CA3272A

The CA3272A and CA3292A are Quad-Gated Inverting Power Drivers for interfacing low-level logic to inductive and resistive loads such as: relays, solenoids, AC and DC motors and resistive loads such as incandescent lamps and other power drivers. Each output is an open collector protected power transistor driver. The CA3292A is similar to the CA3272A, except for an added collector-to-base Zener diode that provides over-voltage clamping protection on each power switching output. The CA3292A block diagram is shown for one switching channel with fault detection logic plus the output fault driver circuit for all four switching channels. The FAULT output pin provides a flag
output when a fault condition occurs. All four Output Power Driver stages are shown in the Block Diagrams.

The ENABLE input is common to each of the four power switches and when low, disables the FAULT output. From the Input to Output, each switch is inverting. When IN is high, OUT is low and the transistor switch is "ON" (conducting). The block diagram shows the functional logic associated with fault detection. The Fault Sense circuit detects the IN and OUT states and switches QF "ON" if a fault is detected. When a fault is detected, transistor QF activates a current sink pull-down at the FAULT pin. A resistive load from the FAULT pin to the power supply is used to detect a fault as a low state. Both shorted and open load conditions are detected.

Note: The CA3272A replaces the CA3272 for new designs. Refer to the Fault Sink Current specifications when making design changes. The CA3272A and CA3292A have increased pull-down current drive from the FAULT output pin.