TPS61010, TPS61011
TPS61012, TPS61013
TPS61014, TPS61015, TPS61016
www.ti.com
SLVS314C–SEPTEMBER 2000–REVISED OCTOBER 2003
Terminal Functions
terminal
I/O
description
name
no.
ADEN
8
I
Autodischarge input. The autodischarge function is enabled if this pin is connected to VBAT, it is disabled if ADEN
is tied to GND.
COMP
EN
2
1
I
I
Compensation of error amplifier. Connect an R/C/C network to set frequency response of control loop.
Chip-enable input. The converter is switched on if this pin is set high, it is switched off if this pin is connected to
GND.
FB
3
I
Feedback input for adjustable output voltage version TPS61010. Output voltage is programmed depending on the
output voltage divider connected there. For the fixed output voltage versions, leave FB-pin unconnected.
GND
LBI
4
9
Ground
I
Low-battery detector input. A low battery warning is generated at LBO when the voltage on LBI drops below the
threshold of 500 mV. Connect LBI to GND or VBAT if the low-battery detector function is not used. Do not leave
this pin floating.
LBO
10
O
Open-drain low-battery detector output. This pin is pulled low if the voltage on LBI drops below the threshold of
500 mV. A pullup resistor must be connected between LBO and VOUT.
SW
7
5
6
I
O
I
Switch input pin. The inductor is connected to this pin.
VOUT
VBAT
Output voltage. Internal resistor divider sets regulated output voltage in fixed output voltage versions.
Supply pin
DETAILED DESCRIPTION
Controller Circuit
The device is based on a current-mode control topology using a constant frequency pulse-width modulator to
regulate the output voltage. The controller limits the current through the power switch on a pulse by pulse basis.
The current-sensing circuit is integrated in the device, therefore, no additional components are required. Due to
the nature of the boost converter topology used here, the peak switch current is the same as the peak inductor
current, which will be limited by the integrated current limiting circuits under normal operating conditions.
The control loop must be externally compensated with an R-C-C network connected to the COMP-pin.
Synchronous Rectifier
The device integrates an N-channel and a P-channel MOSFET transistor to realize a synchronous rectifier. There
is no additional Schottky diode required. Because the device uses a integrated low rDS(on) PMOS switch for
rectification, the power conversion efficiency reaches 95%.
A special circuit is applied to disconnect the load from the input during shutdown of the converter. In conventional
synchronous rectifier circuits, the backgate diode of the high-side PMOS is forward biased in shutdown and
allows current flowing from the battery to the output. This device, however, uses a special circuit to disconnect
the backgate diode of the high-side PMOS and so, disconnects the output circuitry from the source when the
regulator is not enabled (EN = low).
The benefit of this feature for the system design engineer, is that the battery is not depleted during shutdown of
the converter. So, no additional effort has to be made by the system designer to ensure disconnection of the
battery from the output of the converter. Therefore, design performance will be increased without additional costs
and board space.
Power-Save Mode
The TPS61010 is designed for high efficiency over a wide output current range. Even at light loads, the efficiency
stays high because the switching losses of the converter are minimized by effectively reducing the switching
frequency. The controller enters a powersave-mode if certain conditions are met. In this mode, the controller only
switches on the transistor if the output voltage trips below a set threshold voltage. It ramps up the output voltage
with one or several pulses, and goes again into powersave-mode once the output voltage exceeds a set
threshold voltage.
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