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Texas Instruments UC2901DTR
- Part No.:
- UC2901DTR
- Manufacturer:
- Texas Instruments
- Category:
- Power Management - Specialized
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
UC2901DTR.pdf
- Description:
- IC ISOLATED FB GENERATOR 14-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,187
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Product details
Overview
UC2901DTR from Texas Instruments is an isolated feedback generator IC designed for closed-loop regulation across voltage isolation boundaries in switch-mode power supplies. It implements amplitude modulation using an internal 130–170 kHz oscillator (typ. 150 kHz), features a 1.5 V ±1.5% reference, integrated error amplifier with 60 dB CMRR and 100 dB PSRR, and dual driver outputs capable of sourcing ≥15 mA, serving as a low-cost alternative to optical couplers in AC-coupled feedback paths.
For engineers reviewing the UC2901DTR datasheet, UC2901DTR pinout, UC2901DTR application, or UC2901DTR equivalent, this device is selected for high-reliability isolated error signal transmission in industrial SMPS designs where transformer coupling replaces optocouplers, requiring precise reference stability, UVLO-enabled startup control, and status monitoring within ±150 mV input window.
Technical Context
The UC2901DTR uses an internal amplitude-modulation architecture: the error amplifier output modulates a high-frequency carrier (130–170 kHz) generated by an RC-oscillator (RT/CT pins), producing square-wave driver outputs synchronized either internally or via external clock at Pin 2. The STATUS output asserts active-low when error voltage deviates ≤±150 mV from the 1.5 V reference.
Driver outputs (DRIVERA and DRIVERB) are emitter-follower stages with 12 dB fixed gain from compensation pin (Pin 12) to output, supporting RF transformer coupling. Startup is controlled by UVLO thresholds at 3.9–4.5 V on VIN, disabling drivers and STATUS until supply stabilization.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.5 V ±1.5% over –40°C to +85°C - enables stable error comparison without external precision reference |
| Oscillator Frequency | 130–170 kHz (TYP 150 kHz) - sets carrier frequency for transformer-coupled feedback; supports up to 5 MHz with external clock |
| Error Amplifier Gain | 60 dB open-loop gain - provides sufficient loop gain for stable compensation in isolated SMPS feedback networks |
| Driver Output Sink/Source | Sinks 700 µA / sources ≥15 mA - drives small-signal RF transformers or capacitive coupling elements directly |
| Status Input Window | ±150 mV around reference - detects loop-in-regulation condition for system monitoring or fault signaling |
| Supply Range | 4.5 V to 40 V - accommodates wide-input industrial and telecom SMPS rails with built-in UVLO |
| CMRR / PSRR | 60 dB / 100 dB - rejects common-mode noise and supply ripple in noisy power-conversion environments |
Pinout & Package
UC2901DTR is housed in a 14-pin SOIC (D package), 3.90 mm width, RoHS-compliant, moisture sensitivity level 2 (260°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (CR) | Oscillator timing capacitor connection | Connects external CT capacitor to set internal carrier frequency; grounding disables oscillator |
| Pin 2 (CLK) | External clock input | Accepts TTL/CMOS clock to synchronize carrier; overrides internal oscillator when driven |
| Pin 3 (COMP) | Error amplifier compensation node | Feedback point for error amp; requires series DC-blocking capacitor in most applications |
| Pin 4 (EA–) | Error amplifier inverting input | Receives isolated feedback signal; referenced to internal 1.5 V reference at Pin 5 |
| Pin 5 (REF) | Precision 1.5 V reference output | Stable reference for EA–; supplies ≤5 mA; short-circuit protected |
| Pin 6 (EA+) | Error amplifier non-inverting input | Internally tied to REF; used for direct reference monitoring or biasing |
| Pin 7 (GND) | Analog ground reference | All voltages referenced to this pin; must be low-impedance analog return |
| Pin 8 (VIN) | Power supply input | 4.5–40 V input; powers all internal circuits; UVLO threshold at 3.9–4.5 V |
| Pin 9 (DRIVERB) | Modulated driver output B | Emitter-follower output; complements DRIVERA; used for push-pull transformer drive |
| Pin 10 (DRIVERA) | Modulated driver output A | Emitter-follower output; 12 dB gain from COMP; drives primary side of RF transformer |
