U5020M

U5020M Digital Window Watchdog Timer Description The digital window watchdog timer, U5020M, is a CMOS integrated circuit. In application where safety is critical, it is especially important to monitor the microcontroller. Normal microcontroller operation is indicated by a cyclically transmitted trigger signal, which is received by a window watchdog timer within a defined time window. A missing or a wrong trigger signal makes the watchdog timer reset the microcontroller. The IC is tailored for microcontrollers which can work in both full-power and sleep mode. With an additional voltage monitoring (power-on reset and supply voltage drop reset) U5020M offers a complete monitoring solution for microsystems in automotive and industrial applications. Features D Low current consumption: IDD < 100 mA D RC–oscillator D Internal reset during power-up and supply voltage drops (POR) D Trigger input D Six wake-up inputs D Reset output D Enable output D “Short” trigger window for active mode “long” trigger window for sleep mode D Cyclical wake-up of microcontroller in sleep mode Ordering Information Extended Type Number U5020M–FP Package SO16 Remarks Block Diagram C R1 VDD C1 Reset 10 Input ts 16 OSC Trigger 11 Input signal conditioning POR State machine 9 Enable Power–on reset POR Test logic External switching circuitry OSC 15 RC Oscillator OSC VDD 10 nF 13 95 10387 mC Mode 12 Wake up 3–8 14 GND 2 Test 1 Test Figure 1. Block diagram with external circuit TELEFUNKEN Semiconduc...