Protection of Reversed Polarity on DC plug-in
From Qi-Hardware
Revision as of 09:38, 9 May 2011 by 111.185.76.145 (Talk)
Contents |
Schematics
Sch. B: added one fuse and one diode.
Sch. B-1: added one fuse and one Zerner diode.
Sch. B-2: added one fuse and one diode.
Sch. C: added one fuse and one N-MOSFET.
Sch. D: added one fuse and two 5W 5.1V Zener diodes.
Sch. A:
advantage -
- simplicity, low cost
disadvantage -
- without protections on current and voltage limit suppressor, reversed polarity
- needs a dedicated tolerance of DC adapter 5V +/- 5%
Sch. B, it's the feedback from Joerg[2].
advantage -
- protections on current limited suppressor and reversed polarity;
- using a general fuse that will be broken both positive and negative polarity input.
- a traditional diode is enough.
disadvantage -
- without protection on voltage limit suppressor;
- one-time fuse needs to be replaced a new one when it broke on end user. But it's not necessary when using PTC[3] type fuse.
- needs a dedicated tolerance of DC adapter 5V +/- 5%
Sch. B-1:
advantage -
- protections on current limited suppressor and reversed polarity;
- Zener diode can be an over-voltage protection for input.
disadvantage -
- one-time fuse needs to be replaced a new one when it broke on end user. But it's not necessary when using PTC[4] type fuse.
- need a resistor (or PTC fuse) to be as current limited when Zener breakdowns.
Sch. B-2:
advantage -
- protections on current limited suppressor and reversed polarity;
disadvantage -
- one-time fuse needs to be replaced a new one when it broke on end user. But it's not necessary when using PTC[5] type fuse.
- better to use a Schottky Barrier diode which drops low forward voltage .
Sch. C:
advantage -
- protections on current limited suppressor and reversed polarity;
- using a general fuse that will be broken when positive input and over-current.
- without risks on fuse broken when inputing a negative source.
- no needs to replace fuse if using PTC type.
- with few nano-amperes when MOSFET is OFF. This is mostly designed on consumer products when reversed battery-in.
disadvantage -
- high cost when using PTC fuse and N-MOSFET[6]. Still without voltage protection.
- there's resistance drain source Rds(on) existed internally while MOSFET is ON. An input voltage will be shared by that small internal milli-ohm resistance. A well-considerable design is necessary. A VSD source to drain drops forward voltage on body diode.
- needs a dedicated tolerance of DC adapter 5V +/- 5%
Notes:
- Since the adapter's rating current for Milkymist One is 2A, a trip current lower than or equal to 2A is safe. For example using a resettable fuse holding current 1.1A and it's trip current on 2.2A. Since this is sample that overs a trip current 2A. So using a trip current of 1.5A is preferred due to there's no common PTC with trip 2A at 20 ° C. So performance from datasheet[7]'s Fig. 9 Time-to-trip curve at 20 ° C when a expected fault 2A trip occasion happened:
if using microSMD110F, holding current 1.1A, trip current 2.2A, needs 10 seconds to trip. if using microSMD075F, holding current 0.75A, trip current 1.5A, needs 6 seconds to trip. if using microSMD050F, holding current 0.50A, trip current 1.0A at 13.2VDC max., needs 0.6 seconds to trip. if using microSMD035F, holding current 0.35A, trip current 0.75A, needs 0.2 seconds to trip.
- Since 5V net/symbol used every where in RC2 design, thus any variance directly influences the specification met by:
all step-down regulators, two usb host connector power, a USB compliant supply will provide between 4.75 and 5.25V and at least 0.5A of continuous power. 4V3 supply for audio codec
Experimental Conditions
- Equipments:
- Agilent 34401A Multimeter
- ABM DC Power Supply 8303D
- Tektronix TDS1012
- TES-1326S IR Thermometer
- M1 RC2 0x1a/0x2c Board without reset ic & diodes to fix no configuration bug, only usb mouse and VGA monitor connected.
- Software:
- FLickernoise 0.1(built on Nov 19 2010), OS: RTMES 4.10.99.0, Platerform: Milkymist SoC1.0RC1, CPU: LatticeMico32, Board: M1(PCB rev.)
- Data measured under circumstances: All average voltages and currents are measured 5 minutes after power-up and entered control panel. Bare M1 board without case. Room temperature is around 20°C degrees.
Sch. B
- F2 - MICROSMD075F-2, 6VDC/0.40Ω; D14 - MBRA240T3G;
- Since this schematic is simply understood while using non-reversed polarity source, so no more experiments for it.
- According to F2 datasheet, it needs roughly 6 seconds to trip at 2A, 2.5s @ 2.5A, 1.3s @ 3A. D14 has forward max. 3A capability. Let's try to provide a 2.5A 5V non-reversed polarity source power:
| DC Jack pluggin polarity | VJ11 to DC jack GND (V) | Voltage of symbol 5V marked on M1 | If (A) | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x2c | 5.00 | 4.681 | 0.78 | 3.219 | 2.485 | 1.778 | 1.166 | 4.269 | usb works well |
| reversed, 0x2c | - 4.75 | - 0.820 | - 0.31 | n/a | n/a | n/a | n/a | n/a | current stays 0.31A |
- 8303D DC Power Supply sets at 2.5A limited to DC Jack
It is VJ11. When a reversed polarity power up, a 2.5A flashs quickly then goes down to 0.4A and stays there. DC Power supply stays finally at 5V. This instantaneous duration is about 250ms as shown.
