Datasheet LT8625S (Analog Devices) - 9
| Fabricante | Analog Devices |
| Descripción | 18V/8A Step-Down Silent Switcher 3 with Ultralow Noise Reference |
| Páginas / Página | 39 / 9 — TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. … |
| Formato / tamaño de archivo | PDF / 4.9 Mb |
| Idioma del documento | Inglés |
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Start-Up Time with and
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LT8625S
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Start-Up Time with and ISET During Start-Up with Fast ISET During Start-Up with Fast without Fast Start-Up Circuitry Start-Up Enabled Start-Up Enabled for Large CSET
4.0 4.0 VSET = 1V VPGFB = 400mV 3.5 3.5 WITH FAST START-UP 3.0 3.0 V 2.5 2.5 OUT 250mV/DIV WITHOUT FAST START-UP (mA) 2.0 (mA) 2.0 I SET I SET V 1.5 1.5 EN 2V/DIV 1.0 1.0 SVIN = 3V 8625s G36 0.5 SV 50ms/DIV IN = 12V 0.5 SVIN = 18V 0 0 SVIN = 5V –50 –25 0 25 50 75 100 125 0 2 4 6 8 10 12 14 16 18 RSET = 10kΩ, CSET = 4.7µF TEMPERATURE (°C) SV F IN – VSET DIFFERENTIAL (V) SW = 2MHz, L = 330nH, COUT = 5× 22µF 8625s G34 8625s G35 RL = 1Ω
Soft-Start Waveforms PG High Thresholds PG Low Thresholds
545.0 475.0 CSET = 1μF 542.5 472.5 VOUT 540.0 470.0 500mV/DIV CSET = 4.7μF TAGE (mV) V TAGE (mV) PGFB RISING VPGFB RISING C 537.5 467.5 SET = 10μF 535.0 465.0 VEN 2V/DIV 532.5 462.5 V V PGFB FALLING PGFB FALLING 530.0 460.0 500µs/DIV 8625s G37 PG HIGH THRESHOLD VOL 527.5 PG LOW THRESHOLD VOL 457.5 SVIN = 5V 525.0 455.0 RSET = 10kΩ, WITH FAST START-UP –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 FSW = 2MHz, L = 330nH, COUT = 5× 22µF TEMPERATURE (°C) TEMPERATURE (°C) RL = 1Ω 8625s G38 8625s G39
SVIN Pin Current vs Frequency SVIN Pin Current vs PVIN Error Amp Output Current
20 12.0 500 SVIN = 12V SVIN = 12V 18 PVIN = 12V 11.8 VOUT = 1V 400 VOUT = 1V 16 fSW = 2MHz 11.6 300 FC MODE IL = 2A 14 11.4 200 12 11.2 100 10 11.0 0 8 10.8 –100 PIN CURRENT (mA) PIN CURRENT (mA) PIN CURRENT (µA) IN 6 IN 10.6 –200 SV SV V C 4 10.4 –300 2 10.2 VC = 1.2V –400 VSET = 1V 0 10.0 –500 0.2 0.6 1 1.4 1.8 2.2 2.6 3.0 3.4 3.8 4.2 2 4 6 8 10 12 14 16 18 –150 –100 –50 0 50 100 150 SWITCHING FREQUENCY (MHz) PVIN (V) VOUTS – VSET ERROR (mV) 8625s G40 8625s G41 8625s G42 Rev. B For more information www.analog.com 9 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Start-Up Time with and ISET During Start-Up with Fast ISET During Start-Up with Fast without Fast Start-Up Circuitry Start-Up Enabled Start-Up Enabled for Large CSET
4.0 4.0 VSET = 1V VPGFB = 400mV 3.5 3.5 WITH FAST START-UP 3.0 3.0 V 2.5 2.5 OUT 250mV/DIV WITHOUT FAST START-UP (mA) 2.0 (mA) 2.0 I SET I SET V 1.5 1.5 EN 2V/DIV 1.0 1.0 SVIN = 3V 8625s G36 0.5 SV 50ms/DIV IN = 12V 0.5 SVIN = 18V 0 0 SVIN = 5V –50 –25 0 25 50 75 100 125 0 2 4 6 8 10 12 14 16 18 RSET = 10kΩ, CSET = 4.7µF TEMPERATURE (°C) SV F IN – VSET DIFFERENTIAL (V) SW = 2MHz, L = 330nH, COUT = 5× 22µF 8625s G34 8625s G35 RL = 1Ω
Soft-Start Waveforms PG High Thresholds PG Low Thresholds
545.0 475.0 CSET = 1μF 542.5 472.5 VOUT 540.0 470.0 500mV/DIV CSET = 4.7μF TAGE (mV) V TAGE (mV) PGFB RISING VPGFB RISING C 537.5 467.5 SET = 10μF 535.0 465.0 VEN 2V/DIV 532.5 462.5 V V PGFB FALLING PGFB FALLING 530.0 460.0 500µs/DIV 8625s G37 PG HIGH THRESHOLD VOL 527.5 PG LOW THRESHOLD VOL 457.5 SVIN = 5V 525.0 455.0 RSET = 10kΩ, WITH FAST START-UP –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 FSW = 2MHz, L = 330nH, COUT = 5× 22µF TEMPERATURE (°C) TEMPERATURE (°C) RL = 1Ω 8625s G38 8625s G39
SVIN Pin Current vs Frequency SVIN Pin Current vs PVIN Error Amp Output Current
20 12.0 500 SVIN = 12V SVIN = 12V 18 PVIN = 12V 11.8 VOUT = 1V 400 VOUT = 1V 16 fSW = 2MHz 11.6 300 FC MODE IL = 2A 14 11.4 200 12 11.2 100 10 11.0 0 8 10.8 –100 PIN CURRENT (mA) PIN CURRENT (mA) PIN CURRENT (µA) IN 6 IN 10.6 –200 SV SV V C 4 10.4 –300 2 10.2 VC = 1.2V –400 VSET = 1V 0 10.0 –500 0.2 0.6 1 1.4 1.8 2.2 2.6 3.0 3.4 3.8 4.2 2 4 6 8 10 12 14 16 18 –150 –100 –50 0 50 100 150 SWITCHING FREQUENCY (MHz) PVIN (V) VOUTS – VSET ERROR (mV) 8625s G40 8625s G41 8625s G42 Rev. B For more information www.analog.com 9 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts