MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER

MP4653 Rev 1.01

www.MonolithicPower.com

21

6/28/2012

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2012 MPS. All Rights Reserved.

Setting the Over Current Protection for the

bus stage (Pin3 VOCP)

This pin implements the over current protection

for the bus stage. The current of the bus stage is

sensed to this pin with a negative polarity. When

the voltage on this pin is lower than -100mV, the

IC triggers the bus stage protection.

OCP _ Bus

VOCP

100mV

I

R



Usually, the protection point is around 1.5 to 3

times of the normal current of the bus stage.

Setting the Over Current Protection for the

LED stage (Pin8 SSD)

This pin detects the current through the LED

stage with a negative polarity. When the voltage

on this pin gets lower than -200mV, IC triggers

LED stage protection.

OCP _ LED

OCP

200mV

I

R



The over current protection point for the LED

stage could usually set at around 1.5 to 2 times

of the total current through the LED strings.

Setting the Voltage loop compensation (Pin5

VCOMP)

This pin is connected to the output of the inner

error amplifier for the voltage control loop through

network on this pin for compensating the voltage

control loop.

Usually, a ceramic capacitor in range of 47nF to

470nF and a resistor in range of 2kΩ to 200kΩis

recommended for the compensation.

This pin is also used as the hiccup mode fault

timer. When fault condition in the bus stage

occurs, the inner switch which connects this pin

to the output of error amplifier for voltage control

loop turns off and a 2μA current source will

charge this pin to 3V and then discharge it to

0.45V. IC auto recovers after the hiccup timer.

The hiccup delay time is:

VCOMP

VCOMP

VCOMP

hiccup _ V

C(3V V

) C

2.5V

T

2A

2A









Setting the current loop compensation (Pin6

ICOMP)

This pin is connected to the output of the inner

error amplifier for the current control loop through

network on this pin for the current control loop

compensation.

Usually, a ceramic capacitor in range of 47nF to

470nF and a resistor in range of 200Ω to 5kΩis

recommended for the compensation.

This pin is also used as the hiccup mode fault

timer for the LED stage. When fault condition

occurs in the LED stage, the inner switch which

connects this pin to the output of the error

amplifier for current control loop turns off and a

current source will charge this pin to 3V and then

discharge it to 0.45V. The control for the LED

stage auto recovers after this hiccup timer.

The hiccup delay time is:

ICOMP

ICOMP0

ICOMP

hiccup _ I

C(3V V

) C

2.5V

T

2A

2A









Analog Dimming (Pin 13, A-Dim)

This pin is for analog dimming. Applying a

voltage in range of 0V to 1.18V dims the LED

current from 0 to 100%. It has positive polarity for

the analog dimming. A ceramic capacitor is

recommended on this pin to bypass it.

PWM Dimming input (Pin 14, PWMIN)

This pin is for PWM dimming input. Applying a

PWM dimming signal with frequency in range of

100Hz to 2kHz on this pin. It has positive polarity

for the PWM dimming.

At PWM on interval, the LED current is regulated

and at PWM off interval, the voltage control loop

for the DC bus functions. The DC bus voltage is

regulated at the value of that in PWM on interval.

Supply Input (Pin 15, VIN)

This pin is the supply input voltage for the IC.

Bypass this pin with a 0.1uF or larger ceramic

capacitor.

IC starts to work when the VIN voltage is applied.

If PWMIN pin is high, the LED current control

loop is effective and if the PWMIN pin is low, the

voltage control loop for the DC bus control is

effective. If an “Enable” signal is required to