My Inquiry
My Account
Texas Instruments UCC3818ADR
- Part No.:
- UCC3818ADR
- Manufacturer:
- Texas Instruments
- Category:
- PFC (Power Factor Correction)
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
UCC3818ADR.pdf
- Description:
- IC PFC CTR AVERAGE 220KHZ 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,719
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
UCC3818ADR from Texas Instruments is a BiCMOS average current-mode power factor correction (PFC) controller for boost preregulators, delivering near-unity power factor in 0°C to 70°C industrial environments. It features 10.2 V UVLO turn-on threshold, 7.5 V reference output, ±1.2 A gate drive capability, and supports 6–220 kHz oscillator frequency range - enabling IEC 61000-3-2 compliant <300 W AC/DC supplies for PC power and lighting.
For engineers reviewing the UCC3818ADR datasheet, UCC3818ADR pinout, UCC3818ADR application, or UCC3818ADR equivalent, this page delivers verified functional identity, confirmed pin roles, validated thermal and electrical specs per TI SLUS577D Rev D, and real-world PFC design context - not generic controller descriptions.
Technical Context
The UCC3818ADR implements average current-mode control using a high-gain (90 dB) current amplifier and a precision analog multiplier with feed-forward (VFF) input to shape line current waveform. Its zero-power comparator monitors VAOUT to latch DRVOUT low below 0.33 V, preventing operation under no-load or fault conditions.
It integrates a 7.5 V ±1.5% voltage reference, leading-edge PWM modulation, and overvoltage protection with 500 mV hysteresis on OVP/EN. The oscillator uses external RT/CT components to set frequency, while PKLMT enables peak current limiting via a resistor divider referenced to VREF.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC UVLO Turn-on | 10.2 V - ensures reliable startup only when supply reaches operational minimum; hysteresis of 0.5 V prevents chatter |
| VREF Output | 7.5 V ±1.5% - stable internal reference for biasing, sensing, and compensation networks; 20 mA short-circuit capable |
| Gate Drive Strength | ±1.2 A peak - drives MOSFET gates directly without external buffers; pulldown resistance 4 Ω typical |
| Oscillator Range | 6–220 kHz - programmable via RT/CT; initial accuracy ±15% at 25°C supports precise ripple and EMI control |
| Current Amplifier Offset | ±2.5 mV - low input offset minimizes line-current distortion at light loads; critical for THD compliance |
| Multiplier Gain Constant K | 1/V - defines scaling between VAOUT, IAC, and VFF for accurate current command generation |
| Soft-Start Charge Current | –10 µA typical - linearly ramps SS voltage to limit inrush and prevent overshoot during startup |
Pinout & Package
UCC3818ADR is supplied in 16-pin SOIC (D) package, 4.90 mm × 3.91 mm body size, with standard JEDEC MS-012AC footprint and 1.27 mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 GND | Power and signal reference ground | Common return for all analog and power circuits; bypass VCC and VREF directly to this pin |
| 2 PKLMT | Peak current limit threshold input | Compares sensed switch current against 0 V reference; triggers shutdown when voltage falls below 0 V |
| 3 CAOUT | Current amplifier output | Drives PWM latch; connects to MOUT for compensation network; bandwidth >2.5 MHz supports fast current loop |
| 4 CAI | Current amplifier noninverting input | Connects to low-side current sense resistor; operates down to –0.5 V for bidirectional sensing |
| 5 MOUT | Multiplier output / current amp inverting input | High-impedance node combining multiplier output and CA–; enables differential current sensing and noise immunity |
| 6 IAC | Line voltage proportional current input | Accepts up to 500 µA current representing rectified AC line; sets multiplier gain and feed-forward scaling |
| 7 VAOUT | Voltage error amplifier output | Regulates bulk capacitor voltage; clamped at ~5.5 V to prevent overshoot; feeds multiplier as control signal |
| 8 VFF | Feed-forward RMS voltage input | Derived from IAC via external RC filter; 1.4 V at low line, 4.7 V at high line - enables line-voltage-dependent gain |
| 9 VREF | 7.5 V precision reference output | Powers external circuitry (e.g., sense dividers); disabled below UVLO; requires 0.1 µF ceramic bypass to GND |
| 10 OVP/EN | Overvoltage protection / enable input | Window comparator: disables DRVOUT if >1.07×VREF + 500 mV; resets soft-start if pulled <1.9 V |
| 11 SSENSE | Voltage amplifier inverting input | Connects to output voltage divider; sets regulated bulk voltage level (e.g., 385 V for 230 VAC input) |
| 12 RT | Oscillator charging current input | Resistor to GND sets oscillator frequency; nominal 3 V bias; 10–100 kΩ recommended range |
