Datasheet LT3494, LT3494A (Analog Devices)
| Fabricante | Analog Devices |
| Descripción | Micropower Low Noise Boost Converters with Output Disconnect |
| Páginas / Página | 12 / 1 — FEATURES. DESCRIPTION. Low Quiescent Current. 65μA in Active Mode. 1μA in … |
| Formato / tamaño de archivo | PDF / 273 Kb |
| Idioma del documento | Inglés |
FEATURES. DESCRIPTION. Low Quiescent Current. 65μA in Active Mode. 1μA in Shutdown Mode
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LT3494/LT3494A Micropower Low Noise Boost Converters with Output Disconnect
FEATURES DESCRIPTION
■
Low Quiescent Current
The LT®3494/LT3494A are low noise boost converters
65μA in Active Mode
with integrated power switch, Schottky diode and output
1μA in Shutdown Mode
disconnect circuitry. The parts use a novel* control tech- ■
Switching Frequency is Non-Audible Over Entire
nique resulting in low output voltage ripple as well as high
Load Range
effi ciency over a wide load current range. This technique ■
Integrated Power NPN:
guarantees that the switching frequency stays above the
350mA Current Limit (LT3494A)
audio band for the entire load range. The parts feature a high
180mA Current Limit (LT3494)
performance NPN power switch with a 350mA and 180mA ■
Integrated Schottky Diode
current limit for the LT3494A and LT3494 respectively. The ■
Integrated Output Disconnect
quiescent current is a low 65μA, which is further reduced ■ Integrated Output Dimming to less than 1μA in shutdown. The internal disconnect ■ Wide Input Range: 2.3V to 16V circuitry allows the output voltage to be isolated from the ■ Wide Output Range: Up to 40V input during shutdown. An auxiliary reference input (CTRL ■ Tiny 8-Lead 3mm × 2mm DFN Package pin) overrides the internal 1.225V feedback reference with any lower value allowing full control of the output voltage
APPLICATIONS
during operation. The LT3494/LT3494A are available in a tiny 8-lead 3mm × 2mm DFN package. ■ OLED Power ■ Low Noise Power , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ MP3 Players *Patent pending.
TYPICAL APPLICATION Output Voltage Ripple Effi ciency and Power Loss vs Load Current vs Load Current OLED Power Supply from One Li-Ion Cell
15 90 280 LT3494 VIN = 3.6V LOAD FROM FIGURE 5 CIRCUIT CAPACITOR 15 80 240 V μH IN 100MHz MEASUREMENT BW 3V LOAD FROM POWER LOSS (mW) TO 4.2V 4.7μF 0.22μF 70 200 10 VOUT SW CAP VOUT 60 160 VCC VOUT 16V 16mA LT3494 2.21M 50 120 SHDN FB 2.2μF 5 EFFICIENCY (%) 40 80 CTRL GND PEAK-TO-PEAK RIPPLE (mV) 3494 TA01a OUTV 30 40 0 20 0 0.1 1 10 100 0.1 1 10 100 LOAD CURRENT (mA) LOAD CURRENT (mA) 3494 TA01c 3494 TA01b 3494fb 1
FEATURES DESCRIPTION
■
Low Quiescent Current
The LT®3494/LT3494A are low noise boost converters
65μA in Active Mode
with integrated power switch, Schottky diode and output
1μA in Shutdown Mode
disconnect circuitry. The parts use a novel* control tech- ■
Switching Frequency is Non-Audible Over Entire
nique resulting in low output voltage ripple as well as high
Load Range
effi ciency over a wide load current range. This technique ■
Integrated Power NPN:
guarantees that the switching frequency stays above the
350mA Current Limit (LT3494A)
audio band for the entire load range. The parts feature a high
180mA Current Limit (LT3494)
performance NPN power switch with a 350mA and 180mA ■
Integrated Schottky Diode
current limit for the LT3494A and LT3494 respectively. The ■
Integrated Output Disconnect
quiescent current is a low 65μA, which is further reduced ■ Integrated Output Dimming to less than 1μA in shutdown. The internal disconnect ■ Wide Input Range: 2.3V to 16V circuitry allows the output voltage to be isolated from the ■ Wide Output Range: Up to 40V input during shutdown. An auxiliary reference input (CTRL ■ Tiny 8-Lead 3mm × 2mm DFN Package pin) overrides the internal 1.225V feedback reference with any lower value allowing full control of the output voltage
APPLICATIONS
during operation. The LT3494/LT3494A are available in a tiny 8-lead 3mm × 2mm DFN package. ■ OLED Power ■ Low Noise Power , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ MP3 Players *Patent pending.
TYPICAL APPLICATION Output Voltage Ripple Effi ciency and Power Loss vs Load Current vs Load Current OLED Power Supply from One Li-Ion Cell
15 90 280 LT3494 VIN = 3.6V LOAD FROM FIGURE 5 CIRCUIT CAPACITOR 15 80 240 V μH IN 100MHz MEASUREMENT BW 3V LOAD FROM POWER LOSS (mW) TO 4.2V 4.7μF 0.22μF 70 200 10 VOUT SW CAP VOUT 60 160 VCC VOUT 16V 16mA LT3494 2.21M 50 120 SHDN FB 2.2μF 5 EFFICIENCY (%) 40 80 CTRL GND PEAK-TO-PEAK RIPPLE (mV) 3494 TA01a OUTV 30 40 0 20 0 0.1 1 10 100 0.1 1 10 100 LOAD CURRENT (mA) LOAD CURRENT (mA) 3494 TA01c 3494 TA01b 3494fb 1