Features: · Automatic Feed Forward Compensation
· Programmable Pulse-by-Pulse Current Limiting
· Automatic Symmetry Correction in Push-pull Configuration
· Enhanced Load Response Characteristics
· Parallel Operation Capability for Modular Power Systems
· Differential Current Sense Amplifier with Wide Common Mode Range
· Double Pulse Suppression
· 500mA (Peak) Totem-pole Outputs
· ±1% Bandgap Reference
· Under-voltage Lockout
· Soft Start Capability
· Shutdown Terminal
· 500kHZ OperationPinout
SpecificationsSupply Voltage (Pin 15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V
Collector Supply Voltage (Pin 13). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V
Output Current, Source or Sink (Pins 11, 14). . . . . . . . . . . . . . . . . . . . . 500mA
Analog Inputs (Pins 3, 4, 5, 6, 16) . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +VIN
Reference Output Current (Pin 2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -30mA
Sync Output Current (Pin 10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -5mA
Error Amplifier Output Current (Pin 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . .. -5mA
Soft Start Sink Current (Pin 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA
Oscillator Charging Current (Pin 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
Power Dissipation at TA=25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000mW
Power Dissipation at TC=25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000mW
Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°C
Lead Temperature (soldering, 10 seconds. . . . . . . . . . . . . . . . . . . . . . . . +300°C
Note 1. All voltages are with respect to Ground, Pin 13. Currents are positive into, negative out of the speficied terminal. Consult Packaging Section of Databook for thermal limitations and considerations of packages. Pin numbers refer to DIL and SOIC packages only.
DescriptionThe UC1846/7 family of control ICs provides all of the necessary features to implement fixed frequency, current mode control schemes while maintaining a minimum external parts count. The superior performance of this technique can be measured in improved line regulation, enhanced load response characteristics, and a simpler, easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current limiting capability, automatic symmetry correction for push-pull converters, and the ability to parallel "power modules" while maintaining equal current sharing.
Protection circuitry includes built-in under-voltage lockout and programmable current limit in addition to soft start capability. A shutdown function is also available which can initiate either a complete shutdown with automatic restart or latch the supply off.
Other features include fully latched operation, double pulse suppression, deadline adjust capability, and a ±1% trimmed bandgap reference.
The UC1846 features low outputs in the OFF state, while the UC1847 features high outputs in the OFF state.
UC2846 Data Sheet
