Datasheet LT1374 (Analog Devices) - 4

LT1374
ELECTRICAL CHARACTERISTICS Note 5:
Boost current is the current flowing into the boost pin with the pin
Note 8:
Transconductance and voltage gain refer to the internal amplifier held 5V above input voltage. It flows only during switch on time. exclusive of the voltage divider. To calculate gain and transconductance,
Note 6:
V refer to the SENSE pin on the fixed voltage parts. Divide values shown by IN supply current is the current drawn when the BIAS pin is held at 5V and switching is disabled. If the BIAS pin is unavailable or open the ratio VOUT/2.42. circuit, the sum of VIN and BIAS supply currents will be drawn by the VIN
Note 9:
Slope compensation is the current subtracted from the switch pin. current limit at 80% duty cycle. See Maximum Output Load Current in the
Note 7:
Switch on resistance is calculated by dividing V Applications Information section for further details. IN to VSW voltage by the forced current (4.5A). See Typical Performance Characteristics for the graph of switch voltage at other currents.
W U TYPICAL PERFOR A CE CHARACTERISTICS Switch Voltage Drop Switch Peak Current Limit Feedback Pin Voltage
500 6.5 2.430 450 125°C 6.0 400 TYPICAL 2.425 350 5.5 25°C 300 5.0 250 2.420 MINIMUM – 40°C 4.5 200 150 SWITCH VOLTAGE (mV) 4.0 FEEDBACK VOLTAGE (V) 2.415 100 SWITCH PEAK CURRENT (A) 3.5 50 0 3.0 2.410 0 1 2 3 4 5 0 20 40 60 80 100 – 50 –25 0 25 50 75 100 125 SWITCH CURRENT (A) DUTY CYCLE (%) TEMPERATURE (°C) 1374 G18 1374 G02 1374 G03
Shutdown Pin Bias Current Standby and Shutdown Thresholds Shutdown Supply Current
500 2.40 25 VSHDN = 0V CURRENT REQUIRED TO FORCE SHUTDOWN STANDBY 400 (FLOWS OUT OF PIN). AFTER SHUTDOWN, A) 20 CURRENT DROPS TO A FEW µA 2.36 µ 300 A) µ 2.32 15 200 0.8 10 CURRENT ( 8 AT 2.38V STANDBY THRESHOLD START-UP (CURRENT FLOWS OUT OF PIN) SHUTDOWN PIN VOLTAGE (V) 0.4 INPUT SUPPLY CURRENT ( 5 4 SHUTDOWN 0 0 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 0 5 10 15 20 25 TEMPERATURE (°C) JUNCTION TEMPERATURE (°C) INPUT VOLTAGE (V) 1374 G04 1374 G05 1374 G06 1374fd 4