Texas Instruments

UC3824 - 1.5A High Speed PWM Controller | Texas Instruments

Name: UC3824
Brand: Texas Instruments
Price: 2.19 USD
Availability: InStock

MPN: UC3824 ✓ Active

In Stock Ships in 1-3 business days

30 V (max) Vdss 1.5 A Id 16-PDIP Package 1 MHz Speed

From $2.19 USD / Unit

MOQ: 1 |

Price updated: 2026-08-26

Volume Pricing

Qty	Unit Price	Extended
1	$3.42	$3.42
10	$3.08	$30.80
100	$2.74	$274.00
500	$2.47	$1,235.00
1,000	$2.19	$2,190.00

ℹ️ All prices are in USD

View Datasheet (PDF) View Alternatives

Quantity

Drop-in alternatives for UC3824 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.

Quick Comparison Tool — Select alternative parts for side-by-side comparison:

UC3824N

✅ Drop-In

📦 16-PDIP

Same die, PDIP package variant

📋 Reference alternative (not in catalog)

UC3825

✅ Drop-In

📦 16-PDIP

Higher UVLO thresholds (8.4V/7.6V), same pinout

📋 Reference alternative (not in catalog)

UC3823

✅ Drop-In

📦 16-PDIP

Lower UVLO thresholds (8.4V/7.6V), same pinout

📋 Reference alternative (not in catalog)

TL494CDT

⚡ Same Package

STMicroelectronics

📦 16-PDIP

7 V to 40 V · 250 mA (sink/source) · 1 kHz to 300 kHz · 5 V ±5% · 10 mA (max) · -0.3 V to VCC-2 V · 0% to 100% · 6 mA (typical)

✓ In Stock

$0.3182 / Unit

View Datasheet →

SG3524

⚡ Same Package

📦 16-PDIP

Lower output current (100mA), different pinout, not high-speed

📋 Reference alternative (not in catalog)

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

UC3824 Maximum Ratings & Electrical Characteristics

Input Voltage (VCC)	30 V (max)
Output Current (Source/Sink)	1.5 A
UVLO Threshold (On/Off)	9.2 V / 8.4 V
Maximum Duty Cycle	85%
Switching Frequency (Max)	1 MHz
Propagation Delay to Output	50 ns
Current Limit Threshold	1 V
Operating Temperature Range	0°C to 70°C
Package Type	16-PDIP
Mounting Type	Through Hole
Topology Support	Push-Pull, Half-Bridge, Full-Bridge
Control Method	Current Mode
Shutdown Port	TTL Compatible
Soft-Start	Yes (also max duty clamp)
RoHS Status	Compliant

UC3824 Pin Configuration

Pin 1	INV — Inverting input of error amplifier
Pin 2	NI — Non-inverting input of error amplifier
Pin 3	EAOUT — Error amplifier output
Pin 4	CLK — Clock input for synchronization
Pin 5	RT — Timing resistor for oscillator
Pin 6	CT — Timing capacitor for oscillator
Pin 7	RAMP — Ramp input for current sensing
Pin 8	SS — Soft-start and max duty clamp
Pin 9	ILIM — Current limit sense input
Pin 10	GND — Ground
Pin 11	OUTA — Output A (totem-pole)
Pin 12	VCC — Supply voltage
Pin 13	OUTB — Output B (totem-pole)
Pin 14	VREF — 5V reference output
Pin 15	SD — Shutdown input (TTL compatible)
Pin 16	GND — Ground (second pin)

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

UC3824 is suitable for 6 applications: Push-Pull Converters, Half-Bridge Converters, Full-Bridge Converters, Battery Chargers, Telecom Power Supplies, Industrial Power Converters.

⚡

Push-Pull Converters

The UC3824's dual 1.5-A totem-pole outputs provide complementary drive signals for push-pull converters. Its high-speed operation (up to 1 MHz) allows for smaller transformers and improved power density. The 50-ns propagation delay ensures precise timing between the two output phases, reducing the risk of transformer saturation. With a maximum duty cycle of 85%, it can handle wide input voltage variations while maintaining regulation. The current-mode control provides inherent overcurrent protection, making it ideal for telecom and industrial power supplies.

Recommended

TL494 (Alternative PWM controller for lower-frequency designs) UC3825 (Higher UVLO variant for automotive applications)

🏭

Half-Bridge Converters

In half-bridge topologies, the UC3824 generates the two interleaved gate drive signals needed for the high-side and low-side MOSFETs. Its 1.5-A peak output current can drive large gate capacitances directly, eliminating the need for external buffer stages. The high switching frequency (up to 1 MHz) enables the use of smaller magnetic components, reducing the overall footprint of the power supply. The soft-start feature limits inrush current during startup, protecting the power stage. The TTL-compatible shutdown port allows for easy implementation of protection schemes.