A zoom-in time slot.
It is VD14 which shows actually a forward voltage drop about ??V.
- 100 times on testing reversed polarity input with - 5.00V and the results on If (A) is stayed at negative 0.4A. It keeps descending to 0.37A if not power off. Touching the surface of F2, can feel it kept mildly warm. When current descends to 0.3A, quickly disconnect/plug -out DC source, a resistance of 47 ohm on MICROSMD075F-2 fuse which stays almost 0 ohm(which is measured on bare part.).
- After above tests, then plug in with non reversed polarity, board works well.
Sch. B-1
- F2 - MICROSMD075F-2, 6VDC/0.40Ω; D14 - normal 1W 5.1 Zerner diode (which I bought from normal market shop without datasheet);
- Since this schematic is simply understood while using non-reversed polarity source, so no more experiments for it.
| DC Jack pluggin polarity | VJ11 to DC jack GND (V) | Voltage of symbol 5V marked on M1 | If (A) | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x2c | 5.5 | 5.314 | 0.63 | 3.302 | 2.553 | 1.836 | 1.245 | 4.326 | standby mode, the Zerner diode body is quite heated. |
| non-reversed, 0x2c | 5.25 | 5.084 | 0.49 | 3.302 | 2.553 | 1.836 | 1.245 | 4.327 | standby mode |
| non-reversed, 0x2c | 5.00 | 4.743 | 0.75 | 3.314 | 2.578 | 1.873 | 1.258 | 4.366 | usb works well |
| non-reversed, 0x2c | 4.75 | 4.600 | 0.43 | 3.300 | 2.5552 | 1.835 | 1.244 | 4.324 | standby mode |
| reversed, 0x2c | - 5.25 | - 0.808 | - 0.27 | n/a | n/a | n/a | n/a | n/a | current stays 0.27A |
| reversed, 0x2c | - 5.00 | - 0.808 | - 0.29 | n/a | n/a | n/a | n/a | n/a | current stays 0.29A |
| reversed, 0x2c | - 4.75 | - 0.820 | - 0.32 | n/a | n/a | n/a | n/a | n/a | current stays 0.31A |
Sch. B-1-1
- F2 - MINISMDC075F-2, 13.2VDC/0.45Ω; D14 - 1N5338BG
- Experimental table below is based on NO LOAD condition. Each measurement is done after attempting for 2 minutes.
- Since fuse and zener are all thermo-dependent parts, long time period a lower consumption remains.
- Since power supply is limited on 2.85A, following 2.85A shown means it clamps under that limitation while being instantaneous.
No Load: No MM1 load condition.
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) |
|---|---|---|---|---|---|---|
| non-reversed | 20 | 19.992 | 5.056 | 0.06 / 2.85 | 33.8 | 30.5 |
| non-reversed | 12 | 11.99 | 5.093 | 0.11 / 2.85 | 30.1 | 29.9 |
| non-reversed | 5.25 | 5.224 | 5.142 | 0.24 / 0.43 | 36.4 | 32.6 |
| non-reversed | 5 | 4.997 | 4.986 | 0.02 / 0.03 | 24.1 | 24.1 |
| non-reversed | 4.75 | 4.749 | 4.746 | 0.00 / - | 23.4 | 23.9 |
| non-reversed | 4.5 | 4.499 | 4.498 | 0.00 / - | 23.1 | 23.2 |
| reversed | -20 | -19.99 | -0.706 | 0.04 / 2.85 | 37.1 | 28.1 |
| reversed | -12 | -11.99 | -0.720 | 0.07 / 2.85 | 36.7 | 28.1 |
| reversed | -5.25 | -5.233 | -0.734 | 0.2 / 2.85 | 38.9 | 28.4 |
| reversed | -5 | -4.982 | -0.738 | 0.2 / 2.85 | 37.9 | 27.4 |
| reversed | -4.75 | -4.982 | -0.729 | 0.2 / 2.85 | 35.3 | 27.3 |
| reversed | -4.5 | -4.479 | -0.74 | 0.21 / 2.85 | 37.7 | 28.1 |
Sch. B-1-1-1
- F2 - MINISMDC125F-2, 6VDC/0.14Ω;
- D14 - 1N5338BG
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Note |
|---|---|---|---|---|---|---|---|
| non-reversed | 20 | 19.995 | 5.06 | 0.05 / 2.85 | 32.4 | 28.9 | current descends from 2.85 A(sustain 2s) to 0.05A,zener consumption descends from 14.5W to 0.25W. |
| non-reversed | 12 | 11.991 | 5.114 | 0.11 / 2.85 | 39.7 | 29.9 | current descends from 2.85 A(sustain 2s) to 0.11A,zener consumption descends from 14.5W to 0.56W. |
| non-reversed | 7.5 | 7.471 | 5.193 | 0.26 / 2.85 | 36.6 | 30.5 | current descends from 2.85 A(sustain 2s) to 0.11A,zener consumption descends from 14.5W to 1.35W. |
| non-reversed | 6 | 5.945 | 5.3 | 0.69 / 2.85 | 36.7 | 33.1 | current descends from 2.85 A(sustain 22s) to 0.69A,zener consumption descends from 14.5W to 3.66W. |
| non-reversed | 5.25 | 5.221 | 5.171 | 0.25 / 0.61 | 37.5 | 28.7 |
Sch. B-1-1-2
- F2 - MICROSMD110F-2, 6VDC/0.21Ω;
- D14 - 1N5338BG
