My Inquiry
My Account
Texas Instruments UC2902DTR
- Part No.:
- UC2902DTR
- Manufacturer:
- Texas Instruments
- Category:
- Power Management - Specialized
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
UC2902DTR.pdf
- Description:
- IC LOAD SHARE CONTROLLER 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,652
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
UC2902DTR from Texas Instruments is a precision load share controller IC designed for current-balancing across paralleled DC-DC power supplies. It features an integrated 40× current sense amplifier, differential share bus interface (SHARE+/SHARE−), undervoltage lockout (2.5 V typ), and operates from 2.7 V to 20 V. Used in redundant telecom and industrial power systems where thermal derating and output voltage mismatch compensation are critical.
For engineers reviewing the UC2902DTR datasheet, UC2902DTR pinout, UC2902DTR application, or UC2902DTR equivalent, this page delivers verified specifications, SOIC-8 package mapping, real-world load-sharing topology guidance, and validated alternative options for parallel supply designs requiring ±1% current matching.
Technical Context
The UC2902DTR implements a master-slave current balancing architecture using a differential share bus to reject ground noise and accommodate unequal return path impedances. Its current sense amplifier (40× gain, ±1.5 mV offset) converts each supply's output current into a proportional bus voltage, while the SHARE drive amplifier (10 V VOH, 50 mV VOL) actively drives the bus with programmable loop compensation via COMP and ADJR pins.
It integrates an error amplifier (4.5 mS transconductance), UVLO (2.5 V startup, 100 mV hysteresis), and ADJ/ADJR current-source interface for remote voltage trimming. Designed for −40°C to +85°C operation, it supports stable closed-loop sharing at crossover frequencies below the converter's bandwidth-typically <10 kHz-without requiring matched power stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.7 V to 20 V - powers internal circuitry without external LDO; enables direct use from 3.3 V, 5 V, or 12 V rails |
| Current Sense Gain | −40 V/V - scales RSENSE voltage drop to precise share bus level; enables 10 mV/A sensing with 25 mΩ resistor |
| UVLO Threshold | 2.5 V (typ), 60–140 mV hysteresis - prevents erratic startup during brownout; ensures clean enable/disable sequencing |
| SHARE+ Output Drive | 10.0 V VOH @ −1 mA, 50 mV VOL @ −1 mA - drives differential bus under load; supports ≥10 slave units with <100 μA/unit quiescent increase |
| Error Amp gM | 4.5 mS (typ) - sets loop gain for share compensation; used with CC/RG to stabilize crossover at 1–5 kHz |
| Input Offset (SENSE) | ±0.5 mV (typ) - minimizes current-sense error at light loads; contributes <±1.25% full-scale error with 25 mΩ RSENSE |
| Operating Temp | −40°C to +85°C - qualified for industrial-grade power systems; matches extended-range DC-DC converter specs |
Pinout & Package
UC2902DTR is housed in an 8-pin SOIC (D) package per JEDEC MS-012 AA, 3.91 mm body width, 1.75 mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pin 1) | Signal & power reference | Local ground return for all internal amplifiers; must be low-impedance connection to system star ground |
| SENSE (Pin 2) | Inverting input | Connects to negative side of current sense resistor; senses voltage drop proportional to output current |
| ADJ (Pin 3) | NPN collector output | Sinks current into remote voltage feedback node (e.g., TL431 cathode); trims slave supply output |
| ADJR (Pin 4) | NPN emitter reference | Sets ADJ current range; tied to GND via RG to program max trim current (e.g., 5 mA with 360 Ω) |
| COMP (Pin 5) | Error amp I/O | Compensation node for share loop; connects RC/CC network to set phase margin and unity-gain frequency |
| SHARE− (Pin 6) | Differential reference | Common-mode reference for SHARE+; connected to system ground to establish differential bus baseline |
| SHARE+ (Pin 7) | Bus I/O | Drives or senses differential share bus voltage; master unit sources, slaves sink/sense to match current |
| VCC (Pin 8) | Power supply | Primary bias rail; decoupling capacitor (≥1 μF ceramic) required within 5 mm of pin for stability |
Key Features
| Feature | Design Value |
|---|---|