Recommended

UCC27511A · Texas Instruments TL494 (Alternative for lower-frequency half-bridge designs)

🔧

Full-Bridge Converters

The UC3824 can be used in full-bridge converters by combining its two outputs with external logic to generate four drive signals. Its high-speed operation and 50-ns propagation delay ensure accurate phase-shift control, which is critical for zero-voltage switching (ZVS) techniques. The 1.5-A output current provides sufficient gate drive for high-power MOSFETs, while the current-limit comparator offers cycle-by-cycle protection. The device's wide input voltage range (up to 30 V) makes it suitable for industrial power supplies and battery chargers.

Recommended

UCC21520 · Texas Instruments UC3825 (Alternative with different UVLO thresholds)

🔋

Battery Chargers

The UC3824 is well-suited for battery charger applications requiring high-frequency switching to reduce charger size. Its current-mode control provides accurate current limiting, essential for safe battery charging. The soft-start feature prevents inrush current when charging deeply discharged batteries. The 1.5-A gate drive can directly drive the switching MOSFETs in a buck or boost converter. The device's wide input voltage range accommodates various AC-DC adapter outputs, and the TTL shutdown port allows for easy implementation of charge termination logic.

Recommended

BQ24251RGER · Texas Instruments TL494 (Alternative for lower-frequency chargers)

🌐

Telecom Power Supplies

In telecom power supplies, the UC3824's high-frequency operation (up to 1 MHz) enables compact, high-density designs that meet the strict size constraints of telecom racks. Its 1.5-A output current can drive the large MOSFETs used in high-power converters, while the 50-ns propagation delay ensures fast transient response. The current-mode control provides excellent line and load regulation, critical for maintaining stable output voltages in telecom systems. The device's wide input voltage range (up to 30 V) allows it to operate from standard telecom bus voltages (e.g., 48 V with a pre-regulator).

Recommended

TL494 (Alternative for lower-frequency telecom supplies) UC3825 (Higher UVLO variant for 48V systems)

🏭

Industrial Power Converters

The UC3824 is designed for industrial power converters that require high reliability and precise control. Its fully latched logic prevents multiple pulses, ensuring jitter-free operation in noisy industrial environments. The current-limit comparator with a 1-V threshold provides robust overcurrent protection, while the soft-start feature limits stress during startup. The device's wide operating temperature range (0°C to 70°C) covers most industrial applications. The high-speed operation allows for smaller magnetic components, reducing the overall cost and size of the converter.

Recommended

UCC27511A · Texas Instruments TL494 (Alternative for lower-frequency industrial converters)

Recommended Products Summary

TL494 Alternative PWM controller for lower-frequency designs Used in: Push-Pull Converters, Half-Bridge Converters, Battery Chargers, Telecom Power Supplies, Industrial Power Converters UC3825 Higher UVLO variant for automotive applications Used in: Push-Pull Converters, Full-Bridge Converters, Telecom Power Supplies UCC27511A Texas Instruments Used in: Half-Bridge Converters, Industrial Power Converters UCC21520 Texas Instruments Used in: Full-Bridge Converters BQ24251RGER Texas Instruments Used in: Battery Chargers

What is the UC3824?

The UC3824 is a high-speed, double-ended PWM controller from Texas Instruments. It operates at frequencies up to 1 MHz and provides 1.5-A totem-pole outputs for driving power MOSFETs. According to the TI datasheet, it features a 9.2-V/8.4-V UVLO and 85% maximum duty cycle, making it suitable for push-pull and half-bridge converters.

What is the maximum switching frequency of UC3824?

The UC3824 can operate at switching frequencies up to 1 MHz. This high-frequency capability allows for smaller magnetic components, reducing the size and cost of the power supply. The oscillator frequency is set by external timing components RT and CT, as described in the TI datasheet.

What is the output current capability of UC3824?

The UC3824's totem-pole outputs can source and sink 1.5 A of current. This high drive capability enables direct connection to power MOSFET gates without additional buffer stages, simplifying the gate drive circuit and improving switching performance.

What is the input voltage range of UC3824?

The UC3824 can operate with a supply voltage (VCC) up to 30 V. The undervoltage lockout (UVLO) turns the device on at 9.2 V and off at 8.4 V, ensuring proper operation and preventing erratic behavior at low supply voltages.

What is the duty cycle range of UC3824?

The UC3824 supports a maximum duty cycle of 85%. This allows for a wide range of output voltage regulation in buck and push-pull topologies. The soft-start pin can also be used to clamp the maximum duty cycle, providing additional design flexibility.

What is the propagation delay of UC3824?

The UC3824 has a propagation delay of 50 ns from the comparator input to the output. This fast response is critical for high-frequency operation, minimizing phase lag in the control loop and ensuring stable regulation at frequencies up to 1 MHz.

What is the difference between UC3824 and TL494?

The UC3824 is a high-speed PWM controller with 1.5-A outputs and 50-ns propagation delay, while the TL494 is a slower, general-purpose PWM controller with 200-mA outputs. According to TI's comparison tool, the UC3824 supports push-pull topology and operates at higher frequencies, making it more suitable for modern high-density power supplies.

