Datasheet LT8625S (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | 18V/8A Step-Down Silent Switcher 3 with Ultralow Noise Reference |
| Pages / Page | 39 / 3 — ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply … |
| File Format / Size | PDF / 4.9 Mb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply over the full operating
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LT8625S
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum PVIN VSET = 1V l 2.5 2.7 V Minimum SVIN (Note 8) VSET = 1V l 2.5 2.7 V SET Pin Current (ISET) VSET = VOUTS = 1V 99.7 100 100.3 µA l 99.2 100 100.8 µA Fast Start-Up Set Pin Current SVIN = 12V, VSET = 1V 2.2 2.7 3.2 mA Start-Up Time (Notes 5, 11) VOUT = 1V, CSET = 1μF, SVIN = 12V, VPGFB = 0.5 25 ms VOUT = 1V, CSET = 4.7μF, SVIN = 12V, VPGFB = 0.5 120 ms VOUT = 1V, CSET = 1μF, SVIN = 12V, RPGFB(TOP) = 49.9k, RPGFB(BOT) = 49.9k 1 ms VOUT = 1V, CSET = 4.7μF, SVIN = 12V, RPGFB(TOP) = 49.9k, RPGFB(BOT) = 49.9k 2.5 ms Output Noise Spectral Density (10kHz) SVIN = 12V, VOUT = 1V, COUT = 22µF ×3, L = 180nH, RSET = 10kΩ, CSET = 4.7µF 4 nV/
√
Hz (Notes 5, 6, 7) fSW = 4MHz, RC = 4.99kΩ, CC = 1nF Output RMS Noise (10Hz – 100kHz) SVIN = 12V, VOUT = 1V, BW = 10Hz to 100kHz, COUT = 22µF ×3, L = 180nH 3.5 μVRMS (Notes 5, 6, 7) RSET = 10kΩ, CSET = 4.7µF fSW = 4MHz, RC = 4.99kΩ, CC = 1nF SVIN Quiescent Current VEN/UVLO = 2V, Not Switching 2.8 3.3 mA VEN/UVLO = 0.2V, Shutdown 50 105 µA Oscillator Frequency RT = 392k l 270 300 330 kHz RT = 47k l 1.93 2 2.07 MHz RT = 18k l 3.75 4 4.25 MHz PGFB Upper Threshold VPGFB Rising l 529 537.5 546 mV PGFB Upper Threshold Hysteresis 5 mV PGFB Lower Threshold VPGFB Falling l 455 462.5 470 mV PGFB Lower Threshold Hysteresis 5 mV PGFB Pin Current SVIN = 6V, VEN/UVLO = 3V, VPGFB = 0.5V 25 nA PG Leakage VPG = 3.3V –40 40 nA PG Pull-Down Resistance VPG = 0.5V l 380 1200 Ω SYNC Threshold SYNC DC and Clock Low Level Voltage 0.7 V SYNC DC and Clock High Level Voltage 1.5 V OUTS Pin Output Current VOUTS = 1V 80 160 240 nA Output Voltage Line Regulation (Note 10) VSVIN = 4V to 18V 0.001 0.01 %/V Error Amp Offset VC = 1.2V, VSET = 3V, SVIN = 6V, PNP-Based Input Pair l –2 2 mV (Notes 9, 10) VC = 1.2V, VSET = 5V, SVIN = 5.5V, NPN-Based Input Pair l –2 2 mV Error Amp Transconductance VC = 1.2V, VSET = 1V, SVIN = 6V, PNP-Based Input Pair 9.5 11.5 13.5 mS (Note 9) VC = 1.2V, VSET = 5V, SVIN = 5.5V, NPN-Based Input Pair 7.8 10 12.2 mS Error Amp Gain VC = 1.2V, VSET = 1V, SVIN = 6V 2800 V/V VC Source Current VC = 1.2V, VSET = 1V, VOUTS = 0V, SVIN = 6V, PNP-Based Input Pair 330 µA (Note 9) VC = 1.2V, VSET = 5V, VOUTS = 4.7V, SVIN = 5.5V, NPN-Based Input Pair 330 µA VC Sink Current VC = 1.2V, VSET = 1V, VOUTS = 2V, SVIN = 6V, PNP-Based Input Pair 330 µA (Note 9) VC = 1.2V, VSET = 5V, VOUTS = 5.3V, SVIN = 5.5V, NPN-Based Input Pair 330 µA VC Pin to Switch Current Gain 11.5 A/V VC Clamp Voltage 2.2 V SVIN Current Consumption RT = 47k, fSW =2MHz, SVIN = 6V 11 mA Minimum On-Time ILOAD = 2A l 15 20 ns Minimum Off-Time ILOAD = 2A 70 90 ns Top Power N-Channel MOSFET l 13.5 16 17.5 A Current Limit Bottom Power N-Channel MOSFET 9.25 11.5 13.75 A Current Limit SW Leakage Current PVIN = 18V, VSW = 0V, 18V –15 15 µA Rev. B For more information www.analog.com 3 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