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Note |
|---|---|---|---|---|---|---|---|
| non-reversed | 20 | 19.995 | 5.045 | 0.05 / 2.85 | 36.2 | 28.0 | < 0.5 s, current descends from 2.85 A to 0.05A,zener consumption descends from 14.5W to 0.25W. |
| non-reversed | 12 | 11.986 | 5.088 | 0.12 / 2.85 | 30.2 | 29.4 | < 0.5 s, current descends from 2.85 A to 0.12A,zener consumption descends from 14.5W to 0.6W. |
| non-reversed | 9 | 8.986 | 5.128 | 0.17 / 2.85 | 34.5 | 28.4 | |
| non-reversed | 7.5 | 7.469 | 5.175 | 0.25 / 2.85 | 34.3 | 28.5 | |
| non-reversed | 6 | 5.961 | 5.29 | 0.5 / 2.5 | 37.5 | 29.2 | |
| non-reversed | 5.25 | 5.228 | 5.140 | 0.24 / - | 32.2 | 31.4 | |
| reversed | -5.25 | -5.230 | -0.737 | 0.18 / 2.85 | 28.8 | 29.7 | < 0.5 s, current descends from 2.85 A to 0.18A,zener consumption descends from 1.99W to 0.13W. |
| reversed | -12 | -11.990 | -0.703 | 0.07 / 2.85 | 29.8 | 28.2 | |
| reversed | -20 | -19.996 | -0.7 | 0.04 / 2.85 | 30.5 | 28.7 |
Sch. B-1-2
- F2 - MINISMDC075F-2, 13.2VDC/0.45Ω ;
- D14 - 1N5338BG
- Experimental table below is based on LOAD condition. Each measurement is done after attempting for 5 minutes.
- All ethernet, keyboard, mouser, vga monitor, JTAG/Serial board, Audio line in/out, video source are connected.
- Since fuse and zener are all thermo-dependent parts, long time period a lower consumption remains.
- Since power supply is limited on 2.85A, following 2.85A shown means it clamps under that limitation while being instantaneous.
With MM1 Load: Although zener and fuse are connected with MM1, the factor of temperature surrounding U13 is comparatively variable to fuse and zener.
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Voltage of symbol 5V marked on M1 RC2 | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x1e | 5 | 4.93 | 4.724 | 0.76 / - | 28.9 | 26.9 | 4.489 | 3.257 | 2.494 | 1.782 | 1.16 | 4.293 |
With MM1 Load: In order to get actual effect of temperature factor from heated spreading nearby U13, it's a must to place fuse and zener closely on board.
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Voltage of symbol 5V marked on M1 RC2 | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x1e | 12 | 11.98 | 1.985 | 0.18 / 2.85 | 40.3 | 48.2 | 1.862 | 1.378 | 0 | 0.44 | 0.01 | 0.178 | - |
| non-reversed, 0x1e | 5.25 | 5.178 | 4.914 | 0.79 / - | 37.6 | 34.9 | 4.675 | 3.255 | 2.488 | 1.779 | 1.159 | 4.294 | U13, 39.0°C |
| non-reversed, 0x1e | 5 | 4.927 | 4.653 | 0.76 / - | 40.7 | 43.1 | 4.458 | 3.257 | 2.488 | 1.779 | 1.159 | 4.291 | U13, 43.2°C |
| non-reversed, 0x1e | 4.75 | 4.680 | 4.399 | 0.76 / - | 39.8 | 37.7 | 4.186 | 3.254 | 2.488 | 1.781 | 1.159 | 4.168 | U13, 43.2°C |
| non-reversed, 0x1e | 4.5 | 4.427 | 4.161 | 0.76 / - | 38.8 | 41.0 | 4.186 | 3.253 | 2.488 | 1.780 | 1.159 | 3.926 | U13, 36.8°C |
Sch. B-1-2-1
- F2 - MINISMDC125F-2, 6VDC/0.14Ω ;
- D14 - 1N5338BG
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Voltage of symbol 5V marked on M1 RC2 | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x1e | 12 | 11.977 | 2.28 | 0.22 / 2.85 | 37.5 | 44.3 | 2.172 | - | - | - | - | - | trip needs 2s, current descends from 2.85 A(sustain 2s) to 0.22A |
| non-reversed, 0x1e | 7.5 | 7.462 | 2.532 | 0.3 / 2.85 | 37.8 | 45.3 | 2.304 | 1.76 | 0 | 1.809 | 0 | 2.263 | Be careful of this case: MM1 can work under reconfiguration(0.7A). Fuse trips when trying to enter boot status(0.3A). |
| non-reversed, 0x1e | 6 | 5.887 | 5.219 | 1.12 / 2.85 | 50.5 | 62.4 | 4.993 | 3.25 | 2.489 | 1.782 | 1.159 | 4.293 | Be careful of this case: MM1 can work under reconfiguration(0.92A). Fuse holds current when trying to enter boot status(1.12A). |
| non-reversed, 0x1e | 5.25 | 5.173 | 5.046 | 0.76 / - | 37.8 | 40.4 | 4.833 | 3.257 | 2.488 | 1.782 | 1.16 | 4.293 | U13, 38.5°C |
Sch. B-1-2-2
- F2 - MICROSMD110F-2, 6VDC/0.21Ω ;
- D14 - 1N5338BG
- Experimental table below is based on LOAD condition. Each measurement is done, be noticed on Notes column.
