AD7889-1ACBZ-RL7
数据手册.pdfSingle ADC SAR 105KSPS 12Bit Serial 12Pin WLCSP T/R
Product Details
The AD7879/AD7889 are 12-bit successive approximation analog-to-digital converters SAR ADCs with a synchronous serial interface and low on-resistance switches for driving 4-wire resistive touch screens. The AD7879/AD7889 work with a very low power supply—a single 1.6 V to 3.6 V supply—and feature a throughput rate of 105 kSPS. The devices include a shutdown mode that reduces current consumption to less than 6 μA.
To reduce the effects of noise from LCDs and other sources, the AD7879/AD7889 contain a preprocessing block. The preprocessing function consists of a median filter and an averaging filter. The combination of these two filters provides a more robust solution, discarding the spurious noise in the signal and keeping only the data of interest. The size of both filters is programmable. Other user-programmable conversion controls include variable acquisition time and first conversion delay; up to 16 averages can be taken per conversion. The AD7879/AD7889 can run in slave mode or standalone master mode, using an automatic conversion sequencer and timer.
The AD7879/AD7889 have a programmable pin that can operate as an auxiliary input to the ADCs, as a battery monitor, or as a general-purpose input/output GPIO. In addition, a programmable interrupt output can operate in three modes: as a general-purpose interrupt to signal when new data is available DAV, as an interrupt to indicate when limits are exceeded INT, or as a pen-down interrupt when the screen is touched PENIRQ. The AD7879/AD7889 offer temperature measurement and touch pressure measurement.
The AD7879 is available in a 12-ball, 1.6 mm × 2 mm WLCSP and in a 16-lead, 4 mm × 4 mm LFCSP. The AD7889 is available in a backside coated version of the WLCSP. Both devices support an SPI interface AD7879/AD7889 or an I2C interface AD7879-1/ AD7889-1.
**Applications**
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- Personal digital assistants
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- Smart handheld devices
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- Touch screen monitors
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- Point-of-sale terminals
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- Medical devices
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- Cell phones
### Features and Benefits
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- 4-wire touch screen interface
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- 1.6 V to 3.6 V operation
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- Median and averaging filter to reduce noise
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- Automatic conversion sequencer and timer
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- User-programmable conversion parameters
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- Auxiliary analog input/battery monitor 0.5 V to 5 V
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- 1 optional GPIO
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- Interrupt outputs INT, PENIRQ
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- Touch-pressure measurement
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- Wake-up on touch function
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- Shutdown mode: 6 μA maximum
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- 12-ball, 1.6 mm × 2 mm WLCSP
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- 16-lead, 4 mm × 4 mm LFCSP