| Pin 11 (OUT) | Error amplifier output | Internal node between EA and COMP; not externally accessible |
| Pin 12 (STATUS) | Active-low loop-in-regulation indicator | Asserts low when EA input differential is within ±150 mV of REF; open-collector compatible |
| Pin 13 (NC) | No connect | Not bonded; no internal connection; must remain unconnected |
| Pin 14 (NC) | No connect | Not bonded; no internal connection; must remain unconnected |
Key Features
| Feature | Design Value |
|---|---|
| Amplitude-modulation feedback architecture | Enables transformer-based isolation without optocoupler aging or CTR drift, improving long-term reliability in industrial power supplies |
| 1% accurate internal reference | Eliminates need for external voltage reference IC or resistor divider trimming, reducing BOM count and layout area |
| Programmable carrier oscillator (130–170 kHz) | Allows optimization of RF transformer size and cost while maintaining >1 kV isolation compliance |
| External clock synchronization (Pin 2) | Permits carrier alignment with SMPS switching frequency to suppress beat frequencies and EMI |
| Loop status monitor (Pin 12) | Provides real-time feedback loop health indication for system diagnostics or fault-handling logic |
| UVLO-controlled startup (3.9–4.5 V) | Prevents erratic operation during brown-out or soft-start conditions by disabling outputs until stable supply is reached |
Applications
| Industrial SMPS Regulation | Telecom Rectifier Modules |
|---|---|
|
Use Scenario: Regulating output voltage in 48 V input, 12 V/20 A isolated DC-DC converters used in base station power systems. IC Role / Device Role / Timing Role: Isolated feedback generator providing amplitude-modulated error signal across 2.5 kV reinforced isolation barrier via RF transformer. Use Value: Replaces aging-prone optocouplers with stable, temperature-invariant modulation-reducing field failure rates and calibration drift over 10-year service life. |
Use Scenario: Closed-loop control of high-efficiency LLC resonant converters in telecom rectifier shelves operating at –40°C to +70°C ambient. IC Role / Device Role / Timing Role: Carrier-synchronized feedback transmitter; CLK input locked to 300 kHz switching node to eliminate subharmonic interference. Use Value: Enables deterministic EMI profile and eliminates beat-tone artifacts that would otherwise degrade conducted emissions compliance. |
| Medical Power Adapters | Programmable Lab Power Supplies |
|
Use Scenario: Feedback path in IEC 60601-1 compliant 24 V/5 A medical AC-DC adapter requiring 4 kV reinforced isolation and low leakage current. IC Role / Device Role / Timing Role: Isolation boundary interface generating modulated signal across Y-capacitor-coupled path instead of optocoupler. Use Value: Achieves <1 µA patient leakage while meeting creepage/clearance requirements-impossible with standard optocouplers at same cost. |
Use Scenario: Precision voltage/current regulation in benchtop programmable DC supplies with remote sense and fast transient response. IC Role / Device Role / Timing Role: High-PSRR error amplifier (100 dB) rejecting line noise on isolated secondary side; STATUS pin triggers auto-recovery on overvoltage. Use Value: Maintains ±0.1% output accuracy under 100 mVpp line ripple-critical for calibration-grade instrumentation performance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar isolated feedback generator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UC3901DTR | Commercial temperature range (0°C to +70°C); identical pinout, oscillator spec (120–180 kHz), and reference accuracy (±2% over temp) | Targeted for non-industrial environments; lacks extended –40°C startup capability and reduced thermal derating margin | Select UC3901DTR only for cost-sensitive consumer or lab equipment where ambient stays above 0°C |
| UCC3901DWTR | SOIC-16 wide package; adds dedicated GND and VCC pins for improved noise immunity; same oscillator and reference specs | Designed for high-noise industrial motor drives; extra pins allow separate analog/digital ground routing | Choose UCC3901DWTR when layout-level noise rejection is critical and PCB space permits wider SOIC footprint |
Compared with UC2901DTR, UC3901DTR trades industrial temperature range for lower unit cost, while UCC3901DWTR enhances noise robustness via physical pin separation-neither is pin-compatible nor drop-in; both require minor schematic and layout review.
