33874 datasheet(17/38 Pages) FREESCALE

17 / 38 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

33874

FUNCTIONAL DESCRIPTION

FUNCTIONAL INTERNAL BLOCK DESCRIPTION

ANALOG CONTROL CIRCUITRY

The 33874 is designed to operate from 6.0V to 27V on the

VPWR Pin. The VPWR Pin supplies power to all internal

regulators, analog and logic circuit blocks. The VDD supply is

used for setting communication threshold levels and

supplying power to the SPI interface logic. This IC

architecture provides a very low standby current. The analog

circuitry provides for over-current and over-temperature

protection as well as temperature warning features.

MCU INTERFACE AND OUTPUT CONTROL

The device is designed with 4 inputs for PWM Output

driver control, if desired. MCU programming, control and

diagnostics are accomplished using the 16-bit SPI interface.

Several parallel control and status lines are provided.

HIGH–SIDE DRIVERS: HS0 – HS3

The 33874 provides high side load drive capability for 4

outputs. The RDSON for the output MOSFETs is 35mΩ. The

outputs are protected for over-current and over-temperature.

The MOSFET gate drive can be slew rate controlled using the

SPI interface. There is also an open load detection feature. A

ratioed value of the MOSFET output current is available to

the MCU.

The device allows for control of the 4 outputs through the

SPI interface or by use of the parallel inputs, which allows for

PWM capability.

MC33874 - Functional Block Diagram

Analog Control Circuitry

33874 Datasheet(PDF) 17 Page - Freescale Semiconductor, Inc