My Inquiry
My Account
Texas Instruments UCC3818NG4
- Part No.:
- UCC3818NG4
- Manufacturer:
- Texas Instruments
- Category:
- PFC (Power Factor Correction)
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
UCC3818NG4.pdf
- Description:
- IC PFC CTR AV CURR 220KHZ 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,364
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
UCC3818NG4 from Texas Instruments is a BiCMOS active power factor correction (PFC) controller for boost preregulators, implementing average current-mode control to achieve near-unity power factor and low line current distortion. It features 7.5-V reference output, 10.5 V/10 V UVLO thresholds, leading-edge PWM modulation, and integrated gate driver with 0.2-A continuous sink/source capability - deployed in sub-300 W IEC61000-3-2-compliant PC and industrial power supplies.
For engineers reviewing the UCC3818NG4 datasheet, UCC3818NG4 pinout, UCC3818NG4 application, or UCC3818NG4 equivalent, key selection considerations include its 10.5 V turn-on UVLO, 7.5-V precision reference, soft-start functionality via SS pin, and compatibility with 16-pin SOIC packaging for PFC stage integration in AC-DC front-end designs.
Technical Context
The UCC3818NG4 employs average current-mode control using a high-bandwidth current amplifier (CAI/MOUT inputs) and voltage error amplifier (VSENSE/VAOUT) to shape input current waveform in phase with AC line voltage. Its analog multiplier accepts IAC (line voltage proportional current), VFF (feed-forward RMS signal), and VAOUT to generate IMOUT for precise power limiting and distortion suppression.
It integrates a 16-pin SOIC-packaged oscillator (RT/CT programmable, 6–220 kHz), overvoltage protection (OVP/EN pin with 1.9 V enable threshold and VREF+0.5 V OVP reference), and zero-power detection (0.33 V comparator threshold on VAOUT) - all operating across 0°C to 70°C ambient temperature range with BiCMOS low-power efficiency.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| UVLO Turn-On Threshold | 10.5 V - enables operation only after stable VCC rail reaches minimum startup voltage, preventing erratic latch-up during brownout. |
| Voltage Reference Output | 7.5 V ±1.5% - supplies accurate bias for external sensing networks and supports up to 20 mA load without regulation loss. |
| Oscillator Frequency Range | 6 kHz to 220 kHz - set by RT resistor and CT capacitor per f ≈ 0.6/(RT × CT), enabling flexible EMI optimization and transformer sizing. |
| Gate Driver Sink/Source | 0.2 A continuous / 1.2 A peak - drives MOSFET gates directly with totem-pole output, requiring external series gate resistor (≥11 Ω at 18 V). |
| Operating Temperature | 0°C to 70°C - specified for commercial-grade applications including PC power supplies and consumer electronics front-ends. |
| Current Amplifier Offset | ±2 mV - ensures low-light-load current sensing accuracy, minimizing THD at partial load conditions per IEC61000-3-2 Class D. |
| Soft-Start Charge Current | −10 µA typical - linearly ramps SS voltage to control duty-cycle ramp-up, preventing inrush current and output overshoot during startup. |
Pinout & Package
UCC3818NG4 is housed in a 16-pin SOIC (D) package with 3.91 mm × 9.9 mm body size and standard 1.27 mm pitch. Pin functions are validated per TI SLUS395K Rev K datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pin 1) | Power and signal reference ground | All internal voltages referenced to this node; requires direct 0.1-μF ceramic bypass to VCC and VREF. |
| PKLMT (Pin 2) | Peak current limit input | Threshold at 0 V; accepts level-shifted sense signal to enforce instantaneous current ceiling during boost switch conduction. |
| CAOUT (Pin 3) | Current amplifier output | Drives PWM latch via compensation network between CAOUT and MOUT; wide bandwidth enables fast current loop response. |
| CAI (Pin 4) | Current amplifier non-inverting input | Connects to GND-side of current sense resistor; operates down to below GND for bidirectional sensing capability. |
| MOUT (Pin 5) | Multiplier output / current amp inverting input | High-impedance node combining analog multiplier current and differential amplifier input - critical for noise-immune leading-edge modulation. |
| IAC (Pin 6) | Line voltage proportional current input | Accepts up to 500 μA current representing rectified AC line; primary feed for multiplier's line-voltage tracking function. |
| VAOUT (Pin 7) | Voltage error amplifier output | Regulates bulk capacitor voltage; internally clamped to ~5.5 V to prevent overdrive of multiplier and ensure stable power limit. |
| VFF (Pin 8) | Feed-forward RMS voltage input | Generated externally from IAC mirroring; sets 1.4 V at low line to scale multiplier gain and maintain constant power across universal input range. |
| VREF (Pin 9) | 7.5-V precision reference output | Stable bias source for external circuits; disabled below UVLO; short-circuit protected and load-regulated within 10 mV (1–2 mA). |
| OVP/EN (Pin 10) | Overvoltage protection / enable input | Window comparator: disables DRVOUT if boost output exceeds VREF+0.5 V, or resets SS and halts operation if pulled <1.9 V. |
