Datasheet LTC3874-1 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | PolyPhase Step-Down Synchronous Slave Controller with Sub-Milliohm DCR Sensing |
| Pages / Page | 22 / 3 — elecTrical characTerisTics. The. denotes the specifications which apply … |
| File Format / Size | PDF / 1.0 Mb |
| Document Language | English |
elecTrical characTerisTics. The. denotes the specifications which apply over the specified operating
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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
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
