Datasheet LTC3870-1 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | PolyPhase Step-Down Slave Controller for Digital Power System Management |
| Pages / Page | 20 / 4 — Typical perForMance characTerisTics. Efficiency vs Load Current. Full … |
| File Format / Size | PDF / 1.1 Mb |
| Document Language | English |
Typical perForMance characTerisTics. Efficiency vs Load Current. Full Load (ILOAD = 20A/Phase)
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LTC3870-1
Typical perForMance characTerisTics Efficiency vs Load Current Efficiency vs Load Current
100 100 CCM CCM DCM 90 DCM 85 80 70 70 60 55 50 EFFICIENCY (%) 40 EFFICIENCY (%) 40 VIN = 12V V V IN = 12V OUT = 1.8V 30 VOUT = 3.3V 25 L = 0.56µH f DCR = 1.61mΩ SW = 350kHz 20 L = 1µH fSW = 350kHz DCR = 2.4mΩ 10 10 0.1 1 10 100 0.1 1 10 100 LOAD CURRENT (A) LOAD CURRENT (A) 3874 G01 38701 G02
Full Load (ILOAD = 20A/Phase) Load Step (Discontinuous Conduction Efficiency and Power Loss vs Mode) 4-Phase Operation Input Voltage LTC3887-1 and LTC3870-1
93.5 3.0 I EFFICIENCY LOAD 50A/DIV POWER LOSS 0A TO 20A TO 0A 93.0 2.9 INDUCTOR CURRENT POWER LOSS (W) LTC3887–1 (CH0) 10A/DIV 92.5 2.8 INDUCTOR CURRENT LTC3870–1 (CH0) 10A/DIV 92.0 2.7 EFFICIENCY (%) VOUT 50mV/DIV AC–COUPLED 91.5 2.6 V 38701 G04 OUT = 1.8V 50µs/DIV L = 0.56µH VIN = 12V DCR = 1.61mΩ 91.0 2.5 VOUT = 1.0V 5 6 7 8 9 10 11 11 12 13 14 15 16 INPUT VOLTAGE (V) 38701 G03
Load Step (Forced Continuous Mode) 4-Phase Operation LTC3887-1 and LTC3870-1 Inductor Current at Light Load
ILOAD I 50A/DIV L LTC3870–1 (CH1) 0A TO 20A TO 0A FORCED INDUCTOR CURRENT CONTINUOUS LTC3887–1 (CH0) MODE 10A/DIV 5A/DIV INDUCTOR CURRENT IL LTC3870–1 (CH0) LTC3870–1 (CH1) 10A/DIV DISCONTINUOUS VOUT MODE 50mV/DIV 5A/DIV AC–COUPLED 50µs/DIV 38701 G05 1µs/DIV 38701 G06 VIN = 12V VOUT = 1.0V 38701f 4 For more information www.linear.com/LTC3870-1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
Typical perForMance characTerisTics Efficiency vs Load Current Efficiency vs Load Current
100 100 CCM CCM DCM 90 DCM 85 80 70 70 60 55 50 EFFICIENCY (%) 40 EFFICIENCY (%) 40 VIN = 12V V V IN = 12V OUT = 1.8V 30 VOUT = 3.3V 25 L = 0.56µH f DCR = 1.61mΩ SW = 350kHz 20 L = 1µH fSW = 350kHz DCR = 2.4mΩ 10 10 0.1 1 10 100 0.1 1 10 100 LOAD CURRENT (A) LOAD CURRENT (A) 3874 G01 38701 G02
Full Load (ILOAD = 20A/Phase) Load Step (Discontinuous Conduction Efficiency and Power Loss vs Mode) 4-Phase Operation Input Voltage LTC3887-1 and LTC3870-1
93.5 3.0 I EFFICIENCY LOAD 50A/DIV POWER LOSS 0A TO 20A TO 0A 93.0 2.9 INDUCTOR CURRENT POWER LOSS (W) LTC3887–1 (CH0) 10A/DIV 92.5 2.8 INDUCTOR CURRENT LTC3870–1 (CH0) 10A/DIV 92.0 2.7 EFFICIENCY (%) VOUT 50mV/DIV AC–COUPLED 91.5 2.6 V 38701 G04 OUT = 1.8V 50µs/DIV L = 0.56µH VIN = 12V DCR = 1.61mΩ 91.0 2.5 VOUT = 1.0V 5 6 7 8 9 10 11 11 12 13 14 15 16 INPUT VOLTAGE (V) 38701 G03
Load Step (Forced Continuous Mode) 4-Phase Operation LTC3887-1 and LTC3870-1 Inductor Current at Light Load
ILOAD I 50A/DIV L LTC3870–1 (CH1) 0A TO 20A TO 0A FORCED INDUCTOR CURRENT CONTINUOUS LTC3887–1 (CH0) MODE 10A/DIV 5A/DIV INDUCTOR CURRENT IL LTC3870–1 (CH0) LTC3870–1 (CH1) 10A/DIV DISCONTINUOUS VOUT MODE 50mV/DIV 5A/DIV AC–COUPLED 50µs/DIV 38701 G05 1µs/DIV 38701 G06 VIN = 12V VOUT = 1.0V 38701f 4 For more information www.linear.com/LTC3870-1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
