Datasheet

HSDEN

VLREN

SW1EN

SW2EN

CLKEN

FS1

FS0

Position 1

Position 2

www.ti.com

Setup

S3 – Control Switch is a seven position DIP switch used to set the operating frequency, enable the

external clock and control Switcher 1, Switcher 2, the switched linear regulator, and the high-side switch.

Figure 1. Control Switch Diagram

FS0, FS1, and CLKEN – Set the frequency and to enable the preprogrammed external clock from the

MSP430 to the TPS43331 Synch input. The TPS43331 internal clock source is also used if the No Clock

setting is selected. The user can also apply an optional user defined external clock to the CLK test point, if

the User Defined setting is selected.

Table 2. SYNCH Frequency Select and Enable Switch Settings

Clock Frequency FS0 FS1 CLKEN

No Clock Position 2 Position 2 Don't care

250 kHz Position 1 Position 2 Position 2

333 kHz Position 2 Position 1 Position 2

400 kHz Position 1 Position 1 Position 2

User Defined Don't care Don't care Position 1

The frequency is set when power is applied to the EVM and cannot be changed after power-up. Set the

switch to the desired frequency before applying power to the EVM.

The jumpers can also be used to disable the MSP430 during EMC testing. The procedure to disable the

MSP430 is:

1. Set FS0 and FS1 to the No Clock setting before power up.

2. Apply power to the EVM.

3. Set the regulator conditions on the TPS43331 to be tested.

4. Set FS0 and FS1 to Position 1 to disable the MSP430.

NOTE: Power must to cycled to the EVM to turn the MSP430 back on and send new commands to

the TPS43331 after EMC testing has been completed.

SW1EN – Used to control Switched Regulator 1 on the TPS43331. The switch can be moved at any time

after power has been applied to the EVM. All regulators (except for the standby regulator) are disabled if

Switcher 1 is disabled.

Table 3. Switched Regulator 1 Switch Setting

Switcher 1 SW1EN

Disabled Position 1

Enabled Position 2

SLVU349–October 2009 TPS43331EVM

Submit Documentation Feedback