Datasheet LT3972 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | 33V, 3.5A, 2.4MHz Step-Down Switching Regulator with 75μA Quiescent Current |
| Pages / Page | 24 / 3 — The. ELECTRICAL CHARACTERISTICS. denotes the specifi cations which apply … |
| File Format / Size | PDF / 346 Kb |
| Document Language | English |
The. ELECTRICAL CHARACTERISTICS. denotes the specifi cations which apply over the full operating
Model Line for this Datasheet
Text Version of Document
LT3972
The ELECTRICAL CHARACTERISTICS
●
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 10V, VRUN/SS = 10V, VBOOST = 15V, VBD = 3.3V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
Quiescent Current from BD VRUN/SS = 0.2V 0.01 0.5 μA VBD = 3V, Not Switching ● 90 130 μA VBD = 0, Not Switching 1 5 μA Minimum Bias Voltage (BD Pin) 2.7 3 V Feedback Voltage 780 790 800 mV ● 775 790 805 mV FB Pin Bias Current (Note 3) VFB = 0.8V, VC = 1.2V ● 10 40 nA FB Voltage Line Regulation 4V < VIN < 33V 0.002 0.01 %/V Error Amp gm 500 μmho Error Amp Gain 2000 VC Source Current 60 μA VC Sink Current 60 μA VC Pin to Switch Current Gain 5.3 A/V VC Clamp Voltage 2 V Switching Frequency RT = 8.66k 2.2 2.45 2.7 MHz RT = 29.4k 1.0 1.1 1.25 MHz RT = 187k 200 230 260 kHz Minimum Switch Off-Time ● 60 150 ns Switch Current Limit Duty Cycle = 5% 4.6 5.4 6.2 A Switch VCESAT ISW = 3.5A 335 mV Boost Schottky Reverse Leakage VBD = 0V 0.02 2 μA Minimum Boost Voltage (Note 4) ● 1.5 2 V BOOST Pin Current ISW = 1A 35 50 mA RUN/SS Pin Current VRUN/SS = 2.5V 5 8 μA RUN/SS Input Voltage High 2.5 V RUN/SS Input Voltage Low 0.2 V PG Threshold Offset from Feedback Voltage VFB Rising 65 mV PG Hysteresis 10 mV PG Leakage VPG = 5V 0.1 1 μA PG Sink Current VPG = 0.4V ● 200 800 μA SYNC Low Threshold 0.5 V SYNC High Threshold 0.7 V SYNC Pin Bias Current VSYNC = 0V 0.1 μA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature range. High junction temperatures degrade operating may cause permanent damage to the device. Exposure to any Absolute lifetimes. Operating lifetime is derated at junction temperatures greater Maximum Rating condition for extended periods may affect device than 125°C. reliability and lifetime.
Note 3:
Bias current fl ows out of the FB pin.
Note 2:
The LT3972E is guaranteed to meet performance specifi cations
Note 4:
This is the minimum voltage across the boost capacitor needed to from 0°C to 125°C. Specifi cations over the –40°C to 125°C operating guarantee full saturation of the switch. temperature range are assured by design, characterization and correlation
Note 5:
Absolute Maximum at VIN and RUN/SS pins is 62V for non- with statistical process controls. The LT3972I specifi cations are repetitive 1 minute transients, and 40V for continuous operation. guaranteed over the –40°C to 125°C temperature range. The LT3972H specifi cations are guaranteed over the –40°C to 150°C operating 3972fa 3
The ELECTRICAL CHARACTERISTICS
●
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 10V, VRUN/SS = 10V, VBOOST = 15V, VBD = 3.3V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
Quiescent Current from BD VRUN/SS = 0.2V 0.01 0.5 μA VBD = 3V, Not Switching ● 90 130 μA VBD = 0, Not Switching 1 5 μA Minimum Bias Voltage (BD Pin) 2.7 3 V Feedback Voltage 780 790 800 mV ● 775 790 805 mV FB Pin Bias Current (Note 3) VFB = 0.8V, VC = 1.2V ● 10 40 nA FB Voltage Line Regulation 4V < VIN < 33V 0.002 0.01 %/V Error Amp gm 500 μmho Error Amp Gain 2000 VC Source Current 60 μA VC Sink Current 60 μA VC Pin to Switch Current Gain 5.3 A/V VC Clamp Voltage 2 V Switching Frequency RT = 8.66k 2.2 2.45 2.7 MHz RT = 29.4k 1.0 1.1 1.25 MHz RT = 187k 200 230 260 kHz Minimum Switch Off-Time ● 60 150 ns Switch Current Limit Duty Cycle = 5% 4.6 5.4 6.2 A Switch VCESAT ISW = 3.5A 335 mV Boost Schottky Reverse Leakage VBD = 0V 0.02 2 μA Minimum Boost Voltage (Note 4) ● 1.5 2 V BOOST Pin Current ISW = 1A 35 50 mA RUN/SS Pin Current VRUN/SS = 2.5V 5 8 μA RUN/SS Input Voltage High 2.5 V RUN/SS Input Voltage Low 0.2 V PG Threshold Offset from Feedback Voltage VFB Rising 65 mV PG Hysteresis 10 mV PG Leakage VPG = 5V 0.1 1 μA PG Sink Current VPG = 0.4V ● 200 800 μA SYNC Low Threshold 0.5 V SYNC High Threshold 0.7 V SYNC Pin Bias Current VSYNC = 0V 0.1 μA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature range. High junction temperatures degrade operating may cause permanent damage to the device. Exposure to any Absolute lifetimes. Operating lifetime is derated at junction temperatures greater Maximum Rating condition for extended periods may affect device than 125°C. reliability and lifetime.
Note 3:
Bias current fl ows out of the FB pin.
Note 2:
The LT3972E is guaranteed to meet performance specifi cations
Note 4:
This is the minimum voltage across the boost capacitor needed to from 0°C to 125°C. Specifi cations over the –40°C to 125°C operating guarantee full saturation of the switch. temperature range are assured by design, characterization and correlation
Note 5:
Absolute Maximum at VIN and RUN/SS pins is 62V for non- with statistical process controls. The LT3972I specifi cations are repetitive 1 minute transients, and 40V for continuous operation. guaranteed over the –40°C to 125°C temperature range. The LT3972H specifi cations are guaranteed over the –40°C to 150°C operating 3972fa 3
