How to Use TPIC6B595N: Examples, Pinouts, and Specs

The TPIC6B595N, manufactured by Texas Instruments (Part ID: 296-1956-5-ND), is an 8-bit shift register with output latches and high-current output capability. It is designed to drive LEDs, relays, and other loads requiring high current. This component combines a serial input with parallel outputs, making it ideal for applications where efficient data transfer and control are required.

• LED matrix displays
• Relay and solenoid control
• Industrial automation systems
• Digital signage
• General-purpose high-current switching

• Supply Voltage (Vcc): 4.5V to 5.5V
• Output Voltage (Vout): Up to 50V
• Maximum Output Current (Iout): 150mA per channel
• Shift Register Clock Frequency: Up to 25MHz
• Operating Temperature Range: -40°C to +125°C
• Package Type: 16-pin PDIP (Plastic Dual In-line Package)

The TPIC6B595N has 16 pins, as described in the table below:

1. Power Supply:

   • Connect the Vcc pin to a 5V power supply and the GND pin to ground.
   • Ensure the power supply can handle the current requirements of the connected loads.

2. Data Input:

   • Use the SER pin to input serial data. Data is shifted into the register on the rising edge of the SRCLK signal.
   • The RCLK pin latches the data from the shift register to the output latch on its rising edge.

3. Output Control:

   • The OE pin enables or disables the outputs. Pull this pin low to enable the outputs.
   • Connect your load (e.g., LEDs or relays) between the output pins (Q1-Q8) and the power supply.

4. Clearing the Shift Register:

   • Use the SRCLR pin to clear the shift register. Pull this pin low to reset the register.

5. Driving Loads:

   • Ensure the connected loads do not exceed the maximum current rating of 150mA per channel.
   • Use appropriate resistors or current-limiting devices for LEDs.

The TPIC6B595N can be easily interfaced with an Arduino UNO for controlling multiple LEDs. Below is an example circuit and code:

• SER → Arduino Pin 11 (MOSI)
• SRCLK → Arduino Pin 13 (SCK)
• RCLK → Arduino Pin 10
• OE → Arduino GND (to enable outputs)
• SRCLR → Arduino 5V (to keep the shift register active)
• Vcc → Arduino 5V
• GND → Arduino GND
• Connect LEDs with appropriate resistors to Q1-Q8.

// TPIC6B595N Example Code for Arduino UNO
// This code demonstrates how to control 8 LEDs using the TPIC6B595N shift register.

#define DATA_PIN 11  // SER pin on TPIC6B595N
#define CLOCK_PIN 13 // SRCLK pin on TPIC6B595N
#define LATCH_PIN 10 // RCLK pin on TPIC6B595N

void setup() {
  pinMode(DATA_PIN, OUTPUT);
  pinMode(CLOCK_PIN, OUTPUT);
  pinMode(LATCH_PIN, OUTPUT);
}

void loop() {
  for (int i = 0; i < 256; i++) {
    digitalWrite(LATCH_PIN, LOW); // Disable latch to update shift register
    shiftOut(DATA_PIN, CLOCK_PIN, MSBFIRST, i); // Send data to shift register
    digitalWrite(LATCH_PIN, HIGH); // Latch data to outputs
    delay(500); // Wait for 500ms
  }
}

• Always use current-limiting resistors for LEDs to prevent damage.
• Ensure the total current drawn by all outputs does not exceed the device's thermal limits.
• Use decoupling capacitors (e.g., 0.1µF) near the Vcc pin to stabilize the power supply.

1. Outputs Not Responding:

   • Verify that the OE pin is pulled low to enable the outputs.
   • Check the connections to the RCLK and SRCLK pins to ensure proper clock signals.

2. Shift Register Not Clearing:

   • Ensure the SRCLR pin is pulled high during normal operation. Pulling it low will reset the register.

3. LEDs Not Lighting Up:

   • Check the polarity of the LEDs and ensure appropriate current-limiting resistors are used.
   • Verify that the output pins (Q1-Q8) are correctly connected to the LEDs.

4. Overheating:

   • Ensure the total current drawn by all outputs does not exceed the device's maximum ratings.
   • Use a heatsink or improve ventilation if necessary.

Q: Can I cascade multiple TPIC6B595N chips?
A: Yes, you can cascade multiple chips by connecting the Q7 output of one chip to the SER input of the next chip. This allows you to control more outputs with the same microcontroller.

Q: What is the maximum clock frequency for the shift register?
A: The shift register can operate at clock frequencies up to 25MHz.

Q: Can the TPIC6B595N drive inductive loads like relays?
A: Yes, the TPIC6B595N is designed to handle inductive loads. However, ensure proper flyback diodes are used to protect the device from voltage spikes.

Q: Is the TPIC6B595N compatible with 3.3V logic?
A: No, the TPIC6B595N requires a supply voltage of 4.5V to 5.5V and is not directly compatible with 3.3V logic. Use a level shifter if interfacing with 3.3V systems.