TPS61251 3.5MHz Boost Converter for Battery Backup Charging

1. TPS61251 3.5MHz, 1.5A Current Limit, 92% Efficient Boost Converter for Battery Backu BOOST CONVERTER FOR BATTERY BACKUP CHARGING WITH ADJUSTABLE CONSTANT CURRENT AND SNOOZE MODE diagram schematic Applications Source Current Limited Applications Battery Backup Applications Li-Ion Applications Audio Applications

2. TPS61251 3.5MHz, 1.5A current limit, 92% efficient Boost Converter for Battery Backup Charging Features Benefits • 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 • Resistor Programmable Input CurrentLimit from 100 to 1500mA with ±10% accuracy @ 500mA • Designed to charge large capacitor (Farad Range) • Snooze modedraws only 2 μA (typ) Quiescent Current , • Output voltage up to 6.5 V , , • Power Good in shutdown , • 2x2 QFN + 1.0 µH Inductor Applications • 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 TPS61251EVM-517

3. TPS61251 advantages vs comp • 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.

4. 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.

5. Snooze mode Allows maximum efficiency over the load range LTC3125 TPS61251

6. TPS61252 3.5MHz, 1.5A, 92% Efficient Boost Converter with Adjustable Input Current L 3.5MHz, 1.5A, 92% efficient Boost Converter with adjustable input current limit diagram schematic Applications USB Host Supplies from a single cell Battery Backup Applications Current limited applications Audio Applications

7. TPS61252 3.5MHz, 1.5A, 92% efficient Boost Converter with adjustable input currentlimit Features Benefits • 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 • 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 Applications • USB Host Supplies from a single cell Li-Ion • Current limited applications • Single cell Li-Ion battery power applications • Audio Applications TPS61252EVM-667

8. TPS61252 advantages vs comp • 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%

9. 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