DS3906 Rev 1 2/06 Triple NV Low Step Size Variable Resistor Plus Memory General Description Features Three Programmable Resistors for Low Step-Size The DS3906 is intended for low resistance, small step- Applications (Ohm and Subohm) size applications. It contains three nonvolatile (NV), low- Resistor Settings are NV temperature coefficient, variable digital resistors that are capable of ohm and subohm increments when 16-Byte NV User Memory (EEPROM) 2 used in parallel with a fixed external resistor. All three of I C-Compatible Serial Interface the DS3906s resistors have 64 positions (plus a high-Z Up to 8 Devices Can be Multidropped on the state) with a pseudo-log response cleverly chosen to 2 Same I C Bus have a linear equivalent resistance when paired with an Low Power Consumption external resistor (see graphs below). The DS3906 also Wide Operating Voltage (2.7V to 5.5V) contains 16 bytes of user EEPROM that, in addition to Operating Temperature Range: -40C to +85C 2 the resistors, are controlled through an I C-compatible serial interface. Three address pins allow up to eight Ordering Information 2 DS3906s to be placed on the same I C bus. PART TEMP RANGE PIN-PACKAGE The DS3906 can also be factory cutomized to provide a variety of transfer functions depending on user DS3906U -40C to +85C 10 SOP requirements. Contact mixedsignal.apps dalsemi.com DS3906U+ -40C to +85C 10 SOP for additional information. DS3906U+T&R -40C to +85C 10 SOP DS3906U/T&R -40C to +85C 10 SOP Applications +Denotes lead-free package. Low Ohm, Fine Resolution Driver Control for LED T&R denotes tape-and-reel package. Display Panels Pin Configuration Low Ohm, Fine Resolution Instrumentation Control TOP VEIW A1 1 10 A2 SDA 2 9 A0 SCL3H80 Typical Operating Circuit appears at end of data sheet. DS3906 V 4 7 H1 CC GND 5 6 H2 SOP Resistor Plots RESISTOR 0 AND 1 RESISTANCE vs. POSITION RESISTOR 2 RESISTANCE vs. POSITION (WITH AND WITHOUT EXTERNAL RESISTOR) (WITH AND WITHOUT EXTERNAL RESISTOR) 200 3000 350 1600 R0 R EXT0 R (R = 400) 2 EXT 180 2500 300 1400 R (R = 310) 2 EXT 160 R (R = 150) 0, 1 EXT 2000 250 140 1200 R (R = 105) 0, 1 EXT 120 DS3906 1500 200 R1 R EXT1 100 1000 100 150 R (R = 250) 80 2 EXT 800 R (R = 50) 60 0, 1 EXT 500 100 R WITHOUT R 2 EXT 40 600 20 50 R2 R EXT2 20 R WITHOUT R 0, 1 EXT 0 0 0 400 0616 32 484 0616 32 484 RESISTOR POSITION (dec) RESISTOR POSITION (dec) Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. R = R R () EFFECTIVE 0, 1 EXT R WITHOUT R () 0, 1 EXT R = R R () EFFECTIVE 2 EXT R WITHOUT R () 2 EXTTriple NV Low Step Size Variable Resistor Plus Memory ABSOLUTE MAXIMUM RATINGS Voltage on V , SDA, SCL, and H0-H2 Pins Operating Temperature Range ...........................-40C to +85C CC Relative to Ground.............................................-0.5V to +6.0V EEPROM Programming Temperature Range .........0C to +70C Voltage on A0, A1, and A2 Storage Temperature Range ............................-55C to +125C Relative to Ground .....-0.5V to V + 0.5V, not to exceed +6.0V Soldering Temperature...................See J-STD-020 Specification CC Resistor Current ....................................................................5mA Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS (T = -40C to +85C) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V (Note 1) +2.7 +5.5 V CC 0.7 x V + CC Input Logic 1 V V IH V 0.3 CC 0.3 x Input Logic 0 V -0.3 V IL V CC Resistor Inputs H0, H1, H2 V = 2.7V to 5.5V -0.3 +5.5 V CC Resistor Current I 5mA R DC ELECTRICAL CHARACTERISTICS (V = +2.7V to +5.5V, T = -40C to +85C, unless otherwise noted.) CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 3V 130 Standby Current (Note 2) I A STBY 5V 160 250 Input Leakage for All Pins I (Note 3) -1.0 +1.0 A L 3mA sink current 0 0.4 Low-Level Output Voltage (SDA) V V OL SDA 6mA sink current 0 0.6 I/O Capacitance C 10 pF I/O ANALOG RESISTOR CHARACTERISTICS (V = +2.7V to +5.5V, T = -40C to +85C, unless otherwise noted.) CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Resistor Tolerance From nominal values in Table 3 -20 +20 % INL (Note 4) -2 +2 LSB DNL (Note 4) -0.5 +0.5 LSB Temperature Coefficient At position 3Fh (Note 8) 60 ppm/C Resistor High-Z R 5.5 M HIGH-Z Resistors Guaranteed monotonic by design 2 DS3906