My Inquiry
My Account
Texas Instruments UCC3818DW
- Part No.:
- UCC3818DW
- Manufacturer:
- Texas Instruments
- Category:
- PFC (Power Factor Correction)
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
UCC3818DW.pdf
- Description:
- IC PFC CTR AVERAGE 220KHZ 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,946
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
UCC3818DW from Texas Instruments is a BiCMOS active power factor correction (PFC) controller for boost preregulators, implementing average current-mode control with leading-edge PWM modulation. It features a 7.5-V reference, 10.5 V/10 V UVLO threshold, 93–99% maximum duty cycle, and supports IEC 61000-3-2 compliance for sub-300 W supplies in PC power and lighting applications.
For engineers reviewing the UCC3818DW datasheet, UCC3818DW pinout, UCC3818DW application, or UCC3818DW equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative options, and supply support for industrial and embedded PFC designs.
Technical Context
The UCC3818DW integrates a high-accuracy 7.5-V reference, dual error amplifiers (voltage and current), an analog multiplier with feed-forward (VFF) input, and a totem-pole gate driver delivering up to 1.2 A peak sink current. Its average current-mode architecture uses CAI/MOUT differential sensing and CAOUT-driven PWM latch for low-distortion sinusoidal line current shaping.
UVLO operates at 10.5 V turn-on / 9.7 V turn-off with only 0.5 V hysteresis, distinguishing it from the UCC2818's 16 V/10 V UVLO. The oscillator frequency (6–220 kHz) is set via RT and CT pins using f ≈ 0.6/(RT × CT), and soft-start (SS) employs a –10 µA charge current to ramp duty cycle gradually during startup.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC UVLO Threshold | 10.5 V turn-on / 9.7 V turn-off - enables operation across universal AC inputs without external bias winding dependency |
| Reference Voltage | 7.5 V ±1.5% - stable internal reference for voltage amplifier and PKLMT level-shifting, capable of sourcing 20 mA |
| Oscillator Frequency Range | 6 kHz to 220 kHz - programmable via RT/CT; supports optimized EMI filtering and transformer size reduction |
| Gate Drive Output | 1.2 A peak sink / 0.9 A peak source - drives MOSFET gates directly with <50 ns rise/fall times into 1 nF load |
| Maximum Duty Cycle | 99% - ensures full boost regulation capability even under low-line, high-load conditions |
| Current Amplifier Offset | ±2.5 mV - minimizes light-load current distortion and improves THD performance below 20% load |
| Soft-Start Charge Current | –10 µA - controls ramp rate of SS capacitor to prevent inrush and ensure controlled output voltage rise |
Pinout & Package
UCC3818DW is housed in a 16-pin SOIC (DW) package measuring 7.5 mm × 10.3 mm, with standard 1.27 mm pitch and gull-wing leads suitable for automated assembly and thermal reliability in industrial PFC stages.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (1) | Power and signal reference ground | Common return for VCC, VREF, and all analog circuitry; requires direct 0.1 µF ceramic bypass to minimize noise coupling |
| PKLMT (2) | Peak current limit input | Accepts level-shifted sense voltage; triggers shutdown when falling below 0 V - sets hard current limit independent of line voltage |
| CAOUT (3) | Current amplifier output | Drives PWM latch comparator; compensation network between CAOUT and MOUT sets loop stability and bandwidth |
| CAI (4) | Current amplifier non-inverting input | Connects to GND-side of current sense resistor; operates down to –0.5 V for bidirectional sensing capability |
| MOUT (5) | Multiplier output & current amp inverting input | High-impedance node combining multiplier current and CAI feedback - enables differential sensing and leading-edge modulation |
| IAC (6) | Line voltage proportional current input | Accepts up to 500 µA current from rectified AC line - primary feed-forward path for distortion cancellation |
| VAOUT (7) | Voltage amplifier output | Regulates bulk capacitor voltage; clamped at ~5.5 V to prevent overshoot during transients or OVP events |
| VFF (8) | Feed-forward RMS voltage | Generated by mirroring half of IAC through external RC filter; scales multiplier gain to maintain constant power across line range |
| VREF (9) | 7.5 V reference output | Stable, short-circuit protected reference used for PKLMT scaling, biasing, and external circuitry - disabled below UVLO |
| OVP/EN (10) | Overvoltage protection & enable input | Window comparator: disables DRVOUT above programmed threshold or forces reset when pulled <1.9 V |
| VSENSE (11) | Voltage amplifier inverting input | Connects to output divider network; closed-loop feedback point for bulk voltage regulation accuracy and transient response |
