Ultra-Small, Low-Cost, 210MHz, Single-Supply Op Amps with Rail-to-Rail Outputs

Transcription

1 9-5; Rev 4; /9 Ultra-Small, Low-Cost, MHz, Single-Supply General Description The MAX445 single and MAX445 dual op amps are unity-gain-stable devices that combine high-speed performance with rail-to-rail outputs. Both devices operate from a +4.5V to +V single supply or from ±.5V to ±5.5V dual supplies. The common-mode input voltage range extends beyond the negative power-supply rail (ground in single-supply applications). The MAX445/MAX445 require only 6.5mA of quiescent supply current per op amp while achieving a MHz -3dB bandwidth and a 485V/µs slew rate. Both devices are an excellent solution in low-power/lowvoltage systems that require wide bandwidth, such as video, communications, and instrumentation. The MAX445 is available in the ultra-small 5-pin SC7 package, while the MAX445 is available in spacesaving 8-pin SOT3 and SO packages. Features Ultra-Small SC75 and SOT3 Packages Low Cost High Speed MHz -3dB Bandwidth 55MHz.dB Gain Flatness 485V/µs Slew Rate Single +4.5V to +V Operation Rail-to-Rail Outputs Input Common-Mode Range Extends Beyond VEE Low Differential Gain/Phase:.%/.8 Low Distortion at 5MHz -65dBc SFDR -63dB Total Harmonic Distortion MAX445/MAX445 Set-Top Boxes Surveillance Video Systems Battery-Powered Instruments Video Line Driver Analog-to-Digital Converter Interface CCD Imaging Systems Video Routing and Switching Systems Digital Cameras Applications PART MAX445EXK-T MAX445EUK-T MAX445EKA-T MAX445ESA Ordering Information TEMP RANGE -4 C to +85 C -4 C to +85 C -4 C to +85 C -4 C to +85 C PIN- PACKAGE 5 SC7 5 SOT3 8 SOT3 8 SO TOP MARK AAA ADKP AAAA Typical Operating Circuit Pin Configurations IN TOP VIEW MAX445 75Ω Z o = 75Ω OUT 75Ω OUT V EE 5 V CC MAX445 IN+ 3 4 IN- 5Ω 5Ω SC7/SOT3 VIDEO LINE DRIVER Pin Configurations continued at end of data sheet. Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445/MAX445 ABSOLUTE MAXIMUM RATINGS Supply Voltage (V CC to V EE )...+V IN_-, IN_+, OUT_...(V EE -.3V) to (V CC +.3V) Output Short-Circuit Current to V CC or V EE...5mA Continuous Power Dissipation (T A = +7 C) 5-Pin SC7-5 (derate.5mw/ C above +7 C)...mW 5-Pin SOT3-5 (derate 7.mW/ C above +7 C)...57mW DC ELECTRICAL CHARACTERISTICS 8-Pin SOT3-8 (derate 5.6mW/ C above +7 C)...4mW 8-Pin SO (derate 5.9mW/ C above +7 C)...47mW Operating Temperature Range...-4 C to +85 C Storage Temperature Range C to +5 C Lead Temperature (soldering, s)...+3 C 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 at 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. (V CC = +5V, V EE = V, R L = to V CC /, V OUT = V CC /, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +5 C.) (Note ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Common-Mode Voltage Range Input Offset Voltage (Note ) Input Offset Voltage Matching Input Offset Voltage Temperature Coefficient Input Bias Current Input Offset Current Input Resistance Common-Mode Rejection Ratio Open-Loop Gain (Note ) Output Voltage Swing (Note ) V CM Guaranteed by CMRR test V EE - V CC..5 V OS 4 6. TC VOS I B (Note ) I OS (Note ) R IN CMRR A VOL V OUT Differential mode (-V V IN +V) V mv mv µv/ C Common mode (-.V V CM +.75V) 3 MΩ (V EE -.V) V CM (V CC -.5V).5V V OUT 4.75V, R L = kω.5v V OUT 4.5V, R L = 5Ω V V OUT 4V, R L = 5Ω R L = kω R L = 5Ω R L = 75Ω V CC - V OH V OL - V EE V CC - V OH V OL - V EE V CC - V OH V OL - V EE µa µa kω db db V Output Current Output Short-Circuit Current Open-Loop Output Resistance Power-Supply Rejection Ratio (Note 3) I OUT I SC R OUT PSRR R L = 5Ω Sinking or sourcing V CC = 5V Sourcing Sinking VEE = V, V CM = V VEE = -5V, V CM = V ± ma ma Ω db Operating Supply-Voltage Range V S VCC to VEE 4.5. V Quiescent Supply Current (per amplifier) I S ma

