Datasheet LT1375, LT1376 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | 1.5A, 500kHz Step-Down Switching Regulators |
| Pages / Page | 28 / 4 — ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over … |
| File Format / Size | PDF / 518 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over the full operating
Model Line for this Datasheet
- LT1375CN8#PBF LT1375CN8-5#PBF LT1375CS8#PBF LT1375CS8#TRPBF LT1375CS8-5#PBF LT1375CS8-5#TRPBF LT1375HVCS8#PBF LT1375HVCS8#TRPBF LT1375HVIS8#PBF LT1375HVIS8#TRPBF LT1375IN8#PBF LT1375IN8-5#PBF LT1375IS8#PBF LT1375IS8#TRPBF LT1375IS8-5#PBF LT1375IS8-5#TRPBF
- LT1376CN8#PBF LT1376CN8-5#PBF LT1376CS#PBF LT1376CS#TRPBF LT1376CS8#PBF LT1376CS8#TRPBF LT1376CS8-5#PBF LT1376CS8-5#TRPBF LT1376HVCS#PBF LT1376HVCS#TRPBF LT1376HVCS8#PBF LT1376HVCS8#TRPBF LT1376HVIS#PBF LT1376HVIS#TRPBF LT1376HVIS8#PBF LT1376HVIS8#TRPBF LT1376IN8#PBF LT1376IN8-5#PBF LT1376IS#PBF LT1376IS#TRPBF LT1376IS8#PBF LT1376IS8#TRPBF LT1376IS8-5#PBF LT1376IS8-5#TRPBF
Text Version of Document
LT1375/LT1376
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. TJ = 25
°
C, VIN = 15V, VC = 1.5V, boost open, switch open, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
Shutdown Thresholds VC Open Device Shutting Down ● 0.15 0.37 0.60 V Device Starting Up ● 0.25 0.45 0.60 V VC Open LT1375HV/LT1376HV Device Shutting Down ● 0.15 0.37 0.70 V LT1375HV/LT1376HV Device Starting Up ● 0.25 0.45 0.70 V Minimum Synchronizing Amplitude (LT1375 Only) VIN = 5V ● 1.5 2.2 V Synchronizing Range (LT1375 Only) 580 900 kHz SYNC Pin Input Resistance 40 kΩ
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings 5V. Total input referred supply current is calculated by summing input may cause permanent damage to the device. Exposure to any Absolute supply current (ISI) with a fraction of output supply current (ISO): Maximum Rating condition for extended periods may affect device ITOT = ISI + (ISO)(VOUT/VIN)(1.15) reliability and lifetime. With VIN = 15V, VOUT = 5V, ISI = 0.9mA, ISO = 3.6mA, ITOT = 2.28mA.
Note 2:
Gain is measured with a VC swing equal to 200mV above the low For the LT1375, quiescent current is equal to: clamp level to 200mV below the upper clamp level. ITOT = ISI + ISO(1.15)
Note 3:
Minimum input voltage is not measured directly, but is guaranteed because the BIAS pin is internally connected to V by other tests. It is defined as the voltage where internal bias lines are still IN. For LT1375 or BIAS open circuit, input supply current is the sum of input regulated so that the reference voltage and oscillator frequency remain + output supply currents. constant. Actual minimum input voltage to maintain a regulated output will depend on output voltage and load current. See Applications Information.
Note 7:
Switch-on resistance is calculated by dividing VIN to VSW voltage by the forced current (1.5A). See Typical Performance Characteristics for
Note 4:
This is the minimum voltage across the boost capacitor needed to the graph of switch voltage at other currents. guarantee full saturation of the internal power switch.
