• 한국전기전자재료학회논문지
• /
• 제15권9호
• /
• pp.743-749
• /
• 2002

A 1.5V 70㏈ 100MHz CMOS class-AB complementary operational amplifier is presented. For obtaining the high gain and the high unity gain frequency, the input stage of the amplifier is designed with rail-to-rail complementary differential pairs which are symmetrically parallel-connected with the NMOS and the PMOS differential input pairs, and the output stage is designed to the rail-to-rail class-AB output stage including the elementary shunt stage technique. With this design technique for output stage, the load dependence of the overall open loop gain is improved and the push-pull class-AB current control can be implemented in a simple way. The designed operational amplifier operates perfectly on the complementary mode with 180$^{\circ}$ phase conversion for 1.5V supply voltage, and shows the push-pull class-AB operation. In addition, the amplifier shows the DC open loop gain of 70.4 ㏈ and the unity gain frequency of 102 MHz for $C_{L=10㎊∥}$ $R_{L=1㏁}$ Parallel loads. When the resistive load $R_{L}$ is varied from 1 ㏁ to 1 ㏀, the DC open loop gain of the amplifier decreases by only 2.2 ㏈.a$, the DC open loop gain of the amplifier decreases by only 2.2 dB.

• ETRI Journal
• /
• 제33권3호
• /
• pp.393-400
• /
• 2011

A systematic approach for the design of two-stage class AB CMOS unity-gain buffers is proposed. It is based on the inclusion of a class AB operation to class A Miller amplifier topologies in unity-gain negative feedback by a simple technique that does not modify quiescent currents, supply requirements, noise performance, or static power. Three design examples are fabricated in a 0.5 ${\mu}m$ CMOS process. Measurement results show slew rate improvement factors of approximately 100 for the class AB buffers versus their class A counterparts for the same quiescent power consumption (< 200 ${\mu}W$).

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.905-908
• /
• 2005

본 논문에서는 class AB opamp 를 채용한 384kHz differential PWM 신호를 입력으로 하는 2-channel stereo audio amplifier 블록을 공급전압 3.3V 조건에서 SMIC 0.18um thick oxide 기술을 이용하여 설계한다. 여기서 class AB opamp 는 공정 변화에 따른 quiescent current가 변하는 것을 최소화하기 위하여 adaptive load 를 사용하며, 전체적으로는 3 차 Butterworth lowpass filter 와 differential-to-single converter 로 구성된 2 개의 audio amplifier 와 출력전압이 ${\frac{1}{2}}Vdd$ 인 common output 블록으로 구성된다. 이러한 설계를 통하여 32ohm 의 저항 load 를 구동할 수 있는 -60dB THD, 전체 quiescent current 2mA 대인 CMOS class AB stereo audio amplifier 를 구현하였다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.637-638
• /
• 2006

A novel 1.2V class-AB output stage for the SW-OpAmp technique was presented. By using current mirrors and simple current extraction circuits, the proposed circuit boosts DM signal currents while eliminates CM ones to perform class-AB operation. Hspice simulation results verify the versatility of the proposed circuit technique.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 C
• /
• pp.1605-1607
• /
• 2000

In this paper, the design of class AB BiCMOS log-domain filter for low-voltage and low-power was proposed. This filter is consist of a log-domain integrator using folded junctions with capacitor connected to emitter and it's class AB structure. A comparison between the proposed class AB BiCMOS log-domain filter and classical class A BiCMOS log-domain filter is drawn on the basis of SNR, THD and the frequency response. This comparison shows proposed filter are more than good SNR, THD and frequency characteristics than more class A log-domain filter for low voltage and low power.

