DEMO MANUAL DC1033B LTC2952 Pushbutton On/Off Power Path Controller DESCRIPTION Demonstration circuit 1033B features the LTC©2952, a micropower, multipurpose, pushbutton On/Off PowerPath™ controller that provides voltage monitoring and supervisory features, as well as ideal diode power paths. Selectable PowerPath management modes allow a variety of power on and off configurations, including pushbutton on/off control and voltage detection on/off control. The LTC2952’s pushbutton input has independently programmable ON and OFF de-bounce times. A simple microprocessor interface allows for proper system housekeeping prior to power down. The status of digital pins G1STAT, PFO, RST and INT are displayed with LEDs. Under system fault conditions, the part’s internal KILL timer ensures that the system can be shut down. High reliability systems may PERFORMANCE SUMMARY utilize the LTC2952’s power fail, voltage monitoring, diode status, watchdog and μP reset features to monitor power status and ensure system integrity. The DC1033B operates over the full LTC2952 range of 2.7V to 28V to accommodate a wide variety of input power supplies. Low forward drop ideal diodes and very low standby current (25μA typ) make the LTC2952 ideally suited for battery powered or power conscious applications. Design files for this circuit board are available at http://www.linear.com/demo/DC1033B L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C PARAMETER CONDITIONS VALUE Input Voltage Range V1 and/or V2 2.7V to 28V Output Voltage VS Configuration A V1 or V2* Configuration B V1 or V2* Configuration C, Pushbutton Enable On V1 or V2* Configuration D, Pushbutton Enable On, V2 > V2 Threshold V1 or V2* DC/DC Out 2P6V Configuration A-D, Pushbutton Enable On 2.6V V2 Trip Threshold Default Resistors (R9 and R10), JP2 Set to Monitor V2 4.725V Power Fail Input Voltage PFI Default Resistors (R3 and R4) Monitor VS 3.055V Resistor Options (R17 and R4) Set to Monitor V2 3.055V Voltage Monitor VM Pushbutton On Time ONT Pushbutton Off Time OFFT Default Resistors (R1 and R2) Monitor 2P6V 2.325V Resistor Options (R16 and R2) Set to Monitor VS 3.055V JP3 Set to OPEN, LTC2952 Default ONT 26ms JP3 Set to CAP to Connect 22nF to ONT Pin 26ms + 205ms JP4 Set to OPEN, LTC2952 Default OFFT 26ms JP4 Set to CAP to Connect 68nF to OFFT Pin 26ms + 632ms * VS will be the ideal diode OR of V1 and V2. There is only a slight voltage drop across the ideal diode. dc1033bf 1 DEMO MANUAL DC1033B QUICK START PROCEDURE (Configuration A) 2. Connect a voltmeter across VS and GND. Demonstration circuit 1033B is easy to set up to evaluate the performance of the LTC2952. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below. This Quick Start Procedure sets up the DC1033B for Configuration A. See Operating Principles for further description of the different configurations 3. Apply a voltage of 2.7V to 28V across V2 (WALL). 1. Place jumpers in the following positions: JP1: LO JP2: LO JP3: CAP JP4: CAP JP5: UNTIE V2 WALL 2.7V-28V 4. Apply a voltage of 2.7V to 28V across V1 (BAT). 5. Measure VS, which will be the ideal diode OR of the higher supply V2 or V1. 6. Push down once and hold on Pushbutton SW1 for a