My Inquiry
My Account
Texas Instruments UCC2818N
- Part No.:
- UCC2818N
- Manufacturer:
- Texas Instruments
- Category:
- PFC (Power Factor Correction)
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
UCC2818N.pdf
- Description:
- IC PFC CTR AV CURR 220KHZ 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,363
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
UCC2818N 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, 0.33-V zero-power detection, and integrated gate driver with 93–99% duty cycle range. Used in IEC61000-3-2-compliant sub-300 W AC/DC supplies for PC and industrial power systems.
For engineers reviewing the UCC2818N datasheet, UCC2818N pinout, UCC2818N application, or UCC2818N equivalent, key selection considerations include its −40°C to +85°C operating temperature range, 10.5 V turn-on UVLO, 7.5-V precision reference, soft-start functionality via SS pin, and compatibility with average-current-mode-controlled boost PFC stages requiring feed-forward line regulation and overvoltage protection.
Technical Context
The UCC2818N integrates an analog multiplier with three inputs-VAOUT (voltage error signal), IAC (line-voltage-proportional current), and VFF (feed-forward RMS voltage)-to generate a current-mode command signal at MOUT. Its current amplifier (CAI/CAOUT/MOUT) operates down to and below ground, enabling high-noise-immunity differential sensing of AC line current.
It implements leading-edge PWM modulation synchronized to zero-current detection, reducing bulk capacitor ripple current. The internal oscillator uses RT and CT pins with f ≈ 0.6/(RT × CT), supporting 6 kHz–220 kHz switching; UVLO has 0.5 V hysteresis (10.5 V on / 9.7 V off); OVP/EN pin provides windowed enable and overvoltage shutdown at 1.9 V low-threshold and VREF+0.5 V high-threshold.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating Temperature | −40°C to +85°C - qualified for industrial-grade power supply designs requiring extended thermal margin |
| UVLO Thresholds | 10.5 V (turn-on) / 9.7 V (turn-off) - enables reliable startup across wide input voltage ranges with 0.5 V hysteresis |
| Voltage Reference | 7.5 V ±1.5% - stable, loadable reference for biasing external circuitry and feedback networks |
| Oscillator Frequency Range | 6 kHz to 220 kHz - programmable via RT/CT; supports optimized EMI and efficiency trade-offs |
| Gate Driver Output | DRVOUT with 5–12 Ω pull-up / 2–10 Ω pull-down - drives MOSFET gates directly with controlled rise/fall times (25–50 ns) |
| Zero-Power Detection | 0.33 V threshold on VAOUT - latches output off during no-load or standby to minimize idle power loss |
| Peak Current Limit Input | PKLMT accepts level-shifted sense signal with 0 V threshold - enables precise peak current control in boost inductor |
Pinout & Package
UCC2818N is housed in a 16-pin PDIP (Plastic Dual In-line Package) with body size 6.35 mm × 19.3 mm, suitable for through-hole mounting in industrial and legacy power supply designs.
