19-0157; Rev 1; 1/94 Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators ____________________________Features The MAX913 single and MAX912 dual high-speed, low-power comparators have differential inputs and complementary TTL outputs. Fast propagation delay (10ns typ), extremely low supply current, and a wide common-mode input range that includes the negative rail make the MAX912/MAX913 ideal for low-power, high-speed, single +5V (or ±5V) applications such as V/F converters or switching regulators. ♦ Ultra Fast (10ns) The MAX912/MAX913 outputs remain stable through the linear region. This feature eliminates output instability common to high-speed comparators when driven with a slow-moving input signal. ♦ Stable in the Linear Region The MAX912/MAX913 can be powered from a single +5V supply or a ±5V split supply. The MAX913 is an improved plug-in replacement for the LT1016. It provides significantly wider input voltage range and equivalent speed at a fraction of the power. The MAX912 dual comparator has equal performance to the MAX913 and includes independent latch controls. ________________________Applications Zero-Crossing Detectors Ethernet Line Receivers Switching Regulators High-Speed Sampling Circuits High-Speed Triggers Extended Range V/F Converters Fast Pulse Width/Height Discriminators ♦ Single +5V or Dual ±5V Supply Operation ♦ Input Range Extends Below Negative Supply ♦ Low Power: 6mA (+5V) Per Comparator ♦ No Minimum Input Signal Slew-Rate Requirement ♦ No Power-Supply Current Spiking ♦ Inputs Can Exceed Either Supply ♦ Low Offset Voltage: 0.8mV ______________Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX912CPE 0°C to +70°C 16 Plastic DIP MAX912CSE MAX912C/D MAX912EPE MAX912ESE MAX912MJE 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -55°C to +125°C 16 Narrow SO Dice* 16 Plastic DIP 16 Narrow SO 16 CERDIP MAX913CPA 0°C to +70°C 8 Plastic DIP MAX913CSA MAX913C/D MAX913EPA MAX913ESA MAX913MJA 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -55°C to +125°C 8 SO Dice* 8 Plastic DIP 8 SO 8 CERDIP * Dice are specified at TA = +25°C, DC parameters only. ___________________________________________________________Pin Configurations TOP VIEW QA 1 16 QB MAX912 IN+ 2 3 V- 4 MAX913 DIP/SO Q 7 Q 6 GND 5 LE 14 GND LEA 4 N.C. 5 V- 6 11 V+ INA- 7 10 INB- INA+ 8 9 13 LEB - A + IN- + 8 15 QB 3 + 1 2 B - V+ QA GND 12 N.C. INB+ DIP/Narrow SO ________________________________________________________________ Maxim Integrated Products Call toll free 1-800-998-8800 for free samples or literature. 1 MAX912/MAX913 _______________General Description MAX912/MAX913 Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators ABSOLUTE MAXIMUM RATINGS Positive Supply Voltage............................................................7V Negative Supply Voltage ........................................................-7V Differential Input Voltage .....................................................±15V Input Voltage (Referred to V-)..................................- 0.3V to 15V Latch Pin Voltage .............................................Equal to Supplies Continuous Output Current...............................................±20mA Continuous Power Dissipation (TA = +70°C) 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ...727mW 8-Pin SO (derate 5.88mW/°C above +70°C)................471mW 8-Pin CERDIP (derate 8.00mW/°C above +70°C)........640mW 16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW 16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ...696mW 16-Pin CERDIP (derate 10.00mW/°C above +70°C)....800mW Operating Temperature Ranges: MAX91_ C_ _ ......................................................0°C to +70°C MAX91_ E_ _....................................................-40°C to +85°C MAX91_ MJ_ .................................................