AD5260_10 Datasheet, PDF (1/24 Pages) Analog Devices – 1-/2-Channel 15 V Digital Potentiometer

1-/2-Channel 15 V Digital Potentiometer
AD5260/AD5262
FEATURES
256 positions
AD5260: 1 channel
AD5262: 2 channels (independently programmable)
Potentiometer replacement
20 kΩ, 50 kΩ, 200 kΩ
Low temperature coefficient: 35 ppm/°C
4-wire, SPI-compatible serial data input
5 V to 15 V single-supply; ±5.5 V dual-supply operation
Power on midscale preset
APPLICATIONS
Mechanical potentiometer replacement
Instrumentation: gain, offset adjustment
Stereo channel audio level control
Programmable voltage-to-current conversion
Programmable filters, delays, time constants
Line impedance matching
Low resolution DAC replacement
GENERAL DESCRIPTION
The AD5260/AD5262 provide a single- or dual-channel, 256-
position, digitally controlled variable resistor (VR) device.¹
These devices perform the same electronic adjustment function
as a potentiometer or variable resistor. Each channel of the
AD5260/AD5262 contains a fixed resistor with a wiper contact
that taps the fixed resistor value at a point determined by a
digital code loaded into the SPI-compatible serial-input register.
The resistance between the wiper and either end point of the
fixed resistor varies linearly with respect to the digital code
transferred into the VR latch. The variable resistor offers a
completely programmable value of resistance, between the A
terminal and the wiper or the B terminal and the wiper. The
fixed A-to-B terminal resistance of 20 Ω, 50 Ω, or 200 Ω has a
nominal temperature coefficient of 35 ppm/°C. Unlike the
majority of the digital potentiometers in the market, these
devices can operate up to 15 V or ±5 V provided proper supply
voltages are furnished.
Each VR has its own VR latch that holds its programmed
resistance value. These VR latches are updated from an internal
serial-to-parallel shift register, which is loaded from a standard
3-wire serial-input digital interface. The AD5260 contains an
8-bit serial register whereas the AD5262 contains a 9-bit serial
register. Each bit is clocked into the register on the positive
FUNCTIONAL BLOCK DIAGRAMS
AWB
SHDN
V_DD
V_SS
V_L
CS
CLK
SDI
GND
RDAC
REGISTER
AD5260
LOGIC
POWER-ON
RESET
8
SERIAL INPUT REGISTER
Figure 1. AD5260
A1 W1 B1
A2 W2 B2
PR
SDO
SHDN
V_DD
RDAC1
V_SS
REGISTER
RDAC2
REGISTER
V_L
CS
CLK
SDI
GND
LOGIC
POWER-ON
RESET
8
SERIAL INPUT REGISTER
AD5262
PR
SDO
Figure 2. AD5262
edge of the CLK pin. The AD5262 address bit determines the
corresponding VR latch to be loaded with the last eight bits of
the data word during the positive edging of CS strobe. A serial
data output pin at the opposite end of the serial register enables
simple daisy-chaining in multiple VR applications without
additional external decoding logic. An optional reset pin (PR)
forces the wiper to the midscale position by loading 0x80 into
the VR latch.
The AD5260/AD5262 are available in thin surface-mount
14-lead TSSOP and 16-lead TSSOP packages. All parts are
guaranteed to operate over the extended industrial temperature
range of −40°C to +85°C.
1 _{The terms digital potentiometers, VR, and RDAC are used interchangeably.}
Rev. A
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