diff options
Diffstat (limited to 'source/hardware')
| -rw-r--r-- | source/hardware/maple-mini.rst | 53 | ||||
| -rw-r--r-- | source/hardware/maple-native-beta.rst | 65 | ||||
| -rw-r--r-- | source/hardware/maple-ret6.rst | 31 | ||||
| -rw-r--r-- | source/hardware/maple.rst | 68 |
4 files changed, 168 insertions, 49 deletions
diff --git a/source/hardware/maple-mini.rst b/source/hardware/maple-mini.rst index 986ab4b..36702dd 100644 --- a/source/hardware/maple-mini.rst +++ b/source/hardware/maple-mini.rst @@ -15,7 +15,7 @@ breadboard. Technical Specifications ------------------------ -* MCU: :ref:`STM32F103RCBT6 <maple-mini-stdocs>`, a 32-bit ARM Cortex +* MCU: :ref:`STM32F103CBT6 <maple-mini-stdocs>`, a 32-bit ARM Cortex M3 microprocessor * Clock Speed: **72 MHz** * **128 KB Flash** and **20 KB SRAM** @@ -50,9 +50,40 @@ directly. .. warning:: The silkscreen on the Maple Mini suggests it will accept an input voltage up to 16 V. We recommend applying **no greater - than 12 V**. - - See :ref:`this erratum <maple-mini-vin>` for more information. + than 12 V**, and potentially even lower depending upon the current + draw requirements of the application. Please see :ref:`Power + Regulation on the Maple Mini <maple-mini-power-regulation>` for + more information. + +.. _maple-mini-power-regulation: + +Power Regulation on the Maple Mini +---------------------------------- + +Power regulation on the Maple is provided by two low dropout linear +voltage regulators. (The part is the MCP1703 from Microchip, in the +SOT-23A package. You can download the datasheet `here +<http://ww1.microchip.com/downloads/en/DeviceDoc/22049a.pdf>`_ ). One +of the regulators supplies power to the digital voltage plane; the +other supplies power to the analog voltage plane. + +These voltage regulators nominally take an input of up to 16V. In +addition, while the maximum continuous output current for the board is +250mA, if you are powering the board off higher voltages the amount +off current it can supply goes down, due to the regulators needing to +dissipate the extra power. So if you are powering the board off 12V, +the max current is about 40mA at room temperature. In general (again, +at room temperature) the max power dissipation (PD) for the chip is +about .37W, and output current = PD/(Vin-Vout). For exact max current +calculations, please refer to the datasheet linked above. + +If you are planning to draw a lot of current from the Maple board, it +is necessary to provide input power as close to 3.3V as +possible. Powering the microcontroller circuitry and LEDs on the board +alone takes approximately 30mA, so if you are powering the board with +12V that leaves only 10mA (at best) available for powering any user +circuitry. Attempting to draw more than 10mA runs the risk of shorting +out the power regulators and bricking your board. .. _maple-mini-gpios: @@ -339,14 +370,12 @@ This section lists known issues and warnings for the Maple Mini Rev 2 .. _maple-mini-vin: * **Silkscreen Vin voltage mistake**: The silkscreen on the Maple Mini - falsely indicates that Vin may be supplied with up to 16 V. We - recommend an input voltage **no greater than 12 V**. - - The voltage regulator on the Mini is rated up to 16 V. However, our - tests indicate that as its input voltage approaches 16 V, its output - begins to rise to levels higher than those recommended by ST for - supplying the STM32F103CB. The limit of 12 V keeps the voltage - supplied to the processor at safe levels. + falsely indicates that Vin may be supplied with up to 16V. We + recommend an input voltage **no greater than 12V**, and potentially + even lower depending upon the current draw requirements of the + application. Please see :ref:`Power Regulation on the Maple Mini + <maple-mini-power-regulation>` for more information. + Recommended Reading ------------------- diff --git a/source/hardware/maple-native-beta.rst b/source/hardware/maple-native-beta.rst index f120c05..f1b2284 100644 --- a/source/hardware/maple-native-beta.rst +++ b/source/hardware/maple-native-beta.rst @@ -46,20 +46,57 @@ Technical Specifications Powering the Maple Native ------------------------- -The Maple Native may be powered from the barrel jack connector, USB, -or a LiPo battery. The power source is determined by the header -labeled "PWRSEL" on the silkscreen. Boards are shipped with a jumper -on the USB selector. In order to power it off of an alternative -source, unplug the Maple Native, then move the jumper to the desired -selector before reconnecting power. - -You can also power the Maple Native via the pin labeled "Vin" on the -vertical header to the right of the PWRSEL header. This pin feeds -into both the digital and analog voltage regulators. However, don't -do this while simultaneously