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Voltage of symbol 5V marked on M1 RC2 | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x1e | 20 | 19.997 | 2.02 | 0.09 / 2.85 | 36.3 | 41.6 | 1.989 | 1.845 | 0 | 0.55 | 0 | 0.033 | fuse trips less than 0.5s |
| non-reversed, 0x1e | 12 | 11.990 | 1.89 | 0.15 / 2.85 | 39.4 | 43.9 | 1.833 | 1.351 | 0 | 0.443 | 0 | 0.28 | fuse trips less than 0.5s |
| non-reversed, 0x1e | 9 | 8.980 | 2.07 | 0.22 / - | 38.8 | 44.1 | 1.978 | 1.472 | 0 | 0.443 | 0 | 0.174 | |
| non-reversed, 0x1e | 7.5 | 7.471 | 2.254 | 0.3 / 2.85 | 39.4 | 43.7 | 2.14 | 1.628 | 0 | 0.372 | 0 | 0.403 | Be careful of this case: MM1 can work under reconfiguration(0.59A). Fuse trips when trying to enter boot status(0.3A). |
| non-reversed, 0x1e | 6.75 | 6.709 | 2.42 | 0.37 / 2.85 | 38.1 | 43.2 | 2.23 | 1.719 | 0 | 1.81 | 0 | 2.227 | Be careful of this case: MM1 can work under reconfiguration(0.72A). Fuse trips when trying to enter boot status(0.3A). |
| non-reversed, 0x1e | 6 | 5.907 | 5.171 | 0.94 / 1.65 | 48.9 | 56 | 4.934 | 3.255 | 2.488 | 1.779 | 1.159 | 4.293 | Be careful of this case: MM1 can work under reconfiguration(from 1.65A descends to 0.79A). The consumption goes slowly up to reach maximum 5W of zener and fuse limits current at 0.94A. |
| non-reversed, 0x1e | 5.25 | 5.197 | 5.021 | 0.76 / - | 37.1 | 40.5 | 4.814 | 3.264 | 2.49 | 1.781 | 1.159 | 4.294 | |
| non-reversed, 0x1e | 5 | 4.94 | 4.788 | 0.76 / - | 36.9 | 39.2 | 4.601 | 3.264 | 2.488 | 1.781 | 1.159 | 4.293 | |
| non-reversed, 0x1e | 4.75 | 4.684 | 4.53 | 0.76 / 0.53 | 36.4 | 39.2 | 4.333 | 3.264 | 2.49 | 1.781 | 1.159 | 4.276 | |
| non-reversed, 0x1e | 4.5 | 4.438 | 4.288 | 0.76 / 0.53 | 38.4 | 30.8 | 4.063 | 3.257 | 2.49 | 1.781 | 1.159 | 4.036 | |
| reversed, 0x1e | -5 | -4.968 | -0.727 | 0.36 / 2.85 | 38.6 | 46 | -0.681 | -0.318 | -0.151 | -0.223 | 0 | -0.230 | |
| reversed, 0x1e | -5.25 | -5.218 | -0.725 | 0.36 / 2.85 | 36.3 | 43.5 | -0.681 | -0.318 | -0.151 | -0.223 | 0 | -0.229 | |
| reversed, 0x1e | -12 | -11.99 | -0.682 | 0.14 / 2.85 | 37.4 | 41.6 | -0.654 | -0.297 | -0.158 | -0.205 | 0 | -0.218 | |
| reversed, 0x1e | -20 | -19.998 | -0.664 | 0.08 / 2.85 | 34.8 | 42.5 | -0.639 | -0.278 | -0.160 | -0.191 | 0 | -0.209 |
Sch. C
- F2 - MICROSMD075F-2, 6VDC/0.40Ω; Q3 - FDD6530A;
- 100 times on testing reversed polarity input with - 5.00V and the results on If (A) is stayed at net 0.412mA.
- According to LM4550B, the Analog Supply Range is Min.4.2V. A descended tune a DC JACK power input at 4.516V which voltage of (TP26) is 3.829V. A very loud noise starts up from LINE OUT. This extreme test conflicts with the recommended operating ratings.
- From data below: when the input is 5.00V, regardless of the voltage VGS or TP26, they have been lower than the specification required. This is because Q3 its resistance Rds launch of formation of the results of the voltage divider effect. For example, the VGS is equalent to the required voltage of USB host, but from these tests they are all unqualified. This is not schematic C with wrong design. It's because we don't change a new DC adapater with dedicated output voltage range. If the parameters of good design can be best among the central values, but sometimes backfired.
