±15V, 128-Tap, Low-Drift Digital Potentiometers

Transcription

1 9-265; Rev 2; /4 General Description The are 28-tap high-voltage (±5V to ±5V) digital potentiometers in packages that are half the size of comparable devices in 8-pin SO. They perform the same function as mechanical potentiometers, but replace the mechanics with a simple digital interface. The digital logic is powered by a separate single +2.V to +5.25V supply voltage (V CC ). The resistor string uses its own analog supplies (V DD and V SS ) that require V DD - V SS to be greater than 9V and less than 3.5V. This allows for greater flexibility in voltage ranges that can be used with these devices. Examples of analog supply ranges include not only dual voltages of ±5V to ±5V, but single-supply voltages, such as +V, +5V, +3V, -3V, and more, as long as the ranges of V DD - V SS and V CC - V SS are met. The MAX543/ include an on-chip, highvoltage, uncommitted amplifier, providing additional reductions in board space and cost. Other features include low 35ppm/ C end-to-end and 5ppm/ C ratiometric resistor temperature coefficients, a 3-wire SPI / QSPI /MICROWIRE -compatible serial interface, and a power-on reset to midscale. The MAX5436/MAX5438 are available in -pin µmax packages. The MAX543/ are available in 4- pin TSSOP package. Each device is guaranteed over the extended temperature range of -4 C to +85 C. Applications CD Screen Contrast Adjustment Data-Acquisition Systems Mechanical Potentiometer Replacement ow-drift Programmable Gain Amplifier Audio Volume Control Features +V to +3V Single-Supply Operation -28V to -V Single Negative Supply Operation ±5V to ±5V Dual-Supply Operation 28 Tap Positions Uncommitted igh-voltage Amplifier (MAX543/) ow Temperature Coefficient 35ppm/ C (End-to-End) 5ppm/ C (Ratiometric) Small-Footprint Packages -Pin µmax (MAX5436/MAX5438) 4-Pin TSSOP (MAX543/) Glitchless Switching Between the Resistor Taps 3-Wire SPI/QSPI/MICROWIRE-Compatible Serial Interface 5kΩ/kΩ End-to-End Resistances Power-On Reset: Wiper Goes to Midscale (Position 64) TOP VIEW Ordering Information PART TEMP RANGE PIN- PACKAGE RESISTANCE (kω) MAX5436EUB -4 C to +85 C µmax 5 MAX543EUD -4 C to +85 C 4 TSSOP 5 MAX5438EUB -4 C to +85 C µmax EUD -4 C to +85 C 4 TSSOP Pin Configurations V CC 4 V CC GND V SS MAX5436 MAX W V DD SDN GND MAX W V DD µmax V SS OUT IN+ IN- SPI/QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. TSSOP Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 ABSOUTE MAXIMUM RATINGS V DD to GND, V SS = GND...-.3V to +34V V SS to GND, V DD = GND...-34V to +.3V V DD to V SS...-.3V to +34V V DD to V CC V to +28.5V V CC to V SS...-.3V to +34V V CC to GND...-.3V to +6V,,, SDN...-.3V to (V CC +.3V),, W, IN+, IN-, OUT...(V SS -.3V) to (V DD +.3V) Maximum Continuous Current into,, and W...±mA 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. EECTRICA CARACTERISTI Continuous Power Dissipation (T A = + C) -Pin µmax (derate 6.94mW/ C above + C)...556mW 4-Pin TSSOP (derate 9.mW/ C above + C)...2mW Operating Temperature Range...-4 C to +85 C Junction Temperature...+5 C Storage Temperature Range C to +5 C ead Temperature (soldering, s)...+3 C (V DD = +5V, V SS = -5V, V CC = +5V, V = V DD, V = V SS, T A = -4 C to +85 C, unless otherwise noted. Typical values are at T A = +25 C, unless otherwise noted.) PARAMETER SYMBO CONDITIONS MIN TYP MAX UNITS DC PERFORMANCE (Voltage-Divider Mode) Resolution 2 N 28 Taps Integral Nonlinearity IN (Note ) ± SB Differential Nonlinearity DN (Note ) ± SB End-to-End Resistor Tempco TC R 35 ppm/ C Ratiometric Resistor Tempco 5 ppm/ C Full-Scale Error R = 5kΩ (MAX5436/MAX543) -.3 SB Zero-Scale Error R = 5kΩ (MAX5436/MAX543) +.3 SB Full-Scale Error R = kω (MAX5438/) -.5 SB Zero-Scale Error R = kω (MAX5438/) +.5 SB DC PERFORMANCE (Variable-Resistor Mode) Resolution 2 N 28 Taps Integral Nonlinearity IN (Note 2) ± SB Differential Nonlinearity DN (Note 2) ± SB DC PERFORMANCE (Resistor Characteristics) Wiper Resistance W R (Note 3).9 2 kω Wiper Capacitance W C Midscale 6 pf MAX5438/ 5 25 End-to-End Resistance R MAX5436/MAX kω DIGITA INPUTS Input igh Voltage V CC = 4.5V to 5.25V (Note 4) 2.4 V Input ow Voltage V CC = 4.5V to 5.25V.8 V 2

