PART. MAX5420CEUA -40 C to +85 C 8 µmax 0.5% MAX5421CEUB -40 C to +85 C 10 µmax 0.5% Maxim Integrated Products 1

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1 9-223; Rev 2; 2/5 Digitally Programmable Precision General Description The MX542 and MX542 are digitally programmable precision voltage dividers optimized for use in digitally programmable gain amplifier configurations. The MX542/ MX542 operate from a single supply or dual ±5V supply, and consume only 3µ supply current. These devices consist of a digitally selectable resistor array that provides four precision noninverting gains of, 2, 4, and 8 for PGs. The MX542 and MX542 achieve a resistor ratio accuracy of.25% (MX542_),.9% (MX542_B), and.5% (MX542_C). The MX542 includes an on-chip matching resistor for op amp bias-current compensation. The MX542 and MX542 are available in 8-pin and -pin µmx packages. The devices are specified over the extended temperature range (-4 C to +85 C). pplications General-Purpose Programmable Noninverting mplifiers Programmable Instrumentation mplifiers Functional Diagram Features Four Precision Divider Ratios For Noninverting Gains of, 2, 4, and 8 in PGs.25%,.9%, or.5% Ratio ccuracy Guaranteed Over -4 C to +85 C On-Chip Matching Resistor for Op mp Bias- Current Compensation (MX542) 5V Single or ±5V Dual Supply Operation ow 3µ Supply Current CMOS/TT ogic Compatible 2-ire Parallel Interface Small 8-Pin and -Pin µmx Packages PRT Ordering Information TEMP. RNGE PIN- PCKGE GIN CCURCY MX542EU -4 C to +85 C 8 µmx.25% MX542BEU -4 C to +85 C 8 µmx.9% MX542CEU -4 C to +85 C 8 µmx.5% MX542EUB -4 C to +85 C µmx.25% MX542BEUB -4 C to +85 C µmx.9% MX542CEUB -4 C to +85 C µmx.5% Pin Configurations MX542/MX542 TOP VIE D D MX542 MX542 DECODER D MX542 µmx D MTC_ MTC_ MX542 ONY 2 3 MX D 4 7 MTC_ D 5 6 MTC_ µmx- Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 MX542/MX542 BSOUTE MXIMUM RTINGS to...-.3v to +6V to...+.3v to -6V D, D to...-.3v to ( +.3V),,, MTC_ to...( -.3V) to ( +.3V) Input and Output atchup Immunity...±5m Stresses beyond those listed under bsolute 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. EECTRIC CRCTERISTICS Continuous Power Dissipation (T = +7 C) 8-Pin µmx (derate 4.m/ C above +7 C)...333m -Pin µmx (derate 5.6m/ C above +7 C)...444m Operating Temperature Range...-4 C to +85 C Storage Temperature Range...-6 C to +5 C ead Temperature (soldering, s)...+3 C ( = ±5%, = -5V ±5% or =, T = T MIN to T MX, unless otherwise noted. Typical values are at T = +25 C.) PRMETER SYMBO CONDITIONS MIN TYP MX UNITS Divider Ratio ccuracy MX542_ ±.25 MX542_B ±.9 MX542_C ±.5 -to- Resistance R (Figure ) 5 kω Input Resistance at R 5 kω Input Resistance at R Ratio = = -5V 3 = 5 Ω Ratio = 2, 4, 8 8 kω % Capacitance at,,, MTC_, MTC_ Matching Resistor DYNMIC PERFORMNCE C NOG 5 pf = -5V 3 Ratio = MX542 = 5 Ω Ratio = 2, 4, 8 8 kω Switching Time t S V settl es to.2% of fi nal val ue w i th 2p F V D D = + 5V, V S S = - 5V, d i g i tal i np ut to + 3V, cap aci ti ve l oad. C i r cui t of Fi g ur e 2..5 µs DIGIT INPUTS Input igh Voltage V I 2.4 V Input ow Voltage V I.8 Input eakage Current D, D = or ± µ Input Capacitance 5 pf 2

