Datasheet

VDCDC1
EN_DCDC1
DEFDCDC1
AGND PGND
L1
R1
R2
V
OUT
L
C
OUT
V
CC
VINDCDC1
C
IN
1 Fm
10R
V
bat
V
OUT
+ V
DEFDCDCx
R1 ) R2
R2
R1 + R2
ǒ
V
OUT
V
DEFDCDCx
Ǔ
* R2
Voltage Change on VDCDC3
TPS650240 , , TPS650241
TPS650242 , TPS650243
TPS650244 , TPS650245
SLVS774B – JUNE 2007 – REVISED JULY 2009 .............................................................................................................................................................. www.ti.com
Table 4. Voltage Options
PIN LEVEL DEFAULT OUTPUT VOLTAGE
DEFDCDC1 All versions VCC 3.3V
GND 2.80V
DEFDCDC2 All versions VCC 2.5V
GND 1.8V
DEFDCDC3 TPS650240 VCC 1.3V
GND 1.0V
TPS650241 VCC 1.375V
GND 0.9V
TPS650242 VCC 1.5V
GND 1.0V
TPS650243 VCC 1.2V
GND 1.0V
TPS650244 VCC 1.6V
GND 1.55V
TPS650245 VCC 1.1V
GND 0.9V
If a different voltage is needed, an external resistor divider can be added to the DEFDCDC1 or DEFDCDC2 pin
as shown below:
When a resistor divider is connected to DEFDCDC1 or DEFDCDC2, the output voltage can be set from 0.6V up
to the input voltage V
bat
. The total resistance (R1+R2) of the voltage divider should be kept in the 1M Ω range in
order to maintain a high efficiency at light load. V
DEFDCDCx
= 0.6V
The output voltage of VDCDC3 can be changed during operation from e.g. 1.0V to 1.3V (TPS650240) and back.
While the output voltage at VDCDC1 and VDCDC2 is fixed after the device exits undervoltage lockout (UVLO),
the status of the DEFDCDC3 pin is sensed during operation and the voltage is changed as soon as the logic
level on this pin changes from low to high or vice versa. Therefore it is not possible to connect a resistor divider
to DEFDCDC3 and set a voltage different from the predefined voltages.
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Product Folder Link(s): TPS650240 TPS650241 TPS650242 TPS650243 TPS650244 TPS650245