Datasheet LT1959 (Analog Devices) - 5
| Manufacturer | Analog Devices |
| Description | 4.5A, 500kHz Step-Down Switching Regulator |
| Pages / Page | 24 / 5 — TYPICAL PERFORMANCE CHARACTERISTICS. Maximum Load Current. Frequency … |
| File Format / Size | PDF / 305 Kb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. Maximum Load Current. Frequency Foldback. Switching Frequency. at VOUT = 5V
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LT1959
W U TYPICAL PERFORMANCE CHARACTERISTICS Maximum Load Current Frequency Foldback Switching Frequency at VOUT = 5V
550 µA) 500 4.4 L= 10µH SWITCHING 540 4.2 FREQUENCY 400 530 4.0 L= 5µH 520 3.8 300 510 3.6 L= 3µH 500 3.4 200 490 FREQUENCY (kHz) 3.2 480 LOAD CURRENT (A) 100 470 3.0 L= 1.8µH FEEDBACK 460 2.8 PIN CURRENT 0 450 SWITCHING FREQUENCY (kHz) OR CURRENT ( 2.6 0 0.2 0.4 0.6 0.8 1.0 1.2 – 50 –25 0 25 50 75 100 125 5 7 9 11 13 15 FEEDBACK PIN VOLTAGE (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 1959 • G10 1959 G11 1959 G13
Maximum Load Current at V BOOST Pin Current OUT = 3.3V Current Limit Foldback
100 4.4 7 DUTY CYCLE = 100% L= 10µH FOLDBACK 90 CHARACTERISTICS 4.2 6 80 L= 5µH POSSIBLE UNDESIRED CURRENT STABLE POINT FOR SOURCE 4.0 70 5 CURRENT SOURCE LOAD 60 LOAD* 3.8 L= 3µH 4 RESISTOR 50 LOAD 3.6 40 3 LOAD CURRENT (A) 30 3.4 OUTPUT CURRENT (A) 2 BOOST PIN CURRENT (mA) L= 1.8µH 20 MOS LOAD 3.2 1 10 3.0 0 0 4 6 8 10 12 14 0 1 2 3 4 5 0 20 40 60 80 100 SWITCH CURRENT (A) INPUT VOLTAGE (V) OUTPUT VOLTAGE (%) 1959 G15 1959 G14 1959 G16
V Switch Voltage Drop C Pin Shutdown Threshold
1.4 500 SHUTDOWN 450 125°C 1.2 400 350 25°C 1.0 300 250 – 40°C 0.8 200 150 SWITCH VOLTAGE (mV) THRESHOLD VOLTAGE (V) 0.6 100 50 0.4 0 –50 –25 0 25 50 75 100 125 0 1 2 3 4 5 JUNCTION TEMPERATURE (°C) SWITCH CURRENT (A) 1959 G17 1959 G18 *See “More Than Just Voltage Feedback” in the Applications Information section. 5
W U TYPICAL PERFORMANCE CHARACTERISTICS Maximum Load Current Frequency Foldback Switching Frequency at VOUT = 5V
550 µA) 500 4.4 L= 10µH SWITCHING 540 4.2 FREQUENCY 400 530 4.0 L= 5µH 520 3.8 300 510 3.6 L= 3µH 500 3.4 200 490 FREQUENCY (kHz) 3.2 480 LOAD CURRENT (A) 100 470 3.0 L= 1.8µH FEEDBACK 460 2.8 PIN CURRENT 0 450 SWITCHING FREQUENCY (kHz) OR CURRENT ( 2.6 0 0.2 0.4 0.6 0.8 1.0 1.2 – 50 –25 0 25 50 75 100 125 5 7 9 11 13 15 FEEDBACK PIN VOLTAGE (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 1959 • G10 1959 G11 1959 G13
Maximum Load Current at V BOOST Pin Current OUT = 3.3V Current Limit Foldback
100 4.4 7 DUTY CYCLE = 100% L= 10µH FOLDBACK 90 CHARACTERISTICS 4.2 6 80 L= 5µH POSSIBLE UNDESIRED CURRENT STABLE POINT FOR SOURCE 4.0 70 5 CURRENT SOURCE LOAD 60 LOAD* 3.8 L= 3µH 4 RESISTOR 50 LOAD 3.6 40 3 LOAD CURRENT (A) 30 3.4 OUTPUT CURRENT (A) 2 BOOST PIN CURRENT (mA) L= 1.8µH 20 MOS LOAD 3.2 1 10 3.0 0 0 4 6 8 10 12 14 0 1 2 3 4 5 0 20 40 60 80 100 SWITCH CURRENT (A) INPUT VOLTAGE (V) OUTPUT VOLTAGE (%) 1959 G15 1959 G14 1959 G16
V Switch Voltage Drop C Pin Shutdown Threshold
1.4 500 SHUTDOWN 450 125°C 1.2 400 350 25°C 1.0 300 250 – 40°C 0.8 200 150 SWITCH VOLTAGE (mV) THRESHOLD VOLTAGE (V) 0.6 100 50 0.4 0 –50 –25 0 25 50 75 100 125 0 1 2 3 4 5 JUNCTION TEMPERATURE (°C) SWITCH CURRENT (A) 1959 G17 1959 G18 *See “More Than Just Voltage Feedback” in the Applications Information section. 5
