MP3398E

– 4-STRING, 80V, STEP-UP, WLED CONTROLLER

MP3398E Rev. 1.02

www.MonolithicPower.com

9

7/31/2017

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© 2017 MPS. All Rights Reserved.

PIN FUNCTIONS

TSSOP-16

Pin #

PDIP-16

Pin #

Name

Description

1

13

LED1

LED string 1 current input. LED1 is the open-drain output of an internal

dimming control switch. Connect the LED string 1 cathode to LED1.

2

14

LED2

LED string 2 current input. LED2 is the open-drain output of an internal

dimming control switch. Connect the LED string 2 cathode to LED2.

3

15

GND

Ground.

4

16

LED3

LED string 3 current input. LED3 is the open-drain output of an internal

dimming control switch. Connect the LED string 3 cathode to LED3.

5

1

LED4

LED string 4 current input. LED4 is the open-drain output of an internal

dimming control switch. Connect the LED string 4 cathode to LED4.

6

2

ISET

LED current set. Tie a current-setting resistor from ISET to ground to program

the current in each LED string.

7

3

OVP

Output over-voltage protection. Connect a resistor divider from output to

OVP to program the OVP threshold.

8

4

OSC

Switching frequency set. Connect a resistor between OSC and GND to set

the step-up converter switching frequency. The clock frequency is proportional

to the current source from OSC.

9

5

EN

Enable control input. A voltage greater than 1.5V turns the part on; a voltage

less than 0.6V turns the part off. Do not float EN.

10

6

ISENSE

Current sense input. During normal operation, ISENSE senses the voltage

mode control. ISENSE also limits the inductor current during every switching

cycle. For cascading applications, tie ISENSE of the slave IC to GND. Do not

float ISENSE.

11

7

GATE

Step-up converter power switch driver output. GATE drives the external

power N-channel MOSFET device.

12

8

VCC

The internal 5.9V linear regulator output. VCC provides the power supply for

the external MOSFET switch gate driver and the internal control circuitry.

Bypass VCC to GND with a ceramic capacitor.

13

9

VIN

Supply input. VIN must be bypassed locally.

14

10

ADIM

Input for analog brightness control. The LED current amplitude is

determined by the duty cycle of the PWM signal applied to ADIM. An internal

R-C filter (10M

Ω resistor and 100pF capacitor) is integrated into ADIM. A

frequency greater than 20kHz is recommended to achieve a better PWM signal

1.5V and the low-level voltage is below 0.4V.

15

11

COMP

Step-up converter compensation. COMP compensates for the regulation

control loop. Connect a ceramic capacitor

or a resistor and capacitor from

COMP to GND.

16

12

PWM

Input signal for PWM brightness control. By applying a PWM signal on

PWM, the LED current is chopped, and the average current is equal to ISET x

the high level voltage is above 1.5V and the low-level voltage is below 0.4V. If

PWM is floating, weakly pull it to GND internally.