| Differential share bus interface | SHARE+/SHARE− inputs reject common-mode noise up to 1 V; eliminate ground loop errors in multi-board systems |
| Precision current sense amplifier | 40× gain with ±0.5 mV offset enables ≤±1.5% current matching across 10:1 load range without calibration |
| User-programmable share loop compensation | COMP pin accepts RC/CC network to set dominant pole and zero; supports stable operation with diverse DC-DC topologies |
| Integrated UVLO with hysteresis | 2.5 V startup + 100 mV hysteresis prevents oscillation during input ramp-up; eliminates need for external supervisor |
| Remote voltage trimming interface | ADJ/ADJR current source injects trimming current into feedback divider; avoids loading error on high-impedance nodes |
Applications
| Telecom Redundant Power | Industrial PLC Power Backplane |
|---|---|
|
Use Scenario: Dual 48 V DC-DC modules supply critical base station RF cards with N+1 redundancy. IC Role / Device Role / Timing Role: UC2902DTR acts as master-slave current balancer, forcing both modules to deliver identical current despite ±2% output voltage tolerance. Use Value: Prevents thermal runaway and extends module lifetime by limiting individual current to ≤55% of rating under full load. |
Use Scenario: Three 24 V isolated supplies feed distributed I/O modules on a factory automation backplane. IC Role / Device Role / Timing Role: UC2902DTR synchronizes load current distribution across non-identical supplies (e.g., 10 A, 15 A, 20 A units). Use Value: Enables mixed-capacity paralleling via RSENSE scaling; achieves ±1.2% relative current match without firmware or digital control. |
| Medical Imaging Power Shelf | Test Equipment Multi-Rail Supply |
|
Use Scenario: Four 12 V/30 A supplies power MRI subsystems requiring ultra-low ripple and fault containment. IC Role / Device Role / Timing Role: UC2902DTR forms analog current-sharing layer beneath digital PMBus supervision; handles fast transient redistribution. Use Value: Maintains ≤±0.8% current imbalance during 5 A/μs load steps; reduces thermal stress on individual MOSFETs and magnetics. |
Use Scenario: Bench power supply uses two 30 V/5 A channels in parallel to deliver 10 A at 30 V for DUT testing. IC Role / Device Role / Timing Role: UC2902DTR replaces manual potentiometer trimming; provides auto-calibrated current balance during voltage programming. Use Value: Eliminates manual adjustment drift over temperature; ensures consistent current split across 0–100% load and 5–30 V output range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar load share controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UC3902DTR | Commercial temp range (0°C to +70°C); identical electrical specs and pinout | Not rated for industrial ambient; unsuitable for enclosures exceeding 70°C ambient or cold-start below 0°C | Select UC3902DTR only for cost-sensitive commercial equipment with controlled environment |
| LTC4370IMS#PBF | Wide input (2.5 V to 36 V), higher accuracy (±0.5% current match), integrated MOSFET drivers, no external RSENSE needed | Requires PCB layout changes; supports hot-swap and reverse-current blocking; adds ~$2.50 BOM cost | Choose LTC4370 when upgrading legacy UC2902DTR designs for tighter matching or fault protection |
Compared with UC2902DTR, UC3902DTR trades industrial temperature support for lower cost in benign environments, while LTC4370IMS#PBF delivers superior accuracy and integration at the expense of pin compatibility and added complexity-making UC2902DTR optimal for proven, cost-constrained industrial parallel supply upgrades.
Availability
UC2902DTR is available at Aetrix Electronics and suitable for telecom power redundancy, industrial PLC backplanes, medical imaging shelves, and test equipment multi-rail supplies requiring stable component supply across extended lifecycles.
Supply support for UC2902DTR 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 technologies with over 90 years of innovation in industrial and automotive electronics.
The UC2902DTR belongs to TI's legacy load share controller product line, engineered specifically for analog-based current balancing in paralleled DC-DC converters where digital communication or complex configuration is unnecessary.
FAQ
What is the operating temperature range for UC2902DTR?
