Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsLinear ICsLinear IC - Comparator + lock CMOS, Complementary, Rail-to-rail, TTL MSOP 8

LT1713/LT1714

Single/Dual, 7ns, Low Power,

3V/5V/±5V Rail-to-Rail Comparators

The LT

1713/LT1714 are UltraFast

7ns, single/dual

comparators featuring rail-to-rail inputs, rail-to-rail

complementary outputs and an output latch. Optimized

for 3V and 5V power supplies, they operate over a single

supply voltage range from 2.4V to 12V or from ±2.4V to

±6V dual supplies.

The LT1713/LT1714 are designed for ease of use in a

variety of systems. In addition to wide supply voltage

flexibility, rail-to-rail input common mode range extends

100mV beyond both supply rails and the outputs are

protected against phase reversal for inputs extending

further beyond the rails. Also, the rail-to-rail inputs may be

taken to opposite rails with no significant increase in input

current. The rail-to-rail matched complementary outputs

interface directly to TTL or CMOS logic and can sink 10mA

to within 0.5V of GND or source 10mA to within 0.7V of V

The LT1713/LT1714 have internal TTL/CMOS compatible

latches for retaining data at the outputs. Each latch holds

data as long as its latch pin is held high. Latch pin

hysteresis provides protection against slow moving or

noisy latch signals. The LT1713 is available in the 8-lead

MSOP package. The LT1714 is available in the 16-lead

narrow SSOP package.

■

Ultrafast: 7ns at 20mV Overdrive

8.5ns at 5mV Overdrive

■

Rail-to-Rail Inputs

■

Rail-to-Rail Complementary Outputs

(TTL/CMOS Compatible)

■

Specified at 2.7V, 5V and ±5V Supplies

■

Low Power (Per Comparator): 5mA

■

Output Latch

■

Inputs Can Exceed Supplies Without Phase Reversal

■

LT1713: 8-Lead MSOP Package

■

LT1714: 16-Lead Narrow SSOP Package

, LTC and LT are registered trademarks of Linear Technology Corporation.

■

High Speed Automatic Test Equipment

■

Current Sense for Switching Regulators

■

Crystal Oscillator Circuits

■

High Speed Sampling Circuits

■

High Speed A/D Converters

■

Pulse Width Modulators

■

Window Comparators

■

Extended Range V/F Converters

■

Fast Pulse Height/Width Discriminators

■

Line Receivers

■

High Speed Triggers UltraFast is a trademark of Linear Technology Corporation.

LT1713/LT1714 Propagation Delay

vs Input Overdrive

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

A 4× NTSC Subcarrier Voltage-Tunable Crystal Oscillator

171314 TA01

–

LT1713

390Ω

200pF

* 1% FILM RESISTOR

** NORTHERN ENGINEERING LABS C-2350N-14.31818MHz

FREQUENCY

OUTPUT

3.9k*

0V TO 5V

MV-209

VARACTOR

DIODE

100pF

15pFY1** 100pF

0.047µF

C SELECT

(CHOOSE FOR CORRECT

PLL LOOP RESPONSE)

1M*

1N4148

LT1004-2.5

47k*

1k*

INPUT OVERDRIVE (mV)

PROPAGATION DELAY (ns)

6.5

7.0

7.5

–

171314 TA02

6.0

5.5

5.0

10 20 40

8.0

8.5

9.0

= 25°C

= 5V

–

= 0V

STEP

= 100mV

Summary of content (16 pages)

