TPS61291_16 Datasheet, PDF (1/25 Pages) Texas Instruments – TPS61291 Low Iq Boost Converter with Bypass Operation

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TPS61291
SLVSBX9A – SEPTEMBER 2014 – REVISED SEPTEMBER 2014
TPS61291 Low Iq Boost Converter with Bypass Operation
1 Features
•1 Input Voltage Range 0.9V to 5V
• Startup Voltage 1.5V at 20mA Load
• Pin Selectable Output Voltages: 3.3V, 3V, 2.5V
• 15nA typical Quiescent Current in Bypass Mode
• 5.7μA typical Quiescent Current in Boost Mode
• Bypass Switch from VIN to VOUT
• I_OUT > 200mA at 3.3V V_OUT, V_IN = 1.8V
• Internal Feedback Divider Disconnect (Bypass
Mode)
• Controlled Bypass Transition Prevents Reverse
Current into Battery
• Power-Save Mode at Light Loads
• Overtemperature Protection
• Redundant Overvoltage Protection
• Small 2mm x 2mm SON 6-pin package
2 Applications
• Metering (Gas, Water, Smart Meters)
• Remote Controls
• Home Security / Home Automation
• Single 3V Li-MnO₂ or 2 x 1.5V Alkaline Cell
Powered Applications
3 Description
The TPS61291 is a boost converter with pin
selectable output voltages and an integrated bypass
mode. In bypass operation, the device provides a
direct path from the input to the system and allows a
low power micro controller (MCU) such as the
MSP430 to operate directly from a single 3V Li-MnO2
battery or dual alkaline battery cells.
In bypass mode the integrated feedback divider
network for boost mode operation is disconnected
from the output and the quiescent current
consumption drops down to only 15nA (typical).
In boost mode the device provides a minimum output
current of 200mA at 3.3V V_OUT from 1.8V V_IN. The
boost mode is used for system components which
require a regulated supply voltage and cannot directly
operate from the input source. The boost converter is
based on a current-mode controller using
synchronous rectification to obtain maximum
efficiency and consumes typically 5.7uA from the
output. During startup of the boost converter, the
VSEL pin is read out and the integrated feedback
network sets the output voltage to 2.5V, 3V or 3.3V.
Bypass mode or boost mode operation is controlled
by the system via the EN/BYP pin.
The device integrates an enhanced bypass mode
control to prevent charge, stored in the output
capacitor during boost mode operation, from flowing
back to the input and charging the battery.
The device is packaged in a small 6-pin SON
package (DRV) measuring 2.0mm × 2.0mm x
0.75mm.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS61291
SON (6)
2.00 mm x 2.00 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Simplified Schematic and Efficiency Curves
100
TPS61291
95
L = 3.3mH _{SW Step up}
V_OUT =
2 x 1.5V Alkaline /
converter _VOUT ^VBAT ^{/ 3.3V}
Subsystem
V_CC = 3.3V
90
85
1 x 3V Li-MnO₂
+
-
+
+
-
-
V_BAT
C_IN
10mF
VIN
Bypass
VSEL
GND
EN/BYP
80
C_OUT
MCU
22mF (VCC = VBAT or 3.3V)
75
70
65
60
55
50
0.01
VIN = 1.2V
VIN = 1.8V
VIN = 2.5V
VIN = 3.0V
0.1
1
10
100
Output Current IOUT [mA]
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.