Datasheet LTC3874-1 (Analog Devices) - 3

LTC3874-1
elecTrical characTerisTics The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 12V, VRUN0,1 = 3.3V unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Input Voltage Range 4.5 38 V VOUT Output Voltage Range LOWDCR = INTVCC (Note 3) 3.5 V LOWDCR = 0V 5.5 V IQ Input DC Supply Current Normal Operation VRUN0,1 = 3.3V 4.6 mA Shutdown VRUN0,1 = 0V 1.8 mA VUVLO Undervoltage Lockout Threshold VINTVCC Falling 3.5 V VINTVCC Rising 3.8 V
Control Loop
IISENSE0,1 ISENSE Pins Bias Current VISENSE0,1 < (VINTVCC – 3.3V) l ±0.15 ±0.4 µA VISENSE0,1 > (VINTVCC – 3.3V) ±1 ±3 µA VISENSE(MAX) Maximum Current Sense Threshold (Table 3) ILIM = INTVCC, LOWDCR = INTVCC, l 26.8 28.8 30.8 mV VISENSE0,1 = 1.2V, VITH = 2.18V ILIM = 0V, LOWDCR = INTVCC, l 14.5 16 17.5 mV VISENSE0,1 = 1.2V, VITH = 2.18V ILIM = INTVCC, LOWDCR = 0V, l 65 72 79 mV VISENSE0,1 = 1.2V, VITH = 2.18V ILIM = 0V, LOWDCR = 0V, l 33 40 47 mV VISENSE0,1 = 1.2V, VITH = 2.18V
PWM Outputs
PWM PWM Output High Voltage ILOAD = 500µA l VCC – 0.2 V PWM Output Low Voltage ILOAD = –500µA l 0.2 V PWM Output Current in Hi-Z State –5 5 µA tON(MIN) Minimum On-Time (Note 4) 60 ns
INTVCC Regulator
VINTVCC Internal VCC Voltage No Load 6V < VIN < 38V 5.25 5.5 5.75 V VLDO INT INTVCC Load Regulation ICC = 0mA to 20mA 0.5 2 % VEXTVCC EXTVCC Switchover Voltage VEXTVCC Ramping Positive (Note 5) l 4.5 4.7 V VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5V 50 100 mV VLDOHYS EXTVCC Hysteresis 300 mV
Oscillator and Phase-Locked Loop
fRANGE PLL SYNC Range l 250 1000 kHz fNOM Nominal Frequency VFREQ = 0.9V 500 kHz IFREQ Frequency Setting Current 9 10 11 µA θ SYNC- θ0 SYNC to Ch0 Phase Relationship Based on PHASMD = 0 180 Deg the Falling Edge of SYNC and Rising Edge of PHASMD = 1/3 • INTVCC 60 Deg PWM0 PHASMD = 2/3 • INTVCC 120 Deg PHASMD = INTVCC 90 Deg θ SYNC- θ1 SYNC to Ch1 Phase Relationship Based on PHASMD = 0 0 Deg the Falling Edge of SYNC and Rising Edge of PHASMD = 1/3 • INTVCC 300 Deg PWM1 PHASMD = 2/3 • INTVCC 240 Deg PHASMD = INTVCC 270 Deg
Digital Inputs RUN0, RUN1, MODE0, MODE1, FAULT0, FAULT1, LOWDCR
VIH Input High Threshold Voltage l 2.0 V VIL Input Low Threshold Voltage l 1.4 V 38741f For more information www.linear/LTC3874-1 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Block Diagram Operation Applications Information Typical Application Related Parts