Datasheet
2006-2012 Microchip Technology Inc. DS22025C-page 15
MCP3909
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Ta bl e 3-1.
TABLE 3-1: PIN FUNCTION TABLE
3.1 Digital V
DD
(DV
DD
)
DV
DD
is the power supply pin for the digital circuitry
within the MCP3909 device.
This pin requires appropriate bypass capacitors and
should be maintained to 5V ±10% for specified
operation. Refer to Section 6.0 “Applications
Information”.
3.2 High-Pass Filter Input Logic Pin
(HPF)
HPF controls the state of the high-pass filter in both
input channels. A logic ‘1’ enables both filters, remov-
ing any DC offset coming from the system or the
device. A logic ‘0’ disables both filters allowing DC
voltages to be measured.
MCP3909
Symbol Description
SSOP
1DV
DD
Digital Power Supply Pin
2 HPF High-Pass Filters Control Logic Pin
3AV
DD
Analog Power Supply Pin
4 NC No Connect
5 CH0+ Non-Inverting Analog Input Pin for Channel 0 (Current Channel)
6 CH0- Inverting Analog Input Pin for Channel 0 (Current Channel)
7 CH1- Inverting Analog Input Pin for Channel 1 (Voltage Channel)
8 CH1+ Non-Inverting Analog Input Pin for Channel 1 (Voltage Channel)
9MCLR
Master Clear Logic Input Pin
10 REFIN/OUT Voltage Reference Input/Output Pin
11 A
GND
Analog Ground Pin, Return Path for internal analog circuitry
12 SCK / F2 Serial Clock or Frequency Control for HF
OUT
Logic Input Pin
13 SDI / F1 Serial Data Input or Frequency Control for F
OUT0/1
Logic Input Pin
14 CS
/ F0 Chip Select or Frequency Control for F
OUT0/1
Logic Input Pin
15 G1 Gain Control Logic Input Pin
16 G0 Gain Control Logic Input Pin
17 OSC1 Oscillator Crystal Connection Pin or Clock Input Pin
18 OSC2 Oscillator Crystal Connection Pin or Clock Output Pin
19 NC No Connect
20 SDO / NEG Serial Data Out or Negative Power Logic Output Pin
21 D
GND
Digital Ground Pin, Return Path for Internal Digital Circuitry
22 HF
OUT
High-Frequency Logic Output Pin (Intended for Calibration)
23 F
OUT1
Differential Mechanical Counter Logic Output Pin
24 F
OUT0
Differential Mechanical Counter Logic Output Pin