
The TCA9509 supports Fast-mode I2C bus operation up to 400 kHz. Timing specifications include propagation delay and transition time values measured with VCCA at 1.9 V, VCCB at 5 V, and EN high.
How is the TCA9509 enabled?
The repeater-enable input is active high. EN must be high at least 100 ns before a Start condition and held high at least 100 ns after a Stop condition. Drivers are not enabled below VCCA 0.8 V and VCCB 2.5 V.
Technical Review & Sourcing Note
Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: June 30, 2026.
This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.