Datasheet LT1938 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | 25V, 2.2A, 2.8MHz Step-Down Switching Regulator |
| Pages / Page | 24 / 3 — ELECTRICAL ChARACTERISTICS The. denotes the specifications which apply … |
| File Format / Size | PDF / 271 Kb |
| Document Language | English |
ELECTRICAL ChARACTERISTICS The. denotes the specifications which apply over the full operating
Model Line for this Datasheet
Text Version of Document
LT1938
ELECTRICAL ChARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 10V, VRUN/SS = 10V VBOOST = 15V, VBIAS = 3.3V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
Error Amp gm 330 µMho Error Amp Gain 1000 VC Source Current 75 µA VC Sink Current 100 µA VC Pin to Switch Current Gain 3.5 A/V VC Clamp Voltage 2 V Switching Frequency RT = 8.66k 2.7 3.0 3.3 MHz RT = 29.4k 1.25 1.4 1.55 MHz RT = 187k 250 300 350 kHz Minimum Switch Off-Time ● 100 150 nS Switch Current Limit Duty Cycle = 5% 3.1 3.6 4.0 A Switch VCESAT ISW = 2A 360 mV Boost Schottky Reverse Leakage VSW = 10V, VBIAS = 0V 0.02 2 µA Minimum Boost Voltage (Note 4) ● 1.6 2.1 V BOOST Pin Current ISW = 1A 18 30 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 100 mV PG Hysteresis 10 mV PG Leakage VPG = 5V 0.1 1 µA PG Sink Current VPG = 0.4V ● 100 300 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
Bias current measured in regulation. Bias current flows into the FB may cause permanent damage to the device. Exposure to any Absolute pin. Maximum Rating condition for extended periods may affect device
Note 4:
This is the minimum voltage across the boost capacitor needed to reliability and lifetime. guarantee full saturation of the switch.
Note 2:
The LT1938E is guaranteed to meet performance specifications from 0°C to 125°C. Specifications over the –40°C to 125°C operating temperature range are assured by design, characterization and correlation with statistical process controls. The LT1938I specifications are guaranteed over the –40°C to 125°C temperature range. 1938fa 3 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL ChARACTERISTICS TYPICAL PERFORMANCE ChARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION TYPICAL APPLICATION RELATED PARTS
ELECTRICAL ChARACTERISTICS The
●
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 10V, VRUN/SS = 10V VBOOST = 15V, VBIAS = 3.3V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
Error Amp gm 330 µMho Error Amp Gain 1000 VC Source Current 75 µA VC Sink Current 100 µA VC Pin to Switch Current Gain 3.5 A/V VC Clamp Voltage 2 V Switching Frequency RT = 8.66k 2.7 3.0 3.3 MHz RT = 29.4k 1.25 1.4 1.55 MHz RT = 187k 250 300 350 kHz Minimum Switch Off-Time ● 100 150 nS Switch Current Limit Duty Cycle = 5% 3.1 3.6 4.0 A Switch VCESAT ISW = 2A 360 mV Boost Schottky Reverse Leakage VSW = 10V, VBIAS = 0V 0.02 2 µA Minimum Boost Voltage (Note 4) ● 1.6 2.1 V BOOST Pin Current ISW = 1A 18 30 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 100 mV PG Hysteresis 10 mV PG Leakage VPG = 5V 0.1 1 µA PG Sink Current VPG = 0.4V ● 100 300 µA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
Bias current measured in regulation. Bias current flows into the FB may cause permanent damage to the device. Exposure to any Absolute pin. Maximum Rating condition for extended periods may affect device
Note 4:
This is the minimum voltage across the boost capacitor needed to reliability and lifetime. guarantee full saturation of the switch.
Note 2:
The LT1938E is guaranteed to meet performance specifications from 0°C to 125°C. Specifications over the –40°C to 125°C operating temperature range are assured by design, characterization and correlation with statistical process controls. The LT1938I specifications are guaranteed over the –40°C to 125°C temperature range. 1938fa 3 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL ChARACTERISTICS TYPICAL PERFORMANCE ChARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION TYPICAL APPLICATION RELATED PARTS
