Datasheet LTC3891 (Analog Devices) - 5
| Manufacturer | Analog Devices |
| Description | Low IQ, 60V Synchronous Step-Down Controller |
| Pages / Page | 32 / 5 — ELECTRICAL CHARACTERISTICS Note 1:. Note 4:. Note 2:. Note 5:. Note 6:. … |
| File Format / Size | PDF / 691 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS Note 1:. Note 4:. Note 2:. Note 5:. Note 6:. Note 7:. Note 3:. TYPICAL PERFORMANCE CHARACTERISTICS
Model Line for this Datasheet
Text Version of Document
LTC3891
ELECTRICAL CHARACTERISTICS Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
The LTC3891 is tested in a feedback loop that servos VITH to a may cause permanent damage to the device. Exposure to any Absolute specified voltage and measures the resultant VFB. The specification at Maximum Rating condition for extended periods may affect device 85°C is not tested in production and is assured by design, characterization reliability and lifetime. and correlation to production testing at other temperatures (125°C for
Note 2:
The LTC3891 is tested under pulsed load conditions such that the LTC3891E/LTC3891I, 150°C for the LTC3891H/LTC3891MP). For the TJ ≈ TA. The LTC3891E is guaranteed to meet performance specifications LTC3891MP, the specification at –40°C is not tested in production and is from 0°C to 85°C. Specifications over the –40°C to 125°C operating assured by design, characterization and correlation to production testing junction temperature range are assured by design, characterization and at –55°C. correlation with statistical process controls. The LTC3891I is guaranteed
Note 5:
Dynamic supply current is higher due to the gate charge being over the –40°C to 125°C operating junction temperature range, the delivered at the switching frequency. See Applications Information. LTC3891H is guaranteed over the –40°C to 150°C operating junction
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay temperature range and the LTC3891MP is tested and guaranteed over times are measured using 50% levels the –55°C to 150°C operating junction temperature range. High junction
Note 7:
The minimum on-time condition is specified for an inductor temperatures degrade operating lifetimes; operating lifetime is derated peak-to-peak ripple current ≥ 40% of I for junction temperatures greater than 125°C. Note that the maximum MAX (See Minimum On-Time Considerations in the Applications Information section). ambient temperature consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal impedance and other environmental factors.
Note 3:
The junction temperature (TJ, in °C) is calculated from the ambient temperature (TA, in °C) and power dissipation (PD, in Watts) according to the formula: TJ = TA + (PD • θJA), where θJA is 43°C/W for the QFN or 38°C/W for the TSSOP.
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current Efficiency vs Output Current Efficiency vs Input Voltage
100 10000 100 100 VIN = 12V BURST EFFICIENCY VOUT = 8.5V 90 VOUT = 3.3V 90 98 VOUT = 3.3V 80 1000 80 96 VOUT = 8.5V POWER LOSS (mW) 70 FCM LOSS 70 94 60 100 60 92 50 BURST LOSS 50 90 PULSE-SKIPPING 40 10 LOSS 40 88 VOUT = 3.3V EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 30 30 86 20 FCM EFFICIENCY 1 20 84 Burst Mode OPERATION 10 PULSE-SKIPPING 10 82 EFFICIENCY VIN = 12V ILOAD = 2A 0 0.1 0 80 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 0 5 10 15 20 25 30 35 40 45 50 55 60 OUTPUT CURRENT (A) OUTPUT CURRENT (A) INPUT VOLTAGE (V) FIGURE 12 CIRCUIT 3891 G01 3891 G02 FIGURES 12, 14 CIRCUITS 3891 G03 FIGURES 12, 14 CIRCUITS 3891fa 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts
ELECTRICAL CHARACTERISTICS Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
The LTC3891 is tested in a feedback loop that servos VITH to a may cause permanent damage to the device. Exposure to any Absolute specified voltage and measures the resultant VFB. The specification at Maximum Rating condition for extended periods may affect device 85°C is not tested in production and is assured by design, characterization reliability and lifetime. and correlation to production testing at other temperatures (125°C for
Note 2:
The LTC3891 is tested under pulsed load conditions such that the LTC3891E/LTC3891I, 150°C for the LTC3891H/LTC3891MP). For the TJ ≈ TA. The LTC3891E is guaranteed to meet performance specifications LTC3891MP, the specification at –40°C is not tested in production and is from 0°C to 85°C. Specifications over the –40°C to 125°C operating assured by design, characterization and correlation to production testing junction temperature range are assured by design, characterization and at –55°C. correlation with statistical process controls. The LTC3891I is guaranteed
Note 5:
Dynamic supply current is higher due to the gate charge being over the –40°C to 125°C operating junction temperature range, the delivered at the switching frequency. See Applications Information. LTC3891H is guaranteed over the –40°C to 150°C operating junction
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay temperature range and the LTC3891MP is tested and guaranteed over times are measured using 50% levels the –55°C to 150°C operating junction temperature range. High junction
Note 7:
The minimum on-time condition is specified for an inductor temperatures degrade operating lifetimes; operating lifetime is derated peak-to-peak ripple current ≥ 40% of I for junction temperatures greater than 125°C. Note that the maximum MAX (See Minimum On-Time Considerations in the Applications Information section). ambient temperature consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal impedance and other environmental factors.
Note 3:
The junction temperature (TJ, in °C) is calculated from the ambient temperature (TA, in °C) and power dissipation (PD, in Watts) according to the formula: TJ = TA + (PD • θJA), where θJA is 43°C/W for the QFN or 38°C/W for the TSSOP.
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current Efficiency vs Output Current Efficiency vs Input Voltage
100 10000 100 100 VIN = 12V BURST EFFICIENCY VOUT = 8.5V 90 VOUT = 3.3V 90 98 VOUT = 3.3V 80 1000 80 96 VOUT = 8.5V POWER LOSS (mW) 70 FCM LOSS 70 94 60 100 60 92 50 BURST LOSS 50 90 PULSE-SKIPPING 40 10 LOSS 40 88 VOUT = 3.3V EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 30 30 86 20 FCM EFFICIENCY 1 20 84 Burst Mode OPERATION 10 PULSE-SKIPPING 10 82 EFFICIENCY VIN = 12V ILOAD = 2A 0 0.1 0 80 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 0 5 10 15 20 25 30 35 40 45 50 55 60 OUTPUT CURRENT (A) OUTPUT CURRENT (A) INPUT VOLTAGE (V) FIGURE 12 CIRCUIT 3891 G01 3891 G02 FIGURES 12, 14 CIRCUITS 3891 G03 FIGURES 12, 14 CIRCUITS 3891fa 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts