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum PVIN VSET = 1V l 2.5 2.7 V Minimum SVIN (Note 8) VSET = 1V l 2.5 2.7 V SET Pin Current (ISET) VSET = VOUTS = 1V 99.7 100 100.3 µA l 99.2 100 100.8 µA Fast Start-Up Set Pin Current SVIN = 12V, VSET = 1V 2.2 2.7 3.2 mA Start-Up Time (Notes 5, 11) VOUT = 1V, CSET = 1μF, SVIN = 12V, VPGFB = 0.5 25 ms VOUT = 1V, CSET = 4.7μF, SVIN = 12V, VPGFB = 0.5 120 ms VOUT = 1V, CSET = 1μF, SVIN = 12V, RPGFB(TOP) = 49.9k, RPGFB(BOT) = 49.9k 1 ms VOUT = 1V, CSET = 4.7μF, SVIN = 12V, RPGFB(TOP) = 49.9k, RPGFB(BOT) = 49.9k 2.5 ms Output Noise Spectral Density (10kHz) SVIN = 12V, VOUT = 1V, COUT = 22µF ×3, L = 180nH, RSET = 10kΩ, CSET = 4.7µF 4 nV/
√
Hz (Notes 5, 6, 7) fSW = 4MHz, RC = 4.99kΩ, CC = 1nF Output RMS Noise (10Hz – 100kHz) SVIN = 12V, VOUT = 1V, BW = 10Hz to 100kHz, COUT = 22µF ×3, L = 180nH 3.5 μVRMS (Notes 5, 6, 7) RSET = 10kΩ, CSET = 4.7µF fSW = 4MHz, RC = 4.99kΩ, CC = 1nF SVIN Quiescent Current VEN/UVLO = 2V, Not Switching 2.8 3.3 mA VEN/UVLO = 0.2V, Shutdown 50 105 µA Oscillator Frequency RT = 392k l 270 300 330 kHz RT = 47k l 1.93 2 2.07 MHz RT = 18k l 3.75 4 4.25 MHz PGFB Upper Threshold VPGFB Rising l 529 537.5 546 mV PGFB Upper Threshold Hysteresis 5 mV PGFB Lower Threshold VPGFB Falling l 455 462.5 470 mV PGFB Lower Threshold Hysteresis 5 mV PGFB Pin Current SVIN = 6V, VEN/UVLO = 3V, VPGFB = 0.5V 25 nA PG Leakage VPG = 3.3V –40 40 nA PG Pull-Down Resistance VPG = 0.5V l 380 1200 Ω SYNC Threshold SYNC DC and Clock Low Level Voltage 0.7 V SYNC DC and Clock High Level Voltage 1.5 V OUTS Pin Output Current VOUTS = 1V 80 160 240 nA Output Voltage Line Regulation (Note 10) VSVIN = 4V to 18V 0.001 0.01 %/V Error Amp Offset VC = 1.2V, VSET = 3V, SVIN = 6V, PNP-Based Input Pair l –2 2 mV (Notes 9, 10) VC = 1.2V, VSET = 5V, SVIN = 5.5V, NPN-Based Input Pair l –2 2 mV Error Amp Transconductance VC = 1.2V, VSET = 1V, SVIN = 6V, PNP-Based Input Pair 9.5 11.5 13.5 mS (Note 9) VC = 1.2V, VSET = 5V, SVIN = 5.5V, NPN-Based Input Pair 7.8 10 12.2 mS Error Amp Gain VC = 1.2V, VSET = 1V, SVIN = 6V 2800 V/V VC Source Current VC = 1.2V, VSET = 1V, VOUTS = 0V, SVIN = 6V, PNP-Based Input Pair 330 µA (Note 9) VC = 1.2V, VSET = 5V, VOUTS = 4.7V, SVIN = 5.5V, NPN-Based Input Pair 330 µA VC Sink Current VC = 1.2V, VSET = 1V, VOUTS = 2V, SVIN = 6V, PNP-Based Input Pair 330 µA (Note 9) VC = 1.2V, VSET = 5V, VOUTS = 5.3V, SVIN = 5.5V, NPN-Based Input Pair 330 µA VC Pin to Switch Current Gain 11.5 A/V VC Clamp Voltage 2.2 V SVIN Current Consumption RT = 47k, fSW =2MHz, SVIN = 6V 11 mA Minimum On-Time ILOAD = 2A l 15 20 ns Minimum Off-Time ILOAD = 2A 70 90 ns Top Power N-Channel MOSFET l 13.5 16 17.5 A Current Limit Bottom Power N-Channel MOSFET 9.25 11.5 13.75 A Current Limit SW Leakage Current PVIN = 18V, VSW = 0V, 18V –15 15 µA Rev. B For more information www.analog.com 3 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
