Overview
The UC2843NNTR is a current-mode PWM controller IC produced by Unitrode, which is now part of Texas Instruments. This device is a pin-for-pin compatible improved version of the UC2843 and is designed to control current-mode switched-mode power supplies. It is optimized for off-line and DC-to-DC converters and is qualified for automotive applications, offering extended temperature performance from –40°C to 125°C.
Key Specifications
| Parameter | Min | Typ | Max | Unit | Reference |
|---|---|---|---|---|---|
| Output Voltage | 4.95 | 5 | 5.05 | V | TJ = 25°C, IO = 1 mA |
| Line Regulation | 6 | - | 20 | mV | 12 ≤ VIN ≤ 25 V |
| Load Regulation | 6 | - | 25 | mV | 1 ≤ IO ≤ 20 mA |
| Temperature Stability | 0.2 | 0.4 | - | mV/°C | - |
| Oscillator Frequency | 47 | 52 | 57 | kHz | TJ = 25°C |
| Start-Up Current | 0.3 | 0.5 | - | mA | - |
| Operating Supply Current | 11 | 17 | - | mA | VFB = VISENSE = 0 V |
| Maximum Duty Cycle | 92 | 96 | 100 | % | - |
| UVLO Start Threshold | 7.8 | 8.4 | 9 | V | - |
Key Features
- Qualified for automotive applications with extended temperature performance from –40°C to 125°C.
- Optimized for off-line and DC-to-DC converters.
- Low start-up current of less than 0.5 mA.
- Trimmed oscillator-discharge current.
- Automatic feed-forward compensation.
- Pulse-by-pulse current limiting.
- Enhanced load-response characteristics.
- Under-voltage lockout with hysteresis.
- Double-pulse suppression.
- High-current totem-pole output.
- Internally trimmed bandgap reference.
- Operation up to 500 kHz.
- Low RO Error Amp).
Applications
- Switch mode power supplies (SMPS).
- DC-DC converters.
- Power modules.
- Industrial power supplies (PSU)).
- Battery-operated power supplies (PSU)).
Q & A
- What is the UC2843NNTR used for?
The UC2843NNTR is used to control current-mode switched-mode power supplies, particularly in off-line and DC-to-DC converters.
- What are the key features of the UC2843NNTR?
Key features include low start-up current, trimmed oscillator-discharge current, automatic feed-forward compensation, pulse-by-pulse current limiting, and under-voltage lockout with hysteresis.
- What is the operating temperature range of the UC2843NNTR?
The device operates over a temperature range of –40°C to 125°C.
- What is the maximum switching frequency of the UC2843NNTR?
The device can operate at switching frequencies up to 500 kHz.
- What type of applications is the UC2843NNTR qualified for?
The UC2843NNTR is qualified for automotive applications.
- What is the typical start-up current of the UC2843NNTR?
The typical start-up current is less than 0.5 mA.
- Does the UC2843NNTR have under-voltage lockout protection?
Yes, the device features under-voltage lockout protection with hysteresis.
- What is the maximum duty cycle of the UC2843NNTR?
The maximum duty cycle is up to 100%.
- Can the UC2843NNTR be used in industrial power supplies?
Yes, it can be used in industrial power supplies.
- How does the UC2843NNTR handle load response?
The device has enhanced load-response characteristics.
