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Teilenummer | DS4301U-200 |
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Beschreibung | Nonvolatile/ 32-Position Digital Potentiometer | |
Hersteller | Dallas Semiconducotr | |
Logo | ||
Gesamt 7 Seiten Rev 0; 8/03
Nonvolatile, 32-Position Digital Potentiometer
General Description
The DS4301 is a single 32-position linear digital poten-
tiometer with 200kΩ end-to-end resistance. The wiper
setting is stored in EEPROM, so the DS4301 powers up
with the last stored setting. The position of the wiper is
controlled through a simple three-terminal
increment/decrement interface. The DS4301 is ideal for
white LED backlight brightness control. Its 8-pin µSOP
package, 2.4V to 5.5V supply range, and 200kΩ end-
to-end resistance are especially suited for portable,
battery-powered applications such as cellular tele-
phones and PDAs.
Applications
White LED Backlight Brightness Control
Portable Battery-Powered Devices such as PDAs
and Cellular Phones
Any Application that Requires a Small, Low-Cost
NV Potentiometer
Features
♦ Single, 32-Position, 200kΩ Linear Nonvolatile (NV)
Potentiometer Ideal for Battery-Powered
Applications
♦ Three-Terminal Increment/Decrement Interface to
Adjust Wiper Position
♦ Wide Voltage Supply Range (2.4V to 5.5V)
♦ Command-Initiated NV Wiper Storage
♦ Operates Over the Industrial Temperature Range
(-40°C to +85°C)
♦ Available in 8-Pin µSOP
Ordering Information
PART
DS4301U-200
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
8 µSOP (118 mil)
TOP VIEW
Pin Configuration
INC 1
U/D 2
H3
GND 4
DS4301
µSOP
8 VCC
7 CS
6L
5W
Typical Operating Circuit
VCC
VCC
VREF VCC
10µH
0.1µF
VCC
H 1µF
10µF
CONTROL
INTERFACE
DS4301 W
CS
INC L
U/D
GND
VCC EXT
ADJ
WHITE LED
CURRENT
CS
REGULATOR FB
GND PGND
MBR0540
1µF
WHITE
LEDs
RFB
______________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Nonvolatile, 32-Position Digital Potentiometer
VCC
VCC
CS CONTROL
INC LOGIC UNIT
U/D
GND
NONVOLATILE
MEMORY
POS 31
5-BIT
WIPER
SETTING
POS 0
H
L
W
Figure 1. Block Diagram
Detailed Description
The DS4301 is a single nonvolatile digital potentiome-
ter. This 32-position linear potentiometer has an end-to-
end resistance of 200kΩ, and operates over a wide
2.4V to 5.5V supply voltage range. The wiper position is
controlled by the three interface pins (U/D, CS, and
INC), and the wiper setting can be stored in EEPROM
on command.
Power-Up
On power-up, once a stable supply voltage of VCC MIN
has been reached, the stored wiper setting is loaded
from the EEPROM within tWLT. Also on power-up, the
DS4301 wiper control pins become active approximate-
ly tPU after a stable supply voltage of VCC MIN has
been reached.
Wiper Control
Adjusting the wiper of the DS4301 involves using the
three control pins (U/D, CS, and INC). See the Timing
Diagram in Figure 2. To enable wiper adjustment, a
high-to-low transition on the CS pin is required. Hold
CS low for the duration of the communication. Doing
this enables the INC pin to change the wiper position.
Set the U/D pin high to increment or low to decrement
the wiper position. The state of the U/D pin should be
set more than tDI before the INC signal is transitioned
from high to low. After the CS pin is active low, a high-
to-low transition on the INC pin moves the wiper in the
direction dictated by the U/D pin. Continue to pulse
INC (high to low) until the desired wiper position is
reached. On the last edge, hold the INC line low. With
the desired wiper position set, there are two ways to
proceed. One method terminates communication with-
out allowing the value of the current wiper position to
be written to the EEPROM. This is done by transitioning
the CS signal to the high state before bringing the INC
signal high. As long as the state of the CS pin is high
before the state of the INC pin goes high, the current
wiper setting is not written to EEPROM. Because the
current wiper setting was not stored to the NV memory,
the previously stored wiper setting, not the current
wiper setting, is loaded from memory if power is cycled
to the device
The other method is used to store a new wiper setting
in the EEPROM. This is done by bringing the state of
the INC pin high for a time of tIC before bringing the
state of the CS pin high. Once the states of both CS
and INC pins are high, the current wiper setting is
stored in EEPROM after a time of tWST. If power is
WIPER NON-STORAGE
CONDITION
CS
VIL
tCI
INC
VIL
tIL
tIH
VIH
VIH
tF
tIK
U/D
tIW
POSITION X
WIPER POSITION
tDI
VIL
tIW
POSITION X + 1
tCPH
tR
POSITION X
WIPER STORAGE
CONDITION
tWST
tIC
POSITION X - 1
Figure 2. Timing Diagram
6 _____________________________________________________________________
tCLP
6 Page | ||
Seiten | Gesamt 7 Seiten | |
PDF Download | [ DS4301U-200 Schematic.PDF ] |
Teilenummer | Beschreibung | Hersteller |
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