DS_IPM12S0A008_03202007

9

FEATURES DESCRIPTIONS (CON.)

Output Voltage Programming

The output voltage of IPM can be programmed to any

voltage between 0.8Vdc and 5Vdc by connecting one

resistor (shown as Rtrim in Figure 28, 29) between the

TRIM and GND pins of the module to trim up (0.9V ~ 5V)

and between the Trim and +Output to trim down (0.8V ~

0.9V). Without this external resistor, the output voltage of

the module is 0.9 Vdc. To calculate the value of the

resistor Rtrim for a particular output voltage Vo, please

use the following equation:

Trim up

Rtrim =

3.746

- 0.261 (K

Ω )

Vout

–0.9

Trim Down

Rtrim =

1.070

- 5.612 (K

Ω )

0.9 - Vout

Rtrim is the external resistor in K

Ω

Vout is the desired output voltage

For example: to program the output voltage of the IPM

module to 3.3Vdc, Rtrim is calculated as follows:

Rtrim =

3.746

- 0.261 (K

Ω )

3.3

–0.9

Rtrim = 1.300 K

Ω

IPM can also be programmed by applying a voltage

between the TRIM and GND pins (Figure 30). The

following equation can be used to determine the value of

Vtrim needed for a desired output voltage Vo:

Vtrim = 0.7439

– 0.0488Vo

Vtrim is the external voltage in V

Vo is the desired output voltage

For example, to program the output voltage of a IPM

module to 3.3 Vdc, Vtrim is calculated as follows

Vtrim = 0.7439

– 0.0488 x 3.3

Vtrim = 0.5829V

Figure 28:

Trim up Circuit configuration for programming

output voltage using an external resistor

Rtrim

Load

Vout

Trim

GND

Figure 29:

Trim down Circuit configuration for programming

output voltage using an external resistor

Figure 30: Circuit configuration for programming output voltage

using external voltage source