UNISONIC TECHNOLOGIES CO., LTD LMV393 Preliminary LINEAR INTEGRATED CIRCUIT

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Benedict Potter
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1 UNISONIC TECHNOLOGIES CO., LTD LMV9 Preliminary LINEAR INTEGRATED CIRCUIT DUAL GENERAL PURPOSE, LOW VOLAGE, COMPARATORS DESCRIPTION The UTC LMV9 is a low voltage (.7-5V version of the dual comparators. Its noise performance has been improved by using bipolar differential input and output stages. These comparators also have a unique characteristic in that the input common-mode voltage range includes ground even though operated from a single power supply voltage. The UTC LMV9 is designed for applications in consumer automotive, mobile communications, notebooks and PDA s, battery powered electronics, general purpose portable device, general purpose low voltage applications. FEATURES * High Precision Comparator. * Low Operating Voltage.7-5V. * Low Supply Current μa/channel (Typical. * Low Input Bias Current na (Typical. * Low Input Offset Current na (Typical. * Input Common Mode Voltage Range Includes Ground. * Low Output Saturation Voltage.V. ORDERING INFORMATION Lead-free: LMV9L Halogen-free: LMV9G DIP-8 SOP-8 MSOP-8 Ordering Number Normal Lead Free Plating Halogen Free Package Packing LMV9-D8-T LMV9L-D8-T LMV9G-D8-T DIP-8 Tube LMV9-S8-R LMV9L-S8-R LMV9G-S8-R SOP-8 Tape Reel LMV9-SM-R LMV9L-SM-R LMV9G-SM-R MSOP-8 Tape Reel of Copyright 9 Unisonic Technologies Co., Ltd QW-R4-4,Ba

2 PIN CONFIGURATION UNISONIC TECHNOLOGIES CO., LTD of QW-R4-4,Ba

3 BLOCK DIAGRAM UNISONIC TECHNOLOGIES CO., LTD of QW-R4-4,Ba

4 ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL RATINGS UNIT Supply Voltage V CC.7 ~ 5. V Differential Input Voltage V IN(DIFF ±V CC V Voltage on Any Pin (Referred to V- pin 5.5 V Junction Temperature T J +5 C Operating Temperature T OPR -4 ~ +85 C Storage Temperature T STG -65 ~ +5 C Note Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. THERMAL DATA Junction to Ambient PARAMETER SYMBOL RATINGS UNIT DIP-8 SOP-8 θ JA 5 C /W MSOP-8 9 DC ELECTRICAL CHARACTERISTICS (T J =5 C, V - =V, unless otherwise specified. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Input Offset Voltage V I(OFF.7 7 mv Input Offset Voltage Average Drift I I(OFF 5 μv/ C Input Bias Current I I(BIAS 5 na Input Offset Current I I(OFF 5 na Input Voltage Range V IN V Supply Current I CC μa Voltage Gain G V 5 V/mV Saturation Voltage V SAT I O(SINK 4mA 4 mv Output Sink Current.7V 5 4 I O(SINK V OUT.5V 5.V 5 ma Output Leakage Current I O(LEAK. µa AC ELECTRICAL CHARACTERISTICS (T J =5 C, R L =5.kΩ, V-=V, unless otherwise specified. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT.7V 9 Input Overdrive=mV Propagation Delay 5.V 8 t PHL (High to Low.7V.8 Input Overdrive=mV 5.V.4 us.7v Input Overdrive=mV Propagation Delay 5.V t PLH (Low to High.7V.7 Input Overdrive=mV 5.V.8 us UNISONIC TECHNOLOGIES CO., LTD 4 of QW-R4-4,Ba

