DS1809-050+ Maxim Integrated Products, DS1809-050+ Datasheet - Page 2

• Manufacturer Part Number: DS1809-050+
• Description: IC DALLASTAT 50K 8-DIP
• Manufacturer: Maxim Integrated Products
• Series: Dallastat™r

Specifications of DS1809-050+

• Taps: 64
• Resistance (ohms): 50K
• Number Of Circuits: 1
• Temperature Coefficient: 750 ppm/°C Typical
• Memory Type: Non-Volatile
• Interface: Contact Closure
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Resistance In Ohms: 50K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS1809
The DS1809 is available in standard 10 k, 50 k, and 100 kresistor versions. The DS1809 is
provided as an industrial temperature grade part only. Available packaging for the DS1809 include an 8-
lead (300-mil) DIP an 8-lead (150-mil) SOIC, and an 8-lead (118-mil) SOP.
BLOCK DIAGRAM Figure 1
OPERATION
The DS1809 Dallastat is a digitally controlled, nonvolatile potentiometer. A block diagram of the
DS1809 is shown in Figure 1. The DS1809 is a linear potentiometer providing 64-uniform wiper
positions over the entire resistor range including the end-terminals. All three potentiometer terminals of
the device are accessible. These terminals include R
, R
, and R
. R
and R
are the end-terminals of the
H
L
W
H
L
potentiometer. These terminals will have a constant resistance between them as defined by the
potentiometer value chosen: 10 k, 50 k, or the 100 kversion. Functionally, R
and R
are
H
L
interchangeable. The wiper terminal, R
, is the multiplexed terminal and can be set to one of the 64 total
W
positions that exist on the resistor ladder including the R
and R
terminals.
H
L
Control of the wiper (R
) position setting is accomplished via the two inputs UC and DC. The UC and
W
DC control inputs, when active, determine the direction on the resistor array that the wiper position will
move. The UC (up control) control input is used to move the wiper position towards the R
terminal. The
H
DC (down control) control input is used to move wiper position towards the R
terminal.
L
The control inputs UC and DC are active low inputs that interpret input pulse widths as the means of
controlling wiper movement. Internally, these inputs are pulled up to V
via a 100 kresistance. A
CC
transition from a high-to-low on these inputs is considered the beginning of pulse input activity.
A single pulse on the UC or DC input is defined as being greater than 1 millisecond but lasting no longer
that ½ second. This type pulse input will cause the wiper position of the Dallastat to move one position.
Multiple pulse inputs (repetitive pulse inputs) can be used to step through each wiper position of the
device. The requirement for a repetitive pulse train on the UC or DC inputs is that pulses must be
separated by a minimum high time of 1 millisecond. If this is not the case the Dallastat will ignore that
pulse input.
A continuous pulse input (“push and hold”) is defined as lasting longer that ½ second. A continuous pulse
input will cause the wiper position to move one position every 100 milliseconds following the initial ½-
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