| RT (12) | Oscillator timing resistor connection | Sets charging current for CT capacitor; 10–100 kΩ range yields stable frequency with <±1% line variation |
| SS (13) | Soft-start control | Charged by internal current source; used as voltage error signal during startup to limit initial duty cycle and prevent inrush |
| CT (14) | Oscillator timing capacitor connection | Defines switching frequency with RT; requires short, low-inductance GND trace to avoid jitter and instability |
| VCC (15) | Supply voltage input | Operates from 10–17 V; must deliver ≥20 mA; bypassed directly to GND to support gate drive current spikes |
| DRVOUT (16) | Boost switch gate driver output | Totem-pole MOSFET driver with 5–12 Ω pull-up / 2–10 Ω pull-down - requires series gate resistor to damp ringing |
Key Features
| Feature | Design Value |
|---|---|
| Average current-mode control | Enables stable, low-THD sinusoidal line current without slope compensation - critical for IEC 61000-3-2 Class D compliance |
| Leading-edge PWM modulation | Synchronizes with downstream DC-DC stage to reduce bulk capacitor ripple current, extending capacitor lifetime in compact PSUs |
| Accurate 7.5 V reference | ±1.5% tolerance over temperature supports precise current limiting and voltage regulation without external trimming |
| Low start-up current (150 µA) | Reduces auxiliary supply burden and enables direct startup from rectified AC via high-value resistor networks |
| Integrated OVP/EN window comparator | Provides fail-safe output disable on overvoltage or undervoltage fault - eliminates need for external supervisor IC |
| BiCMOS process technology | Combines bipolar precision analog blocks with CMOS logic density - achieves 4 mA typical operating current at 100 kHz |
Applications
| PC Power Supply | LED Driver Input Stage |
|---|---|
Use Scenario: 200–300 W ATX power supply meeting IEC 61000-3-2 Class D harmonic limits. IC Role / Device Role / Timing Role: Primary PFC controller regulating boost converter to shape input current waveform matching AC voltage phase. Use Value: Enables >98% power factor and <10% THD at full load using single-stage active correction, reducing filter size and cost vs passive solutions. |
Use Scenario: High-bay LED fixture with universal AC input and integrated PFC front-end. IC Role / Device Role / Timing Role: Controls boost preregulator to deliver stable 400 V DC bus for downstream constant-current LED drivers. Use Value: Maintains near-unity PF across 90–264 VAC input while supporting dimming compatibility and thermal derating down to –40°C ambient. |
| Industrial AC-DC Adapter | Consumer Audio Power Stage |
Use Scenario: 250 W industrial control system power module requiring long-term reliability and wide temperature operation. IC Role / Device Role / Timing Role: Active PFC controller managing boost stage before isolated LLC resonant converter. Use Value: Delivers consistent regulation and low EMI across –40°C to +85°C ambient, supported by tight UVLO hysteresis and robust gate drive. |
Use Scenario: High-fidelity AV receiver with multi-rail power supply and strict standby power requirements. IC Role / Device Role / Timing Role: PFC controller enabling efficient bulk conversion while minimizing no-load consumption via zero-power detection. Use Value: Achieves <0.5 W no-load input power using zero-power comparator (0.33 V threshold on VAOUT) and low 4 mA quiescent current. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PFC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC2818DW | Same pinout, but 16 V/10 V UVLO and –40°C to +85°C rating; higher start-up current (300 µA) | Preferred for extended temperature industrial designs requiring wider UVLO margin | Select UCC2818DW when operating beyond 70°C ambient or needing higher UVLO turn-on voltage |
| FAN7930C | Fixed-frequency CCM controller; no feed-forward (VFF) input; lower integration (no VREF, no SS current source) | Better suited for cost-sensitive, fixed-line applications where universal input isn't required | Choose FAN7930C for simplified BOM in 230 V-only systems with relaxed THD targets |
Compared with UCC2818DW and FAN7930C, the UCC3818DW offers tighter UVLO hysteresis (0.5 V), lower start-up current (150 µA), and integrated 7.5 V reference - making it optimal for universal-input, space-constrained, and low-standby-power PFC designs where precision and flexibility outweigh minimal BOM savings.
Availability
UCC3818DW is available at Aetrix Electronics and suitable for PC power supplies, LED driver input stages, industrial AC-DC adapters, and consumer audio power stages requiring stable component supply, long-lifecycle support, and TI-authorized traceability.
