UC3824 - 1.5A High Speed PWM Controller | Texas Instruments
Артикул: UC3824 ✓ Активен| Кол-во | Цена за ед. | Итого |
|---|---|---|
| 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 |
UC3824 Обзор
A PWM controller is an integrated circuit that generates the pulse-width-modulated signals used to control the switching elements in a DC-DC converter or power supply. It forms the core of the control loop, regulating output voltage or current by varying the duty cycle of the switching waveform. The UC3824 belongs to the family of current-mode PWM controllers, which offer superior line regulation and simpler compensation compared to voltage-mode controllers. In the hierarchy of power management, it sits between the power stage (MOSFETs, transformers) and the supervisory circuitry, providing the precise timing and drive signals essential for efficient power conversion.
Key features of the UC3824 include a 50-ns propagation delay to output, enabling high-frequency operation with minimal phase lag. The dual totem-pole outputs can source and sink 1.5 A, providing robust gate drive for large MOSFETs. The device also includes a current-limit comparator with a 1-V threshold, a TTL-compatible shutdown port, and a soft-start pin that doubles as a maximum duty cycle clamp. The logic is fully latched to ensure jitter-free operation and prevent multiple pulses at the output.
Technically, the UC3824 uses a fixed-frequency, current-mode architecture with an internal oscillator whose frequency is set by external timing components RT and CT. The ramp generator is designed so that the voltage at Pin 9 crosses the 1-V threshold at the same time the desired maximum volt-second product is reached, allowing precise control of the duty cycle. The device's high-speed comparator and latch ensure accurate cycle-by-cycle current limiting, making it suitable for demanding applications such as push-pull and half-bridge converters.
Typical applications include switch-mode power supplies for telecommunications, industrial power converters, and battery chargers. The UC3824's high-frequency capability allows for smaller magnetic components, reducing overall system size and cost. Its double-ended output configuration makes it ideal for push-pull and full-bridge topologies where two interleaved drive signals are required.
When designing with the UC3824, careful attention must be paid to grounding and bypassing, as the high-speed switching can introduce noise. A ground plane is highly recommended, and the timing components should be placed close to the IC to minimize parasitic inductance. The soft-start pin should be used to limit inrush current during startup, and the current-limit threshold should be set appropriately for the application.
Аналоги без доработки для UC3824 — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
Инструмент быстрого сравнения — выберите альтернативные компоненты для сравнения бок о бок:
UC3824N
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
UC3825
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
UC3823
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
TL494CDT
⚡ Тот же корпус✓ В наличии
$0.3182 / шт.
Открыть даташит →SG3524
⚡ Тот же корпус ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
UC3824 Максимальные параметры и электрические характеристики
| 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 |
| Диапазон рабочих температур | 0°C to 70°C |
| Package Type | 16-PDIP |
| Тип монтажа | Through Hole |
| Topology Support | Push-Pull, Half-Bridge, Full-Bridge |
| Control Method | Current Mode |
| Shutdown Port | TTL Compatible |
| Плавный пуск | Yes (also max duty clamp) |
| Статус RoHS | Compliant |
Конфигурация выводов UC3824
| Контакт 1 | INV — Inverting input of error amplifier |
| Контакт 2 | NI — Non-inverting input of error amplifier |
| Контакт 3 | EAOUT — Error amplifier output |
| Контакт 4 | CLK — Clock input for synchronization |
| Контакт 5 | RT — Timing resistor for oscillator |
| Контакт 6 | CT — Timing capacitor for oscillator |
| Контакт 7 | RAMP — Ramp input for current sensing |
| Контакт 8 | SS — Soft-start and max duty clamp |
| Контакт 9 | ILIM — Current limit sense input |
| Контакт 10 | GND — Ground |
| Контакт 11 | OUTA — Output A (totem-pole) |
| Контакт 12 | VCC — Supply voltage |
| Контакт 13 | OUTB — Output B (totem-pole) |
| Контакт 14 | VREF — 5V reference output |
| Контакт 15 | SD — Shutdown input (TTL compatible) |
| Контакт 16 | GND — Ground (second pin) |
Типичное применение
UC3824 подходит для 6 применениеs: 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.
Рекомендуется
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.
Рекомендуется
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.
Рекомендуется
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.
Рекомендуется
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).
Рекомендуется
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.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для UC3824 — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | 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 |
Ключевые отличия
- High output current (1.5 A) compared to TL494's 200 mA (против TL494)
- Fast propagation delay (50 ns) vs TL494's 200 ns (против TL494)
- Higher UVLO thresholds (9.2V/8.4V) vs UC3825's 8.4V/7.6V (против UC3825)
Заметки по проектированию
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.
Информация о соответствии
RoHS compliant per TI product page. Not AEC-Q100 qualified. Lead-free per TI's environmental data.
