General description

The 33879 device is an 8-output hardware configurable, high-side/low-side switch

with 16-bit serial input control using the Serial Peripheral Interface (SPI). Two of the

outputs may be controlled directly via a microcontroller for pulse-width modulation

(PWM) applications. The 33879 incorporates SMARTMOS technology, with CMOS logic,

bipolar/MOS analog circuitry, and DMOS power MOSFETs. The 33879 controls various

inductive, incandescent, or LED loads by directly interfacing with a microcontroller. The

circuit’s innovative monitoring and protection features include very low standby currents,

cascade fault reporting, internal +45 V clamp voltage for low-side configuration, –20 V

high-side configuration, output specific diagnostics, and independent overtemperature

protection.

Features and benefits

? Designed to operate at 5.5 V < VPWR < 27.5 V

? 16-bit SPI for control and fault reporting, 3.3 V / 5.0 V compatible

? Outputs are current limited (0.6 A to 1.2 A) to drive incandescent lamps

? Output voltage clamp, + 45 V (low side) and –20 V (high side) during inductive

switching

? On/Off control of open load detect current (LED application)

? Internal reverse battery protection on VPWR

? Loss of ground or supply will not energize loads or damage IC

? Maximum 5.0 μA IPWR standby current at 13 V VPWR

? RDS(ON) of 0.75 Ω at 25 °C typical

? Short-circuit detect and current limit with automatic retry

? Independent overtemperature protection

Applications

? Solenoids

? Relays

? Actuators

? Stepper motors

? Brush DC motors

? Incandescent lamps