Technical Reference Notes (AEH60/ALH60F48)
Basic Operation and Features
AEH60 / ALH60 converters were designed specifically to address applications where ultra high power density is required.
These modules provide basic insulation and 1500V isolation with very high output current capability in an industry
standard half size module. Operating from 36 to 75V input, they have standard features such as remote sense, trim, OVP,
OCP and OTP. AEH60 series devices will accept industry standard heat sinks to enhance thermal performance in
applications with conductive cooling.
Remote Sense (+Sense, -Sense)
Connect the + Sense and – Sense pins close to the load to allow the module to compensate for the voltage drop across
conductors carrying high load current. If remote sense is not required (for example if the load is close to the module) the
sense pins should be connected to the corresponding output pins. Maximum voltage drop compensation is 10% Vout. It is
important to avoid introducing lumped inductance or capacitance into the remote path. Do not connect remote sense lines
“beyond” any external output filter stages used with the module.
Trim Function
Output voltage adjustment is accomplished by connecting an external resistor between the Trim Pin and either the +Sense
or –Sense Pins.
To adjust Vo to a higher value,
please refer to Figure 3.
An external resistor,
Radj_up
should be connected
between the Trim Pin and the +Sense Pin. From Equation
(1), Radj_up resistor can be determined for the required
output voltage increment.
Equation (1)
Radj_up = Vo*(100 + %Vo,adj)
1.225*%Vo,adj
100+ 2%Vo,adj
%Vo,adj
kohm
where: Radj_up - in kΩ
%Vo, adj - percent change in output voltage
Figure 3. Radj_up Setup to increase Output Voltage
To adjust Vo to a lower value,
please refer to Figure 4.
An external resistor,
Radj_down
should be connected
between the Trim Pin and the -Sense Pin. From Equation
(2), Radj_down resistor can be determined for the
required output voltage change.
Equation (2)
Radj_down
100
%Vo, adj
2
. kohm
Figure 4. Radj_down Setup to decrease Output Voltage
where: Radj_down - in kΩ
%Vo, adj - percent change in output voltage
MODEL: AEH/ALH60F48
SEPTEMBER 26, 2002 - REVISION 02
SHEET 7 OF 21
ASTEC [ Astec America, Inc ]
