TY - GEN
T1 - A low power precise current balance LED driver with -0.228% ∼ 0.198% imbalance among three output channels
AU - Wang, Yao Chen
AU - Budiman, Fajar
AU - Li, Ya Ying
AU - Chen, Poki
PY - 2013
Y1 - 2013
N2 - In this paper, a 3-channel LED driver with precise current balance is proposed. Artful layout topologies instead of complicated circuit structure are created and analyzed to achieve accurate current balance among LED channels with excellent insensitivity to process, temperature and voltage (PVT) variations and small standard deviation for trimming-free bandgap reference voltage. With a high yield rate of 99.5%, the maximum imbalance among LED driving currents for 199 test chips is measured to be merely -0.228% ∼ 0.198% which is not only much better than 2% deviation of the conventional one [1] but also very close to the simulated imbalance of -0.18% ∼ 0.09% under gradients up to the 2 nd-order. In addition, the 1.21V bandgap reference voltage accomplishes a 3σ inaccuracy of 3.78% only. This circuit was fabricated in a Vanguard 0.5μm 5V and 12V 2P3M process with a chip size of 1.25 mm 2. Except for the LED driving and setting currents, the power consumption is measured to be 340 μW only.
AB - In this paper, a 3-channel LED driver with precise current balance is proposed. Artful layout topologies instead of complicated circuit structure are created and analyzed to achieve accurate current balance among LED channels with excellent insensitivity to process, temperature and voltage (PVT) variations and small standard deviation for trimming-free bandgap reference voltage. With a high yield rate of 99.5%, the maximum imbalance among LED driving currents for 199 test chips is measured to be merely -0.228% ∼ 0.198% which is not only much better than 2% deviation of the conventional one [1] but also very close to the simulated imbalance of -0.18% ∼ 0.09% under gradients up to the 2 nd-order. In addition, the 1.21V bandgap reference voltage accomplishes a 3σ inaccuracy of 3.78% only. This circuit was fabricated in a Vanguard 0.5μm 5V and 12V 2P3M process with a chip size of 1.25 mm 2. Except for the LED driving and setting currents, the power consumption is measured to be 340 μW only.
UR - http://www.scopus.com/inward/record.url?scp=84880708418&partnerID=8YFLogxK
U2 - 10.1109/PEDS.2013.6527162
DO - 10.1109/PEDS.2013.6527162
M3 - Conference contribution
AN - SCOPUS:84880708418
SN - 9781467317900
T3 - Proceedings of the International Conference on Power Electronics and Drive Systems
SP - 985
EP - 988
BT - 2013 IEEE 10th International Conference on Power Electronics and Drive Systems, PEDS 2013
T2 - 2013 IEEE 10th International Conference on Power Electronics and Drive Systems, PEDS 2013
Y2 - 22 April 2013 through 25 April 2013
ER -