Datasheet LTC3900 (Analog Devices) - 3

LTC3900
elecTrical characTerisTics The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. VCC = 5V unless otherwise specified. (Notes 2, 3) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
tTMRDIS Timer Discharge Time CTMR = 1000pF, RTMR = 4.7k l 40 120 ns VTMRMAX Timer Pin Clamp Voltage CTMR = 1000pF, RTMR = 4.7k 2.5 V
Current Sense
ICS+ CS+ Input Current VCS+ = 0V l ±1 µA ICS– CS– Input Current VCS– = 0V l ±1 µA VCSMAX CS+ Pin Clamp Voltage IIN = 5mA, VSYNC = –5V 11 V VCS Current Sense Threshold Voltage VCS– = 0V 7.5 10.5 13.5 mV LTC3900E/LTC3900I (Note 5) l 3 18 mV LTC3900H/LTC3900MP (Note 5) l 1 20 mV
SYNC Input
ISYNC SYNC Input Current VSYNC = ±10V l ±1 ±10 µA VSYNCP SYNC Input Positive Threshold l 1.0 1.4 1.8 V SYNC Positive Input Hysteresis (Note 6) 0.2 V VSYNCN SYNC Input Negative Threshold l –1.8 –1.4 –1.0 V SYNC Negative Input Hysteresis (Note 6) 0.2 V
Driver Output
RONH Driver Pull-Up Resistance IOUT = –100mA 0.9 1.2 Ω LTC3900E/LTC3900I l 1.6 Ω LTC3900H/LTC3900MP l 2.0 Ω RONL Driver Pull-Down Resistance IOUT = 100mA 0.9 1.2 Ω LTC3900E/LTC3900I l 1.6 Ω LTC3900H/LTC3900MP l 2.0 Ω IPK Driver Peak Output Current (Note 6) 2 A
Switching Characteristics (Note 7)
td SYNC Input to Driver Output Delay CFG = CCG = 4700pF, VSYNC = ±5V LTC3900E/LTC3900I l 60 120 ns LTC3900H/LTC3900MP l 150 ns tSYNC Minimum SYNC Pulse Width VSYNC = ±5V l 75 ns tr, tf Driver Rise/Fall Time CFG = CCG = 4700pF, VSYNC = ±5V 15 ns
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings calculated from the ambient temperature (TA, in °C) and power dissipation may cause permanent damage to the device. Exposure to any Absolute (PD, in watts) according to the formula: Maximum Rating condition for extended periods may affect device TJ = TA + (PD • θJA), where θJA (in °C/W) is the package thermal reliability and lifetime. impedance.
Note 2:
The LTC3900 is tested under pulsed load conditions such that
Note 3:
All currents into device pins are positive; all currents out of device TJ ≈ TA. The LTC3900E is guaranteed to meet performance specifications pins are negative. All voltages are referenced to ground unless otherwise from 0°C to 85°C operating junction temperature. Specifications over specified. the –40°C to 125°C operating junction temperature range are assured
Note 4:
Supply current in normal operation is dominated by the current by design, characterization and correlation with statistical process needed to charge and discharge the external MOSFET gates. This current controls. The LTC3900I is guaranteed over the –40°C to 125°C operating will vary with supply voltage, switching frequency and the external junction temperature range. The LTC3900H is guaranteed over the full MOSFETs used. –40°C to 150°C operating junction temperature range. The LTC3900MP is guaranteed and tested over the full –55°C to 150°C operating junction
Note 5:
The current sense comparator threshold has a 0.33%/°C temperature range. High junction temperatures degrade operating temperature coefficient (TC) to match the TC of the external MOSFET lifetimes; operating lifetime is derated for junction temperatures greater RDS(ON). than 125°C. Note that the maximum ambient temperature consistent
Note 6:
Guaranteed by design, not subject to test. with these specifications is determined by specific operating conditions
Note 7:
Rise and fall times are measured using 10% and 90% levels. Delay in conjunction with board layout, the rated package thermal impedance times are measured from ±1.4V at SYNC input to 20%/80% levels at the and other environmental factors. The junction temperature (TJ, in °C) is driver output. 3900fb 3 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Revision History Typical Application Related Parts