unisonic technologies co., ltd lv2622 preliminary linear integrated circuit www.unisonic.com.tw 1 of 8 copyright ? 2011 unisonic technologies co., ltd qw-r102-045.a 250 a, 3mhz, low voltage rail-to-rail i/o cmos dual op amps ? description the utc lv2622 is low noise, low voltage and low power dual operational amplifiers that can be designed into a wide range of applications. with a 3mhz unity-gain frequency and a guaranteed 1.7v/ s slew rate, the quiescent current is only 250 a/amplifier (5.0v). the utc lv2622 provides rail-to-rail output swing into heavy loads. the input common-mode voltage range includes ground and the maximum input offset voltage is 3mv. it is specified over the extended industrial temperature range ( ? 40c~+125c). the operating range is 2.5v~5.5v. the utc lv2622 provides optimal performance in low voltage and low noise systems. ? features * low cost * rail-to-rail output swing * input rail: - 0.1v~+5.6v with v s =5.5v * typical v os : 0.7mv * gain-bandwidth product: 3mhz * high slew rate: 1.7v/s * settling time to 0.1% with 2v step: 2.1s * overload recovery time: 1s * low noise voltage: 12nv/ hz * operates on 2.5v~5.5v supplies * low power: 250a/amplifier typical supply current sop-8 ? ordering information ordering number lead free halogen free package packing lv2622l-s08-r LV2622G-S08-R sop-8 tape reel lv2622l-s08-t lv2622g-s08-t sop-8 tube lv2622l-s08-r (1)packing type (2)package type (1) r: tape reel, t: tube (2) s08: sop-8 (3) g: halogen free, l: lead free (4)lead free
lv2622 preliminary linear integrated circuit unisonic technologies co., ltd 2 of 8 www.unisonic.com.tw qw-r102-045.a ? pin configuration 1 2 3 4 8 7 6 5 out b -in b +in a -v s +v s out a -in a +in b ? block diagram
lv2622 preliminary linear integrated circuit unisonic technologies co., ltd 3 of 8 www.unisonic.com.tw qw-r102-045.a ? absolute maximum rating (t a =+25 c, unless otherwise specified) parameter symbol ratings unit supply voltage, v+~v- v s 7.5 v common-mode input voltage v cm (-vs)-0.5~(+vs)+0.5 v junction temperature t j 160 c operating temperature t opr -40~+150 c storage temperature t stg -65~+150 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 oper ation is not implied. ? thermal data parameter symbol ratings unit junction to ambient @ t a =25c ja 160 c/w
lv2622 preliminary linear integrated circuit unisonic technologies co., ltd 4 of 8 www.unisonic.com.tw qw-r102-045.a ? electrical characteristics (t a =+25 c,v s =5v,v cm =v s /2,r l =600 ? , unless otherwise specified) parameter symbol test conditions min typ max unit input characteristics 0.7 3 input offset voltage v os (note) 3.5 mv input bias current i b 1 pa input offset current i os 1 pa common-mode voltage range v cm v s =5.5v -0.1~+5.6 v v s =5.5v, v cm =-0.1v~4v 75 90 (note) 73 db v s =5.5v, v cm =-0.1v~5.6v 66 92 common-mode rejection ratio cmrr (note) 64 db r l =600 ? , vo=0.15v~4.85v 92 100 (note) 78 db r l =10k ? , vo=0.05v~4.95v 100 110 open-loop voltage gain a ol (note) 82 db input offset voltage drift v os / t 2.7 v/c output characteristics r l =600 ? 0.1 output voltage swing from rail v o r l =10k ? 0.015 v 45 48 output current i out (note) 30 ma closed-loop output impedance r o f=100khz, g=+1 2.6 ? power supply 2.5 5.5 operating voltage range v s (note) 2.5 5.5 v 79 94 power supply rejection ratio psrr v s =+2.5v~+5.5v, v cm =(-v s )+0.5v (note) 76 db 250 400 quiescent current/ amplifier i q i out =0 (note) 480 a dynamic performance gain-bandwidth product gbp r l =10k ? 3 mhz phase margin o 67 degrees full power bandwidth bw p <1% distortion, r l =600 ? 50 khz slew rate sr g=+1, 2v step, r l =10k ? 1.7 v/ s settling time to 0.1% t s g=+1, 2v step, r l =600 ? 2.1 s overload recovery time t or v in gain=vs, r l =600 ? 1 s noise performance voltage noise density e n f=1khz 12 nv/ hz current noise density i n f=1khz 3 fa/ hz note: denotes the specifications which apply over the operating temperatur e range (-40c~125c).