3 EECTRICA CARACTERISTI (continued) (V DD = +5V, V SS = -5V, V CC = +5V, V = V DD, V = V SS, T A = -4 C to +85 C, unless otherwise noted. Typical values are at T A = +25 C, unless otherwise noted.) PARAMETER SYMBO CONDITIONS MIN TYP MAX UNITS Input igh Voltage V CC = 2.V to 3.6V 2. V Input ow Voltage V CC = 2.V to 3.6V.6 V Input eakage Current ±. µa Input Capacitance 5. pf DYNAMIC CARACTERISTI (Analog) R = 5kΩ, midscale, V =.5V P-P, C WIPER = 2pF, voltage-divider mode Wiper -3dB Bandwidth BW W R = kω, midscale, V =.5V P-P, C WIPER = 2pF, voltage-divider mode Wiper Settling Time t I C WIPER = 2pF, code to code 2, settle to.5sb AMPIFIER CARACTERISTI (Analog) 4 2 kz 5 µs Input Bias Current I B 5 na Input Offset Voltage V OS ±6 mv Offset-Voltage Temperature Drift V OSD µv/ C Input Offset Current I OS 2 na Unity-Gain Bandwidth UBW A C OAD = 25pF kz Slew Rate SR.25 V/µs arge-signal Voltage Gain A VO R OAD = kω, V OUT = ±4V V/mV Input Noise V N f = kz nv/ z Input Compliance CMR I V SS + V DD - 2 V Output Compliance CMR O I OAD = ±5mA V SS + V DD - V DC CMRR CMRR 68 db DC PSRR PSRR db TIMING CARACTERISTI (Digital) (Note 5, Figure 3) Clock Frequency f CK Mz Clock Period t CP ns Pulse Width igh t C 4 ns Pulse Width ow t C 4 ns Fall to Rise Setup Time t S 4 ns Rise to Rise old Time t ns Setup Time t DS 4 ns old Time t D ns Rise to Fall Delay t O ns Rise to Rise old t 4 ns Pulse Width igh t W ns POWER SUPPIES Positive Analog Supply Voltage V DD 3.5 V Negative Analog Supply Voltage V SS V 3

