Datasheet

Board Layout

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2.1 Power Supply Inputs

Table 2 shows the voltage input that should be applied in different places of the EVM.

Table 2. Input Supply Configuration

Device V3P3 TP11 VHV TP7

TPS22981 3.15 – 3.60 V 4.50 – 18.00 V

See Table 2 for the EVM correct input supply voltage setting. Connect the V3P3 +3.3 V input power

supply positive lead to TP11 (V3P3 Force) and the return lead to TP2 GND. Connect the VHV +5 V input

power supply positive lead to TP7 (VHV Force) and the return lead to TP15 GND.

2.2 Jumper Settings

There are four digital signals which can be set with jumpers as defined in Table 3. These signals can be

set to a value of “0” or “1” by setting the jumpers according to the marking on the board. See the

TPS22981 datasheet for more information on the functionality of these signals.

Table 3. Digital Signal Jumpers

Jumper Name

J7 EN

J8 S0

J9 HV_EN

J10 ENHVU

There are two external resistances settings per mode that can be configured by setting a jumper in the

correct position.

• For V3P3 mode, set J1 (402 kΩ) or J2 (80.6 kΩ):

– 402 kΩ will limit the current to around 100 mA on the output.

– 80.6 kΩ will limit the current to around 496 mA on the output.

• For VHV, S3 mode, set J3 (402 kΩ) or J4 (80.6 kΩ):

– 402 kΩ will limit the current to around 100 mA on the output

– 80.6 Ω will limit the current to around 496 mA on the output.

• For VHV, S0 mode (S0 = 1), set J5 (26.7 kΩ) or J6 (80.6 kΩ):

– 26.7 kΩ will limit the current to around 1.5 A on the output.

– 80.6 kΩ will limit the current to around 496 mA on the output

2.3 Measuring Output Voltage

Use a meter to measure the output voltage of the UUT. Connect the positive input of the voltmeter to TP8

(OUT Force) and the negative input of the meter to TP16 (GND). If HV_EN is set to 0V, you will measure

the V3P3 input voltage at the output. If HV_EN is set to 3.3V, you will measure the VHV input voltage at

the output.

2.4 Current Limit

To simulate a current limit condition, a high power resistor could be used in the output (between TP8 and

TP16). This will cause TPS22981 to limit the current based on the external resistor settings.

3 Board Layout

Figure 1, Figure 2 and Figure 3 show the board layout for the TPS22981EVM PCB. The EVM offers

resistors, and jumpers to program different current limits.

TPS22981EVM SLVU817–November 2012

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