diff --git a/pd_blocker.sch b/pd_blocker.sch
index a9da923..3678e10 100644
--- a/pd_blocker.sch
+++ b/pd_blocker.sch
@@ -257,214 +257,149 @@ T -6400 -600 9 10 1 0 0 0 3
 capacitors block PD communication
 by smoothing out the 300 Kpbs signal,
 but still permits Rx identification
-C -1400 6100 1 0 0 LM393D_part-1-2-COMP1.sym
+C -1400 6900 1 0 0 LM393D_part-1-2-COMP1.sym
 {
-T -1400 6100 5 8 0 0 0 0 1
+T -1400 6900 5 8 0 0 0 0 1
 footprint=SOIC127P600X175-8N.lht
-T -1000 7420 5 10 1 1 0 0 1
+T -1000 8220 5 10 1 1 0 0 1
 refdes=U1
-T -200 7360 5 10 1 1 0 0 1
+T -200 8160 5 10 1 1 0 0 1
 device=LM393D
-T -1400 6100 5 10 0 1 0 0 1
+T -1400 6900 5 10 0 1 0 0 1
 lcsc=C2977085
 }
-C 4800 6100 1 0 1 LM393D_part-2-2-COMP2.sym
+C 4800 6900 1 0 1 LM393D_part-2-2-COMP2.sym
 {
-T 4800 6100 5 8 0 0 0 6 1
+T 4800 6900 5 8 0 0 0 6 1
 footprint=SOIC127P600X175-8N.lht
-T 4400 7420 5 10 1 1 0 6 1
+T 4400 8220 5 10 1 1 0 6 1
 refdes=U1
-T 3600 7360 5 10 1 1 0 6 1
+T 3600 8160 5 10 1 1 0 6 1
 device=LM393D
-T 4800 6100 5 10 0 1 0 0 1
+T 4800 6900 5 10 0 1 0 0 1
 lcsc=C2977085
 }
-C 400 7800 1 270 1 40P05.sym
+C 400 8600 1 270 1 40P05.sym
 {
-T 400 7800 5 8 0 0 90 2 1
+T 400 8600 5 8 0 0 90 2 1
 footprint=SOT95P237X112-3N.lht
-T 460 8860 5 10 1 1 180 8 1
+T 460 9660 5 10 1 1 180 8 1
 refdes=Q1
-T 1340 8860 5 10 1 1 0 6 1
+T 1340 9660 5 10 1 1 0 6 1
 device=40P05
-T 400 7800 5 10 0 0 0 0 1
+T 400 8600 5 10 0 0 0 0 1
 lcsc=C2886385
 }
-C -400 5900 1 0 0 GND.sym
-N -2000 8800 400 8800 4
+C -400 6700 1 0 0 GND.sym
+N -2000 9600 400 9600 4
 {
-T -2000 8800 5 10 1 1 0 0 1
+T -2000 9600 5 10 1 1 0 0 1
 netname=VBUS1
 }
-C -1800 6200 1 270 1 ZENER.sym
+N -1400 7600 -1600 7600 4
 {
-T -1800 6200 5 8 0 0 90 2 1
-footprint=SODFL1608X65N.lht
-T -1300 6500 5 10 1 1 0 3 1
-refdes=Z1
-T -1800 6400 5 10 0 1 90 3 1
-device=ZENER
-T -1400 6200 5 10 1 1 0 0 1
-value=4.7V
-T -1800 6200 5 10 0 1 0 6 1
-lcsc=C2832571
+T -1800 7600 5 10 1 1 0 0 1
+netname=VREF
 }
-C -1700 5900 1 0 0 GND.sym
-N -1600 6100 -1600 6200 4
-N -1600 6600 -1600 7500 4
-N -1400 6800 -1600 6800 4
-{
-T -1800 6800 5 10 1 1 0 0 1
-netname=VREF1
-}
-T -6500 6300 9 10 1 0 0 0 2
-R3 ≤ (Vsupply_min - Vzener) / Ileakage 
-R3 ≤ (4.75 - 4.7) / 2E-6 = 25k
-C -1700 8400 1 270 0 resistor-1.sym
-{
-T -1300 8100 5 10 0 0 270 0 1
-device=RESISTOR
-T -1400 8000 5 10 1 1 0 0 1
