ace1117c ACE Technology Co., LTD., ace1117c Datasheet - Page 6

• Manufacturer Part Number: ace1117c
• Description: 1a Bipolar Linear Regulator
• Manufacturer: ACE Technology Co., LTD.

Application Hints
designed in such a way that these external capacitor can be omitted if the PCB layout is tight and system
noise is not very high. For better transient and PSRR performance, the Input and Output capacitors are still
recommended.
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Output voltage of adjustable version
1.25V~13.8V can be available by choosing two external resistors (connection method is shown in chart 2).
In chart 2, R1,R2 is the two external resistors
Explanation
We can ignore Iadj because Iadj (about 50uA) is much less than the current of R1(about 4mA).
normally without any load. To assure the electrical performance showed in table 1, the output current
should be larger than 5mA. If R1 is too large, the minimum output current should be larger than 4mA , The
best working condition is to assure that the output current exceeds 10mA.
The typical Linear regulator would require external capacitors to ensure stability. However, ACE1117C is
ACE1117C adjustable version provide 1.25V Reference Voltage. Any output voltage between
The output voltage of adjustable version satisfies this followed equation: Vout=Vref*(1+R2/R1)+Iadj*R2.
How to choose R1：The value of R1 should be in the range of 200Ω～350Ω to assure chip working
Recommend using 10uF tan capacitor as bypass capacitor(C1) for all application circuit.
Recommend using 22uF tan capacitor to assure circuit stability.
Using a bypass capacitor(CAdj) between the adjust terminal and ground can improve ripple rejection,
This bypass capacitor prevents ripple from being amplified as the output voltage is increased. The
impedance of CAdj should be less than the resistor’s(R1) which is between output and adjust pins to
prevent ripple from being amplified at any ripple frequency. As R1 is normally in the range of
200Ω~350Ω,the value of CAdj should satisfy this equation: 1/(2*Fripple*Cadj)<R1. Recommend
using 10uF tan capacitor.
Chart 2. Application Circuit of ACE1117C adjustable version
C1
Vin
ACE1117C
GND/ADJ
Iadj
Technology
Vout
R2
R1
C2
Rolad
1A Bipolar Linear Regulator
ACE1117C
VER 1.2
6