hierarchy cluster_1 future user: a parent sheet cluster_2 ext_gnd ext_gnd gnd ./gnd ext_gnd->gnd ext_vcc ext_vcc vcc ./vcc ext_vcc->vcc ext_ctrl ext_ctrl ctrl ./ctrl ext_ctrl->ctrl ext_enable ext_enable enable v/enable ext_enable->enable ext top top sheet ext->top chgnd chgnd top->chgnd an an top->an dig dig top->dig agnd ./agnd gnd->agnd dgnd ./dgnd gnd->dgnd avcc ./avcc vcc->avcc dvcc ./dvcc vcc->dvcc agnd->an dgnd->dig avcc->an dvcc->dig ctrl->an ctrl->dig amp1 amp an->amp1 an->amp1 amp2 amp an->amp2 an->amp2 amp3 amp an->amp3 an->amp3 amp4 amp an->amp4 an->amp4 dig->chgnd dig->enable amp1->enable chgnd1 amp1->chgnd1 amp2->enable amp2->chgnd1 amp3->enable amp3->chgnd1 amp4->enable amp4->chgnd1 chgnd1:n->chgnd