PAGE 1
LT1713/LT1714 Single/Dual, 7ns, Low Power, 3V/5V/±5V Rail-to-Rail Comparators DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ The LT®1713/LT1714 are UltraFastTM 7ns, single/dual comparators featuring rail-to-rail inputs, rail-to-rail complementary outputs and an output latch. Optimized for 3V and 5V power supplies, they operate over a single supply voltage range from 2.4V to 12V or from ±2.4V to ±6V dual supplies. Ultrafast: 7ns at 20mV Overdrive 8.
PAGE 2
LT1713/LT1714 W W W AXI U U ABSOLUTE RATI GS (Note 1) Supply Voltage V + to V – ............................................................ 12.6V V + to GND ........................................................ 12.6V V – to GND .............................................– 10V to 0.3V Differential Input Voltage ................................... ±12.6V Latch Pin Voltage ...................................................... 7V Input and Latch Current .....................................
PAGE 3
LT1713/LT1714 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V + = 2.7V or V + = 5V, V – = 0V, VCM = V +/2, VLATCH = 0.8V, CLOAD = 10pF, VOVERDRIVE = 20mV, unless otherwise specified. SYMBOL PARAMETER CONDITIONS PSRR+ 2.
PAGE 4
LT1713/LT1714 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V + = 5V, V – = – 5V, VCM = 0V, VLATCH = 0.8V, CLOAD = 10pF, VOVERDRIVE = 20mV, unless otherwise specified. SYMBOL PARAMETER CONDITIONS VCM Input Voltage Range CMRR Common Mode Rejection Ratio – 5V ≤ VCM ≤ 5V Positive Power Supply Rejection Ratio 2.4V ≤ V + PSRR+ PSRR– Negative Power Supply Rejection Ratio MIN TYP – 5.
PAGE 5
LT1713/LT1714 ELECTRICAL CHARACTERISTICS Note 8: Output voltage swings are characterized and tested at V + = 5V and V – = 0V. They are designed and expected to meet these same specifications at V – = – 5V. Note 9: The input voltage range is tested under the more demanding conditions of V + = 5V and V – = –5V. The LT1713/LT1714 are designed and expected to meet these specifications at V – = 0V. Note 10: The LT1713/LT1714 voltage gain is tested at V + = 5V and V – = – 5V only.
PAGE 6
LT1713/LT1714 U W 40 TA = 25°C + 35 V – = 5V V = 0V 30 CLOAD = 10pF 25 20 15 10 5 0 20 10 30 SWITCHING FREQUENCY (MHz) 40 4.0 3.8 3.6 3.2 V + = 2.7V 3.0 2.8 2.6 2.4 OUTPUT VOLTAGE (V) INPUT BIAS CURRENT (µA) 0 –1 –2 –3 –4 2.2 –5 2.0 –6 0 –3 –4 –2 –5 –6 –1 NEGATIVE SUPPLY VOLTAGE (V) –7 –1 –2 –3 50 75 100 125 TEMPERATURE (°C) 1 2 0 3 4 5 INPUT COMMON MODE VOLTAGE (V) Output Low Voltage vs Sink Current 5.0 1.0 4.9 0.9 4.8 0.8 4.7 4.6 4.5 4.4 4.3 T = 25°C 4.2 VA+ = 5V – 4.
PAGE 7
LT1713/LT1714 U U U PI FU CTIO S LT1713 V + (Pin 1): Positive Supply Voltage, Usually 5V. GND (Pin 6): Ground Supply Voltage, Usually 0V. + IN (Pin 2): Noninverting Input. Q (Pin 7): Noninverting Output. – IN (Pin 3): Inverting Input. Q (Pin 8): Inverting Output. V – (Pin 4): Negative Supply Voltage, Usually 0V or – 5V. LATCH ENABLE (Pin 5): Latch Enable Input. With a logic high the output is latched. LT1714 – IN A (Pin 1): Inverting Input of A Channel Comparator.
PAGE 8
LT1713/LT1714 U W U U APPLICATIO S I FOR ATIO Common Mode Considerations Latch Pin Dynamics The LT1713/LT1714 are specified for a common mode range of – 5.1V to 5.1V on a ±5V supply, or a common mode range of – 0.1V to 5.1V on a single 5V supply. A more general consideration is that the common mode range is from 100mV below the negative supply to 100mV above the positive supply, independent of the actual supply voltage.
PAGE 9