3 Ultra-Small, Low-Cost, MHz, Single-Supply AC ELECTRICAL CHARACTERISTICS (V CC = +5V, V EE = V, V CM = +.5V, R F = 4Ω, R L = Ω to V CC /, V OUT = V CC /, A VCL = +V/V, T A = +5 C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Small-Signal -3dB Bandwidth BW SS V OUT = mv P-P MHz Large-Signal -3dB Bandwidth BW LS V OUT = V P-P 75 MHz Bandwidth for.db Gain Flatness BW.dB V OUT = mv P-P 55 MHz Slew Rate SR V OUT = V step 485 V/µs Settling Time to.% t S V OUT = V step 6 ns Rise/Fall Time t R, t F V OUT = mv P-P 4 ns Spurious-Free Dynamic Range SFDR f C = 5MHz, V OUT = V P-P -65 dbc Harmonic Distortion HD f C = 5MHz, V OUT = V P-P nd harmonic 3rd harmonic Total harmonic distortion dbc MAX445/MAX445 Two-Tone, Third-Order Intermodulation Distortion IP3 f = 4.7MHz, f = 4.8MHz, V OUT = V P-P 66 dbc Channel-to-Channel Isolation CH ISO Specified at DC db Input db Compression Point f C = MHz, A VCL = +V/V 4 dbm Differential Phase Error DP NTSC, R L = 5Ω.8 degrees Differential Gain Error DG NTSC, R L = 5Ω. % Input Noise-Voltage Density e n f = khz nv/ Hz Input Noise-Current Density i n f = khz.8 pa/ Hz Input Capacitance C IN pf Output Impedance Z OUT f = MHz.5 Ω Note : All devices are % production tested at T A = +5 C. Specifications over temperature limits are guaranteed by design. Note : Tested with V CM = +.5V. Note 3: PSR for single +5V supply tested with V EE = V, V CC = +4.5V to +5.5V; PSR for dual ±5V supply tested with V EE = -4.5V to -5.5V, V CC = +4.5V to +5.5V. 3

4 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445/MAX445 Typical Operating Characteristics (V CC = +5V, V EE = V, V CM = +.5V, A VCL = +V/V, R F = 4Ω, R L = Ω to V CC /, T A = +5 C, unless otherwise noted.) GAIN (db) SMALL-SIGNAL GAIN vs. FREQUENCY LARGE-SIGNAL GAIN vs. FREQUENCY V OUT = mv P-P 3 V OUT = V P-P k M M M MAX445- G GAIN (db) -6 k M M M MAX445- G GAIN (db) GAIN FLATNESS vs. FREQUENCY.4.3 V OUT = mv P-P k M M M MAX445-3 G IMPEDANCE (Ω). OUTPUT IMPEDANCE vs. FREQUENCY MAX445-4 DISTORTION (dbc) DISTORTION vs. FREQUENCY V OUT = V P-P A VCL = +V/V ND HARMONIC 3RD HARMONIC MAX445-5 DISTORTION (dbc) DISTORTION vs. FREQUENCY V OUT = V P-P A VCL = +V/V ND HARMONIC 3RD HARMONIC MAX k M M M G - k M M M - k M M M DISTORTION (dbc) DISTORTION vs. FREQUENCY V OUT = V P-P A VCL = +5V/V ND HARMONIC 3RD HARMONIC MAX445-7 DISTORTION (dbc) DISTORTION vs. RESISTIVE LOAD f O = 5MHz V OUT = V P-P A VCL = +V/V ND HARMONIC 3RD HARMONIC MAX445-8 DISTORTION (dbc) DISTORTION vs. VOLTAGE SWING f O = 5MHz A VCL = +V/V 3RD HARMONIC ND HARMONIC MAX k M M M R LOAD (Ω) VOLTAGE SWING (Vp-p) 4