-55°C to +125°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+300°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 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. ELECTRICAL CHARACTERISTICS (V+ = +5V, V- = -5V, VQ = 1.4V, VLE = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Input Offset Voltage (Note 1) Offset Drift Input Offset Current (Note 1) SYMBOL VOS CONDITIONS RS ≤ 100Ω MIN TA = +25°C Input Voltage Range 2 TA = +25°C IOS VCM 0.3 TA = TMIN to TMAX Power-Supply Rejection Ratio Small-Signal Voltage Gain CMRR PSRR AV VOH Output Voltage VOL 2 Positive Supply Current Per Comparator I+ Negative Supply Current Per Comparator I- Latch-Pin High Input Voltage VIH Latch-Pin Low Input Voltage VIL Latch-Pin Current IIL 3 C, E temp. ranges -5.2 +3.5 M temp. range -5.0 +3.5 -0.2 +3.5 M temp. range 0 80 110 Positive supply: 4.5V ≤ V+ ≤ 5.5V 60 85 Negative supply: -2V ≥ V- ≥ -7V 80 100 V+ ≥ 4.5V 1500 3500 IOUT = 1mA 2.7 3.4 IOUT = 10mA 2.4 3.0 ISINK = 4mA 0.3 TA = +25°C, ISINK = 10mA 0.4 C, E temp. ranges µA µA V +3.5 -5.0V ≤ VCM ≤ +3.5V 1V ≤ VQ ≤ 2V, TA = +25°C mV 5 8 10 C, E temp. ranges UNITS µV/°C 0.5 0.8 C, E temp. ranges M temp. range Single +5V Common-Mode Rejection Ratio 2 3 TCVOS IB MAX 0.8 TA = TMIN to TMAX TA = +25°C Input Bias Current TYP 6 M temp. range dB dB V/V 0.5 10 12 0.4 2 2.0 VLE = 0V _______________________________________________________________________________________ V mA mA V 0.8 V -20 µA Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators MAX912/MAX913 ELECTRICAL CHARACTERISTICS (continued) (V+ = +5V, V- = -5V, VQ = 1.4V, VLE = 0V, TA = TMIN to TMAX, unless otherwise noted). PARAMETER SYMBOL Propagation Delay (Note 2) tPD+, tPD- Differential Propagation Delay (Note 2) ∆tPD Channel-to-Channel Propagation Delay (Note 2) MIN CONDITIONS ∆VIN = 100mV, VOD = 5mV TA = +25°C ∆VIN = 100mV, VOD = 20mV TA = +25°C ∆VIN = 100mV, VOD = 5mV TA = +25°C ∆VIN = 100mV, VOD = 5mV (MAX912 only) TA = +25°C TYP MAX 10 14 TA = TMIN to TMAX UNITS 16 9 12 TA = TMIN to TMAX ns 15 MAX913 2 3 MAX912 3 5 ns 500 ps Latch Setup Time (Note 3) tSU 2 0 ns Latch Hold Time (Note 3) tH 3 2 ns Latch Propagation Delay (Note 4) tLPD 7 ns Note 1: Input Offset Voltage (VOS) is defined as the average of the two input offset voltages, measured by forcing first one output, then the other to 1.4V. Input Offset Current (IOS) is defined the same way. Note 2: Propagation Delay (tPD) and Differential Propagation Delay (∆tPD) cannot be measured in automatic handling equipment with low input overdrive values. The MAX912/MAX913 are sample tested to 0.1% AQL with a 1V step and 500mV overdrive at +25°C only. Correlation tests show that tPD and ∆tPD can be guaranteed with this test, if additional DC tests are performed to guarantee that all internal bias conditions are correct. For low overdrive conditions, VOS is added to the overdrive. Differential Propagation Delay is defined as: ∆tPD = tPD+ – tPD-. Note 3: Input latch setup time (tSU) is the interval in which the input signal must be stable prior to asserting the latch signal. The hold time (tH) is the interval after the latch is asserted in which the input signal must be stable. These parameters are guaranteed by design. Note 4: Latch Propagation Delay (tLPD) is the delay time for the output to respond when the latch-enable pin is deasserted. See Timing Diagram. __________________________________________Typical Operating Characteristics (V+ = 5V, V- = -5V, VLE = 0V, CL = 15pF, TA = +25°C, unless otherwise noted.) tPD(-) 8 tPD(+) 6 1 10 INPUT OVERDRIVE (mV) 100 MAX912-02 VOD = 10mV 10 40 30 20 tPD(-) 10 tPD(+) 0 5 11 PROPAGATION DELAY (ns) 9 7 VOD = 10mV PROPAGATION DEALY (ns) VOD = 10mV PROPAGATION DELAY (ns) 50 MAX912-01 10 PROPAGATION DELAY vs. LOAD CAPACITANCE PROPAGATION DELAY vs. SOURCE RESISTANCE MAX912-03 PROPAGATION DELAY vs. INPUT OVERDRIVE tPD(-) 9 8 tPD(+) 7 6 1 10 100 1000 SOURCE RESISTANCE (Ω) 10,000 10 20 30 40 LOAD CAPACITANCE (pF) _______________________________________________________________________________________ 50 3 ____________________________Typical Operating Characteristics (continued) (V+ = 5V, V- = -5V, VLE = 0V, CL = 15pF, TA = +25°C, unless otherwise noted.) POSITIVE SUPPLY CURRENT (PER COMPARATOR) vs. POSTIVE SUPPLY VOLTAGE Q OUTPUT tPD(+) TA = +125°C TA = +25°C 6 TA = -55°C 4 -15 25 65 TEMPERATURE (°C) TA = -55°C 3 105 125 4 OFFSET VOLTAGE vs. TEMPERATURE 5 7 3 4 V- (V) INPUT BIAS CURRENT vs. TEMPERATURE OUTPUT VOLTAGE vs. DIFFERENTIAL INPUT VOLTAGE 600 VCM = 0V 400 3 -15 25 65 TEMPERATURE (°C) 105 125 6 7 TA = +25°C 3 TA = -55°C 2 0 2 -55 5 1 VCM = +3.5V 0 2 TA = +125°C 4 4 1 5 VCM = -5.2V 5 200 