ApplicationsApplications

TPS612513.5MHz, 1.5A Current Limit, 92% Efficient Boost Converter for Battery Backu

BOOST CONVERTER FOR BATTERY BACKUP CHARGING WITH ADJUSTABLE CONSTANT CURRENT AND SNOOZE MODE

Features Benefits

Resistor programmable input current limit from 100 to 1500mA with 10% accuracy @ 500mA

Avoids overloading the source and gives control over the charge current of the capacitor

Capable to charge large capacitor (Farad Range)

Enables back up solution for system current surge

Snooze mode draws only 2 = (typ) Quiescent Current

Drastic reduction (more than 90%) of Iq optimizes efficiency and allows extended battery lifetime

Output voltage up to 6.5 V Bulk capacitors with higher voltage rating can be used which implies bigger amount of energy for a given capacitance.

1.0 B Inductor & 2x2 QFN package Smallest solution size C 10x7 mm2

diagram schematic

• Source Current Limited Applications

• Battery Backup Applications

• Li-Ion Applications

• Audio Applications

• Resistor Programmable Input Current Limit from 100 to 1500mA with ±10% accuracy @ 500mA

• Designed to charge large capacitor (Farad Range)

• Snooze mode draws only 2 μA (typ) Quiescent Current ,

• Output voltage up to 6.5 V , ,

• Power Good in shutdown ,

• 2x2 QFN + 1.0 µH Inductor

TPS612513.5MHz, 1.5A current limit, 92% efficient Boost Converter for Battery Backup Charging

• Current limited Applications with high peak current loads (SSDs, PCMCIA Tx bursts, Memory, GPRS/GSM Tx)

• Battery Backup Applications• Single cell Li-Ion battery power applications• Audio applications• RF-PA buffer

• Avoids overloading the source and gives control over the charge current of the capacitor

• Enables back up solution for system current surge.

• Drastic reduction (more than 90%) of Iq optimizes efficiency and allows extended battery lifetime.

• Bulk capacitors with higher voltage rating can be used which implies bigger amount of energy for a given capacitance:

• Allows to power the follow-on circuit until the output voltage is below 2.3V maximizing the use of energy in the storage capacitor.

• Smallest solution size – 10x7 mm2

RLIM ILIM = Adjustable

VIN ILIM = High limit ( 1.5A )

GND

ILIM = Low limit ( 100mA )

TPS61251EVM-517

)V(V

E2C

22

21

Vout up to 6.5V Higher voltage rate bulk capacitors

• Reduces capacitances for a given energy

• Reduces total solution cost.

Wider programmable input current range, giving higher flexibility in terms of input energy source.

TPS61251 accuracy is 10% vs 5% from LTC. We guarantee the accuracy for a much wider current window (100mA to 1500mA vs 200mA to 1000mA)

Power Good function built in to indicate whether the Vout reaches the programmed value & therefore the capacitor is fully charged. Operation:

• PG is set high if the feedback voltage reaches 95% of its nominal value.

• The PG comparator operates even in shut down mode when EN is set to low and/or VIN is turned off. This guaranties power good functionality until the capacitor is discharged.

• The PG output goes low when:

◘ Vout < 2.3 V and indicates the discharge of the capacitor.

◘ Vout < 2.0 V all internal circuitry is disabled. Therefore the PG open drain output becomes high resistive and follows the voltage the pull-up resistor is connected to.

• While the output capacitors are still charged the converter can be disconnected from its supply but it will still supply a follow-on circuitry with energy needed for a secured shut down.

TPS61251 advantages vs comp

)V(V

E2C

22

21

2

2ΔVCEnergy

Snooze Mode

What is it?

It’s an enhanced power save mode automatically activated when the load goes below 2mA.

• Vout with ±2% is maintained

• Iq for this mode is 2uA (typ)

• We achieve this by switching off as many internal regulation circuits as possible.

• If Iload> 2mA, Vout drops and the converter wakes up to recharge the cap.

Snooze mode

Allows maximum efficiency over the load range

LTC3125 TPS61251

ApplicationsApplications

TPS612523.5MHz, 1.5A, 92% Efficient Boost Converter with Adjustable Input Current L

3.5MHz, 1.5A, 92% efficient Boost Converter with adjustable input current limit

Features Benefits

Resistor Programmable Input Current Limit from 100 to 1500mA with 20% accuracy @ 500mA

Avoids overloading the power source and eliminates the need for an external load switch

100% Duty-Cycle Mode When VIN > VOUT

Output voltage is still regulated if Vin>Vout

Load disconnect Protects the device from reverse current

Power Good (PG) output with wider operating window

PG: - High when feedback voltage is 95% of nominal value. - Low when feedback voltage falls to 90% of nom. value.

2x2 QFN and 1.0 B Inductor Smallest solution size C 10x7 mm2

diagram schematic

• USB Host Supplies from a single cell

• Battery Backup Applications

• Current limited applications

• Audio Applications

• Resistor Programmable Input Current Limit from 100 to 1500mA with ±20% accuracy @ 500mA

• 100% Duty-Cycle Mode When VIN > VOUT

• Load disconnect

• 2x2 QFN and 1.0 µH Inductor

TPS612523.5MHz, 1.5A, 92% efficient Boost Converter with adjustable input current limit

• USB Host Supplies from a single cell Li-Ion • Current limited applications• Single cell Li-Ion battery power applications• Audio Applications

• Avoids overloading the power source and eliminates the need for an external load switch.

• Output voltage is still regulated if Vin>Vout

• Protects the device from reverse current

• Smallest solution size – 10x7 mm2

RLIM ILIM = Adjustable

VIN ILIM = High limit ( 1.5A )TPS61252EVM-667

Wider programmable input current range, giving higher flexibility in terms of input energy source.

Wider output voltage range up to 6.5V

TPS61252 current accuracy is 20% vs 5% from LTC. We guarantee the accuracy for a much wider current window (100mA to 1500mA vs 200mA to 1000mA)

Power Good function built in to indicate whether the Vout reaches the programmed value

• PG is set high if the feedback voltage reaches 95% of its nominal value.

• PG is set low when the feedback voltage falls to 90% of its nominal value.

TPS61252 allows for a smaller total solution size

TPS61252 has a better output voltage accuracy, ±1.5% vs ±2.4%

TPS61252 advantages vs comp

TPS61251 & TPS61252 differences

TPS61251 is optimized for charging bulk capacitors

TPS61252 is a regular boost converter.

TPS61252 current accuracy is 20% vs 10% from TPS61251

Snooze Mode only available with TPS61251

Power Good function is different for both devices:

TPS61251

- PG is set high if the feedback voltage reaches 95% of its nominal value.

- The PG comparator operates even in shut down mode when EN is set to low and/or VIN is turned off. This guaranties power good functionality until the capacitor is discharged.

- The PG output goes low when:

◘ Vout < 2.3 V and indicates the discharge of the capacitor.

◘ Vout < 2.0 V all internal circuitry is disabled. Therefore the PG open drain output becomes high resistive and follows the voltage the pull-up resistor is connected to.

While the output capacitors are still charged the converter can be disconnected from its supply but it will still supply a follow-on circuitry with energy needed for a secured shut down.

TPS61252 – As described before