Overview
The TL2844BDR-8 is a high-performance current-mode PWM (Pulse Width Modulation) controller from Texas Instruments. It is part of the TL284xB and TL384xB series, designed to implement off-line or DC-DC fixed-frequency current-mode control schemes with a minimal number of external components. This device is characterized by its low start-up current, trimmed oscillator discharge current, and automatic feed-forward compensation, making it suitable for a variety of power management applications.
Key Specifications
| Parameter | Test Conditions | Unit | Min | Max | |
|---|---|---|---|---|---|
| Output Voltage | IO = 1 mA, TJ = 25°C | V | 4.95 | 5 | 5.05 |
| Line Regulation | VCC = 12 V to 25 V | mV | 6 | 20 | 6 |
| Load Regulation | IO = 1 mA to 20 mA | mV | 6 | 25 | 6 |
| Oscillator Frequency | TJ = 25°C, RT = 6.2 kΩ, CT = 1 nF | kHz | 44 | 50 | 60 |
| Start Threshold Voltage | V | 15 | 16 | 17 | |
| Minimum Operating Voltage After Start-Up | V | 9 | 10 | 11 | |
| Maximum Duty Cycle | % | 46 | 48 | 50 | |
| High-Level Output Voltage | IOH = –20 mA | V | 13 | 13.5 | 13.5 |
| Low-Level Output Voltage | IOL = 20 mA | V | 0.1 | 0.4 | 0.4 |
| Rise Time | CL = 1 nF, TJ = 25°C | ns | 25 | 150 | 150 |
| Fall Time | CL = 1 nF, TJ = 25°C | ns | 25 | 150 | 150 |
| UVLO Saturation Voltage | VCC = 5 V, IOL = 1 mA | V | 0.7 | 1.2 | 1.2 |
Key Features
- Low start-up current (<0.5 mA)
- Trimmed oscillator discharge current (typical 8.3 mA)
- Current mode operation up to 500 kHz
- Automatic feed-forward compensation
- Latching PWM for cycle-by-cycle current limiting
- Internally trimmed reference with undervoltage lockout (UVLO)
- High-current totem-pole output with UVLO and hysteresis
- Double-pulse suppression
Applications
- Switching regulators of any polarity
- Transformer-coupled DC/DC converters
Q & A
- What is the typical start-up current of the TL2844BDR-8?
The typical start-up current is less than 0.5 mA.
- What is the oscillator frequency range of the TL2844BDR-8?
The oscillator frequency range is typically between 44 kHz and 60 kHz.
- What is the maximum duty cycle for the TL2844BDR-8?
The maximum duty cycle is 50%.
- What are the typical UVLO thresholds for the TL2844BDR-8?
The typical UVLO thresholds are 16 V (on) and 10 V (off).
- What is the high-level output voltage of the TL2844BDR-8?
The high-level output voltage is typically 13.5 V when sinking 20 mA.
- What is the low-level output voltage of the TL2844BDR-8?
The low-level output voltage is typically 0.4 V when sourcing 20 mA.
- What is the rise and fall time of the output signal?
The rise and fall time is typically 150 ns with a load capacitance of 1 nF.
- What is the UVLO saturation voltage for the TL2844BDR-8?
The UVLO saturation voltage is typically 1.2 V when VCC is 5 V and IOL is 1 mA.
- What are the operating temperature ranges for the TL2844BDR-8?
The device is characterized for operation from –40°C to 85°C.
- What types of packages are available for the TL2844BDR-8?
The device is available in SOIC (D) packages.