powering the board from another source, -or you could damage it. - -We recommend an input voltage no greater than 12 V. +The power source is determined by the header labeled "PWRSEL" on the +silkscreen. The Maple Native may be powered from USB (marked "USB" on +the PWRSEL header), a LiPo battery (marked "BAT"), or one of the two +"Vin" pins (marked "EXT"). Boards are shipped with a jumper on the +USB selector. In order to power it off of an alternative source, +unplug the Maple Native, then move the jumper to the desired selector +before reconnecting power. + +The "Vin" line is available on the pin labeled "Vin" on the vertical +header to the right of the PWRSEL header, as well as on the +unpopulated two-pin connector on the upper left corner of the +board. On this latter connector, polarity was accidentally left +unmarked: the leftmost, round pin should be power, while the square +pin should be ground. + +When powering the Maple Native board from a battery or the Vin lines, +care must be taken not to over-voltage the board. In general, an upper +limit of 12V input is acceptable, but this may vary depending upon the +current draw requirements of the application. Please see :ref:`Power +Regulation on the Maple Native <maple-native-b-power-regulation>` for +more information. + +.. _maple-native-b-power-regulation: + +Power Regulation on the Maple Native +------------------------------------ + +Power regulation on the Maple Native is provided by two low dropout +linear voltage regulators. (The part is the MCP1703 from Microchip, in +the SOT-23A package. You can download the datasheet `here +<http://ww1.microchip.com/downloads/en/DeviceDoc/22049a.pdf>`_). One +of the regulators supplies power to the digital voltage plane; the +other supplies power to the analog voltage plane. + +These voltage regulators nominally take an input of up to 16V. In +addition, while the maximum continuous output current for the board is +250mA, if you are powering the board off higher voltages the amount +off current it can supply goes down, due to the regulators needing to +dissipate the extra power. So if you are powering the board off 12V, +the max current is about 40mA at room temperature. In general (again, +at room temperature) the max power dissipation (PD) for the chip is +about .37W, and output current = PD/(Vin-Vout). For exact max current +calculations, please refer to the datasheet linked above. + +If you are planning to draw a lot of current from the Maple Native +board, it is necessary to provide input power as close to 3.3V as +possible. Powering the microcontroller circuitry and LEDs on the board +alone takes approximately 30mA, so if you are powering the board with +12V that leaves only 10mA (at best) available for powering any user +circuitry. Attempting to draw more than 10mA runs the risk of shorting +out the power regulators and bricking your board. Using the Built-in Battery Charger ---------------------------------- diff --git a/source/hardware/maple-ret6.rst b/source/hardware/maple-ret6.rst index d5bf049..21c033b 100644 --- a/source/hardware/maple-ret6.rst +++ b/source/hardware/maple-ret6.rst @@ -58,9 +58,20 @@ standard Maple <maple-powering>`. .. warning:: The RET6 Edition silkscreen falsely indicates that the barrel jack accepts up to 18 V. We recommend a barrel jack input - voltage **no greater than 12 V**. + voltage **no greater than 12V**, and potentially even lower + depending upon the current draw requirements of the + application. The same goes for powering off LiPo batteries. - See :ref:`this erratum <maple-barrel-jack>` for more information. + Please see :ref:`Power Regulation on the Maple + <maple-power-regulation>` for more information. + +.. _maple-ret6power-regulation: + +Power Regulation on the Maple RET6 +---------------------------------- + +Power regulation on the Maple RET6 works in the :ref:`same way as the +standard Maple <maple-power-regulation>`. Using the Built-in Battery Charger ---------------------------------- @@ -373,11 +384,17 @@ features only available on the STM32F103RET6. .. _maple-ret6-barrel-jack: -* **Barrel jack power supply voltage mistake**: The silkscreen next to - the barrel jack connector incorrectly indicates that up to an 18 V - input voltage is allowed. **We do not recommend exceeding 12 V**. - - See this :ref:`Maple erratum <maple-barrel-jack>` for more +* **Barrel jack power supply voltage mistake**: The acceptable voltage + range given next to the barrel jack on the Maple RET6 is + **incorrect**. The given range is 7V — 18V. In fact, **18V is too + high** and should not be supplied to your board. The original + voltage regulators used on the Maple were rated up to 18V. However, + the voltage regulators on current Maple Revs are rated up