Datasheet
Outputvoltage
V +1%
OUT(nom)
V
OUT(nom)
Lightload
PFMMode
moderatetoheavyload
PWMMode
Time
90%
10%
t
RAMP
t
Start
EN
V
OUT
TPS65000, TPS65001, TPS650001
TPS650003, TPS650006, TPS650061
SLVS810B –JUNE 2009–REVISED AUGUST 2010
www.ti.com
Figure 22. PFM Voltage Positioning
Pulling the MODE pin to DC ground will result in automatic transition between PFM and PWM modes to
maximize efficiency.
The DCDC converter output automatically discharges to ground through an internal 450Ω load when EN_DCDC
goes low or when the UVLO condition is met.
SOFT START
The step-down converter has an internal soft start circuit that limits the inrush current during start-up. During soft
start, the output voltage ramp up is controlled as shown in Figure 23.
Figure 23. Soft Start
LINEAR REGULATORS
The two linear dropout regulators (LDOs) in the TPS65000 and TPS65001 are designed to provide flexibility in
system design. Each LDO has a separate voltage input and enable signal. The input can be tied to the output of
the step-down converter or the output of another voltage source. Each LDO output discharge to ground
automatically when EN_LDOx goes low.
A resistor network is needed to set the output voltage of the LDOs. Fixed voltage output versions are also
available; contact Texas Instruments sales representative for more information.
The LDOs are general-purpose devices that can handle inputs from 6V down to 1.6V, making them suitable for
direct connection to the battery. Figure 24 illustrates the necessary connections for LDO1. The same architecture
applies to LDO2.
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