During operation of 4 digit display. segments are overlap with each other

Hello Sir,

During one of display product we are using MSP430FR2433IRGE MCU for operating 4 digit display.

First kindly find datasheet, schematic, and program code of MSP which we are using for display operation.

Issue description : 

We are using 7 GPIO's for 7 Segments, 1 GPIO for colon and 4 GPIO's for Digit control pin to display the current time in POD.

We tested a 7 segment display with an MSP controller. In that we are facing some problems (i.e) while 4 digit control GPIO pins are directly connected from MSP to 7-seg display it is working fine without any overlapping . if 4 digit control GPIO pins are connected from MSP to 7-seg display through LED brightness circuit, some overlapping is happening.

sequence we are following to display the time in 7-seg display:

Case 1: (without switching delay  -> while connecting directly it is working, Not working through while connecting through LED brightness circuit)

Set corresponding values in 7-seg GPIO's
Digit 1 ON
delay->3 milli second to hold the value in a digit for some time
Digit 1 OFF

similarly for...
digit 2
digit 3
digit 4

Case 2: (with from 1sec to 50 milli sec switching delay not overlapping while connecting through LED brightness circuit)

Set corresponding values in 7-seg GPIO's
Digit 1 ON
delay->3 milli second to hold the value in a digit for some time
Digit 1 OFF

delay - eg : 1 second switching delay
digit 2
delay - eg : 1 second switching delay
digit 3
delay - eg : 1 second switching delay
digit 4
delay - eg : 1 second switching delay

case 3: (If we are reduced that switching delay to less than 50 milli seconds overlapping happening when connected through LED brightness circuit)

#define SWITCH_DELAY 800000   // 50 msec 
#define SEG_HLD_TIME 50000    // 3 ms

void tlqi_POD_7SEG_Display_time(unsigned char in_ucHourDig1, unsigned char in_ucHourDig2, unsigned char in_ucMinDig1, unsigned char in_ucMinDig2)
{

    /------------------------Set Hour Digit------------------------/
        tlqi_POD_display_Digit_Val(in_ucHourDig1);
        GPIO_setOutputHighOnPin(GPIO_PORT_P2, GPIO_PIN7); //digit 1
        __delay_cycles(SEG_HLD_TIME);
        GPIO_setOutputLowOnPin(GPIO_PORT_P2, GPIO_PIN7); //digit 1
        __delay_cycles(SWITCH_DELAY); 

        tlqi_POD_display_Digit_Val(in_ucHourDig2);
        GPIO_setOutputHighOnPin(GPIO_PORT_P3, GPIO_PIN0); //digit 2
        __delay_cycles(SEG_HLD_TIME);
        GPIO_setOutputLowOnPin(GPIO_PORT_P3, GPIO_PIN0); //digit 2
        __delay_cycles(SWITCH_DELAY);

     /------------------------Set Minutes Digit------------------------/

        tlqi_POD_display_Digit_Val(in_ucMinDig1);
        GPIO_setOutputHighOnPin(GPIO_PORT_P3, GPIO_PIN1); //digit 3
        __delay_cycles(SEG_HLD_TIME);
        GPIO_setOutputLowOnPin(GPIO_PORT_P3, GPIO_PIN1); //digit 3
        __delay_cycles(SWITCH_DELAY);

        tlqi_POD_display_Digit_Val(in_ucMinDig2);
        GPIO_setOutputHighOnPin(GPIO_PORT_P2, GPIO_PIN0); //digit 4
        __delay_cycles(SEG_HLD_TIME);
        GPIO_setOutputLowOnPin(GPIO_PORT_P2, GPIO_PIN0); //digit 4
        __delay_cycles(SWITCH_DELAY);