4 EECTRICA CARACTERISTI (continued) (V DD = +5V, V SS = -5V, V CC = +5V, V = V DD, V = V SS, T A = -4 C to +85 C, unless otherwise noted. Typical values are at T A = +25 C, unless otherwise noted.) PARAMETER SYMBO CONDITIONS MIN TYP MAX UNITS Analog Supply Separation V DS V DD - V SS V Digital Supply Voltage V CC V Digital Supply to Negative Analog Supply Separation V V CC - V SS V Power-On Reset Threshold POR.6 V Digital Supply Current I CC (Note 4) 3 5 µa Positive Analog Supply Current I DD MAX5436/MAX5438 SDN = GND for MAX543/ 3 6 SDN = V CC 5 25 Negative Analog Supply Current I SS MAX5436/MAX5438 SDN = GND for MAX543/ 55 SDN = V CC 3 25 µa µa Note : The DN and IN are measured with the potentiometer configured as a voltage-divider with = V DD and = V SS. The wiper terminal is unloaded. Note 2: The DN and IN are measured with the potentiometer configured as a variable resistor. is unconnected and = V SS. The wiper terminal is driven with a source current of 8µA for the 5kΩ configuration and 4µA for the kω configuration. Note 3: The wiper resistance is measured assuming the source currents given in Note 2. Note 4: The device draws current in excess of the specified supply current when the digital inputs are driven with voltages between (V CC -.5V) and (GND to 5V). See Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics section. Note 5: Guaranteed by design and characterization. Typical Operating Characteristics (V DD = +5V, V SS = -5V, V CC = +5V, V = V DD, V = V SS, T A = +25 C, unless otherwise noted.) SUPPY CURRENT (ma) SUPPY CURRENT vs. DIGITA INPUT VOTAGE DIGITA INPUT VOTAGE (V) MAX5436 toc RESISTANCE (Ω) WIPER RESISTANCE vs MAX5436 toc2 RESISTANCE (Ω) WIPER RESISTANCE vs. V DD = +5V V SS = -5V MAX5436 toc3 4

5 Typical Operating Characteristics (continued) (V DD = +5V, V SS = -5V, V CC = +5V, V = V DD, V = V SS, T A = +25 C, unless otherwise noted.) END-TO-END RESISTANCE % CANGE END-TO-END RESISTANCE % CANGE vs. TEMPERATURE 5kΩ kω TEMPERATURE ( C) MIDSCAE SWITCING TRANSIENT (CODE 63 TO CODE 64) MAX5436 toc 2V/div V W- mv/div ns/div C WIPER = 2pF MAX5436 toc4 RESISTANCE (kω) DN (SB) W-TO- RESISTANCE CANGE vs. kω 5kΩ VARIABE-RESISTOR DN vs. (5kΩ) MAX5436 toc5 MAX5436 toc8 DIGITA SUPPY CURRENT (µa) DN (SB) DIGITA SUPPY CURRENT vs. TEMPERATURE TEMPERATURE ( C) VARIABE-RESISTOR DN vs. (kω) MAX5436 toc6 MAX5436 toc9 IN (SB) VARIABE-RESISTOR IN vs. (5kΩ) MAX5436 toc IN (SB) VARIABE-RESISTOR IN vs. (kω) MAX5436 toc DN (SB) VOTAGE-DIVIDER DN vs. (5kΩ) MAX5436 toc

6 Typical Operating Characteristics (continued) (V DD = +5V, V SS = -5V, V CC = +5V, V = V DD, V = V SS, T A = +25 C, unless otherwise noted.) DN (SB) VOTAGE-DIVIDER DN vs. (kω) MAX5436 toc3 IN (SB) VOTAGE-DIVIDER IN vs. (5kΩ) MAX5436 toc4 IN (SB) VOTAGE-DIVIDER IN vs. (kω) MAX5436 toc WIPER FREQUENCY RESPONSE AT MIDSCAE (kω) V =.5V P-P C WIPER = 2pF MAX5436 toc6 5 AMPIFIER SMA-SIGNA FREQUENCY RESPONSE V IN = 5mV P-P UNITY GAIN MAX5436 toc AMPIFIER OUTPUT vs. OUTPUT OAD CURRENT V IN = +3V GAIN SETTING. MAX5436 toc8-6 ( ) GAIN (db) GAIN (db) FREQUENCY (kz) -2.. FREQUENCY (kz) AMPIFIER INPUT-REFERRED OFFSET vs. TEMPERATURE MAX5436 toc OAD CURRENT (ma) -.6 OFFSET (mv) TEMPERATURE ( C) 6

