TPIC6C595 vs TPIC6B595: How They Work

Driving LEDs and 7-Segment Displays with Arduino

Overview

TPIC6C595 and TPIC6B595 are 8-bit shift register + latch driver ICs. They operate exactly the same way; the only difference is their current handling capability.

Summary: TPIC6B595 can drive higher current than TPIC6C595.

How It Works

Data is sent through the SERIAL-IN pin
Each clock pulse (SRCK) shifts the data
After 8 bits, data is latched using RCK
Outputs are enabled using OE

Pin Description

Pin	Function	Description
VLED	Load Supply	Power for LEDs or external load
GND	Ground	Common reference
VLOGIC	Logic Supply	Typically 5V (same as MCU)
SERIAL-IN	Data Input	Serial data is fed here
SRCK	Shift Clock	Each pulse shifts one bit
RCK	Latch Clock	Transfers data to outputs
OE (G)	Output Enable	LOW = active, can be used for PWM
SRCLR	Clear	LOW clears the shift register

Data Transfer Sequence

Step	Action
1	Write bit to SERIAL-IN
2	Pulse SRCK (clock)
3	Repeat until 8 bits are loaded
4	Pulse RCK to latch data
5	Set OE LOW to enable outputs

Output Structure

These ICs are low-side (sink) drivers — they do NOT source current!

Use common anode displays
LED positive goes to VLED

TPIC6C595 vs TPIC6B595

Feature	TPIC6C595	TPIC6B595
Max Current (per channel)	~100 mA	~150 mA
Typical Use	LEDs	Relays / Motors
Logic	Same

PWM Brightness Control

The OE pin can be driven with PWM to control brightness:

PWM Value	Result
0	Fully ON
255	OFF

7-Segment Bit Mapping

Digit	Binary
0	00111111
1	00000110
2	01011011
3	01001111
4	01100110
5	01101101
6	01111101
7	00000111
8	01111111
9	01101111

TPIC6x595 Example Application Schematics PDF

Both ICs work exactly the same
The only difference is current capacity
They are low-side (sink) drivers
PWM can be used for brightness control

ALL TPIC6*595* ITEMS

Example Code for Arduino for Test


// TPIC6C595 / TPIC6B595 Single Digit 7-Segment Test Code

// Arduino Nano connection:

// VLED      -> External LED/display supply

// GND       -> Arduino GND and external supply GND

// VLOGIC    -> Arduino 5V

// SRCK      -> Arduino D11

// RCK       -> Arduino D10

// OE(G)     -> Arduino D3 PWM

// SRCLR     -> Arduino D9

// SERIAL-IN -> Arduino D8



const int SER_PIN   = 8;   // Serial data input

const int SRCK_PIN  = 11;  // Shift register clock

const int RCK_PIN   = 10;  // Storage/latch register clock

const int OE_PIN    = 3;   // Output Enable, active LOW, PWM capable

const int SRCLR_PIN = 9;   // Shift register clear, active LOW



// Segment bit order: DP G F E D C B A

// These values assume a common-anode 7-segment display.

// Logic 1 turns the corresponding TPIC output ON, sinking current to GND.

byte digits[10] = {

  B00111111, // 0

  B00000110, // 1

  B01011011, // 2

  B01001111, // 3

  B01100110, // 4

  B01101101, // 5

  B01111101, // 6

  B00000111, // 7

  B01111111, // 8

  B01101111  // 9

};



void setup() {

  pinMode(SER_PIN, OUTPUT);

  pinMode(SRCK_PIN, OUTPUT);

  pinMode(RCK_PIN, OUTPUT);

  pinMode(OE_PIN, OUTPUT);

  pinMode(SRCLR_PIN, OUTPUT);



  digitalWrite(SRCLR_PIN, HIGH); // Enable the shift register

  analogWrite(OE_PIN, 255);      // Outputs OFF at startup

}



void sendToTPIC(byte data) {

  digitalWrite(RCK_PIN, LOW);

  shiftOut(SER_PIN, SRCK_PIN, MSBFIRST, data);

  digitalWrite(RCK_PIN, HIGH);

}



// OE(G) is active LOW:

// PWM 0   = fully ON

// PWM 255 = OFF

void fadeDigit(byte digitData) {

  sendToTPIC(digitData);



  // Fade in

  for (int pwm = 255; pwm >= 0; pwm--) {

    analogWrite(OE_PIN, pwm);

    delay(2);

  }



  delay(500);



  // Fade out

  for (int pwm = 0; pwm <= 254; pwm++) {

    analogWrite(OE_PIN, pwm);

    delay(2);

  }



  delay(500);

}



void loop() {

  for (int i = 0; i <= 9; i++) {

    fadeDigit(digits[i]);

  }

}