MCP434X MICROCHIP [Microchip Technology], MCP434X Datasheet - Page 61
![no-image](/images/no-image-200.jpg)
MCP434X
Manufacturer Part Number
MCP434X
Description
7/8-Bit Quad SPI Digital POT with Non-Volatile Memory
Manufacturer
MICROCHIP [Microchip Technology]
Datasheet
1.MCP434X.pdf
(80 pages)
8.0
Non-volatile digital potentiometers have a multitude of
practical uses in modern electronic circuits. The most
popular uses include precision calibration of set point
thresholds, sensor trimming, LCD bias trimming, audio
attenuation, adjustable power supplies, motor control
overcurrent trip setting, adjustable gain amplifiers and
offset trimming. The MCP434X/436X devices can be
used to replace the common mechanical trim pot in
applications where the operating and terminal voltages
are within CMOS process limitations (V
5.5V).
8.1
All inputs that would be used to interface to a Host
Controller support High Voltage on their input pin. This
allows the MCP43XX device to be used in split power
rail applications.
An example of this is a battery application where the
PIC
(4.8V) and the MCP43XX device is powered by the
3.3V regulated voltage.
For SPI applications, these inputs are:
• CS
• SCK
• SDI (or SDI/SDO)
• WP
• RESET
Figure 8-1
rail systems. In this system, the MCP43XX interface
input signals need to be able to support the PIC MCU
output high voltage (V
In Example #1
input signals need to be able to support the PIC MCU
output high voltage (V
becomes too large, then the customer may be required
to do some level shifting due to MCP43XX V
related to Host Controller V
In Example #2
input signals need to be able to support the lower
voltage of the PIC MCU output high voltage level (V
Table 8-1
voltage
specifications. So this PIC MCU operating at 3.3V will
drive a V
at 5.5V, the V
signals meet specifications.
© 2009 Microchip Technology Inc.
®
MCU is directly powered by the battery supply
APPLICATIONS EXAMPLES
Split Rail Applications
OH
shows an example PIC microcontroller I/O
through
specifications
at 2.64V, and for the MCP43XX operating
IH
(Figure
(Figure
is 2.47V. Therefore, the interface
Figure 8-2
OH
OH
8-1), the MCP43XX interface
8-2), the MCP43XX interface
).
). If the split rail voltage delta
IH
and
levels.
show three example split
the
DD
MCP43XX
= 2.7V to
OH
levels
OH
).
FIGURE 8-1:
System 1.
FIGURE 8-2:
System 2.
TABLE 8-1:
5.5
5.0
4.5
3.3
3.0
2.7
Note 1:
V
DD
5V
PIC
2:
3:
4.4
4.0
3.6
2.64 2.64 4.5
2.4
2.16 2.16 5.5
PIC MCU
V
Voltage
Regulator
3V
IH
(1)
V
V
V
V
V
V
V
V
The only MCP4XXX output pin is SDO,
which is Open-Drain (or Open-Drain with
Internal Pull-up) with High Voltage Support
PIC MCU
SDO
OH
OL
IH
IL
OH
OL
IH
IL
Voltage
Regulator
SCK
SDI
WP
4.4
4.0
3.6
2.4
MCP434X/436X
CS
I/O
V
maximum = 0.2 * V
maximum = 0.2 * V
minimum = 0.8 * V
minimum = 0.45 * V
maximum = 0.6V
maximum = 0.2 * V
OH
minimum = 0.8 * V
minimum (SDA only) =;
SDO
V
SCK
SDI
WP
CS
OH
I/O
2.7
3.0
3.3
5.0
V
Example Split Rail
Example Split Rail
DD
- V
MCP4XXX
IH
3V
1.215 —
1.35
1.485 —
2.025 —
2.25
2.475 —
V
COMPARISONS
IH
DD
DD
DD
—
—
DD
MCP4XXX
(2)
DD
DD
V
SDI
CS
SCK
WP
RESET
SDO
DS22233A-page 61
;
;
OH
(3)
(3)
(3)
(3)
(3)
(3)
;
;
MCP4XXX
SDI
CS
SCK
WP
RESET
SDO
Comment
5V