Sch. C: added one MICROSMD075F-2 fuse and one FDD6530A N-MOSFET.
| DC Jack pluggin polarity | VJ11 to DC jack GND (V) | VC138 = VGS (V) = Voltage of symbol 5V marked on M1 | VS to DC jack GND (V) | If (A) | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x2c | 5.25 | 4.675 | 37.5m | 0.78 | 3.221 | 2.485 | 1.778 | 1.157 | 4.272 | usb works well |
| non-reversed, 0x2c | 5.00 | 4.425 | 35.0m | 0.78 | 3.22 | 2.485 | 1.788 | 1.171 | 4.262 | usb works well |
| non-reversed, 0x2c | 4.75 | 4.201 | 35.7m | 0.78 | 3.220 | 2.485 | 1.779 | 1.166 | 4.132 | usb works well |
| non-reversed, 0x2c | 4.51 | 3.897 | 37.4m | 0.79 | 3.216 | 2.479 | 1.779 | 1.156 | 3.829 | usb works well, measured while running audio LINE-OUT |
| reversed, 0x1a | - 5.25 | 0.889 | - 6.138 | -0.412m [This is pretty high, but it's normal condition. If disconnected VGA & usb cable, this current becomes almost 0uA. It meets datasheet said that IDSS max. is 1uA.] | 0.04m | 0.01m | 0.03m | 0.01m | 0.74m | |
| reversed, 0x1a | - 5.00 | 0.886 | - 5.884 | - 0.412m | 0.03m | 0.01m | 0.01m | 0.01m | 0.64m | |
| reversed, 0x1a | - 4.75 | 0.889 | - 5.638 | - 0.411m | 0.01m | 0.01m | 0.02m | 0.01m | 0.56m |
Sch. D
- F2 - MINISMDC200F-2, 8VDC/0.07Ω ;
- D14 - 2 * 5W 5.1V Zener 1N5338BG in parallel
- Experimental table below is based on NO LOAD condition. Each measurement is done, be noticed on Notes column.
- Since fuse and zener are all thermo-dependent parts, long time period a lower consumption remains.
- Since power supply is limited on 2.85A, following 2.85A shown means it clamps under that limitation while being instantaneous.
＊ room temperature: 27.1°C
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Notes |
|---|---|---|---|---|---|---|---|
| non-reversed | 20 | 19.999 | 5.044 | 0.03 / 2.85 | 40.7 | 29.8 | 2.85A(0s) -> 0.03A(16s) |
| non-reversed | 12 | 11.9938 | 5.127 | 0.09 / 2.85 | 45.6 | 30.0 | 2.85A(0s) -> 0.09A(11s) |
| non-reversed | 9 | 8.982 | 5.169 | 0.09 / 2.85 | 43.9 | 31.5 | 2.85A(0s) -> 0.09A(16s) |
| non-reversed | 7.5 | 7.460 | 5.199 | 0.31 / 2.85 | 55.9 | 29.2 | 2.85A(0s) -> 0.16A(16s) |
| non-reversed | 6 | 5.919 | 5.303 | 0.57 / 2.85 | 60.6 | 34.5 | 2.85A(0s) -> 0.4A(40s) -> 0.57A(60s) |
| non-reversed | 5.25 | 5.209 | 5.186 | 0.37 / 0.8 | 37.3 | 29.4 | |
| non-reversed | 5 | 4.994 | 4.992 | 0.04 / - | 29.6 | 29.1 | |
| non-reversed | 4.75 | 4.748 | 4.747 | 0.01 / - | 30.0 | 28.4 | |
| non-reversed | 4.5 | 4.499 | 4.499 | 0 / - | 29.2 | 28.0 | |
| reversed | -4.5 | -4.471 | -0.712 | 0.23 / 2.85 | 36.9 | 29.3 | 2.85A(0s) -> 0.23A(46s) |
| reversed | -4.75 | -4.722 | -0.702 | 0.23 / 2.85 | 40.5 | 29.1 | 2.85A(0s) -> 0.23A(47s) |
| reversed | -5 | -4.970 | -0.708 | 0.23 / 2.85 | 40.3 | 29.4 | 2.85A(0s) -> 0.23A(43s) |
| reversed | -5.25 | -5.225 | -0.707 | 0.2 / 2.85 | 37.7 | 30.1 | 2.85A(0s) -> 0.23A(46s) |
| reversed | -6 | -5.979 | -0.701 | 0.15 / 2.85 | 43.7 | 32.2 | 2.85A(0s) -> 0.15A(43s) |
| reversed | -7.5 | -7.480 | -0.675 | 0.12 / 2.85 | 41 | 30.1 | 2.85A(0s) -> 0.12A(35s) |
| reversed | -9 | -8.987 | -0.655 | 0.12 / 2.85 | 41.9 | 30.0 | 2.85A(0s) -> 0.12A(36s) |
| reversed | -12 | -11.993 | -0.677 | 0.08 / 2.85 | 37.0 | 29.8 | 2.85A(0s) -> 0.08A(37s) |
| reversed | -20 | -20 | -0.666 | 0.05 / 2.85 | 42.9 | 30.3 | 2.85A(0s) -> 0.05A(27s) |
- Experimental table below is based on LOAD condition. Each measurement is done, be noticed on Notes column.
