MP2410A

– 24V, 2A, 1MHZ, SYNCHRONOUS, STEP-DOWN, LED DRIVER

MP2410A Rev. 1.0

www.MonolithicPower.com

12

4/25/2016

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© 2016 MPS. All Rights Reserved.

Enable and Dimming Control (EN/DIM)

EN/DIM is a control pin that turns the regulator

on and off and dims the output LED current.

Leave EN/DIM floating or drive it high to turn on

the MP2410A. After EN/DIM is pulled low for

turned off. Figure 2 shows the control logic of

EN/DIM.

EN/DIM

Internal

Enable

Figure 2: EN/DIM Time Sequence

Analog Dimming

Apply a DC signal on EN/DIM to dim the

MP2410A in analog dimming mode. When the

LED current is regulated to the minimal scale.

When the

voltage on EN/DIM is

between

from the minimal scale to the full scale of the

LED current. If the voltage on EN/DIM is higher

regulated.

Figure 3 shows the analog dimming curve. Due

to the hysteretic of the EN/DIM on/off threshold,

the chip remains at the minimal LED current

same in the linear dimming range.

ADIM

Full Scale

V

ADIM_MIN

V

ADIM_MAX

0

Min Scale

V

EN_OFF

V

EN_ON

Figure 3: Analog Dimming Curve

PWM Dimming

Apply a PWM signal on EN/DIM to implement

PWM dimming mode. The dimming frequency is

recommended to be in the range of 100Hz to

2kHz to achieve good dimming linearity. The

digital signal’s amplitude must be higher than

1.5V.

Open LED

If the LED is open without a feedback signal, the

MP2410A works at the maximum duty cycle, and

the output voltage rises up close to the input

voltage. Every power component operates at a

safe state.

LED Short-Circuit Protection (SCP)

The

MP2410A

integrates

LED

short-circuit

protection (SCP) circuitry. There are several

features protecting the MP2410A from damage

when an LED short circuit occurs.

The MP2410A features a cycle-by-cycle current

limit to restrict the maximum current of the

inductor. A protection mechanism monitors the

FB level though an internal R-C filter. Once the

stops switching until the FB level drops to a lower

value, and the system works in burst mode.

In the worst-case scenario, the LED is shorted to

GND. If the cycle-by-cycle current-limit function

cannot clamp the current overshoot sufficiently,

then the current through both the high-side and

low-side FETs is also monitored by the over-

current detector inside the chip. If this current is

MP2410A treats this as a short-circuit condition.

When an over-current condition or short-circuit

condition is detected, the MP2410A turns off both

the high-side and low-side MOSFETs for 2.4ms

down to ground, so the restart from the fault

condition is also done with a soft start.