Part A
UC3824DW
Texas Instruments
- Lifecycle
- Active
- Stock
- 5022 PCS
- Package
- SOIC-16
- Series
- PMIC - Reguladores de Voltação - Controladores de Troca DC
Replacement verdict
Compatible functional replacement candidate
The UC3825ADWTR and UC3824DW are both current-mode PWM controllers from the UC382x family in the same 16-pin SOIC package, sharing identical supply voltage range, reference output, and operating temperature range. However, they differ in undervoltage lockout thresholds and maximum duty cycle, so the UC3824DW can serve as a functional replacement for the UC3825ADWTR only after validating the UVLO turn-on/turn-off levels and duty-cycle limit against the target application requirements.
UVLO Thresholds
Validation required
Maximum Duty Cycle
Validation required
Package Type
High match
Supply Voltage Range
High match
Parts at a glance
Part B
UC3825ADWTR
Texas Instruments
- Lifecycle
- Active
- Stock
- 4357 PCS
- Package
- SOIC-16
- Series
- PMIC - Reguladores de Voltação - Controladores de Troca DC
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | UC3825ADWTR | UC3824DW | Why it matters |
|---|---|---|---|
| Control Method | Current-Mode | Voltage-Mode | Determines the fundamental control architecture and feedback loop design; current-mode and voltage-mode are not directly substitutable without redesigning the compensation network. |
| Topology / Function | Double-Ended PWM Controller | Single-Ended PWM Controller | Defines whether the IC drives push-pull/half-bridge (two outputs) or single-ended flyback/forward (one output) topologies, which is a critical system-level compatibility factor. |
| Number of Outputs | 2 | 1 | The number of gate-drive outputs dictates the power stage topology the controller can support and cannot be substituted without changing the converter design. |
| Duty Cycle (Max) | 50% per output | 100% | Maximum duty cycle limits the achievable voltage conversion ratio and affects transformer reset requirements in the power stage. |
| Output Drive Type | Dual alternating totem-pole drivers | Single totem-pole driver | The drive configuration determines how external MOSFETs or transformers are interfaced and whether alternating or simultaneous drive is required. |
| Current Limit / Sense Configuration | Cycle-by-cycle current limiting with current-sense input | Voltage-mode with current-limit comparator | Affects protection behavior and the need for a current-sense resistor or transformer in the design; different sensing schemes impact fault response. |
| Oscillator Frequency Range | Up to 1 MHz | Up to 1 MHz | Switching frequency capability influences magnetics size, efficiency, and EMI; matching ranges allows similar passive component selection. |
| Package | 16-SOIC (wide body) | 16-SOIC (wide body) | Package and pinout compatibility is essential for drop-in replacement on an existing PCB; identical packages simplify substitution. |
| Supply Voltage (VCC) | Up to 30 V | Up to 30 V | The maximum supply voltage defines the input voltage range the controller can tolerate and must match the application's bias rail. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Temperature range determines suitability for industrial versus commercial environments and affects reliability margins. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | UC3824DW | UC3825ADWTR |
|---|---|---|
| Part Status | Active | Active |
| Output Type | Transistor Driver | Transistor Driver |
| Function | Step-Up, Step-Down | Step-Up, Step-Up/Step-Down |
| Output Configuration | Positive | Positive |
| Topology | Buck, Boost | Boost, Flyback, Forward Converter, Full-Bridge, Half-Bridge, Push-Pull |
| Number of Outputs | 1 | 2 |
| Output Phases | 1 | 1 |
| Voltage - Supply (Vcc/Vdd) | 8.4V ~ 30V | 8.4V ~ 22V |
| Frequency - Switching | 340kHz ~ 460kHz | 400kHz ~ 1MHz |
| Duty Cycle(Max) | 85% | 50% |
| Synchronous Rectifier | No | No |
| Clock Sync | No | No |
| Control Features | Current Limit, Enable, Frequency Control, Ramp, Soft Start | Current Limit, Frequency Control, Ramp, Soft Start |
| Operating Temperature | 0°C ~ 70°C (TA) | 0°C ~ 70°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the key differences between the UC3825ADWTR and the UC3824DW?
The UC3825ADWTR is a dual-output PWM controller with a totem-pole output stage designed for high-frequency off-line and DC-to-DC converter applications, while the UC3824DW is a single-ended PWM controller with a single totem-pole output. The UC3825ADWTR features two alternating outputs (OUTA and OUTB) with programmable deadtime, whereas the UC3824DW provides one output with a maximum duty cycle clamp. Both are from Texas Instruments and share similar oscillator, error amplifier, and current-limit architectures, but differ in output configuration and intended topology.
Are the UC3825ADWTR and UC3824DW pin-compatible?
No. The UC3825ADWTR and UC3824DW are not pin-compatible. The UC3825ADWTR uses a 16-pin SOIC (DW) package with two output pins (OUTA and OUTB) and a dedicated deadtime control pin, while the UC3824DW also uses a 16-pin SOIC package but has a different pin function assignment, including a single output pin and a duty-cycle clamp pin. Direct substitution without PCB redesign is not possible.
Can the UC3825ADWTR directly replace the UC3824DW in an existing design?
No. The UC3825ADWTR cannot directly replace the UC3824DW because the two devices have different output configurations, pin functions, and control architectures. The UC3825ADWTR is intended for push-pull or half-bridge topologies requiring two alternating outputs, while the UC3824DW is intended for single-ended topologies. A direct replacement would require circuit redesign and validation against the target application requirements.
What are the typical operating frequencies for the UC3825ADWTR and UC3824DW?
Both the UC3825ADWTR and UC3824DW feature an oscillator frequency range that is programmable via external RT and CT components. According to Texas Instruments datasheets, the oscillator can be programmed up to 1 MHz. The actual switching frequency is half the oscillator frequency for the UC3825ADWTR due to its dual alternating outputs, while the UC3824DW switching frequency equals the oscillator frequency.
What output current can the UC3825ADWTR and UC3824DW sink and source?
Both the UC3825ADWTR and UC3824DW feature totem-pole output stages capable of sourcing and sinking peak currents of approximately 1.5 A, as specified in the Texas Instruments datasheets. This makes them suitable for directly driving power MOSFETs in high-frequency switching applications.
Do the UC3825ADWTR and UC3824DW have the same undervoltage lockout (UVLO) thresholds?
Yes. Both the UC3825ADWTR and UC3824DW share the same UVLO thresholds as part of the UC3824/UC3825 family. The typical UVLO turn-on threshold is 16 V and the turn-off threshold is 10 V for the standard versions, with the "A" suffix versions such as the UC3825ADWTR featuring tighter specifications. Designers should verify the exact UVLO values from the specific device datasheet before finalizing the design.
What package type do the UC3825ADWTR and UC3824DW use?
Both the UC3825ADWTR and UC3824DW are offered in a 16-pin SOIC package with the "DW" suffix. The UC3825ADWTR is supplied in tape and reel packaging as indicated by the "TR" suffix, while the UC3824DW is typically supplied in tube or tray packaging. Both packages are surface-mount and have the same body dimensions but different pin functions.
Which applications are best suited for the UC3825ADWTR versus the UC3824DW?
The UC3825ADWTR is best suited for push-pull, half-bridge, and full-bridge converter topologies that require two alternating gate drive signals with programmable deadtime. The UC3824DW is best suited for single-ended forward, flyback, and boost converter topologies that require a single gate drive output with duty-cycle limiting. Selection depends on the power topology and whether dual alternating outputs or a single output with maximum duty-cycle clamp is required.