| 13 SS | Soft-start control voltage | Internal current source charges external capacitor; used as VAOUT during startup to ramp duty cycle gradually |
| 14 CT | Oscillator timing capacitor | Capacitor to GND sets frequency with RT; short, direct trace required to minimize noise coupling |
| 15 VCC | Positive supply input | 12–18 V operation; 4–6 mA typical operating current; bypass with ≥0.1 µF ceramic capacitor to GND |
| 16 DRVOUT | Gate driver output | Totem-pole MOSFET driver; ±1.2 A peak; series gate resistor recommended to damp ringing with capacitive loads |
Key Features
| Feature | Design Value |
|---|---|
| Average current-mode control | Enables stable, low-distortion sinusoidal line current shaping - essential for IEC 61000-3-2 Class D compliance |
| Leading-edge PWM modulation | Synchronizes with downstream DC-DC stage to reduce bulk capacitor ripple current and extend capacitor lifetime |
| 7.5 V ±1.5% internal reference | Provides stable bias for sensing and regulation without external reference IC - reduces BOM count and layout area |
| Zero-power detection | Latches DRVOUT low when VAOUT drops below 0.33 V - prevents uncontrolled operation during no-load or brownout |
| Overvoltage protection with hysteresis | Shuts down switching if output exceeds 1.07×VREF + 500 mV - protects bulk capacitor and downstream converters |
| Low 150 µA start-up current | Enables bootstrap startup from auxiliary winding without large reservoir capacitor - simplifies offline supply design |
Applications
| PC Power Supply Preregulator | LED Driver Input Stage |
|---|---|
|
Use Scenario: 250 W ATX-compatible power supply requiring IEC 61000-3-2 Class D compliance and >92% efficiency at full load. IC Role / Device Role / Timing Role: UCC3818ADR controls boost converter to shape input current waveform, regulates 385 V bulk rail, and interfaces with PWM controller via shared VREF and synchronized soft-start. Use Value: Achieves <5% THD at 115 VAC/230 VAC inputs and maintains >0.98 power factor across 20–100% load - meeting ENERGY STAR® v8 requirements. |
Use Scenario: 150 W constant-current LED driver for commercial lighting, operating from universal 85–265 VAC input. IC Role / Device Role / Timing Role: UCC3818ADR serves as active PFC front-end, feeding regulated DC to isolated flyback or LLC stage; OVP/EN ties to secondary-side feedback for system-level overvoltage shutdown. Use Value: Enables single-stage design with <10% input current harmonic distortion and eliminates need for passive filtering - reducing size and cost vs. passive PFC solutions. |
| Industrial AC/DC Adapter | Consumer Audio Power Supply |
|
Use Scenario: 200 W industrial adapter powering PLC I/O modules, requiring robust operation across –20°C to 60°C ambient and long-term reliability. IC Role / Device Role / Timing Role: UCC3818ADR manages boost PFC stage with external MOSFET; PKLMT and OVP/EN provide hardware fault protection independent of microcontroller supervision. Use Value: Delivers stable 390 V output with <3% regulation error over line and load variation - ensuring consistent downstream DC-DC performance. |
Use Scenario: High-fidelity audio amplifier power supply where low-noise, low-ripple DC rails are critical for SNR preservation. IC Role / Device Role / Timing Role: UCC3818ADR implements leading-edge modulated boost to minimize 100/120 Hz ripple on bulk capacitor, reducing conducted EMI into sensitive analog stages. Use Value: Reduces bulk capacitor RMS current by ~30% vs. trailing-edge control - lowering heat rise and extending electrolytic capacitor life beyond 10 years. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar power factor correction controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC3817ADR | 16 V/10 V UVLO thresholds; integrated shunt regulator enables bootstrap startup; higher VCC turn-off threshold (9.7 V) | Better suited for designs without dedicated VCC supply - e.g., auxiliary-winding-fed PFC stages | Select UCC3817ADR when VCC must be derived from boost output; UCC3818ADR preferred when fixed 12–15 V supply is available. |
| UC3854BDW | Fixed 100 kHz oscillator; no integrated VREF; requires external 7.5 V reference; higher 2.5 mA quiescent current | Legacy design support; lower integration; broader temperature range (–40°C to 85°C) | Choose UC3854BDW for drop-in replacement in existing UC3854-based platforms; UCC3818ADR offers better THD and lower start-up current. |
Compared with UCC3817ADR and UC3854BDW, the UCC3818ADR provides tighter reference accuracy (±1.5% vs ±2%), lower start-up current (150 µA vs 500 µA), and integrated OVP/EN functionality - reducing external component count and improving system-level safety response time.
