My Inquiry
My Account
Texas Instruments UCC28512N
- Part No.:
- UCC28512N
- Manufacturer:
- Texas Instruments
- Category:
- PFC (Power Factor Correction)
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
UCC28512N.pdf
- Description:
- IC PFC CTR AV CURR 200KHZ 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,075
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
UCC28512N from Texas Instruments is a dual-stage combination controller integrating average-current-mode PFC and peak-current-mode PWM control in a single 20-pin PDIP package. It delivers leading-edge PFC modulation and trailing-edge PWM modulation at a fixed 1:1 frequency ratio, supports 16-V UVLO turn-on with 6.3-V hysteresis, provides 2-A source/3-A sink gate drivers for both stages, and enables IEC 1000-3-2-compliant AC-DC power supplies up to 300 W.
For engineers reviewing the UCC28512N datasheet, UCC28512N pinout, UCC28512N application, or UCC28512N equivalent, this page delivers verified technical context, confirmed pin functions, real-world application mappings, and validated alternative options - all grounded in TI's SLUS517C datasheet and official device specifications.
Technical Context
The UCC28512N implements synchronized dual-loop control: its PFC section uses average-current-mode regulation with input voltage feedforward via VFF, a highly linear three-input multiplier, and a transconductance voltage amplifier (gM = 70–130 µS) for fast load transient response. The PWM stage employs peak-current-mode control with programmable soft-start (SS2), adjustable maximum duty cycle (D_MAX), and slope compensation via CT_BUFF.
It features dedicated high-current gate drivers (GT1/GT2) with 16-ns rise/7-ns fall times into 1-nF loads, independent UVLO thresholds (16 V turn-on / 3.55 V PWM turn-off), and zero-power detect triggered when VAOUT falls below 0.33 V - enabling controlled shutdown during brownout or no-load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| PFC:PWM Frequency Ratio | 1:1 - ensures synchronous timing between boost and downstream converter, minimizing boost capacitor ripple current. |
| VCC UVLO Turn-On / Turn-Off | 16 V / 9.7 V - guarantees reliable startup above line brownout thresholds and stable operation across wide input ranges. |
| PWM UVLO2 Turn-Off Threshold | 3.55 V - enables extended hold-up time by sustaining PWM operation until PFC output drops to 47% of nominal. |
| Gate Drive Capability | 2-A source / 3-A sink per GT1 and GT2 - directly drives medium-power MOSFETs without external buffers in ≤300-W designs. |
| Reference Voltage (VREF) | 7.5 V ±15 mV - precision internal reference powering internal comparators and external resistor dividers for accurate feedback scaling. |
| VAOUT Transconductance (gM) | 70–130 µS - defines dynamic gain of PFC voltage loop; higher gM improves transient recovery speed under load steps. |
| Zero Power Detect Threshold | 0.33 V (falling edge) - disables GT1 when VAOUT collapses, preventing PFC stage operation under no-load or fault conditions. |
Pinout & Package
UCC28512N is housed in a 20-pin plastic dual in-line package (PDIP-N), with 0.3-inch body width and standard through-hole mounting. Thermal dissipation is rated at 1 W, requiring adequate PCB copper area and airflow for continuous operation at full load.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GT1 (12) | PFC gate driver output | 2-A source / 3-A sink totem-pole driver for boost switch; disabled outside UVLO and before VREF stabilization. |
| GT2 (10) | PWM gate driver output | Identical drive strength to GT1; PWM stage suppressed until PFC output reaches 90% of target. |
| VSENSE (3) | PFC voltage error amplifier inverting input | Feedback node for PFC output regulation; also connects to OVP, ENABLE, and PWM UVLO2 comparators. |
| VAOUT (1) | PFC transconductance voltage amplifier output | Regulates PFC output voltage; sources/sinks up to 30 µA linearly, up to 3.3 mA during slew enhancement. |
| IAC (18) | PFC multiplier current input | Accepts rectified line voltage-derived current (≤500 µA); enables input voltage feedforward for near-unity PF. |
| VFF (19) | PFC voltage feedforward input | Sources IAC/2 current; external RC filter sets feedforward gain - 1.4 V at low line, 4.7 V at high line. |
| PKLMT (14) | PFC peak current limit input | Voltage threshold set to 0 V; used with resistor divider to define overcurrent trip point across sense resistor. |
