EVAL-AD7877EB(RevA) 查看數據表（PDF） - Analog Devices
零件编号
产品描述 (功能)
生产厂家
EVAL-AD7877EB Datasheet PDF : 44 Pages
| |||
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
AD7877
32 31 30 29 28 27 26 25
NC 1
24 NC
BAT2 2
23 DAV
BAT1 3
AUX3/GPIO3 4
AUX2/GPIO2 5
AD7877
TOP VIEW
(Not to Scale)
22 ALERT
21 GPIO4
20 STOPACQ
AUX1/GPIO1 6
19 DIN
VCC 7
NC 8
18 CS
17 PENIRQ
9 10 11 12 13 14 15 16
NC = NO CONNECT
Figure 4. Pin Configuration
Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1
NC
No Connect.
2
BAT2
Battery Monitor Input. ADC Input Channel 7.
3
BAT1
Battery Monitor Input. ADC Input Channel 6.
4
AUX3/GPIO3 Auxiliary Analog Input. ADC Input Channel 5. Can be reconfigured as GPIO pin.
5
AUX2/GPIO2 Auxiliary Analog Input. ADC Input Channel 4. Can be reconfigured as GPIO pin.
6
AUX1/GPIO1 Auxiliary Analog Input. ADC Input Channel 3. Can be reconfigured as GPIO pin.
7
VCC
8–9
NC
Power Supply Input. The VCC range for the AD7877 is from 2.2 V to 5.25 V.
No Connect.
10
X−
Touch Screen Position Input.
11
Y−
Touch Screen Position Input. ADC Input Channel 2.
12
X+
Touch Screen Position Input. ADC Input Channel 0.
13
Y+
Touch Screen Position Input. ADC Input Channel 1.
14
AGND
Analog Ground. Ground reference point for all analog circuitry on the AD7877. All analog input signals and any
external reference signal should be referred to this voltage.
15
DGND
Digital Ground. Ground reference for all digital circuitry on the AD7877. All digital input signals should be
referred to this voltage.
16, 32 NC
No Connect.
17
PENIRQ
Pen Interrupt. Digital active low output (has 50 kΩ internal pull-up resistor).
18
CS
Chip Select Input. Active low logic input. This input provides the dual function of initiating conversions on the
AD7877 and enabling the serial input/output register.
19
DIN
SPI® Serial Data Input. Data to be written to the AD7877’s registers should be provided on this input and is
clocked into the register on the rising edge of DCLK.
20
STOPACQ
Stop Acquisition Pin. A signal applied to this pin can be monitored by the AD7877, so that acquisition of new
data by the ADC is halted while the signal is active. Used to reduce the effect of noise from an LCD screen on
the touch screen measurements.
21
GPIO4
Dedicated general-purpose logic input/output pin.
22
ALERT
Digital Active Low Output. Interrupt output, which goes low if a GPIO data bit is set, or if the AUX1, TEMP1,
BAT1, or BAT2 measurements are out of range.
23
DAV
Data Available Output. Active low logic output. Asserts low when new data is available in the AD7877 results
registers. This output is high impedance when CS is high.
24–25 NC
No Connect.
26
DCLK
External Clock Input. Logic input. DCLK provides the serial clock for accessing data from the part.
27
DOUT
Serial Data Output. Logic output. The conversion result from the AD7877 is provided on this output as a serial
data stream. The bits are clocked out on the falling edge of the DCLK input. This output is high impedance
when CS is high.
28
VDRIVE
Logic Power Supply Input. The voltage supplied at this pin determines the operating voltage for the serial
interface of the AD7877.
Rev. A | Page 7 of 44
Share Link: 