to only + 16V, and due to the current draw requirements of the board, operate + properly only up to 12V. The recommended maximum voltage you should + apply is **12V**, and potentially even lower depending upon the + current draw requirements of the application. Please see :ref:`Power + Regulation on the Maple <maple-power-regulation>` for more information. * **Power supply marketing mistake**: We originally sold the Maple diff --git a/source/hardware/maple.rst b/source/hardware/maple.rst index 610fdfc..aff64d5 100644 --- a/source/hardware/maple.rst +++ b/source/hardware/maple.rst @@ -103,15 +103,50 @@ header. This pin feeds into both the digital and analog voltage regulators. However, don't do this while simultaneously powering the board from another source, or you could damage it. +When powering the board from a barrel jack, **double check the +polarity of the barrel.** The appropriate polarity is noted on the +silkscreen right next to the connector. + .. warning:: Silkscreens on Maples up through Rev 5s manufactured in Spring 2011 falsely indicated that the barrel jack could be - supplied by up to 18 V. We recommend a barrel jack input voltage - **no greater than 12 V**. - - Rev5s manufactured after Spring 2011 may still have this error on - the silk, but it has been marked over. - - See :ref:`this erratum <maple-barrel-jack>` for more information. + supplied by up to 18V. (Rev5s manufactured after Spring 2011 may + still have this error on the silk, but it has been marked over.) We + recommend a barrel jack input voltage **no greater than 12V**, and + potentially even lower depending upon the current draw requirements + of the application. The same goes for powering off LiPo batteries. + + Please see :ref:`Power Regulation on the Maple + <maple-power-regulation>` for more information. + +.. _maple-power-regulation: + +Power Regulation on the Maple +----------------------------- + +Power regulation on the Maple is provided by two low dropout linear +voltage regulators. (The part is the MCP1703 from Microchip, in the +SOT-23A package. You can download the datasheet `here +<http://ww1.microchip.com/downloads/en/DeviceDoc/22049a.pdf>`_ ). One +of the regulators supplies power to the digital voltage plane; the +other supplies power to the analog voltage plane. + +These voltage regulators nominally take an input of up to 16V. In +addition, while the maximum continuous output current for the board is +250mA, if you are powering the board off higher voltages the amount +off current it can supply goes down, due to the regulators needing to +dissipate the extra power. So if you are powering the board off 12V, +the max current is about 40mA at room temperature. In general (again, +at room temperature) the max power dissipation (PD) for the chip is +about .37W, and output current = PD/(Vin-Vout). For exact max current +calculations, please refer to the datasheet linked above. + +If you are planning to draw a lot of current from the Maple board, it +is necessary to provide input power as close to 3.3V as +possible. Powering the microcontroller circuitry and LEDs on the board +alone takes approximately 30mA, so if you are powering the board with +12V that leaves only 10mA (at best) available for powering any user +circuitry. Attempting to draw more than 10mA runs the risk of shorting +out the power regulators and bricking your board. Using the Built-in Battery Charger ---------------------------------- @@ -423,15 +458,16 @@ General * **Barrel jack power supply voltage mistake**: The acceptable voltage range given next to the barrel jack on the Maple through Rev 5s - manufactured in Spring 2011 is **incorrect**. The given range is 7 - V — 18 V. In fact, **18 V is too high** and should not be supplied - to your board. The recommended maximum voltage you should apply is - **12 V**. - - The original voltage regulators used on the Maple were rated up to - 18 V. However, the voltage regulators on current Maple Revs are - rated up to 16 V. Our tests indicate that they operate correctly - through 12 V. We do not recommend higher input voltages. + manufactured in Spring 2011 is **incorrect**. The given range is 7V + — 18V. In fact, **18V is too high** and should not be supplied to + your board. The original voltage regulators used on the Maple were + rated up to 18V. However, the voltage regulators on current Maple + Revs are rated up to only 16V, and due to the current draw + requirements of the board, operate properly only up to 12V. The + recommended maximum voltage you should apply is **12V**, and + potentially even lower depending upon the current draw requirements + of the application. Please see :ref:`Power Regulation on the Maple + <maple-power-regulation>` for more information. .. _maple-nrst-pb4: |