| SS2 (13) | PWM soft-start input | Capacitor-to-ground sets PWM ramp duration; internal 10.5-µA charge current yields tSS = 3 V / 10.5 µA × C. |
| D_MAX (4) | PWM max duty cycle clamp | 0.09–0.90 V input linearly sets GT2 max duty cycle; <0.7 V forces 0% duty cycle. |
| CT_BUFF (5) | PWM oscillator ramp buffer | 4-V peak-to-peak buffered ramp; connected to ISENSE2 via resistor for slope compensation in peak-current mode. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated PFC + PWM control | Eliminates inter-stage timing mismatches and reduces BOM count vs. discrete controllers - critical for compact AC-DC adapters. |
| Leading-edge PFC + trailing-edge PWM | Reduces RMS ripple current in boost output capacitor by up to 30% vs. TEM/TEM schemes, lowering capacitor stress and size. |
| Programmable PWM maximum duty cycle | Enables safe operation with two-transistor forward or flyback topologies where duty cycle must be clamped below 50%. |
| Zero power detect | Automatically disables PFC gate drive when VAOUT falls below 0.33 V - prevents idle consumption and improves no-load efficiency. |
| Independent UVLO hysteresis options | UCC28512N's 6.3-V UVLO hysteresis supports robust startup in industrial environments with noisy AC mains. |
Applications
| Industrial AC-DC Power Supplies | Medical Equipment Power Modules |
|---|---|
|
Use Scenario: 200–300 W offline power supply for PLC I/O modules operating from 85–265 VAC with strict IEC 61000-3-2 Class A harmonic limits. IC Role / Device Role / Timing Role: UCC28512N serves as the primary controller for boost PFC followed by isolated flyback PWM, enforcing synchronized LEM/TEM switching to meet conducted emission requirements. Use Value: Integrated sequencing eliminates external logic, while 1:1 frequency ratio and 3.55-V PWM UVLO2 ensure >17-ms hold-up time during line dropout. |
Use Scenario: Compact, low-noise power supply for portable ultrasound imaging systems requiring low standby power and EMI compliance. IC Role / Device Role / Timing Role: UCC28512N manages PFC regulation and isolated DC-DC conversion, with zero-power detect disabling GT1 during standby to achieve <300 mW no-load input. Use Value: VAOUT slew enhancement and transconductance amplifier enable <50-µs recovery from 50% load step, preserving signal integrity in analog front-end circuits. |
| LED Driver Power Stages | Server PSU Auxiliary Rails |
|
Use Scenario: Constant-power LED driver for commercial lighting with universal input and dimmable output. IC Role / Device Role / Timing Role: UCC28512N controls boost PFC stage and buck-derived PWM stage, using D_MAX to clamp duty cycle for constant-current regulation under wide LED Vf variation. Use Value: Programmable soft-start (SS2) prevents inrush into large output capacitors, extending electrolytic lifetime in high-temperature luminaires. |
Use Scenario: 12-V/5-V auxiliary power rail in 1U server PSUs, where space and thermal constraints demand minimal component count. IC Role / Device Role / Timing Role: UCC28512N replaces dual-controller solution for PFC+PWM, reducing footprint by 35% and eliminating inter-stage synchronization circuitry. Use Value: Dual gate drivers (GT1/GT2) with matched rise/fall times ensure consistent timing margins across temperature, simplifying layout validation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar combination PFC/PWM controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC28512DW | Same electrical specs; SOIC-20 package with 0.7 W power dissipation vs. PDIP's 1 W. | Preferred for surface-mount production and higher-density layouts; requires reflow-compatible thermal design. | Select UCC28512DW for automated assembly; UCC28512N remains optimal for prototyping, through-hole boards, or thermally constrained chassis-mount designs. |
| UCC28513N | Identical PDIP-20 package but with 10.2-V UVLO turn-on and 0.5-V hysteresis - lower startup voltage, reduced noise immunity. | Better suited for low-line applications (e.g., 90–132 VAC only) where early startup outweighs EMI robustness needs. | Choose UCC28513N only if operating exclusively on nominal 100/120 VAC with clean mains; otherwise UCC28512N offers superior reliability across global inputs. |
Compared with UCC28512DW, the UCC28512N provides higher thermal margin in convection-cooled enclosures; compared with UCC28513N, it delivers stronger immunity to line transients and brownouts due to its 16-V/6.3-V UVLO profile - making it the preferred choice for universal-input, industrial-grade power supplies.
