ACE557U datasheet(3/5 Pages) ACE

Part #	ACE557U

Description	250mA, Low Consumption, Wide Input Voltage Linear Regulator

PDF	5 Pages

Scroll/Zoom	100%

Manufacturer	ACE [ACE Technology Co., LTD.]

Direct Link	http://www.ace-ele.com

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3 / 5 page

ACE557U

250mA, Low Consumption, Wide Input Voltage Linear Regulator

VER 1.2

Typical Application Circuit

Note 1: Input Capacitor (CIN=1μF) is recommended in all applications.

Note 2: Output Capacitor (COUT=4.7μF/6.8μF) is recommended in all applications to assure the stability of

circuit.

ACE557U Output Voltage Setting

The output voltage of the ACE557U adjustable regulator is programmed using an external resistor divider

as shown in Figure 2. The output voltage is calculated using:

Where: VFB=1.2V (Typ) (the internal reference voltage)

Resistors R1 and R2 should be chosen for approximately 3-

5μA divider current. Lower value resistors can

be used but offer no inherent advantage and waste more power. Higher values should be avoided, as

leakage currents at FB increase the output voltage error. The recommended design procedure is to

cho

ose R2=200kΩ to set the divider current at 5μA and then calculate R1 using:

Where: VFB=1.2V (Typ).

Figure 1

Figure 2

ACE557U Datasheet(PDF) 3 Page - ACE Technology Co., LTD.