UCC28C42QDRQ1 - 1MHz Automotive Current-Mode PWM | Texas Instruments
MPN: UCC28C42QDRQ1 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.15 | $2.15 |
| 10 | $1.94 | $19.40 |
| 100 | $1.73 | $173.00 |
| 500 | $1.56 | $780.00 |
| 1,000 | $1.4 | $1,400.00 |
Drop-in alternatives for UCC28C42QDRQ1 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
UCC28C43QDRQ1
β Drop-Inπ Reference alternative (not in catalog)
UCC28C44QDRQ1
β Drop-Inπ Reference alternative (not in catalog)
UCC28C45QDRQ1
β Drop-Inπ Reference alternative (not in catalog)
UCC28C42QDR
β Drop-Inπ Reference alternative (not in catalog)
UC3842BD1
β Drop-Inβ In Stock
$0.1485 / Unit
View Datasheet βUCC28C42QDRQ1 Maximum Ratings & Electrical Characteristics
| Topology | Flyback, Step-Up/Step-Down (current-mode PWM controller) |
| Control Mode | Peak Current-Mode |
| Maximum Switching Frequency | 1000 kHz (1 MHz) |
| Supply Voltage Range | 9 V to 18 V |
| Maximum Output Current | 1 A (output driver) |
| Technology | BiCMOS |
| Regulation | Primary-side (aux winding) or secondary-side (opto-coupler) |
| UVLO | Yes, family UVLO options |
| Package | 8-SOIC (D) |
| Mounting Type | Surface Mount |
| Temperature Grade | Automotive (AEC-Q100) |
| Pin Compatibility | Pin-for-pin compatible with UCx84xA / UCx84x family |
| Duty Cycle Limit Options | Yes (family option) |
| RoHS Status | Compliant |
| Datasheet | 46 pages, TI UCC28C42-Q1 |
UCC28C42QDRQ1 Pin Configuration
| Pin 1 | COMP β Error amplifier output / loop compensation |
| Pin 2 | VFB β Feedback input (inverting input of error amplifier) |
| Pin 3 | CS β Current sense input for peak current-mode control |
| Pin 4 | RT/CT β Oscillator timing resistor and capacitor |
| Pin 5 | GND β Ground |
| Pin 6 | OUT β Gate drive output to external MOSFET |
| Pin 7 | VCC β Supply voltage (9V~18V range) |
| Pin 8 | VREF β Precision internal reference output |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
UCC28C42QDRQ1 is suitable for 6 applications: Automotive Isolated Flyback Auxiliary Supply, AC-DC Adapter and Charger Power Stages, Infotainment and Cluster Bias Rails, Industrial Isolated Auxiliary Supplies, Low-Standby Smart Meter and IoT Bias Power, LED Driver and Lighting Power.
Automotive Isolated Flyback Auxiliary Supply
The UCC28C42QDRQ1 is purpose-built for automotive isolated auxiliary power supplies thanks to its AEC-Q100 qualification and 9V~18V operating range suited to 12V vehicle battery systems. Its peak current-mode control with cycle-by-cycle current limiting provides robust protection against shorted outputs and transformer saturation faults common in automotive environments. The 1 MHz capability shrinks transformer size for space-constrained ECUs. Placed as the primary-side controller driving an external MOSFET, it regulates isolated low-voltage rails via auxiliary winding or opto-coupler feedback with startup current managed by BiCMOS low-power design.
Recommended
AC-DC Adapter and Charger Power Stages
For off-line AC-DC adapters and chargers, the UCC28C42QDRQ1 provides a proven fixed-frequency flyback control core in a low-cost SOIC-8 footprint. The 1 MHz maximum switching frequency permits compact transformer designs, while BiCMOS low quiescent current improves light-load and no-load efficiency, important for energy-efficiency standards in external adapters. Designers can choose primary-side regulation with an auxiliary winding to eliminate the opto-coupler, reducing BOM cost, or secondary-side opto-coupler feedback when tight cross-regulation is required. Cycle-by-cycle current limiting protects against output short and winding fault events.
Recommended
Infotainment and Cluster Bias Rails
Automotive infotainment head units and instrument clusters require multiple isolated and semi-regulated bias rails derived from the vehicle battery. The UCC28C42QDRQ1 fits as a small, isolated flyback controller generating 5V/12V auxiliary rails, with its UVLO ensuring orderly startup and shutdown during crank and load-dump transients. Peak current-mode control simplifies loop compensation across wide load ranges from standby to full display brightness. The AEC-Q100 rating and SOIC-8 package support the reliability and board-area budgets of tier-one automotive electronics platforms.
