Datasheet LT1776 (Analog Devices) - 4

LT1776
W U TYPICAL PERFORMANCE CHARACTERISTICS Minimum Input Voltage vs Switch-On Voltage vs Switch Current Limit vs Temperature Switch Current Duty Cycle
7.4 1.50 1000 TA = 25°C 7.2 1.25 800 25°C 7.0 – 55°C 1.00 600 6.8 0.75 6.6 125°C 400 0.50 INPUT VOLTAGE (V) 6.4 SWITCH VOLTAGE (V) SWITCH CURRENT LIMIT (mA) 200 6.2 0.25 6.0 0 0 –50 –25 0 25 50 75 100 125 0 100 200 300 400 500 600 700 0 10 20 30 40 50 60 70 80 90 100 TEMPERATURE (°C) SWITCH CURRENT (mA) DUTY CYCLE (%) 1776 G01 1776 G02 1776 G03
SHDN Pin Shutdown Threshold SHDN Pin Input Current SHDN Pin Lockout Thresholds vs Temperature vs Voltage vs Temperature
900 5 1.30 800 µA) 0 1.28 700 UPPER THRESHOLD –5 1.26 600 LOWER THRESHOLD 500 –10 1.24 400 SHDN PIN VOLTAGE (mV) SHDN PIN VOLTAGE (V) –15 25°C 1.22 SHDN PIN INPUT CURRENT ( 300 –55°C 125°C 200 –20 1.20 –50 –25 0 25 50 75 100 125 0 1 2 3 4 5 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) SHDN PIN VOLTAGE (V) TEMPERATURE (°C) LT1776 G04 1776 G05 LT1776 G06
Switching Frequency Minimum Synchronization Voltage Switch Minimum On-Time vs Temperature vs Temperature vs Temperature
215 2.25 600 VIN = 40V R 210 2.00 500 L = 39Ω FB = 205 1.75 400 200 1.50 300 195 1.25 200 SWITCHING FREQUENCY (kHz) 190 1.00 SWITCH MINIMUM ON-TIME (ns) 100 MINIMUM SYNCHRONIZATION VOLTAGE (V) 185 0.75 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 1776 G07 1776 G08 1776 G09 4