5 Ultra-Small, Low-Cost, MHz, Single-Supply Typical Operating Characteristics (continued) (V CC = +5V, V EE =, V CM = +.5V, A VCL = +V/V, R F = 4Ω, R L = Ω to V CC /, T A = +5 C, unless otherwise noted.) DIFF PHASE (degrees) DIFF GAIN (%) DIFFERENTIAL GAIN AND PHASE IRE IRE MAX445- CMR (db) COMMON-MODE REJECTION vs. FREQUENCY k M M M MAX445- G PSR (db) POWER-SUPPLY REJECTION vs. FREQUENCY k M M M MAX445- G MAX445/MAX445 OUTPUT VOLTAGE SWING (V) OUTPUT VOLTAGE SWING vs. RESISTIVE LOAD V CC - V OH V OL - V EE R LOAD (Ω) MAX445-3 INPUT 5mV/div VOLTAGE (V) OUTPUT 5mV/div SMALL-SIGNAL PULSE RESPONSE R F = 4Ω A VCL = +V/V ns/div MAX445-4 INPUT 5mV/div VOLTAGE (V) OUTPUT 5mV/div SMALL-SIGNAL PULSE RESPONSE R F = 5Ω A VCL = +V/V ns/div MAX445-5 SMALL-SIGNAL PULSE RESPONSE LARGE-SIGNAL PULSE RESPONSE LARGE-SIGNAL PULSE RESPONSE INPUT mv/div MAX445-6 INPUT V/div MAX445-7 INPUT 5mV/div VOLTAGE (V) VOLTAGE (V) VOLTAGE (V) MAX445-8 OUTPUT 5mV/div R F = 5Ω A VCL = +5V/V OUTPUT V/div R F = 4Ω A VCL = +V/V OUTPUT V/div R F = 5Ω A VCL = +V/V ns/div ns/div ns/div 5

6 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445/MAX445 Typical Operating Characteristics (continued) (V CC = +5V, V EE =, V CM = +.5V, A VCL = +V/V, R F = 4Ω, R L = Ω to V CC /, T A = +5 C, unless otherwise noted.) VOLTAGE (V) INPUT V/div INPUT V/div LARGE-SIGNAL PULSE RESPONSE R F = 5Ω A VCL = +V/V ns/div MAX445-9 VOLTAGE NOISE (nv/ Hz) VOLTAGE NOISE vs. FREQUENCY R L = Ω k k k M M MAX445- CURRENT NOISE (pa/ Hz) CURRENT NOISE vs. FREQUENCY R L = Ω k k k M M MAX ISOLATION RESISTANCE vs. CAPACITIVE LOAD MAX SMALL-SIGNAL BANDWIDTH vs. LOAD RESISTANCE MAX445-3 RISO (Ω) 4 3 SMALL SIGNAL (V OUT = mv P-P ) BANDWIDTH (MHz) 5 9 LARGE SIGNAL (V OUT = V P-P ) C LOAD (pf) R LOAD (Ω) OPEN-LOOP GAIN (dbc) OPEN-LOOP GAIN vs. RESISTIVE LOAD MAX445-4 CROSSTALK (db) MAX445 CROSSTALK vs. FREQUENCY MAX445-5 k k R LOAD (Ω) -4.M M M M G 6

