TY - GEN
T1 - A piezoelectric actuator driver circuit for automatic focusing of mobile phone cameras
AU - Yu, Sangduk
AU - Jang, Kichang
AU - Cha, Sanghyun
AU - Lee, Yeonjung
AU - Kwon, Ohjo
AU - Kwon, Kyougsoo
AU - Choi, Joongho
PY - 2008
Y1 - 2008
N2 - The analog front end (AFE) chip is presented to perform precise automatic focus operations with a piezoelectric actuator for mobile phone camera applications. In order to achieve the desired frequency response of a piezoelectric actuator, the frequency of a multi-vibrator oscillator can be swept in various manners such as the frequency step and the number of transitions between frequency changes. A novel method using the resistor ladder circuit is incorporated for a bridge-driving signal generator whose frequency can be linearly swept and controlled according to the input digital code. The AFE chip is implemented in a 0.35-μm 1-poly 4-metal CMOS technology and runs at the single supply voltage of 2.8V.
AB - The analog front end (AFE) chip is presented to perform precise automatic focus operations with a piezoelectric actuator for mobile phone camera applications. In order to achieve the desired frequency response of a piezoelectric actuator, the frequency of a multi-vibrator oscillator can be swept in various manners such as the frequency step and the number of transitions between frequency changes. A novel method using the resistor ladder circuit is incorporated for a bridge-driving signal generator whose frequency can be linearly swept and controlled according to the input digital code. The AFE chip is implemented in a 0.35-μm 1-poly 4-metal CMOS technology and runs at the single supply voltage of 2.8V.
KW - Frequency sweep control
KW - Multi-vibrator oscillator
KW - Piezoelectric actuator driver
UR - http://www.scopus.com/inward/record.url?scp=51749118677&partnerID=8YFLogxK
U2 - 10.1109/ISCAS.2008.4541865
DO - 10.1109/ISCAS.2008.4541865
M3 - Conference contribution
AN - SCOPUS:51749118677
SN - 9781424416844
T3 - Proceedings - IEEE International Symposium on Circuits and Systems
SP - 2106
EP - 2109
BT - 2008 IEEE International Symposium on Circuits and Systems, ISCAS 2008
T2 - 2008 IEEE International Symposium on Circuits and Systems, ISCAS 2008
Y2 - 18 May 2008 through 21 May 2008
ER -