MCP4451-503E/ML Microchip Technology, MCP4451-503E/ML Datasheet - Page 87

• Manufacturer Part Number: MCP4451-503E/ML
• Description: IC POT 50K QUAD 8BIT 20QFN
• Manufacturer: Microchip Technology

Specifications of MCP4451-503E/ML

• Package / Case: 20-VFQFN Exposed Pad
• Resistance (ohms): 50K
• Taps: 257
• Number Of Circuits: 4
• Temperature Coefficient: *
• Memory Type: Volatile
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 1.8 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Number Of Pots: Quad
• Taps Per Pot: 257
• Resistance: 50 KOhms
• Wiper Memory: Volatile
• Digital Interface: I2C
• Operating Supply Voltage: 1.8 V to 5.5 V
• Supply Current: 600 uA
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.8 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FIGURE B-6:
Diagram.
The characteristics of the wiper are determined by the
characteristics of the wiper switch at each of the
resistor networks tap points.
example of a wiper switch. As the device operational
voltage becomes lower, the characteristics of the wiper
switch change due to a lower voltage on the V
Figure B-7
When the transistor is turned off, the switch resistance
is in the Giga s. When the transistor is turned on, the
switch resistance is dependent on the V
V
FIGURE B-7:
 2010 Microchip Technology Inc.
R
Note 1:
WCn
AB
Note 1: Wiper Resistance (R
V
N
N
N
N
WCn
WC
R
R
R
R
voltages. This resistance is referred to as R
N
N
N
n-1
n-2
n-3
S
S
S
S
1
n
0
A
B
shows an implementation of a wiper switch.
V
The wiper resistance is dependent on
several factors including, wiper code,
device V
and W), and temperature.
V
V
voltages at the wiper switch nodes
(V
WC(n-2)
A
B
“gate”
“gate”
R
R
R
R
G
W
W
W
, V
W
(1)
(1)
(1)
(1)
W
DD
and V
NMOS
PMOS
Resistor Network Block
Wiper Switch.
, Terminal voltages (on A, B
R
NMOS
PMOS
W
R
WCn
W
(1)
(1)
).
Figure B-7
W
V
) depends on the
G
(V
Wiper
V
DD
W
G
/V
shows an
, V
DV
V
G
SS
W
signal.
W
G
)
W
W
and
.
So looking at the wiper voltage (V
3.0V and 1.8V data gives the graphs in
Figure
0.8V, the voltage increases nonlinearly. Since V = I * R,
and the current (I
device resistance increased nonlinearly at around
wiper code 160.
FIGURE B-8:
Wiper Code (V
FIGURE B-9:
Wiper Code (V
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.2
1.0
0.8
0.6
0.4
0.2
0.0
B-9. In the 1.8V graph, as the V
0
0
32
32
DD
DD
64
W
64
= 3.0V, I
= 1.8V, I
) is constant, it means that the
MCP443X/5X
Wiper Voltage (V
Wiper Voltage (V
96
96
Wiper Code
Wiper Code
128
128
W
W
= 190
= 190
160
160
DS22267A-page 87
192
192
µ
µ
Figure B-8
W
A).
A).
W
W
W
approaches
) vs.
224
) vs.
224
) for the
-40C
+25C
+85C
+125C
-40C
+25C
+85C
+125C
256
256
and