DEPLOYMENT CIRCUIT FOR A PYROTECHNIC DEVICE, RELATED DEPLOYMENT SYSTEM, AND METHOD

A deployment circuit (105) for controlling the deployment of a pyrotechnic device (30) is disclosed. The deployment circuit (105) comprises a deployment driver circuit (20) configured to energize the pyrotechnic device (30) by connecting (20a, 20b) respective terminals (PR, PF) to a supply voltage (VSUP), diagnostic circuitry (160) configured to perform diagnostic controls on the deployment circuit (105), a communication interface (SCLK, SDI, SDO, NCS) configured to be connected to a microcontroller (11), a terminal configured to be connected to the microcontroller (11) in order to provide a fault signal (FAULT) to the microcontroller (11) and a control circuit (110).Specifically, the control circuit (110) comprises a hardware Finite-State Machine configured to execute one or more diagnostic routines (300, 350, 360, 370), wherein each diagnostic routine (300, 350, 360, 370) comprises a sequence of diagnostic operations (301-307; 351-356; 363-364; 374-375). In each diagnostic operation, the control circuit (110) is configured to generate control signals for the diagnostic circuitry (160) in order to execute a respective diagnostic operation of the deployment circuit (105), monitor one or more signals (CS, DS) provided by the diagnostic circuitry (160), and determine whether the one or more signals (CS, DS) indicate one or more faults of the deployment circuit (105). In response to determining that the one or more signals (CS, DS) indicate one or more faults of the deployment circuit (105), the control circuit (110) asserts the fault signal (FAULT) and stores a fault code (ZF) indicative of the fault detected. Moreover, the control circuit (110) is configured to receive via the communication interface (SCLK, SDI, SDO, NCS) a request and, in response to the request, transmit the stored fault code (ZF).