LTC3856 elecTrical characTerisTicsThe l denotes the specifications which apply over the full operatingjunction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 15V, VRUN = 5V, unless otherwise noted.SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITSDifferential Amplifier ADA Gain E-Grade l 0.998 1 1.002 V/V I-Grade l 0.997 1 1.003 V/V RIN Input Resistance Measured at DIFFP Input 80 kΩ VOS Input Offset Voltage VDIFFP = VDIFFOUT = 1.5V, IDIFFOUT = 100µA 2 mV PSRR Power Supply Rejection Ratio 4.5V < VIN < 38V 100 dB ICL Maximum Output Current 2 3 mA VOUT(MAX) Maximum Output Voltage IDIFFOUT = 300µA VINTVCC VINTVCC V –1.4 –1.1 On-Chip Driver TG RUP TG Pull-Up RDS(ON) TG High 2.6 Ω TG RDOWN TG Pull-Down RDS(ON) TG Low 1.5 Ω BG RUP BG Pull-Up RDS(ON) BG High 2.4 Ω BG RDOWN BG Pull-Down RDS(ON) BG Low 1.1 Ω GBW Gain-Bandwidth Product (Note 8) 3 MHz SR Slew Rate (Note 8) 2 V/µs Stage Shedding Mode IISET Programmable Stage Shedding 6.5 7.5 8.5 µA Mode Current AVP (Active Voltage Positioning) VAVP Maximum VOUT with AVP 2.5 V ISINK Sink Current of AVP Pin SENSE+ = 1.2V 250 µA ISOURCE Source Current of AVP Pin SENSE+ = 1.2V 2 mA VAVP-VO(MAX) Maximum Voltage Drop VAVP to VO SENSE+ = 1.2V 120 mV Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 4: The LTC3856 is tested in a feedback loop that servos VITH to a may cause permanent damage to the device. Exposure to any Absolute specified voltage and measures the resultant VFB. Maximum Rating condition for extended periods may affect device Note 5: Dynamic supply current is higher due to the gate charge being reliability and lifetime. delivered at the switching frequency. See the Applications Information Note 2: The LTC3856 is tested under pulse load conditions such that section. TJ ≈ TA. The LTC3856E is guaranteed to meet performance specifications Note 6: Rise and fall times are measured using 10% and 90% levels. Delay from 0°C to 85°C operating junction temperature. Specifications over times are measured using 50% levels. the –40°C to 125°C operating junction temperature range are assured by Note 7: The minimum on-time condition corresponds to the on inductor design, characterization and correlation with statistical process controls. peak-to-peak ripple current ≥40% of I The LTC3856I is guaranteed to meet performance specifications over the MAX (see Minimum On-Time Considerations in the Applications Information section). full –40°C to 125°C operating junction temperature range. Note 8: Guaranteed by design. Note 3: TJ is calculated from the ambient temperature, TA, and power dissipation, PD, according to the following formula: LTC3856UH: TJ = TA + (PD • 34°C/W) LTC3856FE: TJ = TA + (PD • 25°C/W) 3856fa For more information www.linear.com/LTC3856 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Typical Application Typical Application Related Parts
