Overview
The UC2844BN, produced by STMicroelectronics, is a high-performance current mode controller IC designed for off-line and DC-DC converter applications. It is part of the UC284xB family, which offers a cost-effective solution with minimal external components. This IC is ideal for implementing fixed frequency current mode control schemes and is suitable for driving power MOSFETs.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage (low impedance source) | Vi | - | - | 30 | V |
| Output Current | IO | - | - | ±1 A | A |
| Output Energy (capacitive load) | EO | - | - | 5 | µJ |
| Power Dissipation at Tamb ≤ 25 °C (Minidip) | Ptot | - | - | 1.25 | W |
| Storage Temperature Range | Tstg | -65 | - | 150 | °C |
| Junction Operating Temperature | TJ | -40 | - | 150 | °C |
| Reference Output Voltage | Vref | 4.95 | 5.0 | 5.05 | V |
| Oscillator Frequency | fOSC | - | 250 kHz | - | kHz |
| Output Deadtime Adjustable | - | 50% to 70% | - | - | % |
Key Features
- Trimmed Oscillator for Precise Frequency Control: The oscillator frequency is programmable using external components RT and CT, ensuring precise control over the switching frequency.
- Current Mode Operation: Supports output switching frequencies up to 500 kHz, making it suitable for high-frequency applications.
- Adjustable Output Deadtime: The output deadtime can be adjusted from 50% to 70%, allowing for flexible control over the switching cycle.
- Automatic Feed Forward Compensation: Enhances stability and performance in the control loop.
- Latching PWM for Cycle-by-Cycle Current Limiting: Ensures safe operation by limiting the peak inductor current on a cycle-by-cycle basis.
- Internally Trimmed Reference with Undervoltage Lockout: Features a precise reference voltage with undervoltage lockout to ensure reliable startup and operation.
- High Current Totem Pole Output: Capable of sourcing and sinking high peak currents, making it suitable for driving power MOSFETs.
- Low Startup and Operating Current: Minimizes power consumption during startup and operation).
- Pb-Free and RoHS Compliant: Meets environmental standards for lead-free and RoHS compliance).
Applications
- Off-Line Converters: Suitable for off-line power supplies due to its high performance and minimal external component requirements).
- DC-DC Converters: Ideal for DC-DC converter applications, including boost, flyback, and other topologies).
- Power MOSFET Drivers: Designed to drive N-Channel MOSFETs in various power management circuits).
Q & A
- What is the primary function of the UC2844BN IC?
The UC2844BN is a high-performance current mode controller IC designed for off-line and DC-DC converter applications.
- What is the typical oscillator frequency of the UC2844BN?
The oscillator frequency is typically 250 kHz and can be programmed using external components RT and CT).
- What is the adjustable range for output deadtime in the UC2844BN?
The output deadtime can be adjusted from 50% to 70%).
- What type of output stage does the UC2844BN have?
The UC2844BN features a high current totem pole output stage suitable for driving power MOSFETs).
- What are the undervoltage lockout thresholds for the UC2844BN?
The VCC comparator thresholds are 16 V (on) and 10 V (off), and the Vref comparator thresholds are 3.6 V (on) and 3.4 V (off)).
- What is the maximum power dissipation of the UC2844BN at Tamb ≤ 25 °C?
The maximum power dissipation is 1.25 W for the Minidip package and 800 mW for the SO8 package).
- Is the UC2844BN Pb-Free and RoHS Compliant?
Yes, the UC2844BN is Pb-Free and RoHS Compliant).
- What is the storage temperature range for the UC2844BN?
The storage temperature range is -65 °C to 150 °C).
- What is the junction operating temperature range for the UC2844BN?
The junction operating temperature range is -40 °C to 150 °C).
- What types of packages are available for the UC2844BN?
The UC2844BN is available in 8-pin dual-in-line and surface mount (SOIC-8) packages, as well as a 14-pin surface mount (SOIC-14) package).
