Datasheet LT3473, LT3473A (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Micropower 1A Boost Converter with Schottky and Output Disconnect |
| Pages / Page | 12 / 1 — FEATURES. DESCRIPTIO. Tiny Solution Size. Low Quiescent Current:. 150. A … |
| File Format / Size | PDF / 276 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. Tiny Solution Size. Low Quiescent Current:. 150. A in Active Mode (VIN = 3.6V, VOUT = 15V,. No Load)
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LT3473/LT3473A Micropower 1A Boost Converter with Schottky and Output Disconnect
U FEATURES DESCRIPTIO
■
Tiny Solution Size
The LT®3473/LT3473A are micropower step-up DC/DC ■
Low Quiescent Current:
converters with integrated Schottky diode and output
150
µ
A in Active Mode (VIN = 3.6V, VOUT = 15V,
disconnect circuitry in low profile DFN packages. The
No Load)
small package size, high level of integration and the use of
1
µ
A in Shutdown Mode
tiny SMT components yield a solution size of less than ■
Internal 1A, 36V Switch
50mm2. The internal 1A switch allows the device to deliver ■
Integrated Schottky Diode
25V at up to 80mA from a Li-Ion cell, while automatic Burst ■
Integrated PNP Output Disconnect
Mode operation maintains efficiency at light load. An ■
Internal Reference Override Pin
auxiliary reference input (CTRL) allows the user to over- ■ PGOOD Pin ride the internal 1.25V feedback reference with any lower ■ 25V at 80mA from 3.6V Input value, allowing full control of the output voltage during ■ Auxiliary NPNs for Intermediate operation. A PGOOD pin sinks current when the output Bias Voltages (LT3473A) voltage reaches 90% of final value. ■ Automatic Burst Mode® Operation at Light Load ■ Constant Switching Frequency: 1.2MHz The LT3473A includes two NPN transistors for generating ■ Thermal Shutdown intermediate bias voltages from the output and is offered ■ Input Range: 2.2V to 16V in a 12-lead (4mm × 3mm) DFN package. The LT3473 ■ Low Profile (3mm × 3mm) DFN Package (LT3473) does not include these NPNs and is offered in an 8-lead ■ Low Profile (4mm × 3mm) DFN Package (LT3473A) (3mm × 3mm) package.
U
The rugged 36V switch and output disconnect circuitry
APPLICATIO S
allow outputs up to 34V to be easily generated in a simple ■ OLED Bias boost topology. ■ CCD Bias , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
U TYPICAL APPLICATIO Conversion Efficiency and Power Loss vs Output Current
80 500 VIN = 3.6V VOUT = 15V VOUT 75 400 PGOOD OUT 25V POWER LOSS (mW) 2.2µF 80mA CTRL 70 6.8 300 µH V LT3473 IN 3V TO 4.2V SW CAP 65 V 200 IN 2M EFFICIENCY (%) SHDN FB 0.47µF 60 100 4.7µF GND 100k 3473 TA01a 55 0 0.1 1 10 100 OUTPUT CURRENT (mA) 3473 TA01b 3473f 1
U FEATURES DESCRIPTIO
■
Tiny Solution Size
The LT®3473/LT3473A are micropower step-up DC/DC ■
Low Quiescent Current:
converters with integrated Schottky diode and output
150
µ
A in Active Mode (VIN = 3.6V, VOUT = 15V,
disconnect circuitry in low profile DFN packages. The
No Load)
small package size, high level of integration and the use of
1
µ
A in Shutdown Mode
tiny SMT components yield a solution size of less than ■
Internal 1A, 36V Switch
50mm2. The internal 1A switch allows the device to deliver ■
Integrated Schottky Diode
25V at up to 80mA from a Li-Ion cell, while automatic Burst ■
Integrated PNP Output Disconnect
Mode operation maintains efficiency at light load. An ■
Internal Reference Override Pin
auxiliary reference input (CTRL) allows the user to over- ■ PGOOD Pin ride the internal 1.25V feedback reference with any lower ■ 25V at 80mA from 3.6V Input value, allowing full control of the output voltage during ■ Auxiliary NPNs for Intermediate operation. A PGOOD pin sinks current when the output Bias Voltages (LT3473A) voltage reaches 90% of final value. ■ Automatic Burst Mode® Operation at Light Load ■ Constant Switching Frequency: 1.2MHz The LT3473A includes two NPN transistors for generating ■ Thermal Shutdown intermediate bias voltages from the output and is offered ■ Input Range: 2.2V to 16V in a 12-lead (4mm × 3mm) DFN package. The LT3473 ■ Low Profile (3mm × 3mm) DFN Package (LT3473) does not include these NPNs and is offered in an 8-lead ■ Low Profile (4mm × 3mm) DFN Package (LT3473A) (3mm × 3mm) package.
U
The rugged 36V switch and output disconnect circuitry
APPLICATIO S
allow outputs up to 34V to be easily generated in a simple ■ OLED Bias boost topology. ■ CCD Bias , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
U TYPICAL APPLICATIO Conversion Efficiency and Power Loss vs Output Current
80 500 VIN = 3.6V VOUT = 15V VOUT 75 400 PGOOD OUT 25V POWER LOSS (mW) 2.2µF 80mA CTRL 70 6.8 300 µH V LT3473 IN 3V TO 4.2V SW CAP 65 V 200 IN 2M EFFICIENCY (%) SHDN FB 0.47µF 60 100 4.7µF GND 100k 3473 TA01a 55 0 0.1 1 10 100 OUTPUT CURRENT (mA) 3473 TA01b 3473f 1