3 EECTRIC CRCTERISTICS (continued) ( = ±5%, = -5V ±5% or =, T = T MIN to T MX, unless otherwise noted. Typical values are at T = +25 C.) POER SUPPIES PRMETER SYMBO CONDITIONS MIN TYP MX UNITS Positive Supply Voltage Negative Supply Voltage D, D = or 3 7 Positive Supply Current I DD D, D = 3V 5 25 D, D = or 3 7 Negative Supply Current I SS D, D = 3V 5 25,,, MTC_, MTC_ Voltage Range V µ µ V MX542/MX542 Typical Operating Characteristics ( =, = -5V, or =, T = +25 C, unless otherwise noted.) (Note ). MX542_ DIVIDER RTIO CCURCY V = V = -5V RTIO = MX542/2 toc.5.46 MX542_ DIVIDER RTIO CCURCY V = V = -5V MX542/2 toc2.5.4 MX542_ DIVIDER RTIO CCURCY V = V = -5V MX542/2 toc

4 MX542/MX542 Typical Operating Characteristics (continued) ( =, = -5V, or =, T = +25 C, unless otherwise noted.) (Note ) MX542_ DIVIDER RTIO CCURCY V = V = -5V MX542/2 toc MX542_B DIVIDER RTIO CCURCY V = V = -5V RTIO = MX542/2 toc MX542_B DIVIDER RTIO CCURCY V = V = -5V MX542/2 toc MX542_B DIVIDER RTIO CCURCY V = V = -5V MX542/2 toc MX542_B DIVIDER RTIO CCURCY V = V = -5V MX542/2 toc8.. MX542_ RTIO CCURCY vs. POSITIVE SUPPY VOTGE MX542/2 toc RTIO = V = +3V, V = POSITIVE SUPPY VOTGE (V)... MX542_B RTIO CCURCY vs. POSITIVE SUPPY VOTGE MX542/2 toc.. MX542_ RTIO CCURCY vs. NEGTIVE SUPPY VOTGE MX542/2 toc... MX542_B RTIO CCURCY vs. NEGTIVE SUPPY VOTGE V = 5V, V = MX542/2 toc2. V = +3V, V = RTIO = POSITIVE SUPPY VOTGE (V) RTIO = V = 5V, V = NEGTIVE SUPPY VOTGE (V) RTIO = NEGTIVE SUPPY VOTGE (V) 4

5 Typical Operating Characteristics (continued) ( =, = -5V, or =, T = +25 C, unless otherwise noted.) (Note ) SITCING TIME (RTIO -TO-2) ns/div V =, V = -5V MX542/2 toc3 D, 5V/div V 2V/div SITCING TIME (RTIO 2-TO-4) ns/div V =, V = -5V MX542/2 toc4 D, 5V/div V V/div MX542/MX542 SITCING TIME (RTIO 4-TO-8) MX542/2 toc5 5V D, 5V/div V 5mV/div SUPPY CURRENT (µ) SUPPY CURRENT D, D = or MX542/2 toc6 ns/div V =, V = -5V Note : For MX542_C accuracy Typical Operating Characteristics, refer to MX542_B accuracy Typical Operating Characteristics. 5