-refdes=R3
-T -1400 7700 5 10 1 1 0 0 1
-value=20k
-T -1200 8200 5 10 0 1 270 0 1
-footprint=UC1608X55N.lht
-T -1700 8400 5 10 0 1 0 0 1
-description=resistor, chip, 0603 (metric 1608), 1%
-}
-N -1600 8400 -1600 8800 4
-T -6500 8700 9 10 1 0 0 0 2
+T 1900 10000 9 10 1 0 0 0 2
 Vgs limit (± 20V) never reached because
-pulled low only when VBUS ≤ 5.5V
-T -6500 7500 9 10 1 0 0 0 2
-divider_ratio = Vref / Vover
-divider_ratio = 4.7 / 5.5 = 0.8545
-C -2100 8400 1 270 0 resistor-1.sym
+pulled down only when VBUS ≤ 5.5V
+C -2100 9200 1 270 0 resistor-1.sym
 {
-T -1700 8100 5 10 0 0 270 0 1
+T -1700 8900 5 10 0 0 270 0 1
 device=RESISTOR
-T -2200 8000 5 10 1 1 0 6 1
+T -2200 8800 5 10 1 1 0 6 1
 refdes=R1
-T -2200 7700 5 10 1 1 0 6 1
-value=5k1
-T -1600 8200 5 10 0 1 270 0 1
+T -2200 8500 5 10 1 1 0 6 1
+value=34k
+T -1600 9000 5 10 0 1 270 0 1
 footprint=UC1608X55N.lht
-T -2100 8400 5 10 0 1 0 0 1
+T -2100 9200 5 10 0 1 0 0 1
 description=resistor, chip, 0603 (metric 1608), 1%
 }
-C -2100 7000 1 270 0 resistor-1.sym
+C -2100 7800 1 270 0 resistor-1.sym
 {
-T -1700 6700 5 10 0 0 270 0 1
+T -1700 7500 5 10 0 0 270 0 1
 device=RESISTOR
-T -2200 6600 5 10 1 1 0 6 1
+T -2200 7400 5 10 1 1 0 6 1
 refdes=R2
-T -2200 6300 5 10 1 1 0 6 1
-value=30k
-T -1600 6800 5 10 0 1 270 0 1
+T -2200 7100 5 10 1 1 0 6 1
+value=21k
+T -1600 7600 5 10 0 1 270 0 1
 footprint=UC1608X55N.lht
-T -2100 7000 5 10 0 1 0 0 1
+T -2100 7800 5 10 0 1 0 0 1
 description=resistor, chip, 0603 (metric 1608), 1%
 }
-T -6500 7200 9 10 1 0 0 0 1
-R2/(R1+R2) = 30/(5.1+30) = 0.8547
-C -2100 5900 1 0 0 GND.sym
-N -2000 7500 -2000 7000 4
-N -1400 7000 -2000 7000 4
+T -2700 7000 9 10 1 0 90 0 2
+Vref = R2/(R1+R2) * Vover
+2.1 = 21/(34+21) *5.5
+C -2100 6700 1 0 0 GND.sym
+N -2000 8300 -2000 7800 4
+N -1400 7800 -2000 7800 4
 {
-T -1200 7000 5 10 1 1 0 6 1
+T -1200 7800 5 10 1 1 0 6 1
 netname=VOVER1
 }
-N -2000 8800 -2000 8400 4
-C 3000 7800 1 90 0 40P05.sym
+N -2000 9600 -2000 9200 4
+C 3000 8600 1 90 0 40P05.sym
 {
-T 3000 7800 5 8 0 0 90 0 1
+T 3000 8600 5 8 0 0 90 0 1
 footprint=SOT95P237X112-3N.lht
-T 2940 8860 5 10 1 1 180 2 1
+T 2940 9660 5 10 1 1 180 2 1
 refdes=Q2
-T 2060 8860 5 10 1 1 0 0 1
+T 2060 9660 5 10 1 1 0 0 1
 device=40P05
-T 3000 7800 5 10 0 0 0 0 1
+T 3000 8600 5 10 0 0 0 0 1
 lcsc=C2886385
 }
