Datasheet LTC3838 (Analog Devices) - 5

LTC3838
elecTrical characTerisTics The
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denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = 15V unless otherwise noted (Note 3). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Internal VCC Regulator
VDRVCC1 Internally Regulated DRVCC1 Voltage 6V < VIN < 38V 5.0 5.3 5.6 V DRVCC1 Load Regulation IDRVCC1 = 0mA to –100mA –1.5 –3 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Rising 4.4 4.6 4.8 V EXTVCC Switchover Hysteresis 200 mV EXTVCC to DRVCC2 Voltage Drop VEXTVCC = 5V, IDRVCC2 = –100mA 200 mV
PGood Output
OV PGOOD Overvoltage Threshold VFB1,2 Rising, with Respect to Regulated Voltage 5 7.5 10 % UV PGOOD Undervoltage Threshold VFB1,2 Falling, with Respect to Regulated Voltage –5 –7.5 –10 % PGOOD Threshold Hysteresis VFB1,2 Returning to Reference Voltage 2 % VPGOOD(L)1,2 PGOOD Low Voltage IPGOOD = 2mA 0.1 0.3 V tD(PGOOD)1,2 Delay from VFB Fault (OV/UV) to PGOOD 50 µs Falling Delay from VFB Good to PGOOD Rising 20 µs
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
This IC includes overtemperature protection that is intended to may cause permanent damage to the device. Exposure to any Absolute protect the device during momentary overload conditions. The maximum Maximum Rating condition for extended periods may affect device rated junction temperature will be exceeded when this protection is active. reliability and lifetime. Continuous operation above the specified absolute maximum operating
Note 2:
The junction temperature (T junction temperature may impair device reliability or permanently damage J, in °C) is calculated from the ambient temperature (T the device. A, in °C) and power dissipation (PD, in Watts) according to the formula:
Note 5:
The LTC3838 is tested in a feedback loop that adjusts T (V + – V –) or V J = TA + (PD • θJA) OUTSENSE1 OUTSENSE1 FB2 to achieve specified error amplifier where θ output voltages (ITH1,2). JA (in °C/W) is the package thermal impedance.
Note 3:
The LTC3838 is tested under pulsed loading conditions such that
Note 6:
Delay times are measured with top gate (TG) and bottom gate T (BG) driving minimum load, and using 50% levels. J ≈ TA. The LTC3838E is guaranteed to meet specifications over the 0°C to 85°C operating junction temperature range. Specifications over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LTC3838I is guaranteed to meet specifications over the –40°C to 125°C operating junction temperature range . Note that the maximum ambient temperature consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal impedance and other environmental factors. 3838fb For more information www.linear.com/LTC3838 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Typical Applications Package Description Revision History Typical Application Related Parts