7 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445 PIN Pin Description OUT Amplifier Output 4 V EE INA+ 7 OUTB Amplifier B Output MAX NAME INA- 3 IN+ Noninverting Input 4 IN- Inverting Input 5 8 V CC Positive Power Supply OUTA Amplifier A Output INB- INB+ FUNCTION Negative Power Supply or Ground (in singlesupply operation) Amplifier A Inverting Input Amplifier A Noninverting Input Amplifier B Inverting Input Amplifier B Noninverting Input Detailed Description The MAX445/MAX445 are single-supply, rail-to-rail, voltage-feedback amplifiers that employ current-feedback techniques to achieve 485V/µs slew rates and MHz bandwidths. Excellent harmonic distortion and differential gain/phase performance make these amplifiers an ideal choice for a wide variety of video and RF signal-processing applications. The output voltage swings to within 55mV of each supply rail. Local feedback around the output stage ensures low open-loop output impedance to reduce gain sensitivity to load variations. The input stage permits common-mode voltages beyond the negative supply and to within.5v of the positive supply rail. Applications Information Choosing Resistor Values Unity-Gain Configuration The MAX445/MAX445 are internally compensated for unity gain. When configured for unity gain, the devices require a 4Ω resistor (RF) in series with the feedback path. This resistor improves AC response by reducing the Q of the parallel LC circuit formed by the parasitic feedback capacitance and inductance. Inverting and Noninverting Configurations Select the gain-setting feedback (RF) and input (R G ) resistor values to fit your application. Large resistor values increase voltage noise and interact with the amplifier s input and PC board capacitance. This can generate undesirable poles and zeros and decrease bandwidth or cause oscillations. For example, a noninverting gain-of-two configuration (R F = R G ) using kω resistors, combined with pf of amplifier input capacitance and pf of PC board capacitance, causes a pole at 59MHz. Since this pole is within the amplifier bandwidth, it jeopardizes stability. Reducing the kω resistors to Ω extends the pole frequency to.59ghz, but could limit output swing by adding Ω in parallel with the amplifier s load resistor. Table lists suggested feedback and gain resistors, and bandwidths for several gain values in the configurations shown in Figures a and b. Layout and Power-Supply Bypassing These amplifiers operate from a single +4.5V to +V power supply or from dual ±.5V to ±5.5V supplies. For single-supply operation, bypass V CC to ground with a R G IN R TIN R F MAX445 _ R TO V OUT = [+ (R F / R G )] V IN Figure a. Noninverting Gain Configuration IN R TIN R G R S R F MAX445 _ V OUT = -(R F / R G ) V IN R TO Figure b. Inverting Gain Configuration V OUT R O V OUT R O MAX445/MAX445 7

8 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445/MAX445 Table. Recommended Component Values R F (Ω) R G (Ω) R S (Ω) R TIN (Ω) R TO (Ω) Note: COMPONENT Small-Signal -3dB Bandwidth (MHz) R L = R O + R TO ; R TIN and R TO are calculated for 5Ω applications. For 75Ω systems, R TO = 75Ω; calculate R TIN from the following equation: R TIN = 75 Ω - 75 RG.µF capacitor as close to the pin as possible. If operating with dual supplies, bypass each supply with a.µf capacitor. Maxim recommends using microstrip and stripline techniques to obtain full bandwidth. To ensure that the PC board does not degrade the amplifier s performance, design it for a frequency greater than GHz. Pay careful attention to inputs and outputs to avoid large parasitic capacitance. Whether or not you use a constantimpedance board, observe the following design guidelines: Don t use wire-wrap boards; they are too inductive. Don t use IC sockets; they increase parasitic capacitance and inductance. Use surface-mount instead of through-hole components for better high-frequency performance. Use a PC board with at least two layers; it should be as free from voids as possible. Keep signal lines as short and as straight as possible. Do not make 9 turns; round all corners. Rail-to-Rail Outputs, Ground-Sensing Input The input common-mode range extends from (VEE - mv) to (VCC -.5V) with excellent commonmode rejection. Beyond this range, the amplifier output is a nonlinear function of the input, but does not undergo phase reversal or latchup. The output swings to within 55mV of either powersupply rail with a kω load. The input ground sensing GAIN (V/V) and the rail-to-rail output substantially increase the dynamic range. With a symmetric input in a single +5V application, the input can swing.95vp-p and the output can swing 4.9V P-P with minimal distortion. Output Capacitive Loading and Stability The MAX445/MAX445 are optimized for AC performance. They are not designed to drive highly reactive loads, which decrease phase margin and may produce excessive ringing and oscillation. Figure shows a circuit that eliminates this problem. Figure 3 is a graph of the optimal isolation resistor (RS) vs. capacitive load. Figure 4 shows how a capacitive load causes excessive peaking of the amplifier s frequency response if the capacitor is not isolated from the amplifier by a resistor. A small isolation resistor (usually Ω to 3Ω) placed before the reactive load prevents ringing and oscillation. At higher capacitive loads, AC performance is controlled by the interaction of the load capacitance and the isolation resistor. Figure 5 shows the effect of a 7Ω isolation resistor on closed-loop response. Coaxial cable and other transmission lines are easily driven when properly terminated at both ends with their characteristic impedance. Driving back-terminated transmission lines essentially eliminates the line s capacitance

