Technical Reference Notes
AA60A-036L-050D033H Series
(5V / 3V3 Dual Output Half Brick)
Basic Operation and Features
INPUT STARTUP / SHUTDOWN VOLTAGE
To prevent any instability to the converter that may affect and consequently damage the end system, the AA60A series have
been designed to turn-on once V
IN
is in the voltage range of 19 - 20VDC. Likewise, it has also been programmed to turn-off
when V
IN
drops down to 17 - 18VDC.
OUTPUT VOLTAGE ADJUST/TRIM
Each channel/ output comes with a Trim pin (Pin 10 for V
O1
and Pin 7 for V
O2
). This can be used to used to adjust the outputs
up and down per the given trim range in the previous section. This is achieved by connecting an external resistor as described
below.
Output voltage adjustment is accomplished by connecting an external resistor between the Trim Pin and either the +V
O
or
–V
O
Pins. With an external resistor, R
TRIM
between the Trim Pin and +V
O
Pin the output voltage increases. With R
TRIM
connected between the Trim Pin and -V
O
Pin the output voltage decreases. See Figure 3.
The following equation determines the required external resistor value to obtain an adjusted output voltage:
R
TRIM
= (G – ( H * V
O,Adj
)) / (V
O,Adj
– K )
Where: V
O, ADJ
= is the desired output voltage (e.g.
5.2
V = 5V * +4%)
Trim Output Voltage UP (R
TRIM
connect to V+)
Model
Output
G
036H 5/3.3
5
129980.1
036H 5/3.3
3.3
12194.5
H
10220
2000
K
5
3.3
Trim Output Voltage DOWN (R
TRIM
connect to V-)
Model
Output
G
036H 5/3.3
5
25578.4
036H 5/3.3
3.3
3301.2
H
10220
2000
K
5
3.3
OUTPUT OVER VOLTAGE PROTECTION (OVP)
The Over Voltage Protection circuit will shut down the entire converter if any of the two output voltages exceeds the OVP
threshold limits. The output will remain latched until the OVP fault is removed and the input voltage is recycled
MODEL: AA60A-036L-050D033H SERIES
OCTOBER 10, 2002 - REVISION A
SHEET 7 OF 12
ASTEC [ Astec America, Inc ]
