MP5018 –5V, 1A-5A CURRENT LIMIT SWITCH WITH REVERSE CURRENT BLOCKING

AND OUTPUT OVER-VOLTAGE CLAMP

MP5018 Rev. 1.02

www.MonolithicPower.com

13

3/23/2016

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APPLICATION INFORMATION

Setting the Current Limit

The MP5018 current limit value should exceed

the normal maximum load current, allowing the

tolerances in the current sense value. The

current limit is a function of the external current-

limit resistor. Table 2 and Figure 2 list examples

of current limit values as a function of the

resistor value.

Table 2: Current Limit vs. Current Limit Resistor

Current Limit

Resistor (Ω)

1070

560

442

274

215

Current Limit

(A)

1

2

2.5

4

5

Figure 2: Current Limit vs. Current Limit

Resistor

PCB layout is benefit for better performance.

Please follow these guidelines and use Figure 3

as reference.

1. Place the high-current paths (VCC and

VOUT) close to the device using short, direct,

and wide traces.

2. Place the input capacitors as close to the

VCC and GND pins as possible.

3. Connect the VCC and VOUT pads to large

copper to achieve better thermal performance.

4. Place current limit resistor R1 close to the

ILIMIT pin.

5. Place SS capacitor C2 close to SS pin.

Note: The recommend layout is based on the typical application

circuit shown in figure 4.

C1

C3

C2

R1

EN

SAS

GND

GND

VCC

VCC

VCC

VOUT

VOUT

VOUT

GND

Top Layer

Bottom Layer

GND

Figure 3: PCB Layout

Design Example

Below is a design example following the

application

guidelines

for

the

given

specifications:

Table 3: Design Example

5

Current Limit (A)

3

SS Time (ms)

13

The detailed application schematic is shown in

Figure 4. The typical performance and circuit

waveforms have been shown in the Typical

Performance Characteristics section. For more

detailed device applications, please refer to the

related

Evaluation

Board

Datasheets

of

MP5018.