AD5228BUJZ10-R2 Analog Devices Inc, AD5228BUJZ10-R2 Datasheet - Page 16

• Manufacturer Part Number: AD5228BUJZ10-R2
• Description: IC DGTL POT 10K UP/DN TSOT23-8
• Manufacturer: Analog Devices Inc

Specifications of AD5228BUJZ10-R2

• Taps: 32
• Resistance (ohms): 10K
• Number Of Circuits: 1
• Temperature Coefficient: 35 ppm/°C Typical
• Memory Type: Volatile
• Interface: Up/Down Counter
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-8, TSOT-8
• Resistance In Ohms: 10K
• End To End Resistance: 10kohm
• Track Taper: Linear
• No. Of Steps: 32
• Resistance Tolerance: ± 20%
• Supply Voltage Range: 2.7V To 5.5V
• Control Interface: Pushbutton
• No. Of Pots: Single
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD5228EBZ - BOARD EVAL FOR AD5228 DGTL POT
• Lead Free Status / Rohs Status: Compliant

AD5228
AUTOMATIC LCD PANEL BACKLIGHT CONTROL
With the addition of a photocell sensor, an automatic brightness
control can be achieved. As shown in Figure 44, the resistance
of the photocell changes linearly but inversely with the light
output. The brighter the light output, the lower the photocell
resistance and vice versa. The AD5228 sets the voltage level that
is gained up by U2 to drive N1 to a desirable brightness. With
the photocell acting as the variable feedback resistor, the change
in the light output changes the R2 resistance, therefore causing
U2 to drive N1 accordingly to regulate the output. This simple
low cost implementation of an LED controller can compensate
for the temperature and aging effects typically found in high
power LEDs. Similarly, for power efficiency, a PWM signal can
be applied at the gate of N2 to switch the LED on and off
without noticeable effect.
C1
1μF
PUSH-DOWN
PUSH-UP
BUTTON
BUTTON
C2
0.1μF
Figure 44. Automatic LCD Panel Backlight Control
PU
PD
V
DD
PRE
5V
AD5228
A
10kΩ
B
GND
U1
W
1kΩ
R1
PHOTOCELL
–
+
AD8531
5V
U2
V+
V–
0.1μF
C3
PWM
R2
5V
4.75kΩ
N2
R3
N1
2N7002
5V
WHITE
LED
2N7002
D1
Rev. A | Page 16 of 20
AUDIO AMPLIFIER WITH VOLUME CONTROL
The AD5228 and SSM2211 can form a 1.5 W audio amplifier
with volume control that has adequate power and quality for
portable devices such as PDAs and cell phones. The SSM2211
can drive a single speaker differentially between Pins 5 and 8
without any output capacitor. The high-pass cutoff frequency is
f
speakers as shown in Figure 45. However, the speakers must be
configured in single-ended mode, and output coupling capacitors
are needed to block the dc current. The output capacitor and
the speaker load form an additional high-pass cutoff frequency
as f
large to make the frequency as low as f
5V
H1
AUDIO_INPUT
10μF
10kΩ
10kΩ
= 1/(2 × π × R1 × C1). The SSM2211 can also drive two
H2
C6
R3
R4
= 1/(2 × π × R5 × C3). As a result, C3 and C4 must be
5V
PUSH-DOWN
0.1μF
PUSH-UP
BUTTON
BUTTON
C7
–
+
AD8591
Figure 45. Audio Amplifier with Volume Control
U3
±2.5V p-p
V
PRE
PU
PD
DD
GND
A
10kΩ
B
U1
W
1μF
C1
10kΩ
R1
0.1μF
H1
C2
.
4
3
0.1μF
C5
2
SSM2211
–
+
10kΩ
R2
7
U2
5V
V+
V–
6
1
5
8
470μF
470μF
C44
C3
R5
8Ω
R6
8Ω