5 APPLICATION CIRCUITS Basic Comparator A basic comparator circuit can convert analog signals to a digital output. The UTC LMV9 needs a pull-up resistor connected to the positive supply voltage which can make output switch properly. So that when the internal output transistor is off, the output voltage will be pulled up to the external positive voltage. The resister should be chosen properly. The higher resister can reduce the power dissipation. the lower resister can improve the capacity of loading output. The range of resister should between k to kω. The Output voltage of the comparator will be high if the input voltage at the non-inverting pin is greater than the reference voltage at the inverting pin. On the other hand it will be low. Comparator with Hysteresis The comparator may oscillate or produce a noisy output if the applied differential input voltage is near the comparator s offset voltage, especially when the input signal is moving slowly across the comparator s switching threshold. Addition of hysteresis or positive feedback can solve this problem. Inverting Comparator with Hysteresis It requires a three resistor network that is referenced to the supply voltage V CC of the comparator. When the output voltage is high, these resistors can be represented as R // R in series with R. The lower set input voltage is defined as: VCCR Va = (R//R + R UNISONIC TECHNOLOGIES CO., LTD 5 of QW-R4-4,Ba

6 APPLICATION CIRCUITS(Cont. When V IN > V a the output voltage is low close to ground. It can be presented as R // R in series with R. The upper trip voltage V a is defined as VCC(R//R Va = (R//R + R The total hysteresis provided by the network is defined as: Δ Va = Va- Va To assure that the comparator will always switch correctly, the resistors values should be chosen as follow: R PULL-UP << R LOAD and R > R PULL-UP. Non-Inverting Comparator with Hysteresis It requires a two resistor network to implement a non inverting comparator with hysteresis and with a voltage reference at the inverting input. So when V IN is low, the output is also low. If the output will switch from low to high, V IN must rise up to V IN, and V IN can be calculated by: VREF(R + R V IN = R When V IN is high, the output is also high, in order to make the comparator switch back to low, V IN can be calculated by: VREF(R + R - VCCR V IN = R The hysteresis of this circuit is the difference between V IN and V IN. Δ VIN = VCCR/R UNISONIC TECHNOLOGIES CO., LTD 6 of QW-R4-4,Ba

7 APPLICATION CIRCUITS(Cont. Square Wave Oscillator Comparators are suitable for oscillator applications. This application uses the minimum number of external components. The output frequency is set by the RC time constant which is determined by capacitor C and the resistor in the negative feedback R 4 of the comparator. Capacitive load at the output would degrade the output slew rate and limit the maximum operating frequency. V + V + C 75pF R k Vc Va - + R k R4 k R k 4.k V + VOUT Vc -V CC Va Va t = T V OUT Squarewave Oscillator At first, assume that the output is high, so the voltage at the inverting input V C is less than the voltage at the non-inverting input Va, the capacitor C has to be discharged. When it has charged up to value equal to the positive input voltage V a, the comparator output will switch. V a will be given by: VCCR Va = R + (R/R If: R =R =R Then: VCC Va = When the output switches to ground, the value of Va is reset by the resistor network: VCC Va = Then capacitor C discharge through a resistor towards ground. The output will return to its high state when the voltage across the capacitor has discharged to a value equal to V a.the time to charge the capacitor can be calculated from: -t e R C C V max = V Where V MAX =V CC / and V C = V CC / One period will be given by: /freq = t or calculating the exponential gives: /freq = (.694 R 4 C Resistors R and R 4 must be at least two times larger than R 5 to insure a reasonable V O. The frequency stability of this circuit should strictly be a function of the external components. UNISONIC TECHNOLOGIES CO., LTD 7 of QW-R4-4,Ba

8 APPLICATION CIRCUITS(Cont. Free Running Multivibrator This oscillator circuit can generate a train of stable clock for precise timekeeping applications. We can obtain it by using a resonator as the feedback component. A quartz crystal in its series-resonant mode can make the circuit oscillating well. For the comparator be switching symmetrically about +V CC /, the value of R and R must choose equal. The RC time constant of R and C is set to be several times greater than the period of the oscillating frequency. When choose crystal, be sure to order series resonant with desired temperature coefficient. Pulse generator with variable duty cycle: A pulse generator with variable duty cycle can be obtained by creating two separated paths for C charge and discharge into the basic square wave generator. One path, through R and D will charge the capacitor and set the pulse width (t. The other path, R and D will discharge the capacitor and set the time between pulses (t. Varying resistor R, R can alter the time between pulses and the pulse width. Both controls also change the frequency of the generator. The pulse width and time between pulses can be found from: -t V = V (- e /R4C max Rise time -t V = V (- e /R5C max Fall time Where VCC Vmax = And Vmax VCC V = = then -t/r4c = e t is then given by: -t/r5c = e UNISONIC TECHNOLOGIES CO., LTD 8 of QW-R4-4,Ba