| VSENSE (Pin 11) | Voltage amplifier inverting input | Connected to output divider network; forms feedback loop with VAOUT to regulate DC bus voltage with 50–90 dB open-loop gain. |
| RT (Pin 12) | Oscillator timing resistor connection | Sets charging current for CT capacitor; nominal 3 V bias; 10–100 kΩ range recommended for stable frequency programming. |
| SS (Pin 13) | Soft-start control input | Charged by −10 µA current source; used as voltage error signal during startup to ramp duty cycle gradually and avoid inrush. |
| CT (Pin 14) | Oscillator timing capacitor connection | Capacitor to GND sets switching frequency; lead must be short and direct to minimize parasitic inductance and jitter. |
| VCC (Pin 15) | Positive supply input | 10–17 V operation; requires ≥20 mA supply; bypassed directly to GND to support gate drive current spikes without rail collapse. |
| DRVOUT (Pin 16) | Integrated MOSFET gate driver output | Totem-pole output driving boost switch gate; rise/fall times <50 ns into 1 nF; pulldown resistance ~4 Ω, pullup ~9 Ω. |
Key Features
| Feature | Design Value |
|---|---|
| Average current-mode control | Enables stable, low-distortion sinusoidal line current draw across universal AC input (85–265 VAC), meeting IEC61000-3-2 Class D limits. |
| Leading-edge PWM modulation | Synchronizes with downstream DC-DC converter to reduce bulk capacitor ripple current, extending electrolytic capacitor lifetime in compact power supplies. |
| Accurate 7.5-V reference | ±1.5% tolerance over temperature and load ensures consistent scaling of current sense, OVP, and feed-forward signals without external trimming. |
| Integrated zero-power detection | Monitors VAOUT against 0.33 V threshold to disable gate drive when output voltage collapses, preventing uncontrolled restart during fault conditions. |
| Low start-up current | 150 µA typical - minimizes auxiliary supply burden and enables direct startup from rectified AC via high-value resistor, reducing BOM cost. |
| BiCMOS process technology | Delivers lower quiescent power vs bipolar predecessors while maintaining robust gate drive strength and thermal performance in SOIC package. |
Applications
| PC Power Supply Front-End | Industrial AC-DC Converter |
|---|---|
|
Use Scenario: 200–300 W ATX power supply with universal AC input (85–265 VAC) and IEC61000-3-2 compliance requirement. IC Role / Device Role / Timing Role: Primary PFC controller regulating boost stage to deliver stable 380–400 VDC bus with <5% THD at full load. Use Value: Enables single-stage PFC architecture with 95%+ efficiency and reduced filter component count versus passive solutions. |
Use Scenario: DIN-rail mounted 240 W industrial power module operating continuously at 60°C ambient with high reliability demand. IC Role / Device Role / Timing Role: Active PFC controller managing boost converter in CCM mode with fixed 100 kHz switching and thermal derating. Use Value: Delivers stable DC bus under wide line/load transients while supporting extended-life electrolytics via leading-edge modulation. |
| LED Driver Input Stage | Consumer Electronics Adapter |
|
Use Scenario: 150 W constant-current LED driver for commercial lighting, requiring low EMI and harmonic compliance. IC Role / Device Role / Timing Role: PFC controller operating in transition mode (CRM) to minimize switching losses and acoustic noise in enclosed fixtures. Use Value: Achieves >0.99 PF and <10% THD at 230 VAC, allowing compact heatsink design and eliminating audible coil whine. |
Use Scenario: Dual-output 65 W laptop adapter with universal input, compact form factor, and no-fan cooling. IC Role / Device Role / Timing Role: High-frequency PFC controller (150 kHz) enabling smaller magnetics and faster transient response to load steps. Use Value: Reduces total solution size by 25% vs legacy controllers while maintaining 89% efficiency at 115 VAC/20% load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar active PFC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC2818N | Same pinout and functional block diagram, but rated for −40°C to +85°C industrial temperature range; UVLO turn-on at 9.7 V (vs 10.5 V). | Preferred for outdoor or wide-temperature industrial deployments where ambient exceeds 70°C. | Select UCC2818N when extended temperature operation is required; UCC3818NG4 remains optimal for cost-sensitive commercial designs. |
| ICE3PCS01G | Fixed-frequency CCM controller with integrated 650 V MOSFET; no external gate driver needed; different pinout and compensation structure. | Targets simpler, lower-BOM-cost designs where integrated switch suffices and layout space is constrained. | Choose ICE3PCS01G for fully integrated PFC stages; UCC3818NG4 offers greater flexibility with discrete MOSFET selection and fine-tuned loop control. |
Compared with UCC2818N, UCC3818NG4 trades extended temperature rating for tighter UVLO hysteresis (0.5 V vs 0.3 V) and lower start-up current, making it more suitable for stable-line commercial environments. Against ICE3PCS01G, UCC3818NG4 provides higher design freedom in MOSFET selection and loop tuning at the cost of two extra external components.