0 MA912-12 800 IB (µA) 6 V+ (V) 6 MAX912-11 1000 TA = +25°C 0.6 0.2 2 -55 TA = +125°C 0.8 0.4 Q OUTPUT tPD(+) 6 4 MAX912-07 8 MAX912-14 7 1.2 1.0 9 8 V- = 0V TO -5V I- (PER COMPARATOR) Q OUTPUT tPD(-) 10 OUTPUT VOLTAGE (V) PROPAGATION DELAY (ns) 10 Q OUTPUT tPD(-) I+ (PER COMPARATOR) VOD = 10mV MAX912-04 11 NEGATIVE SUPPLY CURRENT (PER COMPARATOR) vs. NEGATIVE SUPPLY VOLTAGE MAX912-08 PROPAGATION DELAY vs. TEMPERATURE VOS (µV) MAX912/MAX913 Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators -55 -15 25 65 TEMPERATURE (°C) 105 125 -3 -2 -1 0 1 2 DIFFERENTIAL INPUT VOLTAGE (mV) _______________________________________________________________________________________ 3 Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators NEGATIVE-TO-POSITIVE PROPAGATION DELAY POSITIVE-TO-NEGATIVE PROPAGATION DELAY INPUT 100mV/div INPUT 100mV/div OUTPUT Q OUTPUT Q 1V/div 1V/div Q Q 5ns/div 5ns/div MAX912/MAX913 RESPONSE TO 50MHz (+10mVP-P) SINE WAVE INPUT 10mV/div OUTPUT Q 2V/div 10ns/div MAX912/MAX913 RESPONSE TO SLOW-MOVING TRIANGLE WAVE INDUSTRY STANDARD 686 RESPONSE MAX912/MAX913 RESPONSE 20µs/div INPUT 20mV/div INPUT 20mV/div OUTPUT Q 1V/div OUTPUT Q 1V/div Q 1V/div Q 1V/div 20µs/div _______________________________________________________________________________________ 5 MAX912/MAX913 ____________________________Typical Operating Characteristics (continued) (V+ = 5V, V- = -5V, VLE = 0V, CL = 15pF, TA = +25°C, unless otherwise noted.) Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators MAX912/MAX913 ____________________________________________________________Pin Descriptions PIN MAX912 1 FUNCTION QA –– QA Comparator A TTL output 2 3, 14 GND 4 LEA Logic ground. Connect both GND pins to ground. –– Comparator A latch enable. QA and Q A are latched when LEA is high or floating. Comparator A latch is transparent when LEA is low. 5, 12 N.C. 6 V- Comparator A complementary TTL output Not internally connected Negative power supply: -5V for dual supplies (bypass to GND with a 0.1µF capacitor), or GND for a single supply 7 INA- Comparator A inverting input 8 INA+ Comparator A noninverting input 9 INB+ Comparator B noninverting input 10 INB- Comparator B inverting input 11 V+ 13 LEB 15 –– QB Comparator B complementary TTL output 16 QB Comparator B TTL output PIN MAX913 NAME 1 V+ Positive power supply. Bypass to GND with a 0.1µF capacitor. 2 IN+ Noninverting input 3 IN- Inverting input 4 V- 5 LE 6 GND 7 Q –– Q 8 6 NAME Positive power supply, +5V. Bypass to GND with a 0.1µF capacitor. –– Comparator B latch enable. QB and Q B are latched when LEB is high or floating. Comparator B latch is transparent when LEB is low. FUNCTION Negative power supply: -5V for dual supplies (bypass to GND with a 0.1µF capacitor), or GND for a single supply –– Latch enable. Q and Q are latched when LE is TTL high or floating. The comparator latch is transparent when LE is low. Logic ground TTL output Complementary TTL output _______________________________________________________________________________________ Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators Resolution Input Amplifier A comparator can be thought of as having two sections: an input amplifier and a logic interface. The MAX912/MAX913’s input amplifier is fully differential, with input offset voltage trimmed to below 2.0mV at +25°C. Input common-mode range extends from 200mV below the negative supply rail to 1.5V below the positive power supply. The total common-mode range is 8.7V when operating from ±5VDC supplies. The MAX912/MAX913’s amplifier has no built-in hysteresis. For highest accuracy, do not add hysteresis. Figure 2 shows how hysteresis degrades resolution. A comparator’s ability to resolve small signal differences—its resolution—is affected by various factors. As with most amplifiers, the most significant factors are the input offset voltage (VOS) and the common-mode and power-supply rejection ratios (CMRR, PSRR). If source impedance is high, input offset current can be significant. If source impedance is unbalanced, the input bias current can introduce another error. For high-speed comparators, an additional factor in resolution is the comparator’s stability in its linear region. Many high-speed comparators are useless