Datasheet LT1372, LT1377 (Analog Devices) - 4

LT1372/LT1377
W U TYPICAL PERFOR A CE CHARACTERISTICS Shutdown Delay and Threshold Minimum Synchronization Error Amplifier Output Current vs Temperature Voltage vs Temperature vs Feedback Pin Voltage
20 2.0 ) 3.0 400 P-P fSYNC = 700kHz (LT1372) 18 1.8 µA) fSYNC = 1.4MHz (LT1377) 300 SHUTDOWN THRESHOLD (V) 2.5 16 1.6 25°C SHUTDOWN THRESHOLD –55°C µs) 14 1.4 200 125 2.0 °C 12 1.2 LT1377 100 10 1.0 1.5 0 8 SHUTDOWN DELAY 0.8 LT1372 1.0 6 0.6 –100 SHUTDOWN DELAY ( 4 0.4 0.5 –200 2 0.2 ERROR AMPLIFIER OUTPUT CURRENT ( 0 0 MINIMUM SYNCHRONIZATION VOLTAGE (V 0 –300 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –0.3 –0.2 –0.1 V 0.1 REF TEMPERATURE (°C) TEMPERATURE (°C) FEEDBACK PIN VOLTAGE (V) LT1372 • G04 LT1372 • G05 LT1372 • G06
S/S Pin Input Current Switching Frequency Error Amplifier Transconductance vs Voltage vs Feedback Pin Voltage vs Temperature
5 110 2000 VIN = 5V ∆I (VC) 4 100 1800 gm = ∆V (FB) 1600 µA) 3 90 2 80 µmho) 1400 1 70 1200 0 60 1000 –1 50 800 –2 40 600 S/S PIN INPUT CURRENT ( –3 30 TRANSCONDUCTANCE ( 400 –4 20 200 SWITCHING FREQUENCY (% OF TYPICAL) –5 10 0 –1 0 1 2 3 4 5 6 7 8 9 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 –50 –25 0 25 50 75 100 125 150 S/S PIN VOLTAGE (V) FEEDBACK PIN VOLTAGE (V) TEMPERATURE (°C) LT1372 • G07 LT1372 • G08 LT1372 • G09
VC Pin Threshold and High Feedback Input Current Negative Feedback Input Current Clamp Voltage vs Temperature vs Temperature vs Temperature
2.4 800 0 V V FB =VREF NFB =VNFR 2.2 µA) 700 2.0 VC HIGH CLAMP –10 600 1.8 1.6 500 –20 1.4 400 1.2 –30 PIN VOLTAGE (V) V 300 C C THRESHOLD V 1.0 200 0.8 –40 FEEDBACK INPUT CURRENT (nA) 0.6 100 NEGATIVE FEEDBACK INPUT CURRENT ( 0.4 0 –50 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) LT1372 • G10 LT1372 • G11 LT1372 • G12 4