Datasheet

MCP453X/455X/463X/465X
DS22096B-page 34  2008-2013 Microchip Technology Inc.
3.1 High Voltage Command / Address 0
(HVC/A0)
The HVC/A0 pin is the Address 0 input for the I
2
C
interface as well as the High Voltage command pin. At
the device’s POR/BOR the value of the A0 address bit
is latched. This input, along with the A2 and A1 pins,
completes the device address. This allows up to eight
MCP45XX/46XX devices on a single I
2
C bus.
During normal operation the voltage on this pin deter-
mines if the I
2
C command is a normal command or a
High Voltage command (when HVC/A0 = V
IHH
).
3.2 Serial Clock (SCL)
The SCL pin is the serial interfaces Serial Clock pin.
This pin is connected to the Host Controllers SCL pin.
The MCP45XX/46XX is a slave device, so its SCL pin
accepts only external clock signals.
3.3 Serial Data (SDA)
The SDA pin is the serial interfaces Serial Data pin.
This pin is connected to the Host Controllers SDA pin.
The SDA pin is an open-drain N-channel driver.
3.4 Ground (V
SS
)
The V
SS
pin is the device ground reference.
3.5 Potentiometer Terminal B
The terminal B pin is connected to the internal
potentiometer’s terminal B.
The potentiometer’s terminal B is the fixed connection
to the Zero Scale wiper value of the digital potentiome-
ter. This corresponds to a wiper value of 0x00 for both
7-bit and 8-bit devices.
The terminal B pin does not have a polarity relative to
the terminal W or A pins. The terminal B pin can
support both positive and negative current. The voltage
on terminal B must be between V
SS
and V
DD
.
MCP46XX devices have two terminal B pins, one for
each resistor network.
3.6 Potentiometer Wiper (W) Terminal
The terminal W pin is connected to the internal potenti-
ometer’s terminal W (the wiper). The wiper terminal is
the adjustable terminal of the digital potentiometer. The
terminal W pin does not have a polarity relative to
terminals A or B pins. The terminal W pin can support
both positive and negative current. The voltage on
terminal W must be between V
SS
and V
DD
.
MCP46XX devices have two terminal W pins, one for
each resistor network.
3.7 Potentiometer Terminal A
The terminal A pin is available on the MCP4XX1
devices, and is connected to the internal potentiome-
ter’s terminal A.
The potentiometer’s terminal A is the fixed connection
to the Full-Scale wiper value of the digital potentiome-
ter. This corresponds to a wiper value of 0x100 for 8-bit
devices or 0x80 for 7-bit devices.
The terminal A pin does not have a polarity relative to
the terminal W or B pins. The terminal A pin can
support both positive and negative current. The voltage
on terminal A must be between V
SS
and V
DD
.
The terminal A pin is not available on the MCP4XX2
devices, and the internally terminal A signal is floating.
MCP46X1 devices have two terminal A pins, one for
each resistor network.
3.8 Address 2 (A2)
The A2 pin is the I
2
C interface’s Address 2 pin. Along
with the A1 and A0 pins, up to eight MCP45XX/46XX
devices can be used on a single I
2
C bus.
3.9 Address 1 (A1)
The A2 pin is the I
2
C interface’s Address 1 pin. Along
with the A2 and A0 pins, up to eight MCP45XX/46XX
devices can be used on a single I
2
C bus.
3.10 Positive Power Supply Input (V
DD
)
The V
DD
pin is the device’s positive power supply input.
The input power supply is relative to V
SS
.
While the device V
DD
< V
min
(2.7V), the electrical
performance of the device may not meet the data sheet
specifications.
3.11 No Connect (NC)
These pins should be either connected to V
DD
or V
SS
.
3.12 Exposed Pad (EP)
This pad is conductively connected to the device’s
substrate. This pad should be tied to the same potential
as the V
SS
pin (or left unconnected). This pad could be
used to assist as a heat sink for the device when
connected to a PCB heat sink.