SLIS032B July 1995 – June 2015 TPIC6B595
PRODUCTION DATA.
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The TPIC6B595 device is a serial-in parallel-out, Power+LogicE 8-bit shift register with low-side switch DMOS outputs rating of a 150 mA per channel. The device is designed for use in systems that require relatively high load power. The device contains a built-in voltage clamp on the outputs for inductive transient protection. Power driver applications include relays, solenoids, and other medium currentor high-voltage loads. The following focuses on automotive cluster applications for the TPIC6B595 device.
The typical application of the TPIC6B595 device is the automotive cluster driver. In this example, two TPIC6B595 power shift registers are cascaded and used to turn on LEDs in the cluster panel. In this case, the LED must be updated after all 16 bits of data have been loaded into the serial shift registers. MCU outputs the data to the serial input (SER IN) while clocking the shift register clock (SRCK). After the 16th clock, a pulse to the register clock (RCK) transfers the data to the storage registers. If output enable (G) is low, then the LEDs are turned ON corresponding to the status word with ones being ON and zeros OFF. With this simple scheme, MCU use SPI interface can turn on 16 LEDs using only two ICs as illustrated in Figure 14.
Use the design parameters in Table 1 for this design example.
DESIGN PARAMETER | EXAMPLE VALUE |
---|---|
VSUPPLY | 9-16 V |
V(D1), V(D2), V(D3), V(D4), V(D5), V(D6),V(D7), V(D8) | 2 V |
V(D9), V(D10),V(D11), V(D12), V(D13), V(D14),V(D15), V(D16) | 3.3 V |
I(D1), I(D2), I(D3), I(D4), I(D5), I(D6),I(D7), I(D8) | 20mA When Vbattery is 12 V |
I(D9), I(D10), I(D11), I(D12), I(D13), I(D14),I(D15), I(D16) | 30mA When Vbattery is 12 V |
To begin the design process, one must decide on a few parameters. The designer must know the following:
When Vsupply is 9 V,
When Vsupply is 16 V,
When Vsupply is 9 V,
When Vsupply is 16 V,
NOTE
If customers can accept the current variation when battery voltage is changing, they can connect to the battery directly. If customers need the less variation of current, they must use the voltage regulator as supply voltage of LED, or change to constant current LED driver directly.