MP5017 – 3V-5.5V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH

MP5017 Rev.1.0

www.MonolithicPower.com

14

10/15/2015

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APPLICATION INFORMATION

Setting the Current Limit

The MP5017 current limit value should exceed

the normal maximum load current to account for

the variations in the current sense value. The

current limit is a function of the external current-

limit resistor. The value can be approximated

with Equation (2):

(2)

Table 2 and Figure 3 below 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)

1400

806

499

324

226

Current Limit (A)

0.9

1.51

2.40

3.61

5.04

Figure 3: Current Limit vs. Current Limit Resistor

PCB Layout Guidelines

Efficient PCB layout is critical for stable

operation. For best results, refer to Figure 4 and

follow the guidelines below.

1. Place the high-current paths (VCC and

VOUT) close to the device using short,

direct, and wide traces.

2. Place the input capacitor (C1) as close to

VCC and GND as possible.

3. Connect the VCC and VOUT pads to large

copper

traces

for

better

thermal

performance.

5. Place DV/DT capacitor (C3) close to DV/DT.

VCC

VOUT

GND

GND

R1

C3

Top Layer

Bottom Layer

Figure 4: Recommended Layout

)

(

R

10

1.16V

(A)

I

LIMIT

3

LIMIT

Ω

×

=