STMicroelectronics

UC3842BD1013TR - Current Mode PWM Controller | STMicroelectronics

MPN: UC3842BD1013TR βœ“ Active
In Stock Ships in 1-3 business days
15 V (nominal) Vdss 1 A (peak) Id 8-SOIC (0.154", 3.90mm Width) Package 500 kHz (max) Speed
From $0.55 USD / Unit
MOQ: 1 |
Price updated: 2026-08-21
Volume Pricing
Qty Unit Price Extended
1 $1.03 $1.03
10 $0.92 $9.20
100 $0.78 $78.00
500 $0.65 $325.00
1,000 $0.55 $550.00
ℹ️ All prices are in USD

Drop-in alternatives for UC3842BD1013TR 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:

UC3842D

βœ… Drop-In
πŸ“¦ 8-SOIC
Supports additional topologies (Buck, Buck-Boost, Forward)

πŸ“‹ Reference alternative (not in catalog)

UC3842BD1R2G

βœ… Drop-In
πŸ“¦ 8-SOIC
Cross-brand, same package and pinout

πŸ“‹ Reference alternative (not in catalog)

UC2842BD1

βœ… Drop-In
πŸ“¦ 8-SOIC
Cross-brand, extended temperature range likely

πŸ“‹ Reference alternative (not in catalog)

UC3843BD1013TR

βœ… Drop-In
πŸ“¦ 8-SOIC
Lower UVLO threshold (8.4V vs 16V)

πŸ“‹ Reference alternative (not in catalog)

ℹ️ 1 cross-package part(s) hidden β€” different package requires PCB rework and is not a true drop-in replacement. Contact us if you need cross-package suggestions.

UC3842BD1013TR Maximum Ratings & Electrical Characteristics

Function Current Mode PWM Controller
Topology Boost, Flyback
Output Type Single
Switching Frequency 500 kHz (max)
Output Current 1 A (peak)
Input Voltage 15 V (nominal)
Operating Temperature 0Β°C to 70Β°C
Package 8-SOIC (0.154", 3.90mm Width)
Mounting Type Surface Mount
Reference Voltage 5 V (internal trimmed)
Current Sense Threshold 1 V
UVLO Yes
RoHS Compliant
REACH Compliant
MSL Level [DATA_NEEDED: MSL Level]

UC3842BD1013TR Pin Configuration

SOP-8 Package Pinout Diagram SOP-8 8-pin small outline, 3.9x4.9mm, P1.27mm, JEDEC MS-012. 1 8 2 7 3 6 4 5 SOP-8
Pin 1 COMP β€” Error amplifier output
Pin 2 VFB β€” Voltage feedback input
Pin 3 ISENSE β€” Current sense input
Pin 4 RT/CT β€” Timing resistor/capacitor
Pin 5 GND β€” Ground
Pin 6 OUT β€” Gate drive output
Pin 7 VCC β€” Supply voltage
Pin 8 VREF β€” 5V reference output

Safe Operating Area (SOA) & Thermal Characteristics

Safe Operating Area Chart Default safe operating area chart for UC3842BD1013TR Drain-to-Source Voltage (Vds) Drain Current (Id)

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

UC3842BD1013TR is suitable for 6 applications: Switch-Mode Power Supplies (SMPS), Flyback Converters, Boost Converters, AC-DC Adapters, Battery Chargers, Industrial Power Converters.

⚑

Switch-Mode Power Supplies (SMPS)

The UC3842BD1013TR is ideal for SMPS designs due to its current-mode control, which provides excellent line and load regulation. Its 500 kHz switching frequency allows for smaller magnetic components, reducing overall size and cost. The device's 1 A peak output current can directly drive power MOSFETs, simplifying the gate drive circuit. In a typical flyback converter, the UC3842BD1013TR regulates the output by modulating the duty cycle based on the primary current sense signal, ensuring stable operation across varying loads. Its built-in UVLO and cycle-by-cycle current limiting enhance reliability, making it a preferred choice for consumer and industrial power supplies.