-C 3800 5900 1 0 1 GND.sym
-N 5400 8800 3000 8800 4
+C 3800 6700 1 0 1 GND.sym
+N 5400 9600 3000 9600 4
 {
-T 5400 8800 5 10 1 1 0 6 1
+T 5400 9600 5 10 1 1 0 6 1
 netname=VBUS2
 }
-C 5200 6200 1 90 0 ZENER.sym
+N 4800 7600 5000 7600 4
 {
-T 5200 6200 5 8 0 0 90 0 1
-footprint=SODFL1608X65N.lht
-T 5200 6400 5 10 0 1 90 5 1
-device=ZENER
-T 5200 6200 5 10 0 1 0 0 1
-lcsc=C2832571
-T 4700 6500 5 10 1 1 0 3 1
-refdes=Z4
-T 4800 6200 5 10 1 1 0 6 1
-value=4.7V
+T 5200 7600 5 10 1 1 0 6 1
+netname=VREF
 }
-C 5100 5900 1 0 1 GND.sym
-N 5000 6100 5000 6200 4
-N 5000 6600 5000 7500 4
-N 4800 6800 5000 6800 4
+C 5500 9200 1 90 1 resistor-1.sym
 {
-T 5200 6800 5 10 1 1 0 6 1
-netname=VREF2
-}
-C 5100 8400 1 90 1 resistor-1.sym
-{
-T 4700 8100 5 10 0 0 270 2 1
+T 5100 8900 5 10 0 0 270 2 1
 device=RESISTOR
-T 4600 8200 5 10 0 1 270 2 1
+T 5000 9000 5 10 0 1 270 2 1
 footprint=UC1608X55N.lht
-T 4800 8000 5 10 1 1 0 6 1
+T 5600 8800 5 10 1 1 0 0 1
+refdes=R5
+T 5600 8500 5 10 1 1 0 0 1
+value=34k
+T 5500 9200 5 10 0 1 0 0 1
+description=resistor, chip, 0603 (metric 1608), 1%
+}
+C 5500 7800 1 90 1 resistor-1.sym
+{
+T 5100 7500 5 10 0 0 270 2 1
+device=RESISTOR
+T 5000 7600 5 10 0 1 270 2 1
+footprint=UC1608X55N.lht
+T 5600 7400 5 10 1 1 0 0 1
 refdes=R6
-T 4800 7700 5 10 1 1 0 6 1
-value=20k
-T 5100 8400 5 10 0 1 0 0 1
+T 5600 7100 5 10 1 1 0 0 1
+value=21k
+T 5500 7800 5 10 0 1 0 0 1
 description=resistor, chip, 0603 (metric 1608), 1%
 }
-N 5000 8400 5000 8800 4
-C 5500 8400 1 90 1 resistor-1.sym
+C 5500 6700 1 0 1 GND.sym
+N 5400 8300 5400 7800 4
+N 4800 7800 5400 7800 4
 {
-T 5100 8100 5 10 0 0 270 2 1
-device=RESISTOR
-T 5000 8200 5 10 0 1 270 2 1
-footprint=UC1608X55N.lht
-T 5600 8000 5 10 1 1 0 0 1
-refdes=R7
-T 5600 7700 5 10 1 1 0 0 1
-value=5k1
-T 5500 8400 5 10 0 1 0 0 1
-description=resistor, chip, 0603 (metric 1608), 1%
-}
-C 5500 7000 1 90 1 resistor-1.sym
-{
-T 5100 6700 5 10 0 0 270 2 1
-device=RESISTOR
-T 5000 6800 5 10 0 1 270 2 1
-footprint=UC1608X55N.lht
-T 5600 6600 5 10 1 1 0 0 1
-refdes=R8
-T 5600 6300 5 10 1 1 0 0 1
-value=30k
-T 5500 7000 5 10 0 1 0 0 1
-description=resistor, chip, 0603 (metric 1608), 1%
-}
-C 5500 5900 1 0 1 GND.sym
-N 5400 7500 5400 7000 4
-N 4800 7000 5400 7000 4
-{
-T 4600 7000 5 10 1 1 0 0 1
+T 4600 7800 5 10 1 1 0 0 1
 netname=VOVER2
 }
