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Texas Instruments UC285TDKTTT-3
- Part No.:
- UC285TDKTTT-3
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
UC285TDKTTT-3.pdf
- Description:
- IC REG LIN 2.5V 5A DDPAK/TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,187
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Product details
Overview
UC285TDKTTT-3 from Texas Instruments is a fixed-output 2.5 V, 5-A low-dropout linear regulator in TO-263 (TD) package with Kelvin-sense capability, 490 mV max dropout at 5 A, short-circuit protection, and fast transient response optimized for GTL/BTL bus powering in high-speed digital systems.
For engineers reviewing the UC285TDKTTT-3 datasheet, UC285TDKTTT-3 pinout, UC285TDKTTT-3 application, or UC285TDKTTT-3 equivalent, this page delivers verified specifications, thermal and electrical behavior across −40°C to 100°C, package-level layout guidance, and real-world substitution options for industrial and telecom power rail design.
Technical Context
The UC285TDKTTT-3 implements a Darlington output stage powered via separate VB and VIN pins, enabling 350 mV typical dropout (VIN–VOUT) at 5 A and 1.8 V minimum VB–VOUT headroom. Its internal 1.2 V bandgap reference feeds a noninverting power amplifier with Kelvin-sense feedback path routed through the ADJ pin.
It features integrated thermal shutdown, reverse current protection, and 80–110 dB VIN PSRR up to 100 kHz. Load regulation holds within ±4 mV from 10 mA to 5 A, and short-circuit current limit is 5.1–7.5 A - all specified over −40°C to 100°C operating junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.5 V ±1% (2.45–2.525 V) at 100 mA load; enables precise GTL/BTL termination without external resistors. |
| Max Dropout (VIN–VOUT) | 500 mV at 5 A, −40°C to 100°C; allows operation with minimal input–output margin in dense PCB layouts. |
| Load Regulation | ±4 mV from 10 mA to 5 A; ensures stable voltage delivery across dynamic CPU/memory load steps. |
| VIN PSRR | 80–110 dB (100 Hz–100 kHz); suppresses ripple from upstream switching supplies feeding VIN. |
| VB PSRR | 50–67 dB (100 Hz–100 kHz); maintains regulation integrity when VB is derived from noisy auxiliary rails. |
| Short-Circuit Limit | 5.1–7.5 A; provides robust fault containment without latch-up during board-level surge events. |
| Operating Temp Range | −40°C to 100°C junction; supports industrial and telecom base station environments without derating. |
Pinout & Package
UC285TDKTTT-3 uses a 5-pin TO-263 (TD) thermally enhanced surface-mount package with exposed tab electrically connected to GND. The tab serves as primary thermal path and must be soldered to a large copper pour for ≤30°C/W junction-to-board thermal resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: ADJ | Feedback reference input | Kelvin sense point for load voltage; connects directly to load ground for precision regulation-bypasses trace IR drop. |
| 2: VOUT | Regulated output | Power delivery node; requires low-inductance path to load and ≥100 µF local tantalum/OSCON decoupling. |
| 3: VB | Bias supply input | Powers control circuitry only; 2 V headroom above VOUT enables Darlington fast-response architecture. |
| 4: VIN | Power transistor collector supply | Feeds output pass element only; dropout <100 mV at light loads, max 500 mV at 5 A full load. |
| 5: GND | Signal and power return | Reference for ADJ and internal circuits; must tie to load ground at single point to avoid ground loop error. |
Key Features
| Feature | Design Value |
|---|---|
| Separate VB and VIN inputs | Enables independent optimization of bias rail stability and power rail efficiency-critical for multi-rail systems. |
| 5-pin Kelvin sensing | Eliminates regulation error from PCB trace resistance; maintains ±1% accuracy at remote load points. |
| Fast transient response | ΔVOUT < ±20 mV under 10 mA–3 A/µs load steps; reduces required bulk capacitance by >50% vs standard LDOs. |
| Reverse current protection | Blocks backfeed from VOUT to VIN or VB during power sequencing or hot-swap events-no external diode needed. |
| Thermal shutdown | Activates at ~150°C junction; latches off until cooldown, preventing thermal runaway in enclosed enclosures. |
Applications
| GTL Bus Termination | BTL Signal Conditioning |
|---|---|
|
Use Scenario: Powering GTL (Gunning Transceiver Logic) termination networks in high-speed memory controllers and ASIC interfaces. IC Role / Device Role / Timing Role: Provides ultra-stable 2.5 V reference rail with sub-20 mV transient deviation during 100+ MHz data bursts. Use Value: Enables clean signal eye diagrams by eliminating droop-induced timing skew on parallel address/data buses. |
Use Scenario: Supplying BTL (Backplane Transceiver Logic) receivers in telecom line cards requiring tight voltage tolerance. IC Role / Device Role / Timing Role: Delivers regulated 2.5 V with <4 mV load regulation across 10 mA–5 A, ensuring consistent receiver threshold alignment. Use Value: Prevents bit errors caused by supply-induced common-mode shift in differential signaling paths. |
| FPGA I/O Bank Supply | Industrial PLC Digital I/O Module |
|
Use Scenario: Powering FPGA I/O banks configured for 2.5 V SSTL or GTL standards in programmable logic systems. IC Role / Device Role / Timing Role: Acts as local point-of-load regulator with Kelvin feedback to compensate for PCB voltage drop to FPGA package. Use Value: Guarantees I/O timing margins by holding VCCIO within ±1% despite 100+ mA dynamic current spikes per bank. |
Use Scenario: Supplying isolated digital input/output modules in programmable logic controllers operating in harsh factory environments. IC Role / Device Role / Timing Role: Serves as ruggedized 2.5 V rail generator with −40°C to 100°C operation and short-circuit survival. Use Value: Maintains deterministic logic levels during ESD transients and 24 V field-wiring faults without system reset. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-dropout, high-current linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS75725 | 2.5 V fixed, 3-A output, 120 mV typical dropout at 3 A; no separate VB pin; TO-220/TO-263 packages available. | Limited to 3 A; lacks Kelvin sensing and VB/VIN separation-less suitable for >4 A GTL/BTL loads with strict transient specs. | Choose for cost-sensitive 3-A designs where fast transient response is secondary to simplicity. |
| LT1585A-2.5 | 2.5 V fixed, 5-A output, 450 mV max dropout at 5 A; single-input (VIN-only); TO-220/TO-263 packages; no VB pin. | No bias rail isolation or Kelvin sense-requires larger output capacitance to meet same transient performance as UC285TDKTTT-3. | Choose when board space permits extra bulk caps and dual-rail sourcing is unavailable. |
Compared with TPS75725 and LT1585A-2.5, UC285TDKTTT-3 uniquely combines 5-A capability, Kelvin sensing, and split VB/VIN architecture-delivering superior transient suppression and layout flexibility for high-speed digital interface rails where voltage accuracy and dynamic response are non-negotiable.