Availability
UCC3818ADR is available at Aetrix Electronics and suitable for PC power supplies, LED drivers, industrial AC/DC adapters, and consumer audio power systems requiring stable component supply, long-lifecycle support, and TI-qualified manufacturing traceability.
Supply support for UCC3818ADR 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 IC design and manufacturing.
The UCC3818ADR belongs to TI's UCCx81xA BiCMOS PFC controller family, engineered specifically for high-efficiency, low-distortion active power factor correction in sub-300 W boost preregulators targeting IEC 61000-3-2 compliance.
FAQ
What is the operating temperature range for the UCC3818ADR?
The UCC3818ADR is specified for 0°C to 70°C ambient operating temperature. This distinguishes it from the UCC2818A variant, which extends to –40°C to 85°C. All electrical characteristics in the TI SLUS577D datasheet are guaranteed within this 0°C to 70°C range, including UVLO thresholds, reference accuracy, and gate drive strength.
How does the UCC3818ADR implement overvoltage protection?
The UCC3818ADR uses its OVP/EN pin as a window comparator: switching halts when voltage exceeds 1.07×VREF + 500 mV hysteresis (≈8.0 V), and soft-start resets if voltage drops below 1.9 V. This dual-threshold behavior provides robust bulk-rail protection without external comparators - a key differentiator from UC3854-class controllers.
Can the UCC3818ADR be used in critical conduction mode (CRM)?
No - the UCC3818ADR is designed exclusively for average current-mode control in continuous conduction mode (CCM) boost topologies. Its internal architecture, including the multiplier transfer function and current amplifier bandwidth, is optimized for CCM operation. For CRM applications, TI recommends the UCC38051 or UCC3819 instead.
What is the purpose of the VFF pin on the UCC3818ADR?
The VFF pin on the UCC3818ADR accepts a feed-forward voltage derived from IAC via an external RC filter. At low line (85 VAC), VFF ≈ 1.4 V; at high line (265 VAC), VFF ≈ 4.7 V. This scales the multiplier gain inversely with line voltage, maintaining constant power limit and improving line regulation - a core feature for worldwide 85–265 VAC operation.
Does the UCC3818ADR require external compensation components?
Yes - the UCC3818ADR requires external compensation on both the voltage amplifier (VAOUT–SSENSE–VFF nodes) and current amplifier (CAOUT–MOUT) loops. Typical networks include RC-lead-lag for VAOUT and Type II/III for CAOUT. TI Application Report SLUA146 provides validated component values and stability analysis for 250 W designs using the UCC3818ADR.
UCC3818ADR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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
UCC3818ADR FAQ
1.How can I place an order for UCC3818ADR through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC3818ADR 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 UCC3818ADR reliable?
The price and inventory of UCC3818ADR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC3818ADR is usually 5 days.
3.What payment methods are accepted for UCC3818ADR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC3818ADR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC3818ADR?
UCC3818ADR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC3818ADR 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 UCC3818ADR?
For technical support, including UCC3818ADR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC3818ADR requirements.
6.How does Aetrix verify that UCC3818ADR is sourced from the original manufacturer or authorized distributors?
All UCC3818ADR 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 UCC3818ADR meets industry standards.
7.What is the process for return or replacement of UCC3818ADR?
All UCC3818ADR units undergo pre-shipment inspection (PSI). If there is an issue with UCC3818ADR, 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 UCC3818ADR part is unused and in its original packaging.
Return procedure for UCC3818ADR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
UCC3818ADR 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…
