Datasheet LT3685 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | 36V, 2A, 2.4MHz Step-Down Switching Regulator |
| Pages / Page | 24 / 3 — The. ELECTRICAL CHARACTERISTICS. denotes the specifi cations which apply … |
| File Format / Size | PDF / 282 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
LT3685
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 ● 0.9 1.3 mA 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) VC = 1.2V ● 7 30 nA FB Voltage Line Regulation 4V < VIN < 36V 0.002 0.01 %/V Error Amp gm 500 μMho Error Amp Gain 1000 VC Source Current 45 μA VC Sink Current 45 μA VC Pin to Switch Current Gain 3.5 A/V VC Clamp Voltage 2 V Switching Frequency RT = 8.66k 2.1 2.4 2.7 MHz RT = 29.4k 0.9 1 1.15 MHz RT = 187k 160 200 240 kHz Minimum Switch Off-Time ● 60 150 nS Switch Current Limit Duty Cycle = 5% 3.2 3.7 4.2 A Switch VCESAT ISW = 2A 500 mV Boost Schottky Reverse Leakage VSW = 10V, VBD = 0V 0.02 2 μA Minimum Boost Voltage (Note 4) ● 1.5 2.1 V BOOST Pin Current ISW = 1A 22 35 mA RUN/SS Pin Current VRUN/SS = 2.5V 5 10 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 90 mV PG Hysteresis 12 mV PG Leakage VPG = 5V 0.1 1 μA PG Sink Current VPG = 0.4V ● 100 600 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
Note 3:
Bias current fl ows out of the FB pin. may cause permanent damage to the device. Exposure to any Absolute
Note 4:
This is the minimum voltage across the boost capacitor needed to Maximum Rating condition for extended periods may affect device guarantee full saturation of the switch. reliability and lifetime.
Note 5:
Absolute Maximum Voltage at VIN and RUN/SS pins is 60V for
Note 2:
The LT3685E is guaranteed to meet performance specifi cations nonrepetitive 1 second transients, and 40V for continuous operation. from 0°C to 125°C. Specifi cations over the –40°C to 125°C operating temperature range are assured by design, characterization and correlation with statistical process controls. The LT3685I specifi cations are guaranteed over the –40°C to 125°C temperature range. 3685fb 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 ● 0.9 1.3 mA 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) VC = 1.2V ● 7 30 nA FB Voltage Line Regulation 4V < VIN < 36V 0.002 0.01 %/V Error Amp gm 500 μMho Error Amp Gain 1000 VC Source Current 45 μA VC Sink Current 45 μA VC Pin to Switch Current Gain 3.5 A/V VC Clamp Voltage 2 V Switching Frequency RT = 8.66k 2.1 2.4 2.7 MHz RT = 29.4k 0.9 1 1.15 MHz RT = 187k 160 200 240 kHz Minimum Switch Off-Time ● 60 150 nS Switch Current Limit Duty Cycle = 5% 3.2 3.7 4.2 A Switch VCESAT ISW = 2A 500 mV Boost Schottky Reverse Leakage VSW = 10V, VBD = 0V 0.02 2 μA Minimum Boost Voltage (Note 4) ● 1.5 2.1 V BOOST Pin Current ISW = 1A 22 35 mA RUN/SS Pin Current VRUN/SS = 2.5V 5 10 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 90 mV PG Hysteresis 12 mV PG Leakage VPG = 5V 0.1 1 μA PG Sink Current VPG = 0.4V ● 100 600 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
Note 3:
Bias current fl ows out of the FB pin. may cause permanent damage to the device. Exposure to any Absolute
Note 4:
This is the minimum voltage across the boost capacitor needed to Maximum Rating condition for extended periods may affect device guarantee full saturation of the switch. reliability and lifetime.
Note 5:
Absolute Maximum Voltage at VIN and RUN/SS pins is 60V for
Note 2:
The LT3685E is guaranteed to meet performance specifi cations nonrepetitive 1 second transients, and 40V for continuous operation. from 0°C to 125°C. Specifi cations over the –40°C to 125°C operating temperature range are assured by design, characterization and correlation with statistical process controls. The LT3685I specifi cations are guaranteed over the –40°C to 125°C temperature range. 3685fb 3
