ZHCSEF5G May 2014 – September 2016 DRV5033

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 DRV5033 device is used in magnetic-field sensing applications.

For this design example, use the parameters listed in Table 2 as the input parameters.

DESIGN PARAMETER | REFERENCE | EXAMPLE VALUE |
---|---|---|

Supply voltage | V_{CC } |
3.2 to 3.4 V |

System bandwidth | ƒ_{BW} |
10 kHz |

COMPONENT | PIN 1 | PIN 2 | RECOMMENDED |
---|---|---|---|

C1 | V_{CC } |
GND | A 0.01-µF (minimum) ceramic capacitor rated for V_{CC} |

C2 | OUT | GND | Optional: Place a ceramic capacitor to GND |

R1 | OUT | REF^{(1)} |
Requires a resistor pullup |

(1) REF is not a pin on the DRV5033 device, but a REF supply-voltage pullup is required for the OUT pin; the OUT pin may be pulled up to V_{CC}.

In a 3.3-V system, 3.2 V ≤ V_{ref} ≤ 3.4 V. Use Equation 3 to calculate the allowable range for R1.

Equation 3.

For this design example, use Equation 4 to calculate the allowable range of R1.

Therefore:

Equation 5. 113 Ω ≤ R1 ≤ 32 kΩ

After finding the allowable range of R1 (Equation 5), select a value between 500 Ω and 32 kΩ for R1.

Assuming a system bandwidth of 10 kHz, use Equation 6 to calculate the value of C2.

Equation 6.

For this design example, use Equation 7 to calculate the value of C2.

Equation 7.

An R1 value of 10 kΩ and a C2 value less than 820 pF satisfy the requirement for a 10-kHz system bandwidth.

A selection of R1 = 10 kΩ and C2 = 680 pF would cause a low-pass filter with a corner frequency of 23.4 kHz.

R1 = 10 kΩ pullup | No C2 |

R1 = 10-kΩ pullup | C2 = 680 pF |

R1 = 10-kΩ pullup | C2 = 680 pF |

For systems that require minimal wire count, the device output can be connected to V_{CC} through a resistor, and the total supplied current can be sensed near the controller.

Current can be sensed using a shunt resistor or other circuitry.

Table 4 lists the related design parameters.

DESIGN PARAMETER | REFERENCE | EXAMPLE VALUE |
---|---|---|

Supply voltage | V_{CC} |
12 V |

OUT resistor | R1 | 1 kΩ |

Bypass capacitor | C1 | 0.1 µF |

Current when B < B_{RP} |
I_{RELEASE} |
About 3 mA |

Current when B > B_{OP} |
I_{OPERATE} |
About 15 mA |

When the open-drain output of the device is high-impedance, current through the path equals the I_{CC} of the device (approximately 3 mA).

When the output pulls low, a parallel current path is added, equal to V_{CC} / (R1 + r_{DS(on)}). Using 12 V and 1 kΩ, the parallel current is approximately 12 mA, making the total current approximately 15 mA.

The local bypass capacitor C1 should be at least 0.1 µF, and a larger value if there is high inductance in the power line interconnect.