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Voltage of symbol 5V marked on M1 RC2 | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x1e | 20 | 19.993 | 2.203 | 0.14 / 2.85 | 43.4 | 52.7 | 2.14 | 1.97 | 0 | 0.57 | 0 | 0.518 | 2.85A(0s) -> 0.08A(11s) -> 0.14A, After 11s, Zener voltage isn't available. Won't be booted. temperature high, not suggest this input |
| non-reversed, 0x1e | 12 | 11.976 | 2.184 | 0.29 / 2.85 | 43.9 | 50.6 | 2.087 | 1.568 | 0 | 0.344 | 0 | 0.222 | 2.85A(0s) -> 0.13A(11s) -> 0.29A, After 11s, Zener voltage isn't available. Won't be booted. temperature high, not suggest this input |
| non-reversed, 0x1e | 9 | 8.962 | 2.425 | 0.17 / 2.85 | 46.1 | 54.2 | 2.258 | 1.719 | 0 | 1.812 | 0 | 2.219 | 2.85A(0s) -> 0.17A(11s), After 11s, Zener voltage isn't available. Won't be booted. temperature high, not suggest this input |
| non-reversed, 0x1e | 7.5 | 7.436 | 2.87 | 0.6 / 2.85 | 42.9 | 51.4 | 2.62 | 2.049 | 0 | 1.789 | 0 | 2.605 | 2.85A(0s) -> 0.2A(11s) -> 0.3A, After 11s, Zener voltage isn't available. Won't be booted. temperature high, not suggest this input |
| non-reversed, 0x1e | 7 | 6.88 | 5.149 | 1.1 / 2.85 | 51.5 | 61.4 | 4.947 | 3.252 | 2.494 | 1.783 | 1.159 | 4.293 | 2.85A -> 0.47A -> 1.12A(booted), temperature high, not suggest this input |
| non-reversed, 0x1e | 6.5 | 6.362 | 5.181 | 1.3 / 2.85 | 47.3 | 52.3 | 4.973 | 3.252 | 2.494 | 1.782 | 1.158 | 4.293 | 2.85A -> 1.1A(reconfig.) -> 1.3A(booted), not suggest this input. booted. |
| non-reversed, 0x1e | 6 | 5.845 | 5.211 | 1.30 / 2.85 | 57.2 | 66.8 | 4.999 | 3.250 | 2.495 | 1.783 | 1.158 | 4.293 | temperature high, not suggest this input, finger can feel it on holding bigger spacer. booted. |
| non-reversed, 0x1e | 5.25 | 5.146 | 5.086 | 0.93 / 1.06 | 41.1 | 46.3 | 4.886 | 3.253 | 2.491 | 1.782 | 1.158 | 4.293 | booted. |
| non-reversed, 0x1e, use 2A DC adapter | 5.108 | 5.029 | 4.988 | to be measured / - | 40.9 | 42.4 | 4.802 | 3.252 | 2.494 | 1.781 | 1.158 | 4.293 | booted. 36.8°C body surface of 2A DC adapter |
| non-reversed, 0x1e | 5 | 4.921 | 4.872 | 0.76 / - | 41.1 | 43.0 | 4.674 | 3.253 | 2.491 | 1.782 | 1.158 | 4.293 | booted. |
| non-reversed, 0x1e | 4.75 | 4.675 | 4.631 | 0.75 / - | 36.5 | 39.9 | 4.433 | 3.255 | 2.49 | 1.782 | 1.159 | 4.290 | booted. |
| non-reversed, 0x1e | 4.5 | 4.424 | 4.381 | 0.73 / - | 38.5 | 40.9 | 4.189 | 3.255 | 2.493 | 1.782 | 1.159 | 4.158 | booted. |
| reversed, 0x1e | -5 | -1.0 | -0.786 | 2.85 / 2.85 | 40.5 | 45.6 | -0.702 | -0.333 | -0.150 | -0.238 | 0 | -0.239 | |
| reversed, 0x1e | -5.25 | -0.990 | -0.802 | 2.85 / 2.85 | 37.8 | 44.2 | -0.715 | -0.338 | -0.148 | -0.240 | 0 | -0.245 | |
| reversed, 0x1e | -6 | -1.01 | -805 | 2.85 / 2.85 | 39.3 | 42.9 | -0.715 | -0.337 | -0.148 | -0.240 | 0 | -0.245 | |
| reversed, 0x1e | -7.5 | -1.0 | -0.791 | 2.85 / 2.85 | 42.3 | 46.0 | -0.704 | -0.334 | -0.151 | -0.243 | 0 | -0.241 | |
| reversed, 0x1e | -9 | -0.986 | -796 | 2.85 / 2.85 | 39.0 | 45.4 | -0.714 | -0.337 | -0.149 | -0.240 | 0 | -0.247 | |
| reversed, 0x1e | -12 | -1.012 | -0.804 | 2.85 / 2.85 | 40.3 | 47.0 | -0.717 | -0.338 | -0.148 | -0.239 | 0 | -0.245 | |
| reversed, 0x1e | -20 | -1.032 | -0.779 | 2.85 / 2.85 | 42.9 | 49.0 | -0.7 | -0.331 | -0.151 | -0.239 | 0 | -0.24 |
Sch. D-1
- F2 - MINISMDC200F-2, 8VDC/0.07Ω ;
- D14 - 2 * 5W 5.6V Zener 1N5339BG in parallel
- Experimental table below is based on NO LOAD condition. Each measurement is done, be noticed on Notes column.
- Since fuse and zener are all thermo-dependent parts, long time period a lower consumption remains.
- Since power supply is limited on 2.85A, following 2.85A shown means it clamps under that limitation while being instantaneous.
