Datasheet LT1073 (Analog Devices) - 4
| Fabricante | Analog Devices |
| Descripción | Micropower DC-DC Converter Adjustable and Fixed 5V, 12V |
| Páginas / Página | 17 / 4 — TYPICAL PERFORMANCE CHARACTERISTICS. Recommended Minimum. Guaranteed … |
| Formato / tamaño de archivo | PDF / 1.4 Mb |
| Idioma del documento | Inglés |
TYPICAL PERFORMANCE CHARACTERISTICS. Recommended Minimum. Guaranteed Minimum Output. Supply Current vs Temperature
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LT1073
TYPICAL PERFORMANCE CHARACTERISTICS Recommended Minimum Guaranteed Minimum Output Supply Current vs Temperature Inductance Value Current at 5V vs VIN
150 300 1000 VIN = 1.5V R 140 LIM = 0V 130 250 120 200 110 100 150 100 90 100 SUPPLY CURRENT (µA) 80 OUTPUT CURRENT (mA) FOR V 70 MINIMUM INDUCTANCE (µH) IN > 1.6V A 50 68Ω RESISTOR 60 MUST BE CONNECTED BETWEEN ILIM AND VIN 50 0 10 –50 –25 0 25 50 75 100 125 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 1.0 1.5 2.0 2.5 3.0 3.5 TEMPERATURE (°C) INPUT VOLTAGE (V) VIN (V) 1073 G07 1073 G08 1073 G09
PIN FUNCTIONS ILIM (Pin 1):
Connect this pin to VIN for normal use. Where
GND (Pin 5):
Ground. lower current limit is desired, connect a resistor between
AO (Pin 6):
Auxiliary Gain Block (GB) Output. Open col- ILIM and VIN. A 220Ω resistor will limit the switch current lector, can sink 100µA. to approximately 400mA.
SET (Pin 7):
GB Input. GB is an op amp with positive
VIN (Pin 2):
Input Supply Voltage input connected to SET pin and negative input connected
SW1 (Pin 3):
Collector of Power Transistor. For step-up to 212mV reference. mode connect to inductor/diode. For step-down mode
FB/SENSE (Pin 8):
On the LT1073 (adjustable) this pin goes connect to VIN. to the comparator input. On the LT1073-5 and LT1073-12,
SW2 (Pin 4):
Emitter of Power Transistor. For step-up this pin goes to the internal application resistor that sets mode connect to ground. For step-down mode connect output voltage. to inductor/diode. This pin must never be allowed to go more than a Schottky diode drop below ground.
BLOCK DIAGRAMS LT1073-5 and LT1073-12
SET +
LT1073
A2 A0 SET + – A2 A0 GAIN BLOCK/ERROR AMP – VIN GAIN BLOCK/ERROR AMP V I IN LIM SW1 212mV I REFERENCE LIM SW1 212mV A1 OSCILLATOR Q1 REFERENCE A1 OSCILLATOR Q1 DRIVER COMPARATOR SW2 GND DRIVER R2 COMPARATOR SW2 R1 940k FB 1073 BD01 SENSE LT1073-5: R1 = 40k LT1073-12: R2 = 16.3k GND 1073 BD02 Rev B 4 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagrams Operation Applications Information Typical Applications Package Description Typical Application Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS Recommended Minimum Guaranteed Minimum Output Supply Current vs Temperature Inductance Value Current at 5V vs VIN
150 300 1000 VIN = 1.5V R 140 LIM = 0V 130 250 120 200 110 100 150 100 90 100 SUPPLY CURRENT (µA) 80 OUTPUT CURRENT (mA) FOR V 70 MINIMUM INDUCTANCE (µH) IN > 1.6V A 50 68Ω RESISTOR 60 MUST BE CONNECTED BETWEEN ILIM AND VIN 50 0 10 –50 –25 0 25 50 75 100 125 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 1.0 1.5 2.0 2.5 3.0 3.5 TEMPERATURE (°C) INPUT VOLTAGE (V) VIN (V) 1073 G07 1073 G08 1073 G09
PIN FUNCTIONS ILIM (Pin 1):
Connect this pin to VIN for normal use. Where
GND (Pin 5):
Ground. lower current limit is desired, connect a resistor between
AO (Pin 6):
Auxiliary Gain Block (GB) Output. Open col- ILIM and VIN. A 220Ω resistor will limit the switch current lector, can sink 100µA. to approximately 400mA.
SET (Pin 7):
GB Input. GB is an op amp with positive
VIN (Pin 2):
Input Supply Voltage input connected to SET pin and negative input connected
SW1 (Pin 3):
Collector of Power Transistor. For step-up to 212mV reference. mode connect to inductor/diode. For step-down mode
FB/SENSE (Pin 8):
On the LT1073 (adjustable) this pin goes connect to VIN. to the comparator input. On the LT1073-5 and LT1073-12,
SW2 (Pin 4):
Emitter of Power Transistor. For step-up this pin goes to the internal application resistor that sets mode connect to ground. For step-down mode connect output voltage. to inductor/diode. This pin must never be allowed to go more than a Schottky diode drop below ground.
BLOCK DIAGRAMS LT1073-5 and LT1073-12
SET +
LT1073
A2 A0 SET + – A2 A0 GAIN BLOCK/ERROR AMP – VIN GAIN BLOCK/ERROR AMP V I IN LIM SW1 212mV I REFERENCE LIM SW1 212mV A1 OSCILLATOR Q1 REFERENCE A1 OSCILLATOR Q1 DRIVER COMPARATOR SW2 GND DRIVER R2 COMPARATOR SW2 R1 940k FB 1073 BD01 SENSE LT1073-5: R1 = 40k LT1073-12: R2 = 16.3k GND 1073 BD02 Rev B 4 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagrams Operation Applications Information Typical Applications Package Description Typical Application Related Parts