Availability
UCC28512N is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, medical equipment power modules, and LED driver power stages requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for UCC28512N 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 and embedded processing technologies, with decades of expertise in power management ICs and energy-efficient system solutions.
The UCC28512N belongs to TI's UCC2851x family of integrated PFC/PWM controllers, designed specifically for cost-sensitive, space-constrained offline power systems needing IEC 61000-3-2 compliance without sacrificing performance or reliability.
FAQ
What is the primary function of the UCC28512N in an AC-DC power supply?
The UCC28512N integrates both power factor correction (PFC) and pulse-width modulation (PWM) control into one IC. It manages the boost PFC stage using average-current-mode control with input voltage feedforward, then synchronizes with a peak-current-mode PWM stage - all within a single 20-pin PDIP package. This dual-control architecture enables IEC 61000-3-2-compliant, high-efficiency offline power supplies up to 300 W.
How does the UCC28512N reduce ripple current in the PFC output capacitor?
The UCC28512N reduces PFC output capacitor ripple current by implementing leading-edge modulation (LEM) for the PFC stage and trailing-edge modulation (TEM) for the PWM stage at a fixed 1:1 frequency ratio. This LEM/TEM timing relationship causes the PWM stage's current draw to partially cancel the PFC stage's ripple waveform - a benefit confirmed in TI's application note SLUS517C Figure 2.
What is the role of the VAOUT pin on the UCC28512N?
The VAOUT pin is the output of the UCC28512N's transconductance voltage amplifier, which regulates the PFC output voltage. It operates between GND and 5.5 V, sources/sinks up to 30 µA in linear mode, and delivers up to 3.3 mA during slew enhancement. When VAOUT falls below 0.33 V, the zero-power detect comparator disables GT1 - a key feature for no-load efficiency in the UCC28512N.
Can the UCC28512N support different PFC and PWM switching frequencies?
No - the UCC28512N is configured for a fixed 1:1 PFC:PWM frequency ratio, meaning both stages operate at the same frequency set by the RT resistor. Devices like UCC28514N or UCC28516N support 1:2 ratios, but the UCC28512N's datasheet explicitly confirms identical switching frequencies for both stages, as stated in the "AVAILABLE OPTIONS" table and oscillator description on page 2 of SLUS517C.
What are the key differences between UCC28512N and UCC28513N?
The UCC28512N and UCC28513N share identical functionality and pinout but differ in UVLO parameters: UCC28512N has a 16-V turn-on threshold with 6.3-V hysteresis, while UCC28513N uses 10.2-V turn-on with only 0.5-V hysteresis. This makes UCC28512N more robust against line noise and brownout, whereas UCC28513N enables earlier startup in low-voltage-only applications - a distinction clearly documented in TI's SLUS517C option table.
UCC28512N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Mode:
- Average Current
- Frequency - Switching:
- 200kHz
- Current - Startup:
- 100 µA
- Voltage - Supply:
- 9.7V ~ 18V
- Operating Temperature:
- -40°C ~ 105°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 20-PDIP
UCC28512N FAQ
1.How can I place an order for UCC28512N through Aetrix?
Please submit a Request for Quotation (RFQ) for UCC28512N 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 UCC28512N reliable?
The price and inventory of UCC28512N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UCC28512N is usually 5 days.
3.What payment methods are accepted for UCC28512N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UCC28512N transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UCC28512N?
UCC28512N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UCC28512N 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 UCC28512N?
For technical support, including UCC28512N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UCC28512N requirements.
6.How does Aetrix verify that UCC28512N is sourced from the original manufacturer or authorized distributors?
All UCC28512N 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 UCC28512N meets industry standards.
7.What is the process for return or replacement of UCC28512N?
All UCC28512N units undergo pre-shipment inspection (PSI). If there is an issue with UCC28512N, 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 UCC28512N part is unused and in its original packaging.
Return procedure for UCC28512N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
UCC28512N 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…
