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MA2004A

Major Power Technology Co., Ltd.

Rev.1.0

Apr/15, 2015



APPLICATION CIRCUIT

1. EC ( Recommend Circuit )

2. MLCC

5V/1A

GND

OFF ON

FB

SW

EN

NC

22

μF

VCC

L1

R1

R2

22

μF

x2

4.7

μH

B340

C1

C2

75K

10K

D1

Figure 3. Typical Application Circuit

The MA2004A uses a 750KHz fixed-frequency, current-mode regulation architecture to

regulate the output voltage. The MA2004A measures the output voltage through an external

resistive voltage divider and compares that to the internal 0.6V reference to generate the

error voltage. The current-mode regulator compares the error voltage to the inductor current

to regulate the output voltage. The use of current-mode regulation improves transient

response and control loop stability.

At the beginning of each cycle, the N-Channel MOSFET switch is turned on, forcing the

inductor current to rise. The current at the source of the switch is internally measured and

converted to a voltage by the current sense amplifier. That voltage is compared to the

error voltage. When the inductor current rises sufficiently, the PWM comparator turns off the

switch, forcing the inductor current to the output capacitor through the SBD, which forces

the inductor current to decrease. The peak inductor current is controlled by the error

voltage, which in turn is controlled by the output voltage. Thus the output voltage controls

the inductor current to satisfy the load.