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 VIN is in the voltage range of 19 - 20VDC. Likewise, it has also been programmed to turn-off
when VIN drops down to 17 - 18VDC.
OUTPUT VOLTAGE ADJUST/TRIM
Each channel/ output comes with a Trim pin (Pin 10 for VO1 and Pin 7 for VO2). 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 +VO or
–VO Pins. With an external resistor, RTRIM between the Trim Pin and +VO Pin the output voltage increases. With RTRIM
connected between the Trim Pin and -VO Pin the output voltage decreases. See Figure 3.
The following equation determines the required external resistor value to obtain an adjusted output voltage:
RTRIM = (G – ( H * VO,Adj)) / (VO,Adj – K )
Where: VO, ADJ = is the desired output voltage (e.g. 5.2 V = 5V * +4%)
Trim Output Voltage UP (RTRIM connect to V+)
Model
036H 5/3.3
036H 5/3.3
Output
5
3.3
G
H
10220
2000
K
5
3.3
129980.1
12194.5
Trim Output Voltage DOWN (RTRIM connect to V-)
Model
036H 5/3.3
036H 5/3.3
Output
5
3.3
G
H
10220
2000
K
5
3.3
25578.4
3301.2
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 ]