πŸ”§

Flyback Converters

The UC3842BD1013TR is specifically designed for flyback converters, offering isolation capability and current-mode control. Its high switching frequency (up to 500 kHz) enables the use of smaller transformers, reducing the footprint of the power supply. The device's 1 A peak output current can drive the gate of a power MOSFET directly, eliminating the need for a separate driver stage. In a flyback topology, the UC3842BD1013TR regulates the output voltage by sensing the primary current and adjusting the duty cycle, providing excellent transient response and overcurrent protection. This makes it suitable for applications such as AC-DC adapters and battery chargers.

⚑

Boost Converters

The UC3842BD1013TR supports boost topology, making it suitable for applications requiring a higher output voltage than the input. Its current-mode control provides fast transient response and stable operation over a wide input voltage range. The device's 500 kHz switching frequency allows for small inductor sizes, which is beneficial in space-constrained designs. The 1 A peak output current can drive the gate of a power MOSFET, enabling efficient power conversion. In a boost converter, the UC3842BD1013TR regulates the output by controlling the duty cycle based on the inductor current, ensuring high efficiency and reliable performance. Typical applications include LED drivers and battery-powered devices.

πŸ”Œ

AC-DC Adapters

The UC3842BD1013TR is widely used in AC-DC adapters for consumer electronics, providing a cost-effective solution for converting mains voltage to a regulated DC output. Its current-mode control ensures stable operation across varying load conditions, while the 500 kHz switching frequency reduces the size of the transformer and output filter. The device's 1 A peak output current can directly drive a power MOSFET, simplifying the gate drive circuit. The built-in UVLO and cycle-by-cycle current limiting protect the adapter from overcurrent and under-voltage conditions, enhancing reliability. The UC3842BD1013TR's wide input voltage range and isolation capability make it ideal for universal input adapters.

πŸ”‹

Battery Chargers

The UC3842BD1013TR is suitable for battery charger applications, particularly in flyback and boost topologies. Its current-mode control allows precise regulation of charging current and voltage, ensuring safe and efficient charging. The device's 500 kHz switching frequency enables compact charger designs, which is important for portable devices. The 1 A peak output current can drive the gate of a power MOSFET, enabling high-efficiency power conversion. The UC3842BD1013TR's cycle-by-cycle current limiting provides overcurrent protection, preventing damage to the battery and the charger circuit. This makes it a reliable choice for Li-ion and lead-acid battery chargers.

🏭

Industrial Power Converters

The UC3842BD1013TR is used in industrial power converters, such as those found in factory automation and process control systems. Its current-mode control provides excellent line and load regulation, ensuring stable output voltage in demanding environments. The device's 500 kHz switching frequency allows for small magnetic components, reducing the overall size of the power supply. The 1 A peak output current can drive power MOSFETs directly, simplifying the design. The UC3842BD1013TR's operating temperature range of 0Β°C to 70Β°C is suitable for most industrial applications, though for extended temperature ranges, alternatives like the UC2842BD1 may be considered. Its robust protection features, including UVLO and cycle-by-cycle current limiting, enhance reliability in industrial settings.

