Measurement and calibration of mismatch in an isolation channel
A method for calibrating an isolator product includes receiving a calibration signal on a differential pair of nodes of a receiver signal path of a first integrated circuit die of the isolator product. The method includes generating a diagnostic signal having a level corresponding to an average amplitude of the calibration signal on the differential pair of nodes. The method includes configuring a programmable receiver signal path based on the diagnostic signal. Generating the diagnostic signal may include providing an analog signal based on a full-wave rectified version of the calibration signal on the differential pair of nodes. Generating the diagnostic signal may include converting the analog signal to a digital signal.
1 . A method for calibrating an isolator device, the method comprising:
receiving, with a receiver signal path of a first integrated circuit die of the isolator device, a first signal across an isolation channel coupled between a differential pair of receiver nodes of the first integrated circuit die and a differential pair of transmitter nodes of a second integrated circuit die of the isolator device;
in response to the first signal, generating a second signal indicative of mismatch of the isolation channel; and
configuring the receiver signal path based on the second signal.
2 . The method of claim 1 further comprising reconfiguring the receiver signal path based on an updated level of the second signal.
3 . The method of claim 2 further comprising storing a configuration code of the receiver signal path in a storage element, the configuration code corresponding to a value of the second signal.
4 . The method of claim 1 further comprising operating the isolator device in a normal mode of operation after configuring the receiver signal path according to the second signal.
5 . The method of claim 1 wherein the second signal is generated based on a rectified version of the first signal.
6 . The method of claim 1 wherein the second signal corresponds to an average of the first signal.
7 . The method of claim 1 wherein the second signal is generated based on a signal representing an equivalent average value of a rectified version of the first signal.
8 . An isolator device comprising:
an isolation channel;
a first integrated circuit die including a transmitter configurable to transmit a first signal across the isolation channel;
a second integrated circuit die including a receiver signal path coupled to the isolation channel to receive the first signal on a differential pair of receiver nodes and further including first circuitry configurable, in response to the first signal, to generate a second signal indicative of mismatch of the isolation channel; and
second circuitry configurable, in response to the second signal, to program the receiver signal path based on the second signal.
9 . The isolator device of claim 8 wherein the second circuitry includes a processor.
10 . The isolator device of claim 9 wherein the second circuitry resides on the second integrated circuit die.
11 . The isolator device of claim 9 wherein the second circuitry resides external to the second integrated circuit die.
12 . The isolator device of claim 8 further comprising storage containing a configuration code, the configuration code corresponding to a value of the second signal.
13 . The isolator device of claim 8 wherein the second signal is generated based on a rectified version of the first signal.
14 . The isolator device of claim 8 wherein the first signal is an analog signal and the second signal is a digital signal.
15 . An isolator product comprising:
an isolation channel;
a receiver signal path including a first gain stage and a second gain stage, the receiver signal path configured, when the isolator product is in a diagnostic mode of operation, to receive a first signal across the isolation channel; and
circuitry coupled to the receiver signal path and responsive to the isolator product being configured in the diagnostic mode of operation to generate a second signal based on the first signal, the receiver signal path further configured, when the isolator product is a normal mode of operation, to operate one or more of the first gain stage and the second gain stage based on a value of the second signal measured while the isolator product was configured in the diagnostic mode of operation.
16 . The isolator product of claim 15 wherein the circuitry generates the second signal based on a rectified version of the first signal.
17 . The isolator product of claim 15 wherein the first signal is an analog signal and the second signal is a digital signal.
18 . The isolator product of claim 15 further comprising a transmitter, the transmitter configured, when the isolator product is in the diagnostic mode of operation, to transmit the first signal across the isolation channel.
19 . The isolator product of claim 18 wherein the receiver signal path and the circuitry resides on a first integrated circuit die and the transmitter resides on a second integrated circuit die.
20 . The isolator product of claim 15 wherein the circuitry includes a processor.