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Texas Instruments TCA9803DGKT
- Part No.:
- TCA9803DGKT
- Manufacturer:
- Texas Instruments
- Category:
- Translators, Level Shifters
- Package:
- Datasheet:
-
TCA9803DGKT.pdf
- Description:
- IC TRANSLTR BIDIRECTIONAL 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:16,405
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Product details
Overview
TCA9803DGKT from Texas Instruments is a dual-channel bidirectional I²C/SMBus level-translating buffer with integrated B-side current source (3.3 mA typical), enabling resistorless B-side bus termination. It supports 0.8 V–3.6 V on A-side and 1.65 V–3.6 V on B-side, delivers ultra-low VOL (~0.13 V on A-side, ~0.26 V on B-side), and operates across –40°C to +125°C for server backplane and industrial control interconnects.
For engineers reviewing the TCA9803DGKT datasheet, TCA9803DGKT pinout, TCA9803DGKT application, or TCA9803DGKT equivalent, this page provides verified supply voltage ranges, propagation delays (75–260 ns), quiescent current (45 µA total at 1.8 V), bus capacitance limit (400 pF on B-side), and enable timing (280–1000 ns), all confirmed from TI's SCPS267B production datasheet.
Technical Context
The TCA9803DGKT implements true buffering-not pass-FET-using an internal current source on the B-side to detect external low-drive contention without static voltage offset. This architecture eliminates fixed-VIL threshold conflicts and enables reliable clock stretching and multi-master arbitration.
It requires no external pull-up resistors on SDAB/SCLB pins, supports independent power sequencing (VCCA ≷ VCCB), and enters high-impedance state on A-side pins when either supply falls below UVLO (0.55 V on VCCA, 1.51 V on VCCB), while maintaining B-side current-source operation until VCCB drops below 1.4 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| A-side VCCA | 0.8 V to 3.6 V - Enables interface between sub-1 V logic (e.g., advanced SoCs) and standard I²C peripherals. |
| B-side VCCB | 1.65 V to 3.6 V - Supports 1.8 V/2.5 V/3.3 V domains without level-shifter biasing constraints. |
| ICS (B-side) | 3.3 mA typical ±25% - Drives up to 400 pF bus capacitance at 400 kHz without external resistors. |
| VOL (A-side) | 0.13 V max at 6 mA - Ensures robust low-level recognition by downstream 0.3×VCCA VIL receivers. |
| VOL (B-side) | 0.26 V max - Maintains <0.3×VCCB margin even at 3.6 V, preventing false low detection. |
| tPHL/tPLH | 75–260 ns - Guarantees timing compliance in 400 kHz Fast-mode Plus I²C systems with distributed loads. |
| Quiescent current | 45 µA total (VCCA=VCCB=1.8 V) - Enables always-on bus isolation in battery-backed subsystems. |
Pinout & Package
Package: VSSOP-8 (DGK), 3.00 mm × 3.00 mm, 0.65 mm pitch, thermal pad optional.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VCCA | A-side supply input | Reference for SCLA/SDAA I/O and EN logic; powers A-side buffer circuitry independently of VCCB. |
| 2 SCLA | A-side serial clock I/O | Open-drain I²C clock line; requires external pull-up to VCCA even if unused per datasheet. |
| 3 SDAA | A-side serial data I/O | Open-drain I²C data line; same pull-up requirement as SCLA for bus integrity. |
| 4 GND | Ground reference | Common return for both sides; must be low-impedance to minimize ground bounce during switching. |
| 5 EN | Active-high enable input | Referenced to VCCA; internal 150–450 kΩ pull-up; asserts repeater function only when HIGH. |
| 6 SDAB | B-side serial data I/O | No external pull-up allowed; driven by internal 3.3 mA current source; floats when unused. |
| 7 SCLB | B-side serial clock I/O | Same current-source drive and floating behavior as SDAB; critical for SMBus/PMBus compatibility. |
| 8 VCCB | B-side supply input | Powers B-side buffer and current source; enables independent voltage domain translation. |
Key Features
| Feature | Design Value |
|---|---|
| Resistorless B-side termination | Integrated 3.3 mA current source eliminates external pull-ups on SDAB/SCLB, reducing BOM count and layout area. |