Recommended Products Summary

UC3842BD1R2G Drop-in alternative from onsemi Used in: Switch-Mode Power Supplies (SMPS), Flyback Converters, AC-DC Adapters UC3842D Same-brand alternative with more topologies Used in: Switch-Mode Power Supplies (SMPS), Boost Converters, Battery Chargers UC2842BD1 Cross-brand alternative Used in: Flyback Converters, Industrial Power Converters
What is the UC3842BD1013TR?
The UC3842BD1013TR is a high-performance current-mode PWM controller from STMicroelectronics, designed for off-line and DC-to-DC converter applications. It operates as a boost or flyback regulator with isolation capability, providing a cost-effective solution for power supply designs. The device is housed in an 8-SOIC package and supports a switching frequency up to 500 kHz, with a peak output current of 1 A. Its input voltage is rated at 15 V, and it operates over a temperature range of 0Β°C to 70Β°C.
What is the switching frequency of UC3842BD1013TR?
The UC3842BD1013TR supports a maximum switching frequency of 500 kHz. The oscillator frequency is set by an external resistor and capacitor, allowing designers to program the frequency from 50 kHz to 500 kHz. According to the STMicroelectronics datasheet, the trimmed oscillator ensures precise frequency control, which is essential for stable operation in power converters.
What is the output current capability of UC3842BD1013TR?
The UC3842BD1013TR can source and sink up to 1 A peak current at its output. This totem-pole output stage is designed to directly drive the gate of a power MOSFET. The high peak current capability ensures fast switching and efficient operation in power supply designs.
What is the input voltage range of UC3842BD1013TR?
The UC3842BD1013TR has a nominal input voltage of 15 V. The device includes under-voltage lockout (UVLO) to ensure proper operation. The absolute maximum input voltage is not specified in the provided data, but the typical operating voltage is 15 V. For detailed specifications, refer to the STMicroelectronics datasheet.
What is the operating temperature range of UC3842BD1013TR?
The UC3842BD1013TR operates over a temperature range of 0Β°C to 70Β°C. This commercial temperature range makes it suitable for consumer and industrial applications where ambient temperatures are within this range. For extended temperature requirements, consider the UC2842BD1 or UC3842BD1R2G alternatives.
What is the package type of UC3842BD1013TR?
The UC3842BD1013TR is available in an 8-SOIC package with a width of 0.154 inches (3.90 mm). This surface-mount package is widely used in power supply designs and offers good thermal performance for moderate power levels. The package is RoHS compliant.
Is UC3842BD1013TR RoHS compliant?
Yes, the UC3842BD1013TR is RoHS compliant. According to the PartGenie listing, the compliance notes indicate RoHS compliance. Additionally, the device is REACH compliant. For detailed compliance information, refer to the STMicroelectronics datasheet or product page.
What are the typical applications of UC3842BD1013TR?
The UC3842BD1013TR is commonly used in switch-mode power supplies (SMPS) for consumer electronics, industrial power converters, and isolated flyback converters for telecom and networking equipment. Its current-mode control architecture provides excellent line and load regulation, making it ideal for applications requiring stable output voltage.
What is the difference between UC3842BD1013TR and UC3842D?
The UC3842BD1013TR and UC3842D are both current-mode PWM controllers from STMicroelectronics, but they differ in topology support. The UC3842BD1013TR supports Boost and Flyback topologies, while the UC3842D supports Boost, Buck, Buck-Boost, Flyback, and Forward topologies. This makes the UC3842D more versatile for a wider range of converter designs.
What is the difference between UC3842BD1013TR and UC3842BD1R2G?
The UC3842BD1013TR is from STMicroelectronics, while the UC3842BD1R2G is from onsemi. Both are current-mode PWM controllers in 8-SOIC packages with similar specifications, including 500 kHz switching frequency and 1 A output current. The main difference is the manufacturer, and they are generally pin-compatible drop-in replacements.
What is the difference between UC3842BD1013TR and UC2842BD1?
The UC3842BD1013TR is from STMicroelectronics, while the UC2842BD1 is from Freescale Semiconductor (now NXP). Both are current-mode PWM controllers in 8-SOIC packages, but the UC2842BD1 may have a different operating temperature range. The UC3842BD1013TR operates from 0Β°C to 70Β°C, while the UC2842BD1 is likely rated for -40Β°C to 85Β°C. Verify the exact specifications before substitution.
What is the best drop-in replacement for UC3842BD1013TR?
The best drop-in replacement for UC3842BD1013TR is the UC3842BD1R2G from onsemi, as it is pin-compatible and has similar specifications. Other alternatives include the UC3842D from STMicroelectronics and the UC2842BD1 from NXP. All are 8-SOIC current-mode PWM controllers with 500 kHz switching frequency and 1 A output current.
Where can I buy UC3842BD1013TR?
The UC3842BD1013TR is available from major distributors such as DigiKey, Mouser, and Newark. As of 2026-08-21, the unit price is approximately $1.03 at quantity 1. You can also check Octopart for bulk pricing from multiple distributors. Lead time is typically immediate for in-stock items.
What is the price of UC3842BD1013TR?
As of 2026-08-21, the price of UC3842BD1013TR is approximately $1.03 per unit at quantity 1. Prices decrease with higher quantities: $0.92 at 10, $0.78 at 100, $0.65 at 500, and $0.55 at 1000. These prices are based on distributor data from Heisener and may vary by supplier.
What is the lead time for UC3842BD1013TR?
The lead time for UC3842BD1013TR is typically immediate for in-stock items. According to Heisener, the estimated delivery time is March 28 to April 2 for expedited shipping. For larger quantities, lead time may vary depending on distributor stock and manufacturer availability.

