Datasheet

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Open Lamp Detect Section
Soft Start Threshold V
EA(-) = 0V 2.9 3.4 3.8 V
Error Amp Threshold V
SS = 4.2V 0.7 1.0 1.3 V
Soft Start Current V
SS = 2V 10 20 40 µA
Error Amp 2 Section
Input Offset Voltage V
O = 2V 0 10 mV
Input Bias Current -0.2 -1 µA
Input Offset Current 0.5 µA
Open Loop Gain V
O = 0.5 to 3V 65 90 dB
Output High V
ID = 100mV, VO = 2V 3.6 4 4.4 V
Output Low V
ID = -100mv, VO = 2V 0.1 0.2 V
Output Source Current V
ID = 100mV, VO = 2V -350 -500 µA
Output Sink Current V
ID = -100mV, VO = 2V 10 20 mA
Common Mode Range 0V
IN-2V V
Unity Gain Bandwidth T
J = 25°C (Note 4) 1 MHz
Isense Section
Threshold 0.475 0.525 0.575 V
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, Outputs C and D 14.7 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
EA1(-) = 1V 100 %
Out C Min Duty Cycle V
EA1(-) = 2V 0 %
Out D Max Duty Cycle V
EA2(+)- VEA2(-) = 100mV 92 96 %
Out D Min Duty Cycle V
EA2(+)- VEA2(-) = -100mV 0 %
Under Voltage Lockout Section
Start-Up Threshold 3.7 4.2 4.5 V
Hysterisis 120 200 280 mV
Enable Section
Input High Threshold 2V
Input low Threshold 0.8 V
Input Current V
ENABLE = 5V 150 400 µA
Supply Current Section
VCC Supply Current V
CC = 20V 8 14 mA
VC Supply Current V
C=20V 7 12 mA
ICC Disabled V
CC = 20V, VENABLE = 0V 1 10 µA
UC1871
UC2871
UC3871
ELECTRICAL
CHARACTERISTICS (cont.)
Unless otherwise stated, these parameters apply for TA = -55°C to +125°C for the UC1871;
-25°C to +85°C for the UC2871; 0°C to +70°C for the UC3871; V
CC = 5V, VC = 15V,
V
ENABLE = 5V, CT = 1nF, Zero Det = 1V.
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 but not 100% tested in production.
Note 5: Impedance below specified maximum guarantees proper operation of the Open Lamp Detect.
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