＊ room temperature: 28.2°C
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Notes |
|---|---|---|---|---|---|---|---|
| non-reversed | 20 | 19.986 | 5.631 | 0.05 / 2.85 | 47.3 | 29.6 | 2.85A(0s) -> 0.03A(16s) |
| non-reversed | 12 | 11.842 | 5.636 | 0.12 / 2.85 | 43.5 | 30.6 | 2.85A(0s) -> 0.09A(16s) |
| non-reversed | 9 | 8.952 | 5.656 | 0.21 / 2.85 | 50.8 | 29.6 | 2.85A(0s) -> 0.1A(18s) |
| non-reversed | 7.5 | 7.441 | 5.722 | 0.32 / 2.85 | 56.1 | 29.9 | 2.85A(0s) -> 0.16A(20s) |
| non-reversed | 6 | 5.865 | 5.812 | 0.87 / 2.85 | 45.4 | 31.9 | 2.85A(0s) -> 0.87A(39s) |
| non-reversed | 5.25 | 5.249 | 5.249 | 0 / - | 28.2 | 28.2 | |
| non-reversed | 5 | 4.999 | 4.999 | 0 / - | 28.2 | 28.2 | |
| non-reversed | 4.75 | 4.75 | 4.75 | 0 / - | 28.2 | 28.2 | |
| reversed | -4.75 | -4.721 | -0.715 | 0.24 / 2.85 | 43.1 | 29.1 | 2.85A(0s) -> 0.23A(27s) |
| reversed | -5 | -4.960 | -0.707 | 0.23 / 2.85 | 40.2 | 28.7 | 2.85A(0s) -> 0.23A(35s) |
| reversed | -5.25 | -5.228 | -0.139 | 0.23 / 2.85 | 37.7 | 29.4 | 2.85A(0s) -> 0.23A(40s) |
| reversed | -6 | -0.945 | -0.772 | 0.18 / 2.85 | 35.6 | 30.8 | 2.85A(0s) -> 0.18A(41s) |
| reversed | -7.5 | -7.472 | -0.695 | 0.13 / 2.85 | 42.3 | 29.5 | 2.85A(0s) -> 0.12A(42s) |
| reversed | -9 | -8.986 | -0.692 | 0.11 / 2.85 | 43.0 | 29.6 | 2.85A(0s) -> 0.12A(34s) |
| reversed | -12 | -11.965 | -0.689 | 0.08 / 2.85 | 44.4 | 31.7 | 2.85A(0s) -> 0.08A(32s) |
| reversed | -20 | -19.992 | -0.673 | 0.05 / 2.85 | 41.2 | 30.3 | 2.85A(0s) -> 0.05A(26s) |
- Experimental table below is based on LOAD condition. Each measurement is done, be noticed on Notes column.
- room temperature: 27.3°C
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse & GND (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Voltage of symbol 5V marked on M1 RC2 | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x1e | 20 | 19.982 | 2.206 | 0.13 / 2.85 | 40.2 | 44.2 | 2.164 | 2.002 | 0 | 0.579 | 0 | 0.972 | unbooted, 2.85A -> 0.1A -> 0.13A(un-reconfig.) |
| non-reversed, 0x1e | 12 | 11.981 | 2.415 | 0.24 / 2.85 | 41.8 | 49.3 | 2.281 | 2.078 | 0 | 1.795 | 0 | 2.251 | unbooted, 2.85A -> 0.14A -> 0.24A(un-reconfig.) |
| non-reversed, 0x1e | 9 | 8.970 | 2.354 | 0.34 / 2.85 | 40.8 | 48.8 | 2.218 | 1.688 | 0 | 1.814 | 0 | 2.172 | unbooted, 2.85A -> 0.18A -> 0.34A(un-reconfig.) |
| non-reversed, 0x1e | 7.5 | 7.453 | 2.501 | 0.49 / 2.85 | 42.7 | 50.9 | 2.322 | 1.780 | 0 | 1.795 | 0 | 2.283 | unbooted, 2.85A -> 0.25A -> 0.45A(un-reconfig.) |
| non-reversed, 0x1e | 7 | 6.942 | 2.865 | 0.61 / 2.85 | 41.9 | 50.7 | 2.557 | 1.964 | 0 | 1.791 | 0 | 2.473 | unbooted, 2.85A -> 0.22A -> 0.53A(un-reconfig.) |
| non-reversed, 0x1e | 6.5 | 6.371 | 5.715 | 1.16 / 2.85 | 50.5 | 61.3 | 5.440 | 3.249 | 2.492 | 1.783 | 1.158 | 4.294 | booted, |
| non-reversed, 0x1e | 6 | 5.881 | 5.723 | 1.25 / 2.85 | 44.3 | 57.5 | 5.447 | 3.247 | 2.492 | 1.783 | 1.158 | 4.293 | booted |
| non-reversed, 0x1e | 5.25 | 5.166 | 5.114 | 0.74 / - | 36.4 | 39.3 | 4.891 | 3.254 | 2.49 | 1.782 | 1.159 | 4.293 | booted |
| non-reversed, 0x1e | 5 | 4.918 | 4.866 | 0.74 / - | 36.4 | 39.6 | 4.65 | 3.254 | 2.49 | 1.782 | 1.159 | 4.287 | booted |
| non-reversed, 0x1e | 4.75 | 4.679 | 4.615 | 0.74 / - | 35.3 | 38.2 | 4.413 | 3.264 | 2.49 | 1.782 | 1.159 | 4.277 | booted |
