Coded data generation or conversion – Analog to or from digital conversion – With particular solid state devices
Patent
1994-01-14
1995-08-15
Hoff, Marc S.
Coded data generation or conversion
Analog to or from digital conversion
With particular solid state devices
333 81R, H01P 122
Patent
active
054423520
ABSTRACT:
A linear attenuator (23) for applications such as front/rear audio fading receives an input current to be programmably attenuated according to an input code at an input node (29). A transistor (30) is connected between the input node (29) and inputs of current-steering cells (40, 50, 60), which pass portions of the input current to either an output node (32) or a second node in response to the input code. An amplifier (22) has a negative input terminal connected to the input node (29), a positive input terminal receiving a reference voltage, and an output terminal connected to a control electrode of the transistor (30). The operational amplifier (22) and the transistor (30) together regulate the voltage at the input node (29) to prevent distortion of the input current by making the input node (29) a virtual ground node. Thus the attenuator (23) avoids nonlinearities normally associated with transistors and the need to duplicate a digital-to-analog converter (DAC) (21) providing the input current.
REFERENCES:
patent: 4716321 (1987-12-01), Erratico
patent: 5008671 (1991-04-01), Tuthill
patent: 5032801 (1991-07-01), Woo et al.
patent: 5134401 (1992-07-01), McCartney et al.
patent: 5293166 (1994-03-01), Ta
patent: 5331322 (1994-07-01), Cha et al.
patent: 5351030 (1994-09-01), Kobayashi et al.
Hoff Marc S.
Motorola Inc.
Polansky Paul J.
LandOfFree
Linear attenuator for current-mode digital-to-analog converter ( does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Linear attenuator for current-mode digital-to-analog converter (, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Linear attenuator for current-mode digital-to-analog converter ( will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2185496