Datasheet

0
10
20
30
40
50
60
70
80
90
100
0.01 0.1 1 2
Output Current (mA)
Efficiency (%)
V
OUT
= 16.0 V
V
IN
= 3.0 V
G000
0
10
20
30
40
50
60
70
80
90
100
0.01 0.1 1 2
Output Current (mA)
Efficiency (%)
V
OUT
= 16.0 V
V
IN
= 3.7 V
G000
0
10
20
30
40
50
60
70
80
90
100
0.01 0.1 1 2
Output Current (mA)
Efficiency (%)
V
OUT
= 16.0 V
V
IN
= 4.2 V
G000
0
10
20
30
40
50
60
70
80
90
100
0.01 0.1 1 2
Output Current (mA)
Efficiency (%)
V
OUT
= 16.0 V
V
IN
= 5.5 V
G000
TPS65735
www.ti.com SLVSAI6–JUNE 2011
2.9 Boost Converter Operation
The boost converter in this device is designed for the load of active shutter 3D glasses. This load is
typically a light load where the average current is 2 mA or lower and the peak current out of a battery is
limited in operation. This asynchronous boost converter operates with a minimum off time / maximum on
time for the integrated low side switch, these values are specified in the electrical characteristics table of
this datasheet.
The peak output voltage from the boost converter is adjustable and set by using an external resistor
divider connected between BST_OUT, the BST_FB pin, and ground. The peak output voltage is set by
choosing resistors for the feedback network such that the voltage on the BST_FB pin is V
REF(BST)
= 1.2 V.
See Section 3.3 for more information on calculating resistance values for this feedback network.
The efficiency curves for various input voltages over the typical 3D glasses load range (2 mA and lower)
are shown below. All curves are for a target V
OUT
of 16 V. For output voltages less than 16 V, a higher
efficiency at each operating input voltage should be expected. Note that efficiency is dependent upon the
external boost feedback network resistances, the inductor used, and the type of load connected.
Figure 2-6. Boost Efficiency vs. I
OUT
, V
IN
= 3.0 V, Figure 2-7. Boost Efficiency vs. I
OUT
, V
IN
= 3.7 V,
V
OUT
= 16 V V
OUT
= 16 V
Figure 2-8. Boost Efficiency vs. I
OUT
, V
IN
= 4.2 V, Figure 2-9. Boost Efficiency vs. I
OUT
, V
IN
= 5.5 V,
V
OUT
= 16 V V
OUT
= 16 V
2.9.1 Boost Thermal Shutdown
An internal thermal shutdown mode is implemented in the boost converter that shuts down the device if
the typical junction temperature of 105°C is exceeded. If the device is in thermal shutdown mode, the
main switch of the boost is open and the device enters the "SLEEP / POWER OFF" state.
Copyright © 2011, Texas Instruments Incorporated POWER MANAGEMENT CORE 19
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