Can UC3824 be used in push-pull converters?

Yes, the UC3824 is specifically designed for double-ended topologies like push-pull and half-bridge converters. Its dual totem-pole outputs provide the complementary drive signals required for these topologies, and its high-speed operation ensures efficient switching at high frequencies.

What is the soft-start feature of UC3824?

The UC3824 includes a soft-start pin that limits inrush current during startup by gradually increasing the duty cycle. This pin also doubles as a maximum duty cycle clamp, allowing designers to set an upper limit on the duty cycle to protect the power stage.

What is the current limit threshold of UC3824?

The UC3824 has a current limit comparator with a 1-V threshold. This allows cycle-by-cycle current limiting by sensing the voltage across a sense resistor in the source path. The logic is fully latched to prevent multiple pulses, ensuring jitter-free operation.

Where can I buy UC3824?

The UC3824 is available from major distributors such as DigiKey and Mouser. As of 2026-08-27, the UC3824N in a 16-PDIP package is in stock at DigiKey with pricing starting at $3.42 for single units. You can also purchase directly from TI's website.

What is the price of UC3824?

As of 2026-08-27, the UC3824N is priced at $3.42 for a single unit, $3.08 for 10 units, $2.74 for 100 units, $2.47 for 500 units, and $2.19 for 1000 units at DigiKey. Prices may vary by distributor and quantity.

What is the lead time for UC3824?

The lead time for UC3824 depends on the distributor and current stock levels. As of 2026-08-27, DigiKey lists the UC3824N as 'ships today' for in-stock items. For larger quantities or backordered parts, lead times may range from a few days to several weeks.

Is UC3824 in stock?

As of 2026-08-27, the UC3824N is in stock at DigiKey and can ship immediately. Availability may vary by package variant and distributor, so it is recommended to check current stock levels on distributor websites.

What is the best drop-in replacement for UC3824?

The UC3824N is the standard PDIP version, and the UC3824DW is the SOIC version with the same functionality. For a drop-in replacement with identical pinout and package, the UC3824N is the direct choice. Cross-brand equivalents may exist but require verification of pin compatibility.

Engineering reference data for UC3824 — comparison, design guidance, and compliance information.

Selection Guide

Choose the UC3824 when you need a high-speed PWM controller with 1.5-A output drive for double-ended topologies like push-pull or half-bridge converters. Its 50-ns propagation delay and 1-MHz operation make it ideal for compact, high-density power supplies. If you require a lower UVLO threshold (e.g., for automotive applications with lower supply voltages), consider the UC3825. For lower-frequency, lower-cost designs, the TL494 is a viable alternative but offers only 200-mA output current and a maximum duty cycle of 45%, limiting its use in high-power applications. The UC3824N is the PDIP version, while the UC3824DW is the SOIC version; both are functionally identical but have different packages.

Comparison with Alternatives

Parameter	This Product	UC3824N	UC3825	TL494
Package	16-PDIP	16-PDIP	16-PDIP	16-PDIP
Brand	Texas Instruments	Texas Instruments	Texas Instruments	Texas Instruments
Output Current (Source/Sink)	1.5 A	1.5 A	1.5 A	0.2 A
Maximum Switching Frequency	1 MHz	1 MHz	1 MHz	300 kHz
Propagation Delay to Output	50 ns	50 ns	50 ns	200 ns
UVLO Threshold (On/Off)	9.2 V / 8.4 V	9.2 V / 8.4 V	8.4 V / 7.6 V	7.0 V / 4.9 V
Maximum Duty Cycle	85%	85%	85%	45%
Current Limit Threshold	1 V	1 V	1 V	0.7 V

Key Differentiators

High output current (1.5 A) compared to TL494's 200 mA (vs TL494)
Fast propagation delay (50 ns) vs TL494's 200 ns (vs TL494)
Higher UVLO thresholds (9.2V/8.4V) vs UC3825's 8.4V/7.6V (vs UC3825)

Design Notes

For high-speed operation up to 1 MHz, careful PCB layout is essential. Use a ground plane to minimize noise and ensure low-inductance paths for the gate drive signals. Place the timing components (RT, CT) close to the IC to reduce parasitic capacitance and inductance. Bypass the VCC pin with a 0.1-uF ceramic capacitor and a 10-uF electrolytic capacitor near the device.

The UC3824's 1.5-A output stage can dissipate significant power when driving large capacitive loads at high frequencies. Ensure adequate thermal management by providing copper pour on the PCB and considering the total power dissipation. The device's power dissipation can be estimated as P = VCC * ICC + (f * Qg * VCC) for each output, where Qg is the gate charge of the MOSFET.

Avoid exceeding the absolute maximum VCC of 30 V. The soft-start pin should not be left floating; connect a capacitor to ground to set the startup time. The current-limit sense resistor should be placed in the source path of the power MOSFET, and the ILIM pin should be filtered to avoid false triggering due to noise. Ensure the shutdown pin is properly terminated to prevent unintended shutdown.