• IMMUNE NETWORK
• /
• 제10권6호
• /
• pp.239-246
• /
• 2010

Background: Monoclonal antibodies (mAbs) recognizing Class III epitope of CD34 are essential for flow cytometric diagnosis of leukemia. Methods: 27H2 mAb was developed from a mouse alternatively immunized with human acute leukemia cell lines, KG1 and Molm-1. Using flow cytometric analysis of various leukemic cell lines and peripheral blood, immunohistochemical study of frozen tonsil, we characterized 27H2 mAb. Antigen immunoprecipitated with 27H2 mAb immunobloted with anti-CD34 mAb. A case of bone marrow sample of acute lymphoblastic leukemia (ALL) patient was obtained at CBNU Hospital. For epitope identification enzyme treatment with neuraminidase and O-sialoglycoprotein endopeptidase (OSGE) and blocking assay with known classIII mAb (HPCA-2) were done. Results: Only KG1 and Molm-1 revealed positive immunoreactivity. Immunohistochemical staining disclosed strong membranous immunoreactivity on high endothelial venules. Antigen immunoprecipitated by 27H2 mAb showed approximately 100 kDa sized band immunoblotted with anti-CD34 under non-reducing conditions. Epitope recognized by 27H2 mAb disclosed resistancy to both neuraminidase and OSGE treatment and completely blocked with known class III mAb preincubation. CD34 positive leukemic cells in BM of pre B cell ALL patient detected by FITC-conjugated 27H2 and HPCA-2 were identified with similar sensitivity. Conclusion: A novel murine mAb recognizing class III epitope of human CD34 with high affinity, which is useful for flow cytometric diagnosis of leukemia, was developed.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
• /
• pp.403-408
• /
• 2008

In this paper, the high efficiency and linearity Doherty power amplifier using DGS and adaptive bias technique has been designed and realized for 2.3GHz WiBro applications. The Doherty amplifier has been implemented us-ing silicon MRF 281 LDMOS FET. The RF performances of the Doherty power amplifier (a combination of a class AB carrier amplifier and a bias-tuned class C peaking amplifier) have been compared with those of a class AB amplifier alone, and conventional Doherty amplifier. The Maximum PAE of designed Doherty power amplifier with DGS and adaptive bias technique has been 36.6% at 34.01dBm output power. The proposed Doherty power amplifier showed an improvement 1dB at output power and 7.6% PAE than a class AB amplifier alone.

• 대한치과교정학회지
• /
• 제34권3호
• /
• pp.205-218
• /
• 2004

III급 부정교합을 조기에 치료했을 때, 치료 후 retention 기간 중에 교합이 안정적으로 유지되는 경우와, 재발되어 성장 완료시기에 악교정수술을 해야 하는 경우를 경험하게 된다. 어린 년생부터 장기간에 걸쳐 교정치료를 했음에도 재발되어 악교정수술을 하는 경우에, 환자와 보호자는 소모된 시간과 경비에 대해 많은 실망을 하는 경우를 볼 수 있다. 교정치료 후 보정기간 중에 있는 30증례를 조사했다. 치료 완료된 교합상태를 교합안정 정도에 따라 good, fair, relapse군으로 나누어 치료 전 골격형태를 관찰한 결과, AB-MP 항목이 유의성 있는 차이를 보였다. 조기에 III급 부정교합을 치료하는 경우에, 치료 후 안정에 관한 예후를 평가하는데 AB-MP를 활용할 수 있다. AB-MP이 65이상인 경우에 조기치료가 권장되고, 60이하인 경우에는 성장이 완료될 때까지 연기할 수 있다.

• 대한치과교정학회지
• /
• 제17권1호
• /
• pp.107-117
• /
• 1987

The study was designed to examinate the discrimination rate of 4 antero-posterior cephalometric measurements from Angle's malocclusion groups. The material was 246 cephalometric radiographs taken from 42 Normal occlusions, 83 Class I malocclusions, 64Class II Division I malocclusions, 57Class III malocclusions. ANB angle, APDI, AB/OP angle, and Wits appraisal as measurements of antero-posterior skeletal relationship were measured on the cephalometric radiographs and statistically analyzed by the Canonical Discriminant Function. The results of this study were as follows: 1. ANB angle, APDI, AB/OP angle, and Wits appraisal were clinically useful measurements for the evaluation of the antero-posterior skeletal relationship. 2. The rates that discriminate actual malocclusion groups were $77.45\%$ in Wits appraisal, $74.02\%$ in AB/OP angle, $71.08\%$ in ANB angle, and $70.59\%$ in APDI. 3. The discrimination rate of actual Class III malocclusion show above $93\%$, but actual Class I and Class II division I malocclusions were relatively low.

• 전자공학회논문지C
• /
• 제34C권10호
• /
• pp.19-26
• /
• 1997

Novel class AB CMOS second-generation current conveyors (CCII) using 0.6.mu.m n-well CMOS process for high-frequency current-mode signal processing were developed. The CCII for low power operation consists of a class AB push-pull stage for the current input, a complementary source follower for the voltage input, and a cascode current mirror for the current output. In this architecture, the two input stages are coupled by current mirrors to reduce the current input impedance. Measurements of the fabricated CCII show that the current input impedance is 875.ohm. and the bandwidth of flat gain when used as a voltage amplifier extends beyond 4MHz. The power dissipation is 1.25mW and the active chip area is 0.2*0.15[mm$\^$2/].