Engineering reference data for UC3842BD1013TR β€” comparison, design guidance, and compliance information.

Selection Guide

Choose the UC3842BD1013TR when you need a reliable current-mode PWM controller for boost or flyback converters in commercial temperature environments. It is ideal for cost-sensitive applications such as AC-DC adapters and battery chargers. If you require additional topologies (buck, buck-boost, forward), consider the UC3842D from the same manufacturer. For extended temperature ranges or automotive applications, the UC2842BD1 from NXP is a better choice. If you prefer a cross-brand alternative with identical specifications, the UC3842BD1R2G from onsemi is a drop-in replacement. All alternatives share the same 8-SOIC package, ensuring PCB compatibility.

Comparison with Alternatives

Parameter This Product UC3842D UC3842BD1R2G UC2842BD1
Package 8-SOIC 8-SOIC 8-SOIC 8-SOIC
Brand STMicroelectronics STMicroelectronics onsemi NXP Semiconductors
Switching Frequency 500 kHz 500 kHz 500 kHz 500 kHz
Output Current 1 A 1 A 1 A 1 A
Topology Boost, Flyback Boost, Buck, Buck-Boost, Flyback, Forward Boost, Flyback Boost, Flyback
Operating Temperature 0Β°C to 70Β°C 0Β°C to 70Β°C 0Β°C to 70Β°C -40Β°C to 85Β°C (likely)
Input Voltage 15 V 15 V 15 V 15 V
RoHS Compliant Compliant Compliant Compliant

Key Differentiators

  • Supports boost and flyback topologies (vs UC3842D)
  • STMicroelectronics quality and availability (vs UC3842BD1R2G)
  • Commercial temperature range (vs UC2842BD1)

Design Notes

Place the timing resistor (RT) and capacitor (CT) as close to the RT/CT pin (pin 4) as possible to minimize parasitic capacitance and ensure accurate frequency setting. Keep the current sense trace from the sense resistor to the ISENSE pin (pin 3) short and direct, with a small RC filter (e.g., 100Ξ© and 1nF) to suppress switching noise. Use a solid ground plane to reduce noise coupling.

The UC3842BD1013TR requires a stable VCC supply (typically 15V) with a bypass capacitor of at least 0.1Β΅F placed close to the VCC pin (pin 7). For high-current applications, use a larger electrolytic capacitor (e.g., 10Β΅F) to handle transient currents. Ensure the VCC voltage stays within the UVLO hysteresis to avoid erratic operation.

The 8-SOIC package has limited thermal dissipation capability. For power levels above 1W, provide adequate copper area on the PCB around the IC to act as a heatsink. Consider using thermal vias to connect to a ground plane. If the ambient temperature exceeds 70Β°C, consider using a controller with an extended temperature range, such as the UC2842BD1.

Compliance Information

RoHS
Compliant
REACH
Compliant
AEC-Q100
Not Applicable
Lead Free
Yes
Halogen Free
Unknown
Conflict Minerals
Unknown

RoHS and REACH compliance confirmed from PartGenie listing. AEC-Q100 not applicable for commercial-grade part.

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