-N 5400 8800 5400 8400 4
-N 1600 8800 1800 8800 4
+N 5400 9600 5400 9200 4
+N 1600 9600 1800 9600 4
 {
-T 1500 8800 5 10 1 1 0 0 1
+T 1500 9600 5 10 1 1 0 0 1
 netname=VBUS
 }
 C -1200 -800 1 0 0 HEADER-2.54-1x10.sym
@@ -530,7 +465,7 @@ T 800 2300 5 8 0 0 0 0 1
 footprint=CONNECTOR_XKB_U262-24XN-4BV60.lht
 T 1200 4960 5 10 1 1 0 0 1
 refdes=J2
-T 3760 2640 5 10 1 1 0 2 1
+T 3760 2640 5 10 0 1 0 2 1
 device=XKB_U262-24XN-4BV60
 T 3300 5000 5 10 1 1 0 0 1
 value=USB-C receptacle
@@ -543,7 +478,7 @@ T -5600 2300 5 8 0 0 0 0 1
 footprint=CONNECTOR_XKB_U261-24XN-4BC2LS.lht
 T -5200 4960 5 10 1 1 0 0 1
 refdes=J1
-T -2540 2640 5 10 1 1 0 2 1
+T -2540 2640 5 10 0 1 0 2 1
 device=XKB_U261-24XN-4BC2LS
 T -5600 2300 5 10 0 0 0 0 1
 lcsc=C2880648
@@ -553,96 +488,100 @@ value=USB-C plug
 N -2700 2100 -2700 2300 4
 N -2900 2100 -2900 2300 4
 N -3100 2100 -3100 2300 4
-T -6500 9900 9 10 1 0 0 0 1
+T -6900 10200 9 10 1 0 0 0 1
 over-voltage protection
 T -6500 1500 9 10 1 0 0 0 1
 communication protection
-T -6500 9300 9 10 1 0 0 0 2
+T -1600 10000 9 10 1 0 0 0 2
 two pMOS are required to
-block VBUS in both direction
-C -1300 9700 1 0 0 BAV74_part-1-2-D1.sym
+block VBUS in both directions
+C -5800 9300 1 0 0 BAV74_part-1-2-D1.sym
 {
-T -1300 9700 5 8 0 0 0 0 1
+T -5800 9300 5 8 0 0 0 0 1
 footprint=SOT95P237X112-3N.lht
-T -1100 10060 5 10 1 1 0 3 1
+T -5600 9660 5 10 1 1 0 3 1
 refdes=D1
-T -1100 9740 5 10 1 1 0 5 1
+T -5600 9340 5 10 1 1 0 5 1
 device=BAV74
 }
-C -100 9700 1 0 1 BAV74_part-2-2-D2.sym
+C -4600 9300 1 0 1 BAV74_part-2-2-D2.sym
 {
-T -100 9700 5 8 0 0 0 6 1
+T -4600 9300 5 8 0 0 0 6 1
 footprint=SOT95P237X112-3N.lht
-T -300 10060 5 10 1 1 0 3 1
+T -4800 9660 5 10 1 1 0 3 1
 refdes=D1
-T -300 9740 5 10 1 1 0 5 1
+T -4800 9340 5 10 1 1 0 5 1
 device=BAV74
 }
-T -6500 8100 9 10 1 0 0 0 2
+T -6600 8700 9 10 1 0 0 0 2
 diodes prevent VBUS
 cross-leakage
-C -900 9900 1 0 0 VCC.sym
-N -1300 9900 -2000 9900 4
+C -5400 9500 1 0 0 VCC.sym
+N -5800 9500 -6500 9500 4
 {
-T -1300 9900 5 10 1 1 0 6 1
+T -5800 9500 5 10 1 1 0 6 1
 netname=VBUS1
 }
-N -900 9900 -500 9900 4
-N -100 9900 600 9900 4
+N -5400 9500 -5000 9500 4
+N -4600 9500 -3900 9500 4
 {
-T -100 9900 5 10 1 1 0 0 1
+T -4600 9500 5 10 1 1 0 0 1
 netname=VBUS2
 }
-C 3500 7700 1 0 0 VCC.sym
-C -500 7700 1 0 0 VCC.sym
-C 500 8800 1 90 1 resistor-1.sym
