The UC3843 series of control integrated circuits provide the features that are necessary to implement off-line or DC-to-DC fixed-frequency current-mode control schemes, with a minimum number of external components. The internally implemented circuits include an under voltage lockout (UVLO), featuring a start-up current of less than 1 mA, and a precision reference trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (PWM) comparator that also provides current-limit control, and a totem-pole output stage that is designed to source or sink high-peak current. The output stage, suitable for driving N-channel MOSFETs, is low when it is in the off state. It offers a variety of package options, temperature range options, choice of maximum duty cycle, and choice of turnon and turnoff thresholds and hysteresis ranges. Devices with higher turnon or turnoff hysteresis are ideal choices for off-line power supplies, while the devices with a narrower hysteresis range are suited for DC-DC applications. The UC3843 is specified for operation from 0°C to 70°C.
Features:-
- Optimized for Off-Line and DC-to-DC Converters
- Low Start-Up Current (< 1 mA)
- Automatic Feedforward 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
- Up to 500-kHz Operation
- Error Amplifier With Low Output Resistance
Specification:-
Parameter | Value |
Part number | UC3843 |
Topology | Boost, Buck, Buck-Boost, Flyback, Forward |
Control method | Peak Current Mode |
VCC (Min) (V) | 8.4 |
VCC (Max)(V) | 28 |
Frequency (Max) (kHz) | 500 |
UVLO thresholds on/off (V) | 8.4/7.6 |
Duty cycle (Max) (%) | 100 |
Gate drive (Typ) (A) | 1 |
Features | Adjustable Switching Frequency, Current Limiting, Dead Time Control, Error Amplifier, Multi-topology |
Operating temperature range | 0 to 70 |
Package Group | PDIP|8 |
Package size: mm2:W x L (PKG) | 8PDIP: 93 mm2: 9.43 x 9.81 (PDIP|8) |
* product image for illustration purposes only. actual product may vary.
There are no reviews yet.