Availability
UC285TDKTTT-3 is available at Aetrix Electronics and suitable for GTL bus termination, BTL signal conditioning, FPGA I/O supply, industrial PLC modules, and telecom line card power applications requiring stable component supply across extended temperature ranges.
Supply support for UC285TDKTTT-3 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 leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in high-reliability power regulation solutions.
The UC285 series belongs to TI's high-current LDO family designed specifically for fast-transient, low-noise powering of GTL, BTL, and SSTL logic interfaces in telecom, computing, and industrial infrastructure equipment.
FAQ
What is the maximum junction temperature specification for UC285TDKTTT-3?
The UC285TDKTTT-3 has an absolute maximum junction temperature of 150°C and is rated for continuous operation from −40°C to 100°C junction temperature. Thermal shutdown activates near 150°C to protect the device during overload or poor heatsinking conditions. Derating applies above 100°C ambient when mounted on standard 2-layer PCBs without enhanced thermal pads.
Does UC285TDKTTT-3 require external resistors to set its output voltage?
No, UC285TDKTTT-3 is a fixed-output 2.5 V regulator and does not require external resistors. Unlike the adjustable UC285TDKTTT-ADJ variant, the -3 suffix denotes factory-trimmed 2.5 V output with ±1% tolerance at 100 mA. The ADJ pin is internally tied to VOUT to establish the default 1.2 V reference but remains accessible for Kelvin sensing.
How does the separate VB pin improve performance in UC285TDKTTT-3?
The VB pin powers only the control circuitry-including reference, error amplifier, and protection logic-while VIN supplies only the output pass transistor. This separation allows VB to be sourced from a clean, low-noise rail (e.g., filtered LDO), improving PSRR and transient immunity. It also enables 2 V headroom (VB–VOUT), supporting the Darlington output stage for faster response than single-supply LDOs.
Can UC285TDKTTT-3 be used with ceramic output capacitors only?
UC285TDKTTT-3 is stable with ≥100 µF tantalum or OSCON capacitors, which provide optimal ESR for phase margin. While ceramic capacitors may be used in parallel for high-frequency bypassing (e.g., 2.2 µF X7R close to VOUT), they must be combined with ≥47 µF tantalum/OSCON to ensure stability under full 5-A load transients. Pure-ceramic output configurations risk oscillation due to insufficient ESR.
What is the purpose of the ADJ pin on UC285TDKTTT-3 if the output is fixed at 2.5 V?
On UC285TDKTTT-3, the ADJ pin serves exclusively as the Kelvin sense point for remote load voltage feedback-not for output adjustment. It must be connected directly to the load ground reference to eliminate PCB trace IR drop from regulation sensing. This preserves ±1% output accuracy at the load, even with milliohm-level trace resistance between VOUT pin and actual load connection.
UC285TDKTTT-3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 7.5V
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 2.2V @ 5A
- Current - Output:
- 5A
- Current - Quiescent (Iq):
- -
- Current - Supply (Max):
- -
- PSRR:
- -
- Control Features:
- -
- Protection Features:
- Over Temperature, Reverse Polarity, Short Circuit
- Operating Temperature:
- -40°C ~ 100°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263 (DDPAK-5)
UC285TDKTTT-3 FAQ
1.How can I place an order for UC285TDKTTT-3 through Aetrix?
Please submit a Request for Quotation (RFQ) for UC285TDKTTT-3 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 UC285TDKTTT-3 reliable?
The price and inventory of UC285TDKTTT-3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC285TDKTTT-3 is usually 5 days.
3.What payment methods are accepted for UC285TDKTTT-3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC285TDKTTT-3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC285TDKTTT-3?
UC285TDKTTT-3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC285TDKTTT-3 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 UC285TDKTTT-3?
For technical support, including UC285TDKTTT-3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC285TDKTTT-3 requirements.
6.How does Aetrix verify that UC285TDKTTT-3 is sourced from the original manufacturer or authorized distributors?
All UC285TDKTTT-3 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 UC285TDKTTT-3 meets industry standards.
7.What is the process for return or replacement of UC285TDKTTT-3?
All UC285TDKTTT-3 units undergo pre-shipment inspection (PSI). If there is an issue with UC285TDKTTT-3, 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 UC285TDKTTT-3 part is unused and in its original packaging.
Return procedure for UC285TDKTTT-3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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