TPS61251_15 Datasheet, PDF (1/24 Pages) Texas Instruments – TPS61251 Boost Converter for Battery Backup Charging With Adjustable Constant Current and Snooze Mode

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TPS61251
SLVSAF7B – SEPTEMBER 2010 – REVISED JULY 2015
TPS61251 Boost Converter for Battery Backup Charging With Adjustable Constant
Current and Snooze Mode
1 Features
•1 Resistor Programmable Input Current Limit
– ±10% Current Accuracy at 500 mA over Full
Temperature Range
– Programmable from 100 mA up to 1500 mA
• Snooze Mode Draws Only 2 μA (Typical)
Quiescent Current
• Designed to Charge Large Capacitor Values in the
Farad Range
• Up to 92% Efficiency
• Power Good Indicates Appropriate Output Voltage
Level even in Shut Down
• V_IN Range from 2.3 V to 6 V
• Adjustable Output Voltage up to 6.5 V
• 100% Duty-Cycle Mode When V_IN > V_OUT
• Load Disconnect and Reverse Current Protection
• Short-Circuit Protection
• Typical Operating Frequency 3.5 MHz
• Available in a 2 × 2-mm WSON-8 Package
2 Applications
• Current Limited Applications With High Peak
Power Loads (SSD, PCMCIA Tx Bursts, Memory,
GPRS/GSM Tx)
• Li-Ion Applications
• Battery Backup Applications
• Audio Applications
• RF-PA Buffer
3 Description
The TPS61251 device provides a power supply
solution for products powered by either a three-cell,
NiCd or NiMH battery, or a one-cell Li-Ion or Li-
polymer battery. The wide input voltage range is ideal
to power portable applications like mobile phones,
solid state drives (SSD) and wireless modems. The
converter is designed to charge large capacitors in
the Farad range to support battery back up
applications. During capacitor charging, the
TPS61251 device is working as a constant current
source until V_OUT has reached its programmed value.
The charge current can be programmed by an
external resistor R_ILIM and provides a ±10% accuracy
for the average input current limit.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS61251
WSON (8)
2.00 mm × 2.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
V_IN
2.3 V to
6.0 V
L1
1 μH
C1
10 µF
R_ILIM
20 kΩ
Simplified Schematic
L
VOUT
VIN
EN
FB
ILIM
R1
1 MΩ
R2
280 kΩ
C_FF
1 nF
R4
1 MΩ
C_OUT
4.7 µF
V_OUT
5.5 V
C_BULK
>150 µF
GND
PG
TPS61251
Power Good
Output
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.