lv2622 preliminary linear integrated circuit unisonic technologies co., ltd 5 of 8 www.unisonic.com.tw qw-r102-045.a ? application notes driving a capacitive load the utc lv2622 can directly drive 1000pf in unity-gain without oscillation. the unity-gain follower (buffer) is the most sensitive configurat ion to capacitive loading. when the amplifier is configured in this manner, capacitive loading directly on the output will decrease the dev ice?s phase margin leading to high frequency ringing or oscillations. it is recommended that an isolation resistor ( r iso ) is placed in series with the output of the amplifier when the greater capacitive load is required. the circuit is shown in figure 1. the r iso and the load capacitor c l form a zero to increase stability, but this me thod results in a loss of gain accuracy for r iso dividing the voltage with r load. the circuit in figure 2 provides dc accuracy and ac stability. to increase the dc accuracy, r f should be connected between the inverting input and the output. to pr eserve the phase margin in the overall feedback loop, c f is required and can compensate the lo ss of phase margin together with r iso by feeding the high frequency component of the output signal back to the amplifier?s inverting input . utc lv2622 - + figure 2. indirectly driving hea vy capacitive load with dc accuracy v in c f r iso c l r l v out r f 1/2 for no-buffer configuration, there ar e two others ways to increase the phase margin: (a) by increasing the amplifier?s gain or (b) by placing a capacitor in paralle l with the feedback resistor to counteract the parasitic capacitance associated with inverting node.
lv2622 preliminary linear integrated circuit unisonic technologies co., ltd 6 of 8 www.unisonic.com.tw qw-r102-045.a ? application notes(cont.) power-supply bypassing and layout the utc lv2622 can apply for a single +2.5v~+5.5v supply or dual 1.25v~2.75v supplies. for single-supply operation, a 0.1f ceramic capacitor should be placed close to the v dd pin to bypass the power supply v dd . for dual-supply operation, separate 0.1f cera mic capacitors should be placed to the v dd and the v ss supplies to bypass them to ground, and 2.2f tantalum capacitor for better performance. by decreasing the amount of stray ca pacitance at the op amp?s inputs and output, pc board l performance can be optimized. for example, placing external components as close to the device as possible can minimize trace lengths and widths. and using surface-mount components is a better way. for the operational amplifier, solderin g the part to the board directly is strongly recommended. the emi can be minimized because keeping the high frequency big current loop area small. grounding a ground plane layer is important for utc lv2622 circuit design. the length of the current path speed currents in an inductive ground return will create an unwanted voltag e noise. broad ground plane areas will reduce the parasitic inductance. input-to-output coupling the input and output signal traces s hould not be parallel to minimize capac itive coupling. this helps reducing unwanted positive feedback.
lv2622 preliminary linear integrated circuit unisonic technologies co., ltd 7 of 8 www.unisonic.com.tw qw-r102-045.a ? typical application circuits figure 4 is the differential amplifier. if the re sistors ratios are equal (r4/r3=r2/r1), then v out =(vp-vn)r2/r1+vref. figure 5 performs the same function as that in figure 4 but with the high input impedance.
lv2622 preliminary linear integrated circuit unisonic technologies co., ltd 8 of 8 www.unisonic.com.tw qw-r102-045.a ? typical application circuits(cont.) figure 6 is the low pass filter. it?s dc gain is -r2/r1 and the ?3db corner frequency is 1/2 r 2 c. 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.
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