Datasheet

3
UC1872
UC2872
UC3872
ELECTRICAL CHARACTERISTICS:
Unless otherwise stated, these parameters apply for TJ = −55°C to +125°C for the
UC1872, –40°C to +85°C for the UC2872, −0°C to +70°C for the UC3872; VCC= 5V, VC = 15V, V
ENBL
= 5V, CT = 1nF, ZD = 1V.
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Error Amp Section (cont.)
Output Low V
INV
= 1.7V 0.1 0.2 V
Output Source Current V
INV
= 1.3V, V
O
= 2V –350 –500 µA
Output Sink Current V
INV
= 1.7V, V
O
= 2V 10 20 mA
Common Mode Range 0V
IN
-1V V
Unity Gain Bandwidth T
J
= 25°C (Note 4) 1 MHz
Open Lamp Detect Section
Soft Start Threshold V
INV
= 0V 2.9 3.4 3.8 V
Open Lamp Detect Threshold V
SS
= 4.2V 0.6 1.0 1.4 V
Soft Start Current V
SS
= 2V 10 20 40 µA
Output Section
Output Low Level I
OUT
= 0, Outputs A and B 0.05 0.2 V
I
OUT
= 10mA 0.1 0.4 V
I
OUT
= 100mA 1.5 2.2 V
Output High Level I
OUT
= 0, Output C 13.9 14.9 V
I
OUT
= −10mA 13.5 14.3 V
I
OUT
= −100mA 12.5 13.5 V
Rise Time T
J
= 25°C, Cl = 1nF (Note 4) 30 80 ns
Fall Time T
J
= 25°C, Cl = 1nF (Note 4) 30 80 ns
Output Dynamics
Out A and B Duty Cycle 48 49.9 50 %
Out C Max Duty Cycle V
INV
= 1V 100 %
Out C Min Duty Cycle V
INV
= 2V 0 %
Under Voltage Lockout Section
Startup Threshold Voltage 3.7 4.2 4.5 V
Hysteresis 120 200 280 mV
Enable Section
Input High Threshold 2V
Input Low Threshold 0.8 V
Input Current V
ENBL
= 5V 150 400 µA
Supply Current Section
VCC Supply Current VCC = 24V 6 14 mA
VC Supply Current VC = 24V 5 12 mA
ICC Disabled VCC = 24V, V
ENBL = 0V 1 10 µA
Note 3: Unless otherwise specified, all voltages are with respect to ground. Currents are positive into, and negative out of the
specified terminal.
Note 4: Guaranteed by design. Not 100% tested in production.