Availability
UCC3818NG4 is available at Aetrix Electronics and suitable for PC power supplies, industrial AC-DC converters, and LED driver front-ends requiring stable component supply, long-term lifecycle support, and traceable sourcing for production programs.
Supply support for UCC3818NG4 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 designing analog ICs, embedded processors, and power management solutions for industrial, automotive, and communications markets.
The UCC3818NG4 belongs to TI's BiCMOS PFC controller product line, engineered specifically for high-efficiency, low-distortion active power factor correction in sub-300 W AC-DC power supplies compliant with IEC61000-3-2.
FAQ
What is the UVLO behavior of the UCC3818NG4?
The UCC3818NG4 features an undervoltage lockout with 10.5 V turn-on threshold and 10 V turn-off threshold, providing 0.5 V hysteresis. When VCC drops below 10 V, the device disables DRVOUT and discharges the SS pin to halt switching. This prevents erratic operation during brownout conditions and ensures clean restart once VCC recovers above 10.5 V. The UCC3818NG4 UVLO is distinct from the UCC2818N variant, which uses 9.7 V/9.4 V thresholds.
How does the UCC3818NG4 implement leading-edge modulation?
The UCC3818NG4 achieves leading-edge modulation through synchronized PWM timing where the switch turns on at the beginning of each oscillator cycle, controlled by the current amplifier output (CAOUT) and latch circuit. This reduces RMS current in the bulk capacitor compared to trailing-edge schemes. The MOUT/CAI differential configuration enhances noise immunity during zero-crossing detection, and the technique is especially effective when coordinated with a downstream DC-DC controller's clock. UCC3818NG4's internal oscillator and latch architecture make this modulation intrinsic to its operation.
Can the UCC3818NG4 operate in discontinuous conduction mode (DCM)?
Yes, the UCC3818NG4 supports operation in discontinuous conduction mode (DCM) as well as continuous conduction mode (CCM) and transition mode (CRM). Its average current-mode control architecture adapts to inductor current waveform shape without mode-switching artifacts. In DCM, the current amplifier maintains regulation by sensing peak current and adjusting duty cycle accordingly. Designers select mode via inductor value, switching frequency, and load range - all supported natively by UCC3818NG4's control loop without external mode-select pins or firmware.
What is the purpose of the VFF pin on the UCC3818NG4?
The VFF (feed-forward voltage) pin on the UCC3818NG4 accepts an externally generated RMS-representative voltage derived from the IAC current input, typically via a single-pole RC filter. At low AC line (e.g., 85 VAC), VFF should be 1.4 V; at high line (265 VAC), it rises to ~4.7 V. This scales the analog multiplier's gain to maintain constant power delivery across universal input range and improve line regulation. VFF directly impacts power limiting accuracy and THD performance - incorrect VFF amplitude or filtering causes overcurrent at low line or poor PF at high line.
Does the UCC3818NG4 require external compensation components?
Yes, the UCC3818NG4 requires external compensation components for both control loops: a Type II or Type III network between CAOUT and MOUT for the current loop, and a network between VAOUT and VSENSE for the voltage loop. These components set crossover frequency, phase margin, and transient response. TI's SLUS395K datasheet provides design equations and example values (e.g., 1 nF + 10 kΩ + 100 kΩ for voltage loop). Incorrect compensation leads to instability, oscillation, or poor load step recovery - proper placement and layout of these components adjacent to UCC3818NG4 pins is critical for reliable operation.
UCC3818NG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Discontinued at Digi-Key
- 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:
- Through Hole
- Supplier Device Package:
- 16-PDIP
UCC3818NG4 FAQ
1.How can I place an order for UCC3818NG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC3818NG4 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 UCC3818NG4 reliable?
The price and inventory of UCC3818NG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC3818NG4 is usually 5 days.
3.What payment methods are accepted for UCC3818NG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC3818NG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC3818NG4?
UCC3818NG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC3818NG4 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 UCC3818NG4?
For technical support, including UCC3818NG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC3818NG4 requirements.
6.How does Aetrix verify that UCC3818NG4 is sourced from the original manufacturer or authorized distributors?
All UCC3818NG4 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 UCC3818NG4 meets industry standards.
7.What is the process for return or replacement of UCC3818NG4?
All UCC3818NG4 units undergo pre-shipment inspection (PSI). If there is an issue with UCC3818NG4, 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 UCC3818NG4 part is unused and in its original packaging.
Return procedure for UCC3818NG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
UCC3818NG4 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…