Availability
UC2901DTR is available at Aetrix Electronics and suitable for industrial SMPS regulation, telecom rectifier modules, and medical AC-DC adapters requiring stable component supply with guaranteed long-term availability and full traceability.
Supply support for UC2901DTR 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.
The UC2901DTR belongs to TI's legacy power management analog interface product line, engineered specifically to replace optocouplers in isolated feedback loops of offline and DC-DC converters-prioritizing reliability, temperature stability, and EMI resilience.
FAQ
What is the operating temperature range for UC2901DTR?
The UC2901DTR is rated for operation from –40°C to +85°C, making it suitable for industrial environments where ambient temperatures exceed commercial-grade limits. This range is confirmed in TI's temperature and package selection guide and distinguishes UC2901DTR from UC3901DTR (0°C to +70°C) and UC1901J (–55°C to +125°C). All electrical specifications in the datasheet apply across this full range unless otherwise noted.
Does UC2901DTR require external components to operate?
Yes, UC2901DTR requires at minimum an external timing capacitor (CT) on Pin 1 to set oscillator frequency, a series DC-blocking capacitor between Pin 3 (COMP) and the error amplifier output network, and pull-up resistors on DRIVERA/DRIVERB if driving transformer secondaries. No external reference or clock is needed-the 1.5 V reference and internal oscillator are fully integrated. The UC2901DTR datasheet specifies typical values: CT = 820 pF with RT = 10 kΩ yields ~150 kHz.
Can UC2901DTR be used with optical couplers?
Yes, UC2901DTR can drive optical couplers directly as a DC-coupled driver: its DRIVERA and DRIVERB outputs source ≥15 mA and sink 700 µA, compatible with standard LED inputs. The device's 4.5–40 V supply range, 1% reference, and high-gain error amplifier provide advantages even in non-RF configurations-TI explicitly states this dual-mode capability in the description section of the UC1901/UC2901/UC3901 datasheet.
How does the STATUS output function in UC2901DTR?
The STATUS output (Pin 12) is an active-low open-collector indicator that asserts low when the differential voltage at the error amplifier inputs (Pins 4 and 6) falls within ±150 mV of the 1.5 V reference. It remains high during startup until UVLO releases, then monitors regulation continuously. TI specifies saturation voltage ≤0.45 V at 1.6 mA sink, enabling direct interfacing with microcontroller GPIO or latch circuits without additional level-shifting.
Is UC2901DTR pin-compatible with UC3901DTR?
Yes, UC2901DTR and UC3901DTR share identical SOIC-14 (D package) pinouts, pin functions, and electrical behavior-including reference voltage, oscillator range, driver strength, and STATUS logic. The only differences are temperature grade (–40°C to +85°C vs. 0°C to +70°C) and minor parameter tolerances over temperature. Layout and schematic reuse is fully supported, though thermal validation is required for UC2901DTR in cold-start scenarios.
UC2901DTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Applications:
- Feedback Generator
- Current - Supply:
- 5mA
- Voltage - Supply:
- 4.5V ~ 40V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
UC2901DTR FAQ
1.How can I place an order for UC2901DTR through Aetrix?
Please submit a Request for Quotation (RFQ) for UC2901DTR 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 UC2901DTR reliable?
The price and inventory of UC2901DTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC2901DTR is usually 5 days.
3.What payment methods are accepted for UC2901DTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC2901DTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC2901DTR?
UC2901DTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC2901DTR 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 UC2901DTR?
For technical support, including UC2901DTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC2901DTR requirements.
6.How does Aetrix verify that UC2901DTR is sourced from the original manufacturer or authorized distributors?
All UC2901DTR 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 UC2901DTR meets industry standards.
7.What is the process for return or replacement of UC2901DTR?
All UC2901DTR units undergo pre-shipment inspection (PSI). If there is an issue with UC2901DTR, 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 UC2901DTR part is unused and in its original packaging.
Return procedure for UC2901DTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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