Datasheet LTC3870 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | PolyPhase Step-Down Slave Controller for Digital Power System Management |
| Pages / Page | 22 / 4 — e lecTrical characTerisTics The. denotes the specifications which apply … |
| File Format / Size | PDF / 928 Kb |
| Document Language | English |
e lecTrical characTerisTics The. denotes the specifications which apply over the specified operating
Model Line for this Datasheet
Text Version of Document
LTC3870
e lecTrical 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 = 15V, VRUN0,VRUN1 = 3.3V, fSYNC = 350kHz (externally driven) unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Digital Inputs RUN0/RUN1, MODE0/MODE1, FAULT0/FAULT1
VIH Input High Threshold Voltage l 2.0 V VIL Input Low Threshold Voltage l 1.4 V
Note 1:
Stresses beyond those listed in under Absolute Maximum Ratings
Note 3:
When VIN >15V, EXTVCC is recommended to reduce IC may cause permanent damage to the device. Exposure to any Absolute Temperature. Maximum Rating condition for extended periods may affect device
Note 4:
Output voltage is set and controlled by the master controller in reliability and lifetime. multiphase operations.
Note 2:
The LTC3870 is tested under pulsed load conditions such that
Note 5:
Dynamic supply current is higher due to the gate charge being TJ ≈ TA. The LTC3870E is guaranteed to meet specifications from delivered at the switching frequency. See Application Information. 0°C to 85°C junction temperature. Specifications over the –40°C to
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay 125°C operating junction temperature range are assured by design, times are measured using 50% levels. characterization and correlation with statistical process controls. The LTC3870I is guaranteed over the full –40°C to 125°C operating junction
Note 7:
The minimum on-time condition corresponds to an inductor temperature range. Note that the maximum ambient temperature peak-to-peak ripple current ≥40% of IMAX (see Minimum On-Time consistent with these specifications is determined by specific operating Considerations in the Applications Information section. conditions in conjunction with board layout, the related package thermal
Note 8:
EXTVCC is enabled only if VIN is higher than 6.5V. impedance and other environmental factors. The junction temperature TJ
Note 9:
Guaranteed by design. is calculated from the ambient temperature TA and power dissipation PD according to the following formula: TJ = TA + (PD • 43°C/W)
Typical perForMance characTerisTics Full Load Efficiency and Power Efficiency vs Load Current Efficiency vs Load Current Loss vs Input Voltage
100 100 94 3 DCM DCM POWER LOSS 90 CCM 90 CCM EFFICIENCY 93 2.5 80 80 70 70 92 POWER LOSS (W) 2 60 60 91 50 50 1.5 40 40 90 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 1 30 V 30 IN = 12V VIN = 12V 89 20 VOUT = 1.8V 20 VOUT = 3.3V fSW = 400kHz fSW = 400kHz 88 0.5 10 L = 0.56µH 10 L = 0.56µH VIN = 12V DCR = 1.8mΩ DCR = 1.8mΩ VOUT = 1.8V 0 0 87 0 0.1 1 10 100 0.1 1 10 100 5 7 9 11 13 15 17 19 LOAD CURRENT (A) LOAD CURRENT (A) INPUT VOLTAGE (V) 3870 G01 3870 G02 3870 G03 3870fb 4 For more information www.linear.com/LTC3870
e lecTrical 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 = 15V, VRUN0,VRUN1 = 3.3V, fSYNC = 350kHz (externally driven) unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Digital Inputs RUN0/RUN1, MODE0/MODE1, FAULT0/FAULT1
VIH Input High Threshold Voltage l 2.0 V VIL Input Low Threshold Voltage l 1.4 V
Note 1:
Stresses beyond those listed in under Absolute Maximum Ratings
Note 3:
When VIN >15V, EXTVCC is recommended to reduce IC may cause permanent damage to the device. Exposure to any Absolute Temperature. Maximum Rating condition for extended periods may affect device
Note 4:
Output voltage is set and controlled by the master controller in reliability and lifetime. multiphase operations.
Note 2:
The LTC3870 is tested under pulsed load conditions such that
Note 5:
Dynamic supply current is higher due to the gate charge being TJ ≈ TA. The LTC3870E is guaranteed to meet specifications from delivered at the switching frequency. See Application Information. 0°C to 85°C junction temperature. Specifications over the –40°C to
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay 125°C operating junction temperature range are assured by design, times are measured using 50% levels. characterization and correlation with statistical process controls. The LTC3870I is guaranteed over the full –40°C to 125°C operating junction
Note 7:
The minimum on-time condition corresponds to an inductor temperature range. Note that the maximum ambient temperature peak-to-peak ripple current ≥40% of IMAX (see Minimum On-Time consistent with these specifications is determined by specific operating Considerations in the Applications Information section. conditions in conjunction with board layout, the related package thermal
Note 8:
EXTVCC is enabled only if VIN is higher than 6.5V. impedance and other environmental factors. The junction temperature TJ
Note 9:
Guaranteed by design. is calculated from the ambient temperature TA and power dissipation PD according to the following formula: TJ = TA + (PD • 43°C/W)
Typical perForMance characTerisTics Full Load Efficiency and Power Efficiency vs Load Current Efficiency vs Load Current Loss vs Input Voltage
100 100 94 3 DCM DCM POWER LOSS 90 CCM 90 CCM EFFICIENCY 93 2.5 80 80 70 70 92 POWER LOSS (W) 2 60 60 91 50 50 1.5 40 40 90 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 1 30 V 30 IN = 12V VIN = 12V 89 20 VOUT = 1.8V 20 VOUT = 3.3V fSW = 400kHz fSW = 400kHz 88 0.5 10 L = 0.56µH 10 L = 0.56µH VIN = 12V DCR = 1.8mΩ DCR = 1.8mΩ VOUT = 1.8V 0 0 87 0 0.1 1 10 100 0.1 1 10 100 5 7 9 11 13 15 17 19 LOAD CURRENT (A) LOAD CURRENT (A) INPUT VOLTAGE (V) 3870 G01 3870 G02 3870 G03 3870fb 4 For more information www.linear.com/LTC3870