7 MAX5436/ MAX5438 PIN MAX543/ NAME Serial Clock Input 2 2 Serial Data Input 3 3 Chip Select 4 SDN Amplifier Shutdown 4 5 GND Analog and Digital Ground DESCRIPTION 5 6 V SS Negative Analog Supply. Bypass with a.µf capacitor to GND. OUT Amplifier Output 8 IN- Amplifier Negative Input 9 IN+ Amplifier Positive Input 6 V DD Positive Analog Supply. Bypass with a.µf capacitor to GND. igh Terminal of Resistor 8 2 W Wiper Terminal of Resistor 9 3 ow Terminal of Resistor 4 V CC Digital Supply. Bypass with a.µf capacitor to GND. Pin Description Detailed Description Digital Interface Operation The use a 3-wire SPI/QSPI/ MICROWIRE-compatible serial data interface to control the wiper position. This write-only interface contains three inputs: chip select (), data in (), and serial clock (). When is taken low, data from is synchronously loaded into the serial shift register on the rising edge of each pulse (Figure 2). The 8-bit data word requires 8 clock pulses to input the serial data. Note that the first bit of the data word, D, is unused and should be ignored. Therefore, the second rising edge of loads the MSB. After all the data bits have been shifted in, they are latched into the potentiometer control register when transitions from low to high, the wiper position is then updated. Note that if is not kept low during the entire data stream, the data will be corrupted and the device will need to be reloaded. Applications Information Adjustable Gain Amplifier The MAX5436/MAX5438 are used with the MAX42 to make a digitally adjustable gain circuit as shown in Figure 4. The normal feedback resistor is replaced with the MAX5436/MAX5438 in a variable-resistor configuration so that the gain of the circuit can be digitally controlled. The MAX543/ can use the internal high-voltage amplifier to make this digitally adjustable gain circuit. CD Biasing Control Applications The are ideal for CDs that require separate voltage for contrast control in addition to the main supply voltage. Figure 5a shows the MAX5436 being used for CD contrast control along with the MAX629, which provides the CD supply voltage. A similar circuit with an additional buffer circuit is shown in Figure 5b. Power-Up Sequencing The have been designed so that any of the supplies can turn on first without causing any unwanted crowbar currents to flow. Note that both digital and analog supplies are required to power up the wiper and uncommitted amplifier (MAX543/ only).

8 DATA WORD D D6 D5 D4 D3 D2 D D Don t Care (MSB) (SB) First Bit oaded Figure. Serial Data Format WIPER POSITION UPDATED ast Bit oaded MSB OADED AST BIT OADED D D6 D5 D4 D3 D2 D D MSB SB TIME Figure 2. Serial Interface Timing Diagram t W t O t S t C t C t CP t t t DS t D Figure 3. Detailed Serial-Interface Timing Diagram 8

9 +5V V S MAX42-5V R2 R W Figure 4. Noninverting Amplifier MAX5436 V O /V S = + R 2 /R V BATT V O DC/DC CONVERTER (SIMPIFIED) CONTRO V OUT (CD BIAS) FIXED ±28V IN CD PANE MAX629 MAX5436 ±6V TO ±26V CONTRAST ADJUST MICROCONTROER/MICROPROCESSOR Figure 5a. Simplified CD Contrast Control Circuit V BATT DC/DC CONVERTER (SIMPIFIED) CONTRO V OUT (CD BIAS) FIXED ±28V IN CD PANE MAX629 MAX543/ ±6V TO ±26V CONTRAST ADJUST MICROCONTROER/MICROPROCESSOR Figure 5b. Simplified CD Contrast Control Circuit with Buffer 9

10 V CC R -BIT SIFT REGISTER COCK OGIC R -BIT ATC GND POR DECODE 28 MAX5436/ MAX5438 W V DD V SS V CC R -BIT SIFT REGISTER COCK OGIC Functional Diagrams R -BIT ATC POR DECODE MAX543/ 28 GND IN+ IN- SDN W V DD V SS OUT Chip Information TRANSISTOR COUNT: 2556 PROCESS: BiCMOS

11 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to A2 e.5±..6±. TOP VIEW D2 D b A 4X S A GAGE PANE α BOTTOM VIEW E2 E INCES DIM A A MIN -.2 MAX.43.6 MIN -.5 MAX..5 A D D2 E E MIIMETERS REF.94 REF b e.9 BSC.5 BSC c S.96 REF.498 REF α 6 6 c UMAX.EPS FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITE: PACKAGE OUTINE, umax/usop APPROVA DOCUMENT CONTRO NO. REV. 2-6 I TSSOP4.4mm.EPS Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 2 San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.