Datasheet LT8645S, LT8646S (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | 65V, 8A Synchronous Step-Down Silent Switcher 2 with 2.5μA Quiescent Current |
| Pages / Page | 30 / 6 — Burst Mode Operation Efficiency. vs Inductor Value (LT8645S). Reference … |
| File Format / Size | PDF / 457 Kb |
| Document Language | English |
Burst Mode Operation Efficiency. vs Inductor Value (LT8645S). Reference Voltage. EN Pin Thresholds. LT8645S Load Regulation
Text Version of Document
LT8645S/LT8646S TYPICAL PERFORMANCE CHARACTERISTICS
Burst Mode Operation Efficiency vs Inductor Value (LT8645S) Reference Voltage EN Pin Thresholds
100 979 1.03 95 977 1.02 VIN = 12V 975 EN RISING 1.01 90 973 1.00 85 TAGE (mV) 971 VIN = 24V 0.99 80 969 EFFICIENCY (%) 0.98 967 75 EN THRESHOLD (V) REFERENCE VOL 965 0.97 EN FALLING VOUT = 5V 70 ILOAD = 10mA 963 0.96 L = WE–LHMI7050 65 961 0.95 1 2 3 4 5 6 7 8 9 10 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 INDUCTOR VALUE (µH) TEMPERATURE (°C) TEMPERATURE (°C) 8645S G10 8645S G11 8645S G12
LT8645S Load Regulation LT8646S Load Regulation LT8645S Line Regulation
0.20 0.40 0.20 0.30 0.15 0.15 0.20 (%) 0.10 (%) 0.10 (%) 0.10 OUT OUT 0.00 OUT 0.05 0.05 –0.10 0 –0.20 0.00 CHANGE IN V CHANGE IN V CHANGE IN V –0.30 –0.05 VOUT = 5V VOUT = 5V –0.05 VIN = 12V –0.40 VIN = 12V VOUT = 5V VSYNC = 0V VSYNC = 0V ILOAD = 2A –0.10 –0.50 –0.10 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 5 15 25 35 45 55 65 LOAD CURRENT (A) LOAD CURRENT (A) INPUT VOLTAGE (V) 8645S G13 8645S G14 8645S G15
LT8646S Line Regulation LT8646S Line Regulation LT8645S No-Load Supply Current LT8646S No-Load Supply Current
0.30 4.5 225 V V OUT = 3.3V OUT = 5V 0.25 L = 4.7µH 200 L = 4.7µH 4.0 IN-REGULATION IN REGULATION 0.20 175 3.5 (%) 0.15 150 OUT 3.0 0.10 125 2.5 0.05 100 CHANGE IN V INPUT CURRENT (µA) 2.0 INPUT CURRENT (µA) 0 75 –0.05 V 1.5 50 OUT = 5V ILOAD = 2A –0.10 1.0 25 5 15 25 35 45 55 65 0 10 20 30 40 50 60 0 10 20 30 40 50 60 INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V) 8645S G16 8645S G17 8645S G18 8645Sfa 6 For more information www.linear.com/LT8645S
Burst Mode Operation Efficiency vs Inductor Value (LT8645S) Reference Voltage EN Pin Thresholds
100 979 1.03 95 977 1.02 VIN = 12V 975 EN RISING 1.01 90 973 1.00 85 TAGE (mV) 971 VIN = 24V 0.99 80 969 EFFICIENCY (%) 0.98 967 75 EN THRESHOLD (V) REFERENCE VOL 965 0.97 EN FALLING VOUT = 5V 70 ILOAD = 10mA 963 0.96 L = WE–LHMI7050 65 961 0.95 1 2 3 4 5 6 7 8 9 10 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 INDUCTOR VALUE (µH) TEMPERATURE (°C) TEMPERATURE (°C) 8645S G10 8645S G11 8645S G12
LT8645S Load Regulation LT8646S Load Regulation LT8645S Line Regulation
0.20 0.40 0.20 0.30 0.15 0.15 0.20 (%) 0.10 (%) 0.10 (%) 0.10 OUT OUT 0.00 OUT 0.05 0.05 –0.10 0 –0.20 0.00 CHANGE IN V CHANGE IN V CHANGE IN V –0.30 –0.05 VOUT = 5V VOUT = 5V –0.05 VIN = 12V –0.40 VIN = 12V VOUT = 5V VSYNC = 0V VSYNC = 0V ILOAD = 2A –0.10 –0.50 –0.10 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 5 15 25 35 45 55 65 LOAD CURRENT (A) LOAD CURRENT (A) INPUT VOLTAGE (V) 8645S G13 8645S G14 8645S G15
LT8646S Line Regulation LT8646S Line Regulation LT8645S No-Load Supply Current LT8646S No-Load Supply Current
0.30 4.5 225 V V OUT = 3.3V OUT = 5V 0.25 L = 4.7µH 200 L = 4.7µH 4.0 IN-REGULATION IN REGULATION 0.20 175 3.5 (%) 0.15 150 OUT 3.0 0.10 125 2.5 0.05 100 CHANGE IN V INPUT CURRENT (µA) 2.0 INPUT CURRENT (µA) 0 75 –0.05 V 1.5 50 OUT = 5V ILOAD = 2A –0.10 1.0 25 5 15 25 35 45 55 65 0 10 20 30 40 50 60 0 10 20 30 40 50 60 INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V) 8645S G16 8645S G17 8645S G18 8645Sfa 6 For more information www.linear.com/LT8645S