Supply support for UCC3818DW 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 decades of expertise in power conversion ICs.
The UCC3818DW belongs to TI's BiCMOS PFC controller product line, designed specifically for high-efficiency, low-THD active power factor correction in universal-input AC-DC power supplies under 300 W.
FAQ
What is the UVLO behavior of the UCC3818DW?
The UCC3818DW features an undervoltage lockout with 10.5 V turn-on and 9.7 V turn-off thresholds, yielding only 0.5 V hysteresis. This narrow window enables reliable startup across universal AC inputs while minimizing dropout risk during brownouts. Unlike the UCC2818DW, the UCC3818DW does not assert shunt-mode VCC regulation - its UVLO is strictly comparator-based. The UCC3818DW remains fully functional within this band and disables DRVOUT outside it.
How does the UCC3818DW implement average current-mode control?
The UCC3818DW implements average current-mode control using a differential current-sense architecture: CAI connects to the GND side of the sense resistor, while MOUT serves as the inverting input of the current amplifier and carries the multiplier output current. This configuration rejects common-mode noise and enables accurate reconstruction of average line current. The UCC3818DW then compares CAOUT against a ramp signal to generate PWM duty cycle - ensuring low distortion and inherent stability without slope compensation.
Can the UCC3818DW be used in discontinuous conduction mode (DCM)?
The UCC3818DW is optimized for continuous conduction mode (CCM) boost PFC operation and does not include dedicated DCM or transition-mode (CRM) control logic such as zero-current detection (ZCD). Its average current-mode architecture, fixed-frequency oscillator, and lack of valley-switching capability make it unsuitable for true DCM/CRM topologies. For CRM applications, TI recommends the UCC28070 or UCC28051. The UCC3818DW must be applied in CCM with appropriate inductor sizing and loop compensation.
What is the role of the VFF pin on the UCC3818DW?
The VFF pin on the UCC3818DW provides a feed-forward voltage derived from half the IAC current through an external RC filter, producing an RMS-representative signal (e.g., 1.4 V at low line, ~4.7 V at high line). This voltage scales the analog multiplier's gain to maintain constant power delivery across the AC input range - directly enabling near-unity power factor and low THD without software or adaptive tuning. The UCC3818DW's VFF path is integral to its line-voltage adaptive current shaping capability.
Does the UCC3818DW include overvoltage protection?
Yes, the UCC3818DW includes hardware-based overvoltage protection via the OVP/EN pin, which functions as a window comparator. When the sensed boost output voltage exceeds the internal threshold (VREF + 0.50 V, typically 8.0 V), the controller immediately disables DRVOUT and halts switching. The OVP feature has 500 mV hysteresis to prevent chatter and is fully independent of the main voltage amplifier loop - providing fail-safe protection even if VAOUT saturates or compensation fails. This OVP action is identical across all UCCx81x variants.
UCC3818DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Mode:
- Average Current
- Frequency - Switching:
- 6kHz ~ 220kHz
- Current - Startup:
- 150 µA
- Voltage - Supply:
- 12V ~ 17V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
UCC3818DW FAQ
1.How can I place an order for UCC3818DW through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC3818DW 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 UCC3818DW reliable?
The price and inventory of UCC3818DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC3818DW is usually 5 days.
3.What payment methods are accepted for UCC3818DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC3818DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC3818DW?
UCC3818DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC3818DW 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 UCC3818DW?
For technical support, including UCC3818DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC3818DW requirements.
6.How does Aetrix verify that UCC3818DW is sourced from the original manufacturer or authorized distributors?
All UCC3818DW 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 UCC3818DW meets industry standards.
7.What is the process for return or replacement of UCC3818DW?
All UCC3818DW units undergo pre-shipment inspection (PSI). If there is an issue with UCC3818DW, 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 UCC3818DW part is unused and in its original packaging.
Return procedure for UCC3818DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
UCC3818DW Tags
-
ICE2PCS01GXUMA1
Infineon Technologies
-
NCP1654BD133R2G
onsemi
-
MC33262DR2G
onsemi
-
ICE3PCS03GXUMA1
Infineon Technologies
-
NCP1631DR2G
onsemi
-
L4981BD013TR
STMicroelectronics
-
UCC28070DWR
Texas Instruments
-
UCC28070PWR
Texas Instruments
-
UC3854DWTR
Texas Instruments
-
L4981AD013TR
STMicroelectronics
-
UCC2817D
Texas Instruments
-
UC2854BDWTR
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…
