Datasheet LT1940, LT1940L (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Dual Monolithic 1.4A, 1.1MHz Step-Down Switching Regulator |
| Pages / Page | 20 / 3 — ELECTRICAL CHARACTERISTICS The. denotes the specifications which apply … |
| File Format / Size | PDF / 288 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS The. denotes the specifications which apply over the full operating
Model Line for this Datasheet
Text Version of Document
LT1940/LT1940L
ELECTRICAL CHARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 5V, VBOOST = 8V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
Foldback Frequency VFB = 0V 150 kHz Switch Current Limit Note 3 1.8 2.4 3.2 A Switch VCESAT ISW = 1A 210 320 mV Switch Leakage Current 10 µA Minimum Boost Voltage Above Switch (Note 4) ISW = 1A 1.8 2.5 V BOOST Pin Current ISW = 1A 20 30 mA RUN/SS Current 2.3 µA RUN/SS Threshold 0.3 0.6 V PG Threshold Offset VFB Rising 90 125 160 mV PG Voltage Output Low VFB = 1V, IPG = 250µA 0.22 0.4 V PG Pin Leakage VPG = 2V 0.1 1 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 3:
Current limit is guaranteed by design and/or correlation to static of a device may be impaired. test. Slope compensation reduces current limit at high duty cycle.
Note 2:
The LT1940E is guaranteed to meet performance specifications
Note 4:
This is the minimum voltage across the boost capacitor needed to from 0°C to 70°C. Specifications over the –40°C to 85°C operating guarantee full saturation of the internal power switch. temperature range are assured by design, characterization and correlation with statistical process controls.
W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency, V Efficiency, V OUT = 1.8V OUT = 3.3V Efficiency, VOUT = 5V
90 100 100 VOUT = 1.8V VOUT = 3.3V VOUT = 5V L = 2.2µH (SUMIDA CR43-2R2) L = 3.3µH (SUMIDA CR43-3R3) L = 4.7µH (SUMIDA CR43-4R7) TA = 25°C T 90 TA = 25°C A = 25°C 80 V 90 IN = 5V VIN = 8V VIN = 5V 80 70 80 V V IN = 12V IN = 12V 70 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) V V IN = 18V IN = 18V 60 70 60 50 50 60 0 0.5 1.0 1.5 0 0.5 1.0 1.5 0 0.5 1.0 1.5 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A) 1940 G01 1940 G02 1940 G03 1940fa 3
ELECTRICAL CHARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 5V, VBOOST = 8V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
Foldback Frequency VFB = 0V 150 kHz Switch Current Limit Note 3 1.8 2.4 3.2 A Switch VCESAT ISW = 1A 210 320 mV Switch Leakage Current 10 µA Minimum Boost Voltage Above Switch (Note 4) ISW = 1A 1.8 2.5 V BOOST Pin Current ISW = 1A 20 30 mA RUN/SS Current 2.3 µA RUN/SS Threshold 0.3 0.6 V PG Threshold Offset VFB Rising 90 125 160 mV PG Voltage Output Low VFB = 1V, IPG = 250µA 0.22 0.4 V PG Pin Leakage VPG = 2V 0.1 1 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 3:
Current limit is guaranteed by design and/or correlation to static of a device may be impaired. test. Slope compensation reduces current limit at high duty cycle.
Note 2:
The LT1940E is guaranteed to meet performance specifications
Note 4:
This is the minimum voltage across the boost capacitor needed to from 0°C to 70°C. Specifications over the –40°C to 85°C operating guarantee full saturation of the internal power switch. temperature range are assured by design, characterization and correlation with statistical process controls.
W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency, V Efficiency, V OUT = 1.8V OUT = 3.3V Efficiency, VOUT = 5V
90 100 100 VOUT = 1.8V VOUT = 3.3V VOUT = 5V L = 2.2µH (SUMIDA CR43-2R2) L = 3.3µH (SUMIDA CR43-3R3) L = 4.7µH (SUMIDA CR43-4R7) TA = 25°C T 90 TA = 25°C A = 25°C 80 V 90 IN = 5V VIN = 8V VIN = 5V 80 70 80 V V IN = 12V IN = 12V 70 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) V V IN = 18V IN = 18V 60 70 60 50 50 60 0 0.5 1.0 1.5 0 0.5 1.0 1.5 0 0.5 1.0 1.5 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A) 1940 G01 1940 G02 1940 G03 1940fa 3