in their linear region because they oscillate. This makes the differential input voltage region around 0V unusable, as does a high VOS. Hysteresis does not cure the problem, but acts to keep the input away from its linear range (Figure 2). The MAX912/MAX913 do not oscillate in the linear region, which greatly enhances the comparator’s resolution. __________Applications Information Power Supplies and Bypassing The MAX912/MAX913 are tested with ±5V power supplies that provide an input common-mode range (VCM) of 8.7V (-5.2V to +3.5V). Operation from a single +5V supply provides a common-mode input range of 3.7V (-0.2V to +3.5V). Connect V- to GND for single-supply operation. The MAX912/MAX913 will operate from a minimum single-supply voltage of +4.5V. The V+ supply provides power to both the analog input stage and digital output circuits, whereas the V- supply only powers the analog section. Bypass V+ and V- to ground with 0.1µF to 1.0µF ceramic capacitors in parallel with 10µF or greater tantalum capacitors. Connect the ceramic capacitors very close to the MAX912/MAX913’s tSU VIN (DIFFERENTIAL) tH LATCH ENABLE (LE) tLPDR tPD+ Q ∆tPD Q tPD- Figure 1. Timing Diagram _______________________________________________________________________________________ 7 MAX912/MAX913 _______________Detailed Description The MAX913 (single) and MAX912 (dual) high-speed comparators have a unique design that prevents oscillation when the comparator is in its linear region. No minimum input slew rate is required. Many high-speed comparators oscillate in the linear region, as shown in the Typical Operating Characteristics’ industry-standard 686 response graph. One way to overcome this oscillation is to sample the output after it has passed through the unstable region. Another practical solution is to add hysteresis. Either solution results in a loss of resolution and bandwidth. Because the MAX912/MAX913 do not need hysteresis, they offer high resolution to all signals—including lowfrequency signals. The MAX912/MAX913 provide a TTL-compatible latch function that holds the comparator output state (Figure 1). As long as Latch Enable (LE) is high or floating, the input signal has no effect on the output state. With LE low, the outputs are controlled by the input differential voltage and the latch is transparent. MAX912/MAX913 Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators supply pins, keeping leads short to minimize lead inductance. For particularly noisy applications, use ferrite beads on the power-supply lines. Board Layout As with all high-speed components, careful attention to layout is essential for best performance. 1) Use a printed circuit board with an unbroken ground plane. 2) Pay close attention to the bandwidth of bypass components and keep leads short. 3) Avoid sockets; solder the comparator and other components directly to the board to minimize unwanted parasitic inductance and capacitance. Input Slew Rate The MAX912/MAX913 design eliminates the input slewrate requirement imposed on many standard comparators. As long as LE is high after the maximum propagation delay and the input is greater than the comparator’s total DC error, the output will be valid without oscillations. Maximum Clock (LE) and Signal Rate The maximum clock and signal rate is 70MHz, based on the comparator’s rise and fall time with a 5mV overdrive at +25°C (Figure 1). With a 20mV overdrive, the maximum propagation delay is 12ns and the clock and signal rate is 85MHz. IN+ HYSTERESIS BAND* IN- Q . . . . . . .. . . . . . . WITH HYSTERESIS IDEAL (WITHOUT HYSTERESIS) * WHEN HYSTERESIS IS ADDED, A COMPARATOR CANNOT RESOLVE ANY INPUT SIGNAL WITHIN THE HYSTERESIS BAND. Figure 2. Effect of Hysteresis on Input Resolution __________________________________________________________Chip Topographies MAX912 MAX913 INB+ INAINBINA+ IN- V- V+ GND V+ V0.071" (1.80mm) LEA GND LEB IN+ V+ LE Q GND QB QB QA QA 0.080" (2.03mm) 0.056" (1.42mm) Q 0.058" (1.47mm) TRANSISTOR COUNT: 197; SUBSTRATE CONNECTED TO V-. TRANSISTOR COUNT: 100; SUBSTRATE CONNECTED TO V-. 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. 8 ___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1994 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.