Datasheet LTC7800 (Analog Devices) - 5
| Fabricante | Analog Devices |
| Descripción | Low IQ , 60V, High Frequency Synchronous Step-Down Controller |
| Páginas / Página | 32 / 5 — ELECTRICAL CHARACTERISTICS Note 4:. Note 6:. Note 7:. Note 5:. Note 8:. … |
| Formato / tamaño de archivo | PDF / 1.3 Mb |
| Idioma del documento | Inglés |
ELECTRICAL CHARACTERISTICS Note 4:. Note 6:. Note 7:. Note 5:. Note 8:. TYPICAL PERFORMANCE CHARACTERISTICS
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LTC7800
ELECTRICAL CHARACTERISTICS Note 4:
The LTC7800 is tested in a feedback loop that servos VITH to a
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay specified voltage and measures the resultant VFB. The specification at 85°C times are measured using 50% levels is not tested in production and is assured by design, characterization and
Note 7:
The minimum on-time condition is specified for an inductor correlation to production testing at other temperatures (125°C for the peak-to-peak ripple current ≥ 40% of IMAX (See Minimum On-Time LTC7800E/LTC7800I and 150°C for the LTC7800H.) Considerations in the Applications Information section).
Note 5:
Dynamic supply current is higher due to the gate charge being
Note 8:
Do not apply a voltage or current source to these pins. They must delivered at the switching frequency. See Applications Information. be connected to capacitive loads only, otherwise permanent damage may occur.
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current Efficiency vs Output Current Efficiency vs Input Voltage
100 10 100 100 VIN = 12V VOUT = 5V 90 V BURST EFFICIENCY OUT = 3.3V 90 80 FCM LOSS 1 80 V 95 OUT = 3.3V 70 POWER LOSS (W) 70 VOUT = 5V 60 0.1 60 90 PULSE-SKIPPING 50 LOSS 50 VOUT = 3.3V 40 0.01 40 85 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 30 BURST FCM EFFICIENCY 30 LOSS 20 0.001 20 80 PULSE–SKIPPING 10 Burst Mode OPERATION 10 EFFICIENCY VIN = 12V ILOAD = 5A 0 0.0001 0 75 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 5 10 15 20 25 30 35 OUTPUT CURRENT (A) OUTPUT CURRENT (A) INPUT VOLTAGE (V) 7800 G03 FIGURE 11 CIRCUIT 7800 G02 7800 G01 FIGURES 11, 12 CIRCUITS FIGURES 11, 12 CIRCUITS
Load Step Load Step Load Step Burst Mode Operation Pulse-Skipping Mode Forced Continuous Mode
V V OUT VOUT OUT 100mV/DIV 100mV/DIV 100mV/DIV AC- AC- AC- COUPLED COUPLED COUPLED IL I 5A/DIV L I 5A/DIV L 5A/DIV 20µs/DIV 7800 G04 20µs/DIV 7800 G05 50µs/DIV 7800 G06 LOAD STEP = 500mA TO 5A LOAD STEP = 500mA TO 5A LOAD STEP = 500mA TO 5A VIN = 12V VIN = 12V VIN = 12V VOUT = 3.3V VOUT = 3.3V VOUT = 3.3V FIGURE 11 CIRCUIT FIGURE 11 CIRCUIT FIGURE 11 CIRCUIT 7800f For more information www.linear.com/LTC7800 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Typical Application Related Parts
ELECTRICAL CHARACTERISTICS Note 4:
The LTC7800 is tested in a feedback loop that servos VITH to a
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay specified voltage and measures the resultant VFB. The specification at 85°C times are measured using 50% levels is not tested in production and is assured by design, characterization and
Note 7:
The minimum on-time condition is specified for an inductor correlation to production testing at other temperatures (125°C for the peak-to-peak ripple current ≥ 40% of IMAX (See Minimum On-Time LTC7800E/LTC7800I and 150°C for the LTC7800H.) Considerations in the Applications Information section).
Note 5:
Dynamic supply current is higher due to the gate charge being
Note 8:
Do not apply a voltage or current source to these pins. They must delivered at the switching frequency. See Applications Information. be connected to capacitive loads only, otherwise permanent damage may occur.
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current Efficiency vs Output Current Efficiency vs Input Voltage
100 10 100 100 VIN = 12V VOUT = 5V 90 V BURST EFFICIENCY OUT = 3.3V 90 80 FCM LOSS 1 80 V 95 OUT = 3.3V 70 POWER LOSS (W) 70 VOUT = 5V 60 0.1 60 90 PULSE-SKIPPING 50 LOSS 50 VOUT = 3.3V 40 0.01 40 85 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 30 BURST FCM EFFICIENCY 30 LOSS 20 0.001 20 80 PULSE–SKIPPING 10 Burst Mode OPERATION 10 EFFICIENCY VIN = 12V ILOAD = 5A 0 0.0001 0 75 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 5 10 15 20 25 30 35 OUTPUT CURRENT (A) OUTPUT CURRENT (A) INPUT VOLTAGE (V) 7800 G03 FIGURE 11 CIRCUIT 7800 G02 7800 G01 FIGURES 11, 12 CIRCUITS FIGURES 11, 12 CIRCUITS
Load Step Load Step Load Step Burst Mode Operation Pulse-Skipping Mode Forced Continuous Mode
V V OUT VOUT OUT 100mV/DIV 100mV/DIV 100mV/DIV AC- AC- AC- COUPLED COUPLED COUPLED IL I 5A/DIV L I 5A/DIV L 5A/DIV 20µs/DIV 7800 G04 20µs/DIV 7800 G05 50µs/DIV 7800 G06 LOAD STEP = 500mA TO 5A LOAD STEP = 500mA TO 5A LOAD STEP = 500mA TO 5A VIN = 12V VIN = 12V VIN = 12V VOUT = 3.3V VOUT = 3.3V VOUT = 3.3V FIGURE 11 CIRCUIT FIGURE 11 CIRCUIT FIGURE 11 CIRCUIT 7800f For more information www.linear.com/LTC7800 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions FUNCTIONAL Diagram Operation Applications Information Typical Application Related Parts