Technical Reference Notes

AEH/ALH80 Series

MODEL: AEH/ALH80 SERIES

SHEET 7 OF 17

OCTOBER 9, 2003 - REVISION B

+Vin

-Vin

Enable

-Vout

+Vout

-Sense

+Sense

Vadj

Rload

Radj_up

Case

Figure 3. External resistor configuration to increase the output.

+Vin

-Vin

Enable

-Vout

+Vout

-Sense

+Sense

Vadj

Rload

Radj_down

Case

Figure 4. External resistor configuration to decrease the output.

Basic Operation and Features

INPUT UNDER VOLTAGE LOCKOUT

To prevent any instability to the converter, which may affect the end system, the AEH/ALH80 series have been designed to

down to 32.5-34.5 VDC.

OUTPUT VOLTAGE ADJUST/TRIM

The converter comes with a TRIM pin (PIN 8), which is used to adjust the output by as much as 90% to 110% of its set point.

This is achieved by connecting an external resistor as described below.

should be connected between TRIM PIN (Pin8) and

+SENSE PIN (Pin 7). Please refer to Equation (1) for the

required external resistance and output adjust

relationship.

1.8V / 1.5V

Equation (1a):

1.2V

Equation (1b):

should be connected between TRIM PIN (Pin 8) and

-SENSE PIN (Pin 9). Please refer to Equation (2) for the

required external resistance and output adjust

relationship.

1.8V / 1.5V

Equation (2a)

1.2V

Equation (2b):

Where: Radj = resistance in kohms

? % = percent change in the output

Radj_up

Vo 100

∆%

+

(

)

1.225

∆%

⋅

100

∆%

−

2

−









k

Ω

⋅

Radj_up

5.1 Vo 100

∆%

+

(

)

⋅

0.6

∆%

⋅

510

∆%

−

6.1

−









k

Ω

⋅

Radj_down

100

∆%

2

−









k

Ω

⋅

Radj_down

510

∆%

6.1

−









k

Ω

⋅