6 MX542/MX542 MX542 PIN MX542 Detailed Description The MX542/MX542 are digitally programmable precision voltage dividers for programmable-gain amplifiers. Operationally, these devices consist of digitally selectable precision resistor-dividers providing noninverting gains of, 2, 4, and 8 for PG applications (see Functional Diagram and Figure ). Ratio = + NME Positive Supply Voltage 2 2 Negative Supply Voltage 3 3 Ground 4, 5 4, 5 D, D 6 8 ow Terminal of Resistor-Divider 7 9 Resistor-Divider Output 8 igh Terminal of Resistor-Divider 6 MTC_ Matching Resistor ow Terminal 7 MTC_ Matching Resistor igh Terminal R_ B R_ The MX542/MX542 achieve divider ratio accuracy of.25% (MX542/MX542),.9% (MX542B/ MX542B) or.5% (MX542C/MX542C). The end-to-end resistance from to is 5kΩ. The impedance seen at is designed to be the same 8kΩ for divider ratios 2, 4, and 8, ensuring excellent impedance matching and constant switching times. In gain of + configuration, is internally connected to with a typical resistance of 5Ω. Matching Resistor (MX542) The MX542 includes a matching resistor to compensate for offset voltage due to input bias current of the op amp. The resistance from MTC_ to MTC_, equals the resistance seen at for gains of 2, 4, and 8. In the gain of +, an internal switch connects MTC_ and MTC_. This internal switch matches the impedance of the switch between and. FUNCTION Pin Description Digital Control Inputs. Drive D and D logic high or logic low to set the divider ratio. See ogic Control Truth Table. Table. ogic Control Truth Table DIGIT INPUTS DIVIDER D D RTIO Digital Interface Operation The MX542/MX542 feature a simple two-bit parallel programming interface. D and D program the divider ratio setting according to the ogic Control Truth Table (Table ). The digital interface is CMOS/TT logic compatible. pplications Information Programmable-Gain mplifier The MX542/MX542 are ideally suited for high-precision PG applications. The typical application circuit of Figure 3 uses the MX542 with matching resistor to compensate for voltage offset due to op amp input bias currents. Use the MX542 with an ultra-low input bias current op amp such as the MX4237 (Figure 4). Power Supplies and Bypassing The MX542/MX542 operate from dual ±5V supplies, or a single supply. For dual supplies, bypass and with.µf ceramic capacitors to. For single supply, connect to and bypass with a.µf ceramic capacitor to. 6

7 RTIO = R3B R2B RB R3 R2 R RTIO = ( ) R_B + R_ V IN MTC_ MX542 V IN MTC_ MX4237 MX4493 Figure 3. Programmable-Gain mplifier with Op mp Bias- Current Matching V OUT V OUT MX542/MX542 Figure. Simplified Functional Diagram.µF RTIO = MX542 R3B R2B RB Figure 4. Programmable-Gain mplifier R3.µF R2 RTIO = R ( ) R_B + R_ MX542 D D TEKTRONIX P6245 OSCIOSCOPE FET PROBE C < pf MΩ Switching Time and ayout Concerns The switching time of the MX542/MX542 depends on the capacitive loading at. For best performance, reduce parasitic board capacitance by minimizing the circuit board trace from to the op amp inverting input, and choose an op amp with low input capacitance. TRNSISTOR COUNT: 8 PROCESS: CMOS Chip Information -5V PUSE GENERTOR Figure 2. Switching Time Test Circuit 7

8 MX542/MX542 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 8 Ø.5±. D TOP VIE E 4X S BOTTOM VIE 8 DIM INCES MIN MX BSC 2.3 b c D e E α S.27 BSC MIIMETERS MIN MX BSC BSC 8UMXD.EPS 2 e b c α FRONT VIE SIDE VIE PROPRIETRY INFORMTION TITE: PCKGE OUTINE, 8 umx/usop PPROV DOCUMENT CONTRO NO. REV J 8

9 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to e Ø.5±..6±. TOP VIE 4X S BOTTOM VIE DIM MIN -.2 MX.43.6 MIN -.5 MX D D2 E E2 b e c S α INCES MIIMETERS REF.94 REF BSC.5 BSC REF.498 REF 6 6 UMX.EPS MX542/MX542 D2 E2 GGE PNE 2 c D b α E FRONT VIE SIDE VIE PROPRIETRY INFORMTION TITE: PCKGE OUTINE, umx/usop PPROV DOCUMENT CONTRO NO. 2-6 REV. 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, C Maxim Integrated Products Printed US is a registered trademark of Maxim Integrated Products.