9 Ultra-Small, Low-Cost, MHz, Single-Supply R G R F R ISO V OUT MAX445 _ V IN C L R TIN 5Ω Figure. Driving a Capacitive Load Through an Isolation Resistor CAPACITIVE LOAD, C L (pf) Figure 3. Capacitive Load vs. Isolation Resistance ISOLATION RESISTANCE, RISO (Ω) MAX445/MAX C L = 5pF 3 R ISO = 7Ω C L = 47pF 3 GAIN (db) - C L = pf C L = 5pF GAIN (db) C L = 68pF C L = pf k M M M G -7 k M M M G Figure 4. Small-Signal Gain vs. Frequency with Load Capacitance and No Isolation Resistor Figure 5. Small-Signal Gain vs. Frequency with Load Capacitance and 7Ω Isolation Resistor 9

10 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445/MAX445 Pin Configurations (continued) TOP VIEW OUTA INA- 8 7 V CC OUTB MAX445 INA+ V EE INB- INB+ SOT3/SO MAX445 TRANSISTOR COUNT: 86 MAX445 TRANSISTOR COUNT: 7 Chip Information

11 Ultra-Small, Low-Cost, MHz, Single-Supply Package Information For the latest package outline information and land patterns, go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 5 SC7 X SOT3 U SOT3 K SO S SC7, 5L.EPS MAX445/MAX445 PACKAGE OUTLINE, 5L SC7-76 E

12 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445/MAX445 Package Information (continued) For the latest package outline information and land patterns, go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. SOT-3 5L.EPS

13 Ultra-Small, Low-Cost, MHz, Single-Supply Package Information (continued) For the latest package outline information and land patterns, go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. MARKING MAX445/MAX445 PACKAGE OUTLINE, SOT-3, 8L BODY -78 I 3

14 Ultra-Small, Low-Cost, MHz, Single-Supply MAX445/MAX445 Package Information (continued) For the latest package outline information and land patterns, go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. N TOP VIEW E H INCHES MILLIMETERS DIM A A MIN.53.4 MAX.69. MIN.35. MAX.75.5 B C e.5 BSC.7 BSC E H L VARIATIONS: DIM D D D INCHES MILLIMETERS MIN MAX MIN MAX N MS AA AB AC SOICN.EPS D A C e B A FRONT VIEW L SIDE VIEW -8 PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE,.5" SOIC APPROVAL DOCUMENT CONTROL NO. REV. -4 B 4

15 Ultra-Small, Low-Cost, MHz, Single-Supply REVISION NUMBER REVISION DATE DESCRIPTION Revision History PAGES CHANGED 4 /9 Corrected TOC 6 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. 5 Maxim Integrated Products, San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.