| Zero static-voltage offset | Eliminates fixed offset-induced lockup; ensures VOL ≤ 0.26 V on B-side meets strict VIL thresholds of modern slaves. |
| Asymmetric supply independence | VCCA and VCCB may be powered in any sequence or ratio - no sequencing constraints simplify system power design. |
| Powered-off A-side protection | SCLA/SDAA enter high-Z when VCCA or VCCB drops below UVLO, preventing back-powering of unpowered domains. |
| Back-power protection | All I²C pins include protection circuitry blocking current flow into VCCA/VCCB, safeguarding supplies during hot-swap events. |
Applications
| Server Backplane Interconnect | Rack-Level Power Management |
|---|---|
Use Scenario: Isolating I²C control buses between 0.8 V FPGA management cores and 3.3 V PMBus-compliant DC-DC controllers across PCB connectors. IC Role / Device Role / Timing Role: Dual-channel bidirectional buffer with independent A/B supply domains and 400 kHz timing compliance. Use Value: Eliminates external B-side pull-ups and ensures VOL ≤ 0.26 V at 3.3 V, guaranteeing reliable ACK/NACK signaling under varying load conditions. |
Use Scenario: Bridging I²C sensors (1.8 V) and microcontrollers (3.3 V) in modular power shelf units with hot-swap capability. IC Role / Device Role / Timing Role: Level-translating repeater with powered-off A-side high-Z and back-power protection. Use Value: Prevents back-feeding from powered B-side into unpowered A-side domains during insertion/removal, meeting IEC 61000-4-2 ESD immunity requirements. |
| Industrial PLC I/O Expansion | Automotive ADAS Camera Hub |
Use Scenario: Extending I²C distance between 2.5 V main controller and remote 1.8 V sensor nodes over 15 cm FR4 traces with 200 pF loading. IC Role / Device Role / Timing Role: Low-capacitance buffer (2–10 pF I/O) with 75 ns A→B propagation delay and 400 pF B-side drive. Use Value: Maintains signal integrity at 400 kHz with <1% duty-cycle distortion, avoiding clock stretching failures in time-critical motion control loops. |
Use Scenario: Interfacing 1.2 V image signal processors with 3.3 V camera module EEPROMs and temperature sensors in compact camera housings. IC Role / Device Role / Timing Role: Ultra-low-power (45 µA) repeater supporting –40°C to +125°C ambient with no static offset. Use Value: Enables always-on thermal monitoring without compromising battery runtime in parking-assist systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I²C level-shifting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TCA9802DGKT | 2.2 mA B-side current source (vs. 3.3 mA); lower drive strength reduces max bus capacitance to 250 pF. | Suitable for shorter traces (<10 cm) or lower-speed (100 kHz) systems where power budget is tighter. | Select when 400 pF load is not required and lower ICCB (65 µA vs. 75 µA at 1.8 V) improves system efficiency. |
| PCA9515ADGKR | Pass-FET architecture with static voltage offset (~0.5 V); requires external B-side pull-ups; no integrated current source. | Lacks resistorless operation and zero-offset benefits; higher VOL risks VIL violations with low-threshold slaves. | Choose only for legacy designs already using PCA9515A footprint; not recommended for new designs requiring robust low-VOL performance. |
Compared with TCA9802DGKT and PCA9515ADGKR, the TCA9803DGKT uniquely combines resistorless B-side drive, zero static offset, and 400 pF load support - delivering superior noise margin and layout simplicity in high-density, multi-voltage I²C systems.
Availability
TCA9803DGKT is available at Aetrix Electronics and suitable for server backplanes, industrial PLCs, automotive ADAS hubs, and power management subsystems requiring stable component supply across extended temperature and voltage ranges.
Supply support for TCA9803DGKT 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 company specializing in analog, embedded processing, and connectivity technologies, with decades of leadership in interface ICs and power management solutions.
