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==Packaging of the M377== | |||
The packaged M377 die has the following Tek part numbers: | The packaged M377 die has the following Tek part numbers: | ||
* [[165-2129-03]] | * [[165-2129-03]] | ||
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* [[155-2089-05]] (11A33) | * [[155-2089-05]] (11A33) | ||
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==Output Control Signals== | |||
The M377 has one input (differential) and three differential outputs which are identical circuits. | |||
Each output has a its own control pins for: | |||
* Output invert | |||
* Output enable. When an output is disabled, it has no offset and maintains the specified termination impedance. That is, the internal parallel output termination remains connected, but the signal current is shut off. The self-calibration of 11k systems makes use of this property. | |||
* High-frequency adjustment. The HF ADJ pins have 2k ohms input resistance to ground. The nominally acceptable inputs are ±1V to ground. Because the input resistance tracks the nichrome standard resistors inside the chip, the input is actually current sensitive, not that it makes much difference. This current affects the standing current in a feedback amplifier and hence its open loop gain. At low frequencies, the gain of the M377 is determined entirely by resistor values. At high frequencies, there is phase shift and changing the open loop gain will also change the closed loop gain, hence the transient response. | |||
==Var Gain Control Signal== | |||
The M377 has a single VAR GAIN control input, which affects all three outputs. | |||
This control signal has a range of −1 V to +1 V. | |||
−1 V results in 0 gain. | |||
+1 V results in full gain. | |||
==165-2089-xx Pinout== | ==165-2089-xx Pinout== |