AD8403AR10

The AD8403AR10 belons to AD8400/AD8402/AD8403 family which provide a single, dual or quad channel, 256 position digitally controlled variable resistor (VR) device. These devices perform the same electronic adjustment function as a potentiometer or variable resistor. The reset (RS) pin forces the wiper to the midscale position by loading 80 H into the VR latch. The SHDN pin forces the resis- tor to an end-to-end open circuit condition on the A terminal and shorts the wiper to the B terminal, achieving a microwatt power shutdown state. The digital interface is still active in shutdown so that code changes can be made which will produce new wiper positions when the device is taken out of shutdown. When SHDN is returned to logic high, the previous latch settings put the wiper in the same resistance setting prior to shutdown. The AD8403 contains four independent variable resistors in 24-lead PDIP, SOIC and TSSOP packages. Each part 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 controlling serial input register. A unique switching cir- cuit minimizes the high glitch inherent in traditional switched resistor designs avoiding any make-before-break or break-before- make operation. The resistance between the wiper and either endpoint of the fixed resistor varies linearly with respect to the digital code transferred into the VR latch. each 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 1 k, 10 k, 50 k or 100 k has a ±1% channel-to-channel matching tolerance with a nominal temperature coefficient of 500 ppm/°C.

The features of AD8403AR10 can be summarized as (1)256 position; (2)replaces 1, 2 or 4 potentiometers; (3)1 k, 10 k, 50 k, 100 k; (4)power shut down-less than 5 mA; (5)3-wire SPI compatible serial data input; (6)10 MHz update data loading rate; (7)+2.7 V to +5.5 V single-supply operation midscale preset.

The absolute maximum ratings of AD8403AR10 are (1)V DD to GND: 0.3 V, +8 V; (2)V A , V B , V W to GND: 0 V, V DD; (3)A X B X , A X W X , B X W X: ± 20 mA; (4)digital input and output voltage to GND: 0 V, +8 V; (5)operating temperature range: 40°C to +85°C; (6)maximum junction temperature (T J max) : +150°C; (7)storage temperature: 65°C to +150°C; (8)lead temperature (soldering, 10 sec) : +300°C; (9)package power dissipation: (T J maxT A )/ JA; (10)thermal resistance ( JA ): P-DIP (N-14) +83°C/W, P-DIP (N-24) +63°C/W, SOIC (SO-14) : +70°C/W, SOIC (SOL-24) : +120°C/W, TSSOP-14 (RU-14) +180°C/W, TSSOP-24 (RU-24) +143°C/W.