9 APPLICATION CIRCUITS(Cont. V + R M R k D * D 5k C 8pF - 6µs 6µs tot t -V + V+ R5 M + VOUT R M R4 M *FOR LARGE RATIOS OF R/R. D CAN BE OMITTED. At last, we get, Pulse Generator t = R4C ln t = R5C ln These terms have a slight error because V max is not exactly equal to / V CC but is actually reduced by the diode drop to: Vmax = (VCC - VBE (- -t = e VBE /R4C -t = e (- VBE And that s the exact value we get. /R5C t = R4C t = R5C ln(- VBE ln(- VBE UNISONIC TECHNOLOGIES CO., LTD 9 of QW-R4-4,Ba

10 APPLICATION CIRCUITS(Cont. Positive Peak Detector: Positive peak detector is basically the comparator operated as a unit gain follower with a large holding capacitor from the output to ground. Additional transistor is added to the output to provide a low impedance current source. When the output of the comparator goes high, current is passed through the transistor to charge up the capacitor. The only discharge path will be the M ohm resistor shunting C and any load that is connected to the output. The decay time can be altered simply by changing the MΩ resistor. The output should be used through a high impedance follower to a avoid loading the output of the peak detector. Negative Peak Detector: For the negative detector, the output transistor of the comparator acts as a low impedance current sink. The only discharge path will be the MΩ resistor and any load impedance used. Decay time is changed by varying the MΩ resistor. UNISONIC TECHNOLOGIES CO., LTD of QW-R4-4,Ba

11 TYPICAL CHARACTERISTICS Output Voltage, VOUT (mv Output Voltage vs Output Current at 5V Supply С Output Current, I OUT (ma +5 С 4 5 Output Voltage, VOUT (mv Output Voltage vs Output Current at.7 Supply Output Current, I OUT (ma Input Bias Current, II(BIAS (na Input Bias Current vs Supply Voltage 5 VIN=V +5 С С Supply Voltage, V CC (V 5.5 Output Voltage VOUT (V Input Voltage VIN (mv 5 4 Response Time vs Input Overdrives Negative Transition mv Overdrive m V.5.5 Time (µs Vcc=5V Ta=5 С RL=5.kΩ mv ~ ~.5 Output Voltage VOUT (V Input Voltage (mv Response Time for Input Overdrive Positive Transition mv mv 5mV ~ Overdrive ~ 6 Time (µs 9 Vcc=5V Ta=5 С RL=5.kΩ Output Voltage VOUT (V Input Voltage VIN (mv ~ Response Time vs Input Overdrives Negative Transition mv mv Overdrive..5 5 Time (µs Vcc=.7V Ta=5 С RL=5.kΩ mv ~ UNISONIC TECHNOLOGIES CO., LTD of QW-R4-4,Ba

12 TYPICAL CHARACTERISTICS (Cont. Output Voltage VOUT (V Response Time for Input Overdrive Positive Transition mv mv 5mV Vcc=.7V Ta=5 RL=5.kΩ Input Voltage (mv - ~ Overdrive ~ 6 Time ( µs 9 UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD of QW-R4-4,Ba

UNISONIC TECHNOLOGIES CO., LTD UC3842B/3843B

UNISONIC TECHNOLOGIES CO., LTD UC3842B/3843B HIGH PERFORMANCE CURRENT MODE CONTROLLERS DESCRIPTION The UTC UC3842B/3843B are specifically designed for off-line and dc-to-dc converter applications offering