Datasheet LT1940, LT1940L (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | Dual Monolithic 1.4A, 1.1MHz Step-Down Switching Regulator |
| Pages / Page | 20 / 4 — TYPICAL PERFOR A CE CHARACTERISTICS. Maximum Load Current,. VOUT = 1.8V. … |
| File Format / Size | PDF / 288 Kb |
| Document Language | English |
TYPICAL PERFOR A CE CHARACTERISTICS. Maximum Load Current,. VOUT = 1.8V. Switch V. OUT = 3.3V. CESAT. Boost Pin Current
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Text Version of Document
LT1940/LT1940L
W U TYPICAL PERFOR A CE CHARACTERISTICS Maximum Load Current, Maximum Load Current, VOUT = 1.8V V Switch V OUT = 3.3V CESAT
1.8 1.8 400 SLOPE COMPENSATION REQUIRES TA = 25°C L > 2.2µH FOR VIN < 7 WITH VOUT = 3.3V 1.6 1.6 300 L = 4.7µH L = 2.2µH 1.4 L = 1.5µH 1.4 L = 3.3µH 200 LOAD CURRENT (A) L = 1µH LOAD CURRENT (A) L = 2.2µH SWITCH VOLTAGE (mV) 1.2 1.2 100 1.0 1.0 0 0 2 4 6 8 10 12 14 16 0 5 10 15 20 25 0 0.5 1.0 1.5 2.0 INPUT VOLTAGE (V)* INPUT VOLTAGE (V)* SW CURRENT (A) 1940 G06 1940 G04 1940 G05
Boost Pin Current Current Limit vs Duty Cycle VOUT vs Temperature
40 3.0 3.40 CHANNEL 1, FIGURE 1, VIN = 12V 2.5 30 TYPICAL 3.35 2.0 (V) 20 1.5 MINIMUM 3.30 OUTV 1.0 CURRENT LIMIT (A) BOOST CURRENT (mA) 10 3.25 0.5 0 0 3.20 0 0.5 1.0 1.5 2.0 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 SWITCH CURRENT (A) DUTY CYCLE (%) TEMPERATURE (°C) 1940 G07 1940 G08 1940 G09
Frequency vs Temperature Frequency Foldback IRUN/SS vs Temperature
1.3 1.4 3.0 1.2 2.5 1.2 1.0 µA) 2.0 0.8 1.1 1.5 0.6 FREQUENCY (MHz) 1.0 0.4 1.0 RUN/SS CURRENT ( SWITCHING FREQUENCY (MHz) 0.2 0.5 0.9 0 0 –50 –25 0 25 50 75 100 125 0 0.2 0.4 0.6 0.8 1.0 1.2 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) FEEDBACK VOLTAGE (V) TEMPERATURE (°C) 1940 G10 1940 G11 1940 G12 *Maximum VIN is 7V for LT1940L. 1940fa 4
W U TYPICAL PERFOR A CE CHARACTERISTICS Maximum Load Current, Maximum Load Current, VOUT = 1.8V V Switch V OUT = 3.3V CESAT
1.8 1.8 400 SLOPE COMPENSATION REQUIRES TA = 25°C L > 2.2µH FOR VIN < 7 WITH VOUT = 3.3V 1.6 1.6 300 L = 4.7µH L = 2.2µH 1.4 L = 1.5µH 1.4 L = 3.3µH 200 LOAD CURRENT (A) L = 1µH LOAD CURRENT (A) L = 2.2µH SWITCH VOLTAGE (mV) 1.2 1.2 100 1.0 1.0 0 0 2 4 6 8 10 12 14 16 0 5 10 15 20 25 0 0.5 1.0 1.5 2.0 INPUT VOLTAGE (V)* INPUT VOLTAGE (V)* SW CURRENT (A) 1940 G06 1940 G04 1940 G05
Boost Pin Current Current Limit vs Duty Cycle VOUT vs Temperature
40 3.0 3.40 CHANNEL 1, FIGURE 1, VIN = 12V 2.5 30 TYPICAL 3.35 2.0 (V) 20 1.5 MINIMUM 3.30 OUTV 1.0 CURRENT LIMIT (A) BOOST CURRENT (mA) 10 3.25 0.5 0 0 3.20 0 0.5 1.0 1.5 2.0 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 SWITCH CURRENT (A) DUTY CYCLE (%) TEMPERATURE (°C) 1940 G07 1940 G08 1940 G09
Frequency vs Temperature Frequency Foldback IRUN/SS vs Temperature
1.3 1.4 3.0 1.2 2.5 1.2 1.0 µA) 2.0 0.8 1.1 1.5 0.6 FREQUENCY (MHz) 1.0 0.4 1.0 RUN/SS CURRENT ( SWITCHING FREQUENCY (MHz) 0.2 0.5 0.9 0 0 –50 –25 0 25 50 75 100 125 0 0.2 0.4 0.6 0.8 1.0 1.2 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) FEEDBACK VOLTAGE (V) TEMPERATURE (°C) 1940 G10 1940 G11 1940 G12 *Maximum VIN is 7V for LT1940L. 1940fa 4
