Patent ID: 7382064

Claim:
A supply voltage identifier comprising: supply voltage sensing means incorporating enable/disable input and receiving supply voltage, a reference generator incorporating enable/disable input for generating reference voltage, a comparison means having first input connected to the output of said sensing means, a second input connected to said reference generator and a third input for enabling/disabling its operation, a registering means connected to the output of said comparison means at its first input for storing the comparison output, a selecting means having a first input connected to the supply voltage, a second input connected to the output of a voltage regulating means, a third input for enabling/disabling and a selection input connected to the output of said registering means, a control means having a first output coupled to the enable/disable input of each of said supply voltage sensing means, reference generator, comparison means, a second output connected to said third input of said selecting means and a third output coupled to the store input of said registering means; the arrangement being such that said selecting means is disabled by said control means on receipt of a control signal at the input of said control means, said supply voltage sensing means, reference generator, comparison means are enabled for a predefined period, after which the output of each comparison means is stored in each corresponding registering means, and finally the selection means are enabled, and said supply voltage sensing means, reference generator, comparison means are disabled.