UC3844BD1 STMicroelectronics Integrated Circuit (Small Outline Packages) In Stock
UC3844BD1 is a current-mode PWM controller IC by STMicroelectronics for boost and flyback converters. Key specs include 11.5 V to 30 V input, 1 A gate drive, 500 kHz maximum frequency, and 8-pin SOIC package. Available from stock with worldwide shipping.
- Manufacturer
- STMicroelectronics
- Package
- Small Outline Packages
- Pin Count
- 8
- Lifecycle
- ACTIVE
- Datasheet
- UC3844BD1 Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $0.3032(MOQ 4)
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of UC3844BD1?
- Current-mode PWM control enables cycle-by-cycle peak current limiting for inherent short-circuit protection
- Up to 500 kHz oscillator frequency reduces transformer and filter size in compact converter designs
- 1 A totem-pole gate driver provides fast MOSFET switching without external buffer transistors
What is UC3844BD1 used for?
UC3844BD1 is used as the primary controller in offline flyback and boost switch-mode power supplies for industrial and telecom equipment. Its 11.5 V to 30 V operating range makes it well-suited for auxiliary supply rails derived from rectified mains through a startup resistor. The device also serves in DC-DC converter stages within uninterruptible power supplies and laboratory bench power instruments.
What are the specifications of UC3844BD1?
| YTEOL | 7 |
| Analog IC - Other Type | SWITCHING CONTROLLER |
| Control Mode | CURRENT-MODE |
| Control Technique | PULSE WIDTH MODULATION |
| Input Voltage-Max | 30V |
| Input Voltage-Min | 11.5V |
| Input Voltage-Nom | 15V |
| JESD-30 Code | R-PDSO-G8 |
| JESD-609 Code | e4 |
| Number of Functions | 1 |
| Output Current-Max | 1A |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP8,.25 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | NOT SPECIFIED |
| Qualification Status | Not Qualified |
| Surface Mount | YES |
| Switcher Configuration | SINGLE |
| Switching Frequency-Max | 500kHz |
| Technology | BIPOLAR |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | Nickel/Palladium/Gold (Ni/Pd/Au) |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | NOT SPECIFIED |
| ## UC3844BD1 Alternates Showing results | Image |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.60 |
| Country of Origin | Morocco |
Where can I find the UC3844BD1 datasheet?
UC3844BD1 Datasheet DownloadOfficial datasheet from STMicroelectronics
What are equivalent replacements for UC3844BD1?
Compatible alternatives and drop-in replacements for UC3844BD1:
suggested
suggested
suggested
Switching Controller, Current-mode, 1A, 500kHz Switching Freq-Max, BIPolar, PDSO8
Frequently Asked Questions
How does the 500 kHz oscillator capability of UC3844BD1 affect transformer design compared to lower-frequency controllers?
Running UC3844BD1 at 500 kHz allows the flyback transformer core size to shrink substantially compared to 100 kHz designs, because higher frequency reduces the volt-second product per cycle. This translates to a ferrite core roughly 4 times smaller by volume, lowering both cost and PCB footprint in the power stage.
What is the startup voltage threshold for UC3844BD1, and how should the bias supply circuit be designed?
UC3844BD1 requires at least 11.5 V on the VCC pin to start switching, with an 8.5 V undervoltage lockout release point that latches the output off during low-voltage conditions. Designers typically use a 15 V auxiliary winding and a startup resistor from the rectified bus to bring VCC above 11.5 V within the required startup time.
When evaluating UC3844BD1 versus UC3845BD1 for a flyback converter, which device suits duty-cycle-limited topologies?
UC3844BD1 is pinned for duty cycles up to 100%, making it suitable for boost converters and continuous-conduction flyback designs, whereas UC3845BD1 limits duty cycle to below 50% for two-switch forward converters. Choosing UC3844BD1 in a 30 V input flyback stage avoids the added complexity of a duty-cycle clamp circuit.
Related Guides
CSD87313DMS Synchronous Buck Power Stage Design Guide
Design a compact CSD87313DMS synchronous buck stage with practical guidance for loss, gate drive, PCB layout, EMI, thermal validation, and sourcing.
Aug 6, 2026
STEF05SGR eFuse Selection Guide for 5 V Overcurrent Protection
Choose STEF05SGR for 5 V overcurrent protection by checking current-limit margin, inrush, thermal loss, fault response, and sourcing.
Aug 6, 2026
C0402C103K3RACTU Selection Guide: Choosing a 10 nF 0402 MLCC
Select C0402C103K3RACTU by voltage margin, X7R behavior, tolerance, 0402 assembly risk, and qualified alternatives.
Aug 4, 2026
STM32H753VIT6 MCU Selection Guide: Memory, Package, Connectivity, and Security
Choose STM32H753VIT6 by evaluating memory architecture, LQFP-100 pin fit, connectivity, security, power, and sourcing tradeoffs.
Aug 4, 2026
Why Buy from FindMyChip
About STMicroelectronics
STMicroelectronics is a global semiconductor leader serving customers across the spectrum of electronics applications. ST's products are found in a wide range of applications including automotive, industrial, personal electronics, and communications.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 4+ | $0.4947 | $1.98 |
| 8+ | $0.4921 | $3.94 |
| 16+ | $0.3792 | $6.07 |
| 1500+ | $0.3350 | $502.50 |
| 2000+ | $0.3032 | $606.40 |
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“FindMyChip sourced our entire STM32 BOM in 48 hours when our usual distributor had 16-week lead times.”
You May Also Like
ACS770ECB-200U-PFF-T
Allegro Microsystems
Integrated Circuit
ACS770KCB-150U-PFF-T
Allegro Microsystems
Integrated Circuit
MC33901WEF
NXP
Integrated Circuit
MC7808BDTRKG
ON Semiconductor
Integrated Circuit
PA94EC
Apex Microtechnology
Integrated Circuit
AP7315-28SR-7
Diodes Inc.
Integrated Circuit
74HCT245D
Nexperia
Integrated Circuit
CY62256VNLL-70ZXCT
Cypress Semiconductor
Integrated Circuit
EPM7032AETC44-4N
Intel
Integrated Circuit
EPM3512AQC208-10N
Intel
Integrated Circuit
EPM3256ATC144-7N
Intel
Integrated Circuit
EPM3256AQC208-7N
Intel
Integrated Circuit
EPM3256AQC208-10N
Intel
Integrated Circuit
EPM3128ATC100-7N
Intel
Integrated Circuit
EPM1270F256C4N
Intel
Integrated Circuit
EPF8282ATC100-4N
Intel
Integrated Circuit
EPF6016QC208-2N
Intel
Integrated Circuit
EPF6016ATC144-3N
Intel
Integrated Circuit
EPF10K30ATC144-3N
Intel
Integrated Circuit
EPC2TI32N
Intel
Integrated Circuit
EPC2LC20
Intel
Integrated Circuit
EP3SL150F1152C4N
Intel
Integrated Circuit
EP2SGX60DF780C5N
Intel
Integrated Circuit
EP2SGX60CF780C5N
Intel
Integrated Circuit