Note 8:
Transconductance and voltage gain refer to the internal amplifier
Note 5:
Boost current is the current flowing into the BOOST pin with the exclusive of the voltage divider. To calculate gain and transconductance pin held 5V above input voltage. It flows only during switch-on time. refer to sense pin on fixed voltage parts. Divide values shown by the ratio
Note 6:
Input supply current is the bias current drawn by the input pin V when the BIAS pin is held at 5V with switching disabled. Output supply OUT/2.42. current is the current drawn by the BIAS pin when the bias pin is held at
W U TYPICAL PERFORMANCE CHARACTERISTICS Inductor Core Loss Switch Peak Current Limit Feedback Pin Voltage and Current
1.0 20 2.5 2.44 2.0 VOUT = 5V, VIN = 10V, IOUT = 1A 12 8 CORE LOSS (% OF 5W LOAD) TYPICAL 2.0 4 TYPE 52 2.43 1.5 POWDERED IRON 0.1 2 CURRENT ( GUARANTEED MINIMUM 1.2 1.5 Kool Mµ® 0.8 VOLTAGE 2.42 1.0 0.4 µ PERMALLOY 1.0 A) CORE LOSS (W) 0.01 µ = 125 0.2 CORE LOSS IS CURRENT 0.12 FEEDBACK VOLTAGE (V) INDEPENDENT OF LOAD 2.41 0.5 0.08 SWITCH PEAK CURRENT (A) 0.5 CURRENT UNTIL LOAD CURRENT FALLS LOW ENOUGH FOR CIRCUIT TO GO INTO 0.04 DISCONTINUOUS MODE 0.001 0.02 0 2.40 0 0 5 10 15 20 25 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 INDUCTANCE (µH) DUTY CYCLE (%) JUNCTION TEMPERATURE (°C) 1375/76 G01 1375/76 G08 1375/76 G09 13756fd 4
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. TJ = 25
°
C, VIN = 15V, VC = 1.5V, boost open, switch open, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
Shutdown Thresholds VC Open Device Shutting Down ● 0.15 0.37 0.60 V Device Starting Up ● 0.25 0.45 0.60 V VC Open LT1375HV/LT1376HV Device Shutting Down ● 0.15 0.37 0.70 V LT1375HV/LT1376HV Device Starting Up ● 0.25 0.45 0.70 V Minimum Synchronizing Amplitude (LT1375 Only) VIN = 5V ● 1.5 2.2 V Synchronizing Range (LT1375 Only) 580 900 kHz SYNC Pin Input Resistance 40 kΩ
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings 5V. Total input referred supply current is calculated by summing input may cause permanent damage to the device. Exposure to any Absolute supply current (ISI) with a fraction of output supply current (ISO): Maximum Rating condition for extended periods may affect device ITOT = ISI + (ISO)(VOUT/VIN)(1.15) reliability and lifetime. With VIN = 15V, VOUT = 5V, ISI = 0.9mA, ISO = 3.6mA, ITOT = 2.28mA.
Note 2:
Gain is measured with a VC swing equal to 200mV above the low For the LT1375, quiescent current is equal to: clamp level to 200mV below the upper clamp level. ITOT = ISI + ISO(1.15)
Note 3:
Minimum input voltage is not measured directly, but is guaranteed because the BIAS pin is internally connected to V by other tests. It is defined as the voltage where internal bias lines are still IN. For LT1375 or BIAS open circuit, input supply current is the sum of input regulated so that the reference voltage and oscillator frequency remain + output supply currents. constant. Actual minimum input voltage to maintain a regulated output will depend on output voltage and load current. See Applications Information.
Note 7:
Switch-on resistance is calculated by dividing VIN to VSW voltage by the forced current (1.5A). See Typical Performance Characteristics for
Note 4:
This is the minimum voltage across the boost capacitor needed to the graph of switch voltage at other currents. guarantee full saturation of the internal power switch.
Note 8:
Transconductance and voltage gain refer to the internal amplifier
Note 5:
Boost current is the current flowing into the BOOST pin with the exclusive of the voltage divider. To calculate gain and transconductance pin held 5V above input voltage. It flows only during switch-on time. refer to sense pin on fixed voltage parts. Divide values shown by the ratio
Note 6:
Input supply current is the bias current drawn by the input pin V when the BIAS pin is held at 5V with switching disabled. Output supply OUT/2.42. current is the current drawn by the BIAS pin when the bias pin is held at
W U TYPICAL PERFORMANCE CHARACTERISTICS Inductor Core Loss Switch Peak Current Limit Feedback Pin Voltage and Current
1.0 20 2.5 2.44 2.0 VOUT = 5V, VIN = 10V, IOUT = 1A 12 8 CORE LOSS (% OF 5W LOAD) TYPICAL 2.0 4 TYPE 52 2.43 1.5 POWDERED IRON 0.1 2 CURRENT ( GUARANTEED MINIMUM 1.2 1.5 Kool Mµ® 0.8 VOLTAGE 2.42 1.0 0.4 µ PERMALLOY 1.0 A) CORE LOSS (W) 0.01 µ = 125 0.2 CORE LOSS IS CURRENT 0.12 FEEDBACK VOLTAGE (V) INDEPENDENT OF LOAD 2.41 0.5 0.08 SWITCH PEAK CURRENT (A) 0.5 CURRENT UNTIL LOAD CURRENT FALLS LOW ENOUGH FOR CIRCUIT TO GO INTO 0.04 DISCONTINUOUS MODE 0.001 0.02 0 2.40 0 0 5 10 15 20 25 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 INDUCTANCE (µH) DUTY CYCLE (%) JUNCTION TEMPERATURE (°C) 1375/76 G01 1375/76 G08 1375/76 G09 13756fd 4