+C 3500 8500 1 0 0 VCC.sym
+C -500 8500 1 0 0 VCC.sym
+C 500 9600 1 90 1 resistor-1.sym
 {
-T 100 8500 5 10 0 0 270 2 1
+T 100 9300 5 10 0 0 270 2 1
 device=RESISTOR
-T 200 8400 5 10 1 1 0 6 1
+T 200 9200 5 10 1 1 0 6 1
+refdes=R3
+T 200 8900 5 10 1 1 0 6 1
+value=100k
+T 0 9400 5 10 0 1 270 2 1
+footprint=UC1608X55N.lht
+T 500 9600 5 10 0 1 0 6 1
+description=resistor, chip, 0603 (metric 1608), 1%
+}
+N 400 8700 400 8600 4
+N 400 8600 800 8600 4
+C 2900 9600 1 270 0 resistor-1.sym
+{
+T 3300 9300 5 10 0 0 270 0 1
+device=RESISTOR
+T 3400 9400 5 10 0 1 270 0 1
+footprint=UC1608X55N.lht
+T 3200 9200 5 10 1 1 0 0 1
 refdes=R4
-T 200 8100 5 10 1 1 0 6 1
+T 3200 8900 5 10 1 1 0 0 1
 value=100k
-T 0 8600 5 10 0 1 270 2 1
-footprint=UC1608X55N.lht
-T 500 8800 5 10 0 1 0 6 1
+T 2900 9600 5 10 0 1 0 6 1
 description=resistor, chip, 0603 (metric 1608), 1%
 }
-N 400 7900 400 7800 4
-N 400 7800 1000 7800 4
-C 1000 7600 1 0 0 BAV74_part-1-2-D1.sym
+N 3000 8700 3000 8600 4
+N 2600 8600 3000 8600 4
+N 800 8600 800 7700 4
+T 700 7400 9 10 1 0 0 0 1
+open-collector output
+C -6400 7100 1 0 0 HT75xx-3.sym
 {
-T 1000 7600 5 8 0 0 0 0 1
-footprint=SOT95P237X112-3N.lht
-T 1200 7960 5 10 1 1 0 3 1
-refdes=D2
-T 1200 7640 5 10 1 1 0 5 1
-device=BAV74
+T -6400 7100 5 8 0 0 0 0 1
+footprint=SOT95P280X145-5N.fp
+T -5850 8260 5 10 1 1 0 3 1
+refdes=U2
+T -5340 7440 5 10 0 1 0 2 1
+device=HT75xx-3
+T -5500 8300 5 10 1 1 0 0 1
+value=HT7521-3
 }
-C 2400 7600 1 0 1 BAV74_part-2-2-D2.sym
+T -6900 6400 9 10 1 0 0 0 2
+Vref ≤ VBUSmin - D1_Vf - LM393_Vicm
+Vref ≤ 4.75 - 0.715 - 1.5 = 2.5V
+C -6600 8000 1 0 0 VCC.sym
+C -5500 6900 1 0 0 GND.sym
+N -4300 8000 -3700 8000 4
 {
-T 2400 7600 5 8 0 0 0 6 1
-footprint=SOT95P237X112-3N.lht
-T 2100 7960 5 10 1 1 0 3 1
-refdes=D2
-T 2200 7640 5 10 1 1 0 5 1
-device=BAV74
+T -4200 8000 5 10 1 1 0 0 1
+netname=VREF
 }
-C 2900 8800 1 270 0 resistor-1.sym
-{
-T 3300 8500 5 10 0 0 270 0 1
-device=RESISTOR
-T 3400 8600 5 10 0 1 270 0 1
-footprint=UC1608X55N.lht
-T 3200 8400 5 10 1 1 0 0 1
-refdes=R5
-T 3200 8100 5 10 1 1 0 0 1
-value=100k
-T 2900 8800 5 10 0 1 0 6 1
-description=resistor, chip, 0603 (metric 1608), 1%
-}
-N 3000 7900 3000 7800 4
-N 2400 7800 3000 7800 4
-N 1400 7800 2000 7800 4
-N 1700 7800 1700 6900 4
-N 1700 6900 800 6900 4
+N 2600 7700 2600 8600 4