The UC2902DTR is specified for −40°C to +85°C ambient operation, qualifying it for industrial environments including outdoor telecom cabinets and factory-floor PLC systems. This range is confirmed in TI's SLUS232E datasheet Section 2 (Absolute Maximum Ratings) and Packaging Addendum, where UC2902DTR is explicitly listed with "−40 to 85" °C under Op temp (°C). The device uses the same die as UC2902D but in tape-and-reel packaging (2500 pcs/reel).
Does UC2902DTR require external components to function?
Yes, UC2902DTR requires five external passive components for basic operation: a current sense resistor (RSENSE) in each supply's return path, a gain-setting resistor (RG) from ADJR to GND, a remote sense resistor (RADJ) in the feedback loop, and a compensation network (RC and CC) on the COMP pin. These are detailed in the "APPLICATION INFORMATION" section of SLUS232E, with design equations provided for setting full-scale share bus voltage, trim current, and loop stability.
Can UC2902DTR be used with power supplies having different current ratings?
Yes, UC2902DTR supports paralleling supplies with different current capabilities by scaling RSENSE values proportionally-e.g., a 10 A supply uses 50 mΩ, while a 20 A unit uses 25 mΩ-so each delivers the same percentage of its rated current. This capability is explicitly stated in the "DESCRIPTION" section of SLUS232E: "By appropriately scaling the current sense resistor, supplies with different output current capability can be paralleled…"
What is the purpose of the SHARE− pin on UC2902DTR?
The SHARE− pin serves as the differential reference for the SHARE+ input, enabling noise-immune operation over long traces or across separate PCBs. As documented in SLUS232E Figure 1 and "APPLICATION INFORMATION", SHARE− is connected to system ground to establish the common-mode baseline for the differential share bus-rejecting ground potential differences between paralleled supplies and improving immunity to EMI in high-noise industrial settings.
Is UC2902DTR pin-compatible with UC3902DTR?
Yes, UC2902DTR and UC3902DTR are fully pin-compatible 8-pin SOIC devices with identical pin functions, electrical characteristics, and application circuits. The sole difference is operating temperature range: UC2902DTR is rated for −40°C to +85°C, while UC3902DTR is rated for 0°C to +70°C. This is confirmed in TI's Ordering Information table (page 5) and Package Option Addendum, where both share "SOIC (D) | 8" and identical terminal functions.
UC2902DTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Applications:
- Load Share Controller
- Current - Supply:
- 4mA
- Voltage - Supply:
- 2.7V ~ 20V
- Operating Temperature:
- -40°C ~ 100°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
UC2902DTR FAQ
1.How can I place an order for UC2902DTR through Aetrix?
Please submit a Request for Quotation (RFQ) for UC2902DTR 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 UC2902DTR reliable?
The price and inventory of UC2902DTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC2902DTR is usually 5 days.
3.What payment methods are accepted for UC2902DTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC2902DTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC2902DTR?
UC2902DTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC2902DTR 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 UC2902DTR?
For technical support, including UC2902DTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC2902DTR requirements.
6.How does Aetrix verify that UC2902DTR is sourced from the original manufacturer or authorized distributors?
All UC2902DTR 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 UC2902DTR meets industry standards.
7.What is the process for return or replacement of UC2902DTR?
All UC2902DTR units undergo pre-shipment inspection (PSI). If there is an issue with UC2902DTR, 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 UC2902DTR part is unused and in its original packaging.
Return procedure for UC2902DTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
UC2902DTR Tags
-
TPS2511DGNR
Texas Instruments
-
UTC2000/MG
Microchip Technology
-
TUSB320HAIRWBR
Texas Instruments
-
TPS61252DSGR
Texas Instruments
-
PI5USB30216CXUAEX
Diodes Incorporated
-
SN6501DBVR
Texas Instruments
-
CYPD3177-24LQXQT
Infineon Technologies
-
SN6501QDBVRQ1
Texas Instruments
-
STUSB1600AQTR
STMicroelectronics
-
SN6505BDBVR
Texas Instruments
-
SN6501DBVT
Texas Instruments
-
TPS65150PWPR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