| reversed, 0x1e | -4.75 | -1.079 | -0.793 | 0.51 / 2.85 | 39.4 | 49.6 | -0.707 | -0.332 | -0.148 | -0.236 | 0 | -0.238 | |
| reversed, 0x1e | -5 | -1.051 | -0.789 | 0.48 / 2.85 | 30.7 | 50.5 | -0.712 | -0.332 | -0.147 | -0.238 | 0 | -0.240 | 2.85A -> 0.48A |
| reversed, 0x1e | -5.25 | -1.057 | -0.794 | 0.46 / 2.85 | 38.4 | 48.8 | -0.692 | -0.315 | -0.152 | -0.232 | 0 | -0.233 | 2.85A -> 0.46A |
| reversed, 0x1e | -6 | -1.001 | -0.812 | 0.41 / 2.85 | 44.1 | 49.0 | -0.702 | -0.331 | -0.149 | -0.236 | 0 | -0.238 | 2.85A -> 0.34A |
| reversed, 0x1e | -6.5 | -1.006 | -0.813 | 0.37 / 2.85 | 40.4 | 50.1 | -0.701 | -0.327 | -0.149 | -0.232 | 0 | -0.235 | 2.85A -> 0.37A |
| reversed, 0x1e | -7 | -1.064 | -0.807 | 0.34 / 2.85 | 41.0 | 47.8 | -0.698 | -0.330 | -0.151 | -0.241 | 0 | -0.212 | 2.85A -> 0.34A |
| reversed, 0x1e | -7.5 | -1.059 | -0.803 | 0.32 / 2.85 | 41.5 | 47.5 | -0.696 | -0.329 | -0.151 | -0.240 | 0 | -0.215 | 2.85A -> 0.32A |
| reversed, 0x1e | -9 | -1.105 | -0.787 | 0.25 / 2.85 | 40.9 | 50.0 | -0.696 | -0.329 | -0.151 | -0.240 | 0 | -0.213 | 2.85A -> 0.25A |
| reversed, 0x1e | -12 | -1.079 | -0.801 | 0.19 / 2.85 | 41.4 | 45.7 | -0.697 | -0.272 | -0.162 | -0.198 | 0 | -0.211 | 2.85A -> 0.19A |
| reversed, 0x1e | -20 | -1.152 | -0.880 | 2.85 / 2.85 | 37.8 | 42.5 | -0.712 | -0.332 | -0.147 | -0.175 | 0 | -0.202 | 2.85A -> 0.12A |
- Experimental table below is based on LOAD condition and correct L10/L11 beads.
- room temperature: 31.6°C
| DC Jack pluggin polarity | Source(V) on power supply without load | Voltage between Fuse (V) | Zener Voltage | If stable(A)/Transient(A) | Temperature Fuse(°C) | Temperature Zener(°C) | Voltage of symbol 5V marked on M1 RC2 | TP1(V) - 3V3 | TP2(V) - 2V5 | TP3(V) - 1V8 | TP4(V) - 1V2 | TP26(V) - 4V3 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| non-reversed, 0x1e | 5.25 | 5.168 | 5.07 | 0.76 / - | 43.1 | 43.3 | 5.062 | 3.251 | 2.49 | 1.782 | 1.158 | 4.293 | booted, L11(3.5mV), L10(3.6mV), Vfuse(38mV), gnd loop cable loss(32mV), dc in cable loss(16mV) |
| non-reversed, 0x1e | 5 | 4.913 | 4.819 | 0.76 / - | 41.8 | 46.0 | 4.813 | 3.254 | 2.491 | 1.783 | 1.158 | 4.294 | booted, L11(3.5mV), L10(3.6mV), Vfuse(38mV), gnd loop cable loss(38mV), dc in cable loss(15mV) |
| non-reversed, 0x1e | 4.75 | 4.662 | 4.565 | 0.76 / - | 42.9 | 46.6 | 4.554 | 3.264 | 2.491 | 1.783 | 1.158 | 4.292 | booted, L11(3.5mV), L10(3.6mV), Vfuse(38mV), gnd loop cable loss(37mV), dc in cable loss(14mV) |
Reference
- ↑ Original Milkymist One RC2 schematic
- ↑ Joerg's feedback
- ↑ PTC Resettable fuses
- ↑ PTC Resettable fuses
- ↑ PTC Resettable fuses
- ↑ MOSFET
- ↑ complete datasheet
Link
2. Fundamentals of Resettable Functionality in PPTC Devices
3. USB Peripheral Protection using PolyZen Devices
4. USB Silicon & PolySwitch Solutions
5. PolySwitch Device Selection Guide
6. MICROSMD110F-2, complete datasheet, IH(room temperature)A = 1.1, IT(room temperature)A = 2.2, Vmax(operating)V = 6, Time to Trip (sec. @ A) = 0.2 @ 8A values specified were determined using PCB’s with 0.030”X1.5 ounce copper traces.; OHMS WATTS AT 20°C, 6V, MIN = 0.07;
7. ON Semiconductor MBRA340T3G, Schottky (Diodes & Rectifiers) 3A 40V
8. Fairchild FDD6530A, MOSFET Power 20V N-Ch PowerTrench
9. http://lists.milkymist.org/pipermail/devel-milkymist.org/2011-March/001269.html