The TCA9803DGKT belongs to TI's I²C/SMBus level-translating buffer family, designed specifically for high-reliability, multi-voltage system interconnects in servers, industrial automation, and automotive electronics.
FAQ
What is the maximum bus capacitance supported by the TCA9803DGKT on the B-side?
The TCA9803DGKT supports up to 400 pF on the B-side (SDAB/SCLB), as specified in Section 7.5 of the SCPS267B datasheet under parameter CBUS. Exceeding this limit violates device functionality - unlike the A-side, which has no capacitive load restriction. This 400 pF rating enables reliable 400 kHz Fast-mode Plus operation across typical PCB trace lengths and connector parasitics in server and industrial applications.
Can external pull-up resistors be used on the SDAB or SCLB pins of the TCA9803DGKT?
No - external pull-up resistors must not be connected to SDAB or SCLB. The TCA9803DGKT uses an integrated 3.3 mA current source on the B-side to provide active pull-up; adding external resistors introduces parasitic current (IEXT-I) that interferes with low-level detection logic and may cause communication failure. Section 9.3.1 and Pin Functions table explicitly prohibit external pull-ups on these pins for proper operation.
Does the TCA9803DGKT require specific power supply sequencing between VCCA and VCCB?
No - the TCA9803DGKT has no power sequencing requirements. VCCA may be powered before, after, or simultaneously with VCCB, and VCCA may be greater than, less than, or equal to VCCB. This flexibility is enabled by its true buffering architecture and independent UVLO thresholds (0.55 V on VCCA, 1.51 V on VCCB), allowing robust integration into complex multi-rail power systems without sequencing circuitry.
What is the VOL specification for the TCA9803DGKT on the A-side and B-side?
Per Section 7.5 Electrical Characteristics, the TCA9803DGKT specifies VOL ≤ 0.13 V on the A-side (SDAA/SCLA at IOL = 6 mA) and VOL ≤ 0.26 V on the B-side (SDAB/SCLB at VIA = 0 V). These values are measured at 25°C and ensure compatibility with I²C VIL thresholds (≤0.3×VCC) across full operating voltage ranges - critical for avoiding false low detection in mixed-voltage systems.
How does the EN pin behave when pulled low while VCCB remains powered?
When EN is logic LOW, the repeater function disables (SCLA ≠ SCLB, SDAA ≠ SDAB), but the B-side current source remains active per Section 9.3.4. This means SDAB/SCLB retain their 3.3 mA pull-up capability and do not float - enabling controlled bus hold during reset sequences. However, A-side pins (SCLA/SDAA) enter high-impedance state if VCCA or VCCB falls below UVLO, preserving isolation integrity.
TCA9803DGKT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Translator Type:
- Voltage Level
- Channel Type:
- Bidirectional
- Number of Circuits:
- 1
- Channels per Circuit:
- 2
- Voltage - VCCA:
- 0.8 V ~ 3.6 V
- Voltage - VCCB:
- 1.65 V ~ 3.6 V
- Input Signal:
- -
- Output Signal:
- -
- Output Type:
- Non-Inverted
- Data Rate:
- -
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Features:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
TCA9803DGKT FAQ
1.How can I place an order for TCA9803DGKT through Aetrix?
Please submit a Request for Quotation (RFQ) for TCA9803DGKT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TCA9803DGKT reliable?
The price and inventory of TCA9803DGKT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TCA9803DGKT is usually 5 days.
3.What payment methods are accepted for TCA9803DGKT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TCA9803DGKT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TCA9803DGKT?
TCA9803DGKT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TCA9803DGKT order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TCA9803DGKT?
For technical support, including TCA9803DGKT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TCA9803DGKT requirements.
6.How does Aetrix verify that TCA9803DGKT is sourced from the original manufacturer or authorized distributors?
All TCA9803DGKT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TCA9803DGKT meets industry standards.
7.What is the process for return or replacement of TCA9803DGKT?
All TCA9803DGKT units undergo pre-shipment inspection (PSI). If there is an issue with TCA9803DGKT, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TCA9803DGKT part is unused and in its original packaging.
Return procedure for TCA9803DGKT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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