ADT7350
APPLICATION INFORMATION
Output Voltage Setting
Enable resistor Setting (R3)
Step 1) Determine R1 value
The current of feedback resistors is
VOUT
Above figure is simplified input stage of ADT7350.
RINT1 RINT 2
IFB_ RES
VEN
VIN
R R2
1
RINT1 RINT 2 R3
In order to get the good sensitivity, increase
this current in spite of such amount of
current consumption.
R_int1=1KΩ , R_Int2=1MΩ
Example) VIN=12V
(Refer to following table for reasonable start)
1) R3=1MΩ
1K1M
1K1M1M
VEN
VIN 5.8V
Step 2) Determine R2 value the basis of
following equation.
The zener diode clips this voltage into 5.8V
R1
VOUT
VREF
R2
@VREF=810mV
2) R3=2MΩ
1
1K1M
1K1M 2M
VEN
VIN 4V
VIN 2V
The voltage of feedback should be equal to internal
reference voltage in well-designed negative
feedback loop.
3) R3=5MΩ
1K1M
1K1M5M
VEN
VOUT (V) R1(KΩ)
R2 (KΩ)
160
L(µH)
2.2
2.2
4.7
4.7
4.7
4.7
10
1.2
1.8
2.5
3.3
5
80.6
80.6
49.9
49.9
49.9
49.9
80.6
80.6
64.9
23.7
16.2
9.53
6.53
6.98
4.53
7
10
15
10
* This specifications are subject to be changed without notice
http://www.ad-tech.co.kr
Aug 21. 2012 / Rev. 0.2
9/10
ADTECH [ ADTECH ]