Recommended
Industrial Isolated Auxiliary Supplies
In industrial systems such as PLCs, motor drives, and gate-driver bias supplies, the UCC28C42QDRQ1 provides a well-understood current-mode flyback controller with wide availability. The pin-for-pin compatibility with the UCx84x legacy family makes it an easy upgrade path from older UC3842 designs to lower standby power and faster switching. Its 1 MHz capability enables compact bias converters feeding isolated gate drivers, while the 9V~18V range suits rectified bus-derived or auxiliary transformer bias configurations. Secondary-side opto feedback achieves tight regulation for precision control electronics.
Recommended
Low-Standby Smart Meter and IoT Bias Power
The BiCMOS low-power technology of the UCC28C42QDRQ1 delivers lower startup and operating current than bipolar UC384x predecessors, benefiting always-on smart meter, IoT gateway, and building automation bias supplies where standby power budgets are strict. The controller can be operated at reduced switching frequency at light load through standard frequency-foldback techniques with the error amplifier. Its SOIC-8 footprint and automotive qualification also make it attractive for outdoor metering exposed to harsh temperature environments, while cycle-by-cycle limiting protects the small flyback transformer.
Recommended
LED Driver and Lighting Power
Isolated LED lighting drivers can use the UCC28C42QDRQ1 as a peak current-mode flyback controller where primary-side current sensing sets LED current via the CS threshold. The 1 MHz capability supports compact designs for luminaires and industrial lighting, while the UVLO ensures the output does not oscillate during brownout. For street lighting and high-bay fixtures on industrial feeds, the cycle-by-cycle protection handles fault events such as LED string shorts. Combining with a linear post-regulator or current sink achieves low output ripple for high-quality illumination.
Recommended
Recommended Products Summary
Engineering reference data for UCC28C42QDRQ1 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | UCC28C43QDRQ1 | UCC28C44QDRQ1 | UCC28C45QDRQ1 | UC3842BD |
|---|---|---|---|---|---|
| Package | 8-SOIC (D) | 8-SOIC (D) - same | 8-SOIC (D) - same | 8-SOIC (D) - same | 8-SOIC - same footprint |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi |
| Max Switching Frequency | 1 MHz | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | 500 kHz max (typ use 100 kHz class) |
| Supply Voltage Range | 9 V to 18 V | [DATA_NEEDED: UVLO differs] | [DATA_NEEDED: UVLO differs] | [DATA_NEEDED: UVLO differs] | 16V/10V UVLO typical |
| Control Mode | Peak current-mode | Peak current-mode | Peak current-mode | Peak current-mode | Peak current-mode |
| Technology | BiCMOS (low power) | BiCMOS | BiCMOS | BiCMOS | Bipolar (higher Iq) |
| Automotive AEC-Q100 | Yes (Q1) | Yes (Q1) | Yes (Q1) | Yes (Q1) | No (industrial grade) |
| Pinout | UCx84x standard 8-pin (COMP, VFB, CS, RT/CT, GND, OUT, VCC, VREF) | Identical | Identical | Identical | Identical (UCx84x standard) |
| Price (1 pc, as of 2026-08-29) | approx $1.86-$2.15 | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- BiCMOS low-power technology with 1 MHz capability (vs UC3842BD)
- AEC-Q100 automotive qualification (vs UCC28C42QDR (non-Q1))
- Family UVLO/duty-cycle options (vs UCC28C43QDRQ1)
Design Notes
Keep the current-sense (CS) trace short and kelvin-connect the sense resistor directly to GND pin 5 to avoid switching-noise pickup that can falsely trigger the cycle-by-cycle current limit. At 1 MHz switching, gate-drive loop (VCC-OUT-MOSFET gate-source-GND) must be minimized in area. Place RT/CT timing components close to pin 4, and route the oscillator node away from the OUT trace to prevent frequency jitter.
Verify UVLO thresholds against the datasheet selection table before substituting within the UCC28C4x-Q1 family - the C42/C43/C44/C45 variants differ in start/stop thresholds and duty-cycle limits, and a mismatch can cause startup failure or hiccup with a bias winding. Also confirm the external MOSFET gate charge is compatible with the 1 A driver at the chosen frequency to control switching losses.
Decouple VCC with 0.1uF ceramic close to pin 7 plus 10uF bulk for start-up energy from the bias winding. Size the startup resistor or auxiliary winding so that VCC crosses the UVLO turn-on threshold cleanly under worst-case low-line input; BiCMOS low startup current allows higher-impedance startup networks than bipolar UC3842 designs, improving adapter no-load power.
Compliance Information
RoHS compliant per LCSC listing (C2657903). AEC-Q100 automotive qualification per TI product page and Partstack listing (temperature grade AUTOMOTIVE). REACH/halogen-free/conflict minerals status not found in retrieved data.
