From 5ea1d7ff1ec782037a8d9b87f3005bde654575a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Fri, 8 Apr 2022 16:32:30 +0200
Subject: [PATCH] sch: use diode for power source

---
 pd_blocker.sch | 95 +++++++++++++++++++++++++-------------------------
 1 file changed, 48 insertions(+), 47 deletions(-)

diff --git a/pd_blocker.sch b/pd_blocker.sch
index 99c84c9..601c55e 100644
--- a/pd_blocker.sch
+++ b/pd_blocker.sch
@@ -348,7 +348,7 @@ N -1400 6800 -1600 6800 4
 T -1800 6800 5 10 1 1 0 0 1
 netname=VREF1
 }
-T -6400 6500 9 10 1 0 0 0 2
+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
@@ -365,9 +365,10 @@ T -1700 8400 5 10 0 1 0 0 1
 description=resistor, chip, 0603 (metric 1608), 1%
 }
 N -1600 8400 -1600 8800 4
-T -6400 8100 9 10 1 0 0 0 1
-Vgs ≤ ±20V
-T -6400 7500 9 10 1 0 0 0 2
+T -6500 8700 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
@@ -396,7 +397,7 @@ footprint=UC1608X55N.lht
 T -2100 7000 5 10 0 1 0 0 1
 description=resistor, chip, 0603 (metric 1608), 1%
 }
-T -6400 7100 9 10 1 0 0 0 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
@@ -528,9 +529,6 @@ N 1600 8800 1800 8800 4
 T 1500 8800 5 10 1 1 0 0 1
 netname=VBUS
 }
-T -6400 8500 9 10 1 0 0 0 2
-Over-Voltage protection with comparator circuit
-nased on Texas Instruments SNOAA20 design
 C -1200 -800 1 0 0 HEADER-2.54-1x10.sym
 {
 T -1200 -800 5 8 0 0 0 0 1
@@ -601,45 +599,6 @@ value=USB-C receptacle
 T 3600 4000 5 10 0 1 0 0 1
 lcsc=C388659
 }
-C -500 8500 1 270 0 SCHOTTKY.sym
-{
-T -500 8500 5 8 0 0 270 0 1
-footprint=SODFL1608X65N.lht
-T -600 8360 5 10 1 1 0 3 1
-refdes=D1
-T -460 8300 5 10 0 1 270 5 1
-device=SCHOTTKY
-T -400 8300 5 10 0 1 270 0 1
-value=RB521S-30
-T -500 8500 5 10 0 0 270 0 1
-lcsc=C122862
-}
-C 3900 8500 1 90 1 SCHOTTKY.sym
-{
-T 3900 8500 5 8 0 0 270 2 1
-footprint=SODFL1608X65N.lht
-T 4000 8360 5 10 1 1 0 3 1
-refdes=D2
-T 3860 8300 5 10 0 1 270 3 1
-device=SCHOTTKY
-T 3800 8300 5 10 0 1 270 2 1
-value=RB521S-30
-T 3900 8500 5 10 0 0 270 2 1
-lcsc=C122862
-}
-N -300 8100 -300 7700 4
-N -300 8500 -300 8800 4
-N 3700 8500 3700 8800 4
-N 3700 8100 3700 7700 4
-N -300 7900 200 7900 4
-N 200 7900 200 7600 4
-N 200 7600 3200 7600 4
-{
-T 1400 7600 5 10 1 1 0 0 1
-netname=V+
-}
-N 3200 7600 3200 7900 4
-N 3200 7900 3700 7900 4
 C -5600 2300 1 0 0 XKB_U261-24XN-4BC2LS.sym
 {
 T -5600 2300 5 8 0 0 0 0 1
@@ -656,3 +615,45 @@ 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
+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
+two pMOS are required to
+block VBUS in both direction
+C -1300 9700 1 0 0 BAV74_part-1-2-D1.sym
+{
+T -1300 9700 5 8 0 0 0 0 1
+footprint=SOT95P237X112-3N.lht
+T -1100 10060 5 10 1 1 0 3 1
+refdes=D1
+T -1100 9740 5 10 1 1 0 5 1
+device=BAV74
+}
+C -100 9700 1 0 1 BAV74_part-2-2-D2.sym
+{
+T -100 9700 5 8 0 0 0 6 1
+footprint=SOT95P237X112-3N.lht
+T -300 10060 5 10 1 1 0 3 1
+refdes=D1
+T -300 9740 5 10 1 1 0 5 1
+device=BAV74
+}
+T -6500 8100 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
+{
+T -1300 9900 5 10 1 1 0 6 1
+netname=VBUS1
+}
+N -900 9900 -500 9900 4
+N -100 9900 600 9900 4
+{
+T -100 9900 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