| 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 comparator input | Threshold = 0 V; used with resistor divider from current-sense resistor negative side to set precise inductor peak current |
| CAOUT (Pin 3) | Current amplifier output | Wide-bandwidth op-amp output driving PWM latch; compensation network placed between CAOUT and MOUT |
| CAI (Pin 4) | Current amplifier non-inverting input | Connects to GND-side of current sense resistor; functional down to and below GND for accurate AC current sensing |
| MOUT (Pin 5) | Multiplier output / current amp inverting input | High-impedance node combining analog multiplier current output and CAI feedback path; enables differential current sensing |
| IAC (Pin 6) | Line voltage proportional current input | Accepts up to 500 μA current representing instantaneous rectified AC line voltage; low-distortion multiplier input |
| VAOUT (Pin 7) | Voltage error amplifier output | Regulates boost output voltage; internally clamped to ~5.5 V; feeds zero-power comparator at 0.33 V threshold |
| VFF (Pin 8) | Feed-forward RMS voltage input | Generated by external RC filter mirroring half IAC; sets 1.4 V at low line to maintain constant power across input range |
| VREF (Pin 9) | 7.5-V precision reference output | Supplies up to 20 mA; disabled below UVLO; bypassed to GND for stability; used for biasing and scaling circuits |
| OVP/EN (Pin 10) | Overvoltage protection / enable input | Window comparator: disables driver if >VREF+0.5 V or <1.9 V; resets soft-start when pulled low |
| VSENSE (Pin 11) | Voltage amplifier inverting input | Connected to output voltage divider; forms feedback loop with VAOUT for closed-loop output regulation |
| RT (Pin 12) | Oscillator timing resistor connection | Resistor to GND programs charging current; nominal 3 V bias; 10 kΩ–100 kΩ recommended range |
| SS (Pin 13) | Soft-start control | Charges external capacitor to ramp duty cycle at startup; rapidly discharges on VCC dropout to disable PWM |
| CT (Pin 14) | Oscillator timing capacitor connection | Capacitor to GND sets frequency per f ≈ 0.6/(RT × CT); short, direct GND trace required for stability |
| VCC (Pin 15) | Positive supply input | 10–17 V operation; requires ≥20 mA supply; bypassed directly to GND to absorb MOSFET gate charge spikes |
| DRVOUT (Pin 16) | Integrated MOSFET gate driver output | Totem-pole output driving boost switch; series gate resistor required to damp overshoot into capacitive load |
Key Features
| Feature | Design Value |
|---|---|
| Average current mode control | Enables stable, low-distortion sinusoidal line current shaping without current transformer, reducing BOM cost and size |
| Leading-edge PWM modulation | Synchronizes switching to zero-current crossing, minimizing boost diode reverse recovery loss and bulk capacitor ripple |
| Integrated 7.5-V reference | Accurate, loadable reference eliminates need for external voltage reference IC in most PFC designs |
| Feed-forward line regulation (VFF) | Compensates for input voltage variation in real time, maintaining constant power delivery across universal AC input range |
| Overvoltage protection with hysteresis | Protects downstream DC-DC stage by disabling PFC when output exceeds VREF+0.5 V, with 500 mV hysteresis to prevent chatter |
| Low start-up current (150 μA typical) | Reduces auxiliary supply burden during initial power-up, enabling simpler, lower-cost startup circuits |
Applications
| PC Power Supply | Industrial AC/DC Adapter |
|---|---|
Use Scenario: 200–300 W ATX-compatible power supply meeting IEC61000-3-2 Class D harmonic limits. IC Role / Device Role / Timing Role: Primary PFC controller regulating boost converter to shape input current waveform and maintain 380–400 V DC bus. Use Value: Enables compliance with global harmonic standards using single-stage active PFC, eliminating need for passive filters or multi-stage conversion. |
Use Scenario: Enclosed 250 W industrial power module operating continuously at −25°C to +70°C ambient. IC Role / Device Role / Timing Role: Core PFC controller managing boost stage under wide input (85–264 VAC) and variable load conditions. Use Value: −40°C to +85°C rating and robust UVLO ensure reliable startup and regulation across full industrial temperature range. |
| LED Driver Front-End | Consumer Audio Power Supply |
Use Scenario: High-efficiency 150 W LED streetlight driver with universal AC input and high PF requirement (>0.95). IC Role / Device Role / Timing Role: Controls boost PFC stage preceding LLC resonant converter; provides regulated 400 V bus. Use Value: Feed-forward (VFF) and average current mode deliver tight line regulation and low THD (<5%) even at light loads. |
Use Scenario: Low-noise 120 W Class D audio amplifier power supply requiring low EMI and minimal standby loss. IC Role / Device Role / Timing Role: PFC controller with zero-power detection (0.33 V threshold) and soft-start to minimize inrush and idle dissipation. Use Value: Zero-power comparator reduces no-load input power to <0.5 W, supporting Energy Star Tier 2 standby requirements. |
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 |
|---|---|---|---|
| UCC2817N | Higher UVLO (16 V/10 V), 0°C to +70°C temp range, same pinout and function | Targeted for commercial-grade supplies with narrower input voltage range and ambient temperature | Select UCC2817N only if design operates strictly within 0°C–70°C and requires higher UVLO for 230 VAC-dominant inputs |
| ICE3PCS01G | Fixed-frequency CCM controller with integrated 650 V MOSFET; no VREF or DRVOUT pins; different topology support | Designed for cost-sensitive, lower-power (<150 W) applications with simplified layout and fewer external components | Choose ICE3PCS01G for compact, integrated solutions where board space and BOM count outweigh flexibility and temperature range needs |
Compared with UCC2817N, the UCC2818N offers extended temperature capability and lower UVLO for universal-input designs, while ICE3PCS01G trades configurability for integration and reduced component count in entry-level PFC applications.
Availability
UCC2818N is available at Aetrix Electronics and suitable for PC power supplies, industrial AC/DC adapters, LED driver front-ends, and consumer audio power supplies requiring stable component supply and long-term manufacturability.
Supply support for UCC2818N 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.
The UCC2818N belongs to TI's BiCMOS PFC controller product line, engineered specifically for high-efficiency, low-distortion active power factor correction in universal-input AC/DC power supplies up to 300 W.
FAQ
What is the UVLO behavior of the UCC2818N?
The UCC2818N features an undervoltage lockout with 10.5 V turn-on threshold and 9.7 V turn-off threshold, providing 0.5 V hysteresis. When VCC drops below 9.7 V, the device disables DRVOUT and resets soft-start via OVP/EN pin. This ensures clean, repeatable startup across universal AC inputs and prevents erratic operation during brownouts. The UCC2818N UVLO is distinct from the UCC2817N's 16 V/10 V thresholds.
How does the UCC2818N implement zero-power detection?
The UCC2818N monitors VAOUT voltage and triggers zero-power shutdown when it falls below 0.33 V. This threshold is fixed and internally generated; no external components are needed. Once triggered, the gate driver is latched off, reducing no-load input power significantly. This feature is critical for meeting Energy Star and other low-standby-power regulations in end equipment using the UCC2818N.
Can the UCC2818N be used in discontinuous conduction mode (DCM)?
Yes-the UCC2818N supports both continuous conduction mode (CCM) and transition mode (critical conduction mode, CRM), which sits at the boundary between CCM and DCM. Its average current mode architecture and leading-edge modulation are optimized for CRM operation, delivering low THD and high efficiency in sub-300 W boost PFC stages. DCM operation is not explicitly supported but may occur transiently under light loads.
What is the purpose of the VFF pin on the UCC2818N?
The VFF (feed-forward voltage) pin on the UCC2818N accepts an externally filtered RMS representation of the AC line voltage, typically derived by mirroring half the IAC current into an RC network. At low line (e.g., 85 VAC), VFF ≈ 1.4 V; at high line (264 VAC), it rises proportionally. This signal scales the multiplier gain to maintain constant power delivery across the full input range-key to achieving IEC61000-3-2 compliance with the UCC2818N.
Does the UCC2818N require external compensation components?
Yes-the UCC2818N requires external compensation on two control loops: (1) voltage loop via RC network between VSENSE and VAOUT, and (2) current loop via components between CAOUT and MOUT. These networks stabilize the dual-loop average current mode control system. Typical configurations use a Type II or Type III compensator on the voltage path and a lead-lag network on the current path, as detailed in TI's SLUS395K datasheet for the UCC2818N.
UCC2818N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Mode:
- Average Current
- Frequency - Switching:
- 6kHz ~ 220kHz
- Current - Startup:
- 150 µA
- Voltage - Supply:
- 12V ~ 17V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-PDIP
UCC2818N FAQ
1.How can I place an order for UCC2818N through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC2818N 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 UCC2818N reliable?
The price and inventory of UCC2818N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC2818N is usually 5 days.
3.What payment methods are accepted for UCC2818N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC2818N transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC2818N?
UCC2818N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC2818N 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 UCC2818N?
For technical support, including UCC2818N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC2818N requirements.
6.How does Aetrix verify that UCC2818N is sourced from the original manufacturer or authorized distributors?
All UCC2818N 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 UCC2818N meets industry standards.
7.What is the process for return or replacement of UCC2818N?
All UCC2818N units undergo pre-shipment inspection (PSI). If there is an issue with UCC2818N, 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 UCC2818N part is unused and in its original packaging.
Return procedure for UCC2818N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
UCC2818N 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…