LT1713/LT1714 U W U U APPLICATIO S I FOR ATIO Poor trace routes and high source impedances are also common sources of problems. Keep trace lengths as short as possible and avoid running any output trace adjacent to an input trace to prevent unnecessary coupling. If output traces are longer than a few inches, provide proper termination impedances (typically 100Ω to 400Ω) to eliminate any reflections that may occur. Also keep source impedances as low as possible, preferably much less than 1kΩ.
PAGE 10
LT1713/LT1714 U W U U APPLICATIO S I FOR ATIO Hysteresis Another useful technique to avoid oscillations is to provide positive feedback, also known as hysteresis, from the output to the input. Increased levels of hysteresis, however, reduce the sensitivity of the device to input voltage levels, so the amount of positive feedback should be tailored to particular system requirements.
PAGE 11
LT1713/LT1714 U TYPICAL APPLICATIO S Simultaneous Full Duplex 75Mbaud Interface with Only Two Wires The circuit of Figure 3 shows a simple, fully bidirectional, differential 2-wire interface that gives good results to 75Mbaud, using the LT1714. Eye diagrams under conditions of unidirectional and bidirectional communication are shown in Figures 4 and 5. Although not as pristine as the unidirectional performance of Figure␣ 4, the performance under simultaneous bidirectional operation is still excellent.
PAGE 12
LT1713/LT1714 U TYPICAL APPLICATIO S 171112 F05 171112 F04 Figure 5. Performance When Operated Simultaneous Bidirectionally (Full Duplex). Crosstalk Appears as Noise. Eye is Slightly Shut But Performance is Still Excellent Figure 4. Performance of Figure 3’s Circuit When Operated Unidirectionally. Eye is Wide Open This amounts to an attenuation factor of 0.0978 with the values shown. (The actual voltage on the lines will be cut in half again due to the 120Ω ZO.
PAGE 13
LT1713/LT1714 U TYPICAL APPLICATIO S 1MHz Series Resonant Crystal Oscillator with Square and Sinusoid Outputs Figure 7 shows a classic 1MHz series resonant crystal oscillator. At series resonance, the crystal is a low impedance and the positive feedback connection is what brings about oscillation at the series resonant frequency. The RC feedback around the other path ensures that the circuit does not find a stable DC operating point and refuse to oscillate.
PAGE 14
LT1713/LT1714 U PACKAGE DESCRIPTIO Dimensions in inches (millimeters) unless otherwise noted. MS8 Package 8-Lead Plastic MSOP (LTC DWG # 05-08-1660) 0.118 ± 0.004* (3.00 ± 0.102) 8 7 6 5 0.118 ± 0.004** (3.00 ± 0.102) 0.193 ± 0.006 (4.90 ± 0.15) 1 2 3 4 0.043 (1.10) MAX 0.007 (0.18) 0° – 6° TYP 0.021 ± 0.006 (0.53 ± 0.015) SEATING PLANE 0.009 – 0.015 (0.22 – 0.38) 0.0256 (0.65) BSC * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
PAGE 15
LT1713/LT1714 U PACKAGE DESCRIPTIO Dimensions in inches (millimeters) unless otherwise noted. GN Package 16-Lead Plastic SSOP (Narrow 0.150) (LTC DWG # 05-08-1641) 0.189 – 0.196* (4.801 – 4.978) 16 15 14 13 12 11 10 9 0.229 – 0.244 (5.817 – 6.198) 0.150 – 0.157** (3.810 – 3.988) 1 0.015 ± 0.004 × 45° (0.38 ± 0.10) 0.007 – 0.0098 (0.178 – 0.249) 0.009 (0.229) REF 2 3 4 5 6 7 0.053 – 0.068 (1.351 – 1.727) 8 0.004 – 0.0098 (0.102 – 0.249) 0° – 8° TYP 0.016 – 0.050 (0.406 – 1.270) 0.008 – 0.
PAGE 16
LT1713/LT1714 U TYPICAL APPLICATIO forte of this particular implementation is that it is rail-torail allowing a full-scale analog input. Once the triangle wave is achieved, the remainder of the pulse width modulator is easy, and is constituted by doing a simple comparison using the second half of the LT1714.