Datasheet LTC3785-1 (Analog Devices) - 4

LTC3785-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = ISVOUT = VDRV = VBST1 = VBST2 = 3.6V, RT = 49.9k, RILSET = 59k. PARAMETER CONDITIONS MIN TYP MAX UNITS
PGOOD Output Low IPGOOD = 500μA 200 500 mV PGOOD Leakage VPGOOD = 5.5V 5 μA VSENSE Input Current VSENSE = Measured FB Voltage 1 500 nA
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature range are assured by design, characterization and correlation may cause permanent damage to the device. Exposure to any Absolute with statistical process controls. Maximum Rating condition for extended periods may affect device
Note 3:
Specifi cation is guaranteed by design and not 100% tested in production. reliability and lifetime.
Note 4:
Current measurements are performed when the outputs are not switching.
Note 2:
The LTC3785E-1 is guaranteed to meet performance specifi cations
Note 5:
The IC is tested in a feedback loop to make the measurement. from 0°C to 85°C. Specifi cations over –40°C to 85°C operating
TYPICAL PERFORMANCE CHARACTERISTICS Li-Ion to 3.3V Effi ciency Two Li-Ion to 7V Effi ciency Li-Ion/9V to 5V VOUT Effi ciency vs Load Current vs Load Current vs Load Current
100 100 100 Burst Mode Burst Mode 90 OPERATION 90 Burst Mode 90 OPERATION OPERATION 80 80 80 70 70 70 FIXED FIXED 60 60 60 FIXED FREQUENCY FREQUENCY FREQUENCY 50 50 50 VIN = 9V 40 V 40 40 V V EFFICIENCY (%) IN = 4.2V EFFICIENCY (%) IN = 8.4V EFFICIENCY (%) IN = 4.2V 30 VIN = 3.6V 30 VIN = 7.2V 30 VIN = 3.6V VIN = 3V VIN = 5.4V VIN = 2.7V 20 20 MOSFET Si7940 20 MOSFET Si7940 MOSFET Si7940 10 L = 4.7μH WURTH WE-PD 10 L = 5.6μH MSS1260 10 L = 5.6μH MSS1260 fOSC = 500kHz fOSC = 430kHz fOSC = 430kHz 0 0 0 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A) 37851 G01 37851 G02 37851 G03
Burst Mode Ripple Line Transient Response VOUT Load Transient
VOUT V V OUT 500mV/DIV OUT 50mV/DIV 200mV/ AC DIV COUPLED INDUCTOR VIN I CURRENT 3V TO 8.5V LOAD 10mA TO 2A 1A/DIV V 5μs/DIV 37851 G04 37851 G05 37851 G06 OUT = 3.3V I 500μs/DIV LOAD = 300μA V 100μs/DIV IN = 3.6V COUT = 100μF VOUT = 5V VOUT = 3.3V C 100μF 37851fa 4