Datasheet

SOIC–8 (TOP VIEW)
D Package
Unless otherwise stated, VCC=24V, ISET=50kΩ to GND, RAMP=1nF to GND, ISNS=
–0.1V, VFB connected to COMP, no load on OUT, –55°C<Ta<+125°C for the UC1852,
–40°C<Ta<+85°C for the UC2852, and 0°C<Ta<+70°C for the UC3852, and Ta=Tj.
UC1852
UC2852
UC3852
ELECTRICAL CHARACTERISTICS
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (Low-impedance Source)..........................30.0V
Supply Current (High-impedance Source) ......................30.0mA
OUT Current, Peak.............................................................±1.0A
OUT Energy, Capacitive Load............................................ 5.0µJ
Input Voltage, ISNS ............................................................±5.0V
Input Voltage, VFB............................................. –0.3V to +10.0V
COMP Current...............................................................±10.0mA
ISET Current..................................................................–10.0mA
Power Dissipation at Ta≤25°C (Note 3) ..............................1.0W
Storage Temperature .......................................–65°C to +150°C
Lead Temperature (Soldering, 10 Seconds)...................+300°C
Note 1: All voltages with respect to GND (Pin 1).
Note 2: All currents are positive into the specified terminal.
Note 3: Refers to DIL-8 Package. Consult Packaging Section of
Unitrode Integrated Circuits databook for thermal limitations and
considerations of package.
DIL–8 (TOP VIEW)
J or N Package
CONNECTION DIAGRAM
PARAMETER TEST CONDITIONS MIN. TYP. MAX. UNITS
Timer Section
ISET Voltage 4.5 5.0 5.5 V
RAMP Charge Current RAMP=2.5V 88 98 108
µA
RAMP Discharge Current ISNS= –1.0V, RAMP=1.0V 12 28 50 mA
RAMP Saturation Voltage
ISNS= –1.0V, I
RAMP=100µA
0.006 0.200 V
RAMP Threshold - Maximum Frequency VFB=10V, COMP open 0.92 1.02 1.12 V
RAMP Threshold - PWM Comparator 3.9 4.3 4.8 V
Current Sense Comparator
ISNS Restart Threshold –18 –10 –4 mV
ISNS Fault Threshold –550 –450 –350 mV
ISNS Input Current –100 –30 100
µA
Error Amplifier Section
VFB Input Voltage 4.6 5.0 5.3 V
VFB Input Bias Current –5.00 –0.03 5.00
µA
COMP Sink Current COMP=7.5V 10 mA
COMP Source Current COMP=2.5V –300 –175 –100
µA
COMP Clamp Voltage VFB=0.0V, COMP open 9.2 10.0 10.6 V
OUT Output
OUT Saturation Voltage High VCC=13V, I
OUT= –200mA, RAMP=2V 0.5 1.7 2.5 V
OUT Saturation Voltage Low I
OUT=200mA, ISNS= –1.0V 0.5 1.6 2.2 V
OUT Saturation Voltage Low @ 10mA I
OUT=10mA, ISNS= –1.0V 0.05 0.40 V
OUT Clamp Voltage I
OUT= –200mA, RAMP=2V 10.0 12.0 14.5 V
OUT Voltage during UVLO I
OUT=100mA, VCC=0V 0.5 1.0 2.2 V
Overall Section
Inactive Supply Current VCC=10V 0.2 0.4 1.0 mA
Active Supply Current 3.0 6.0 10.0 mA
VCC Clamp Voltage ICC=25mA 30 33 36 V
VCC Turn-On Threshold 14.5 16.3 17.5 V
VCC Turn-Off Threshold 10.5 11.5 13.0 V
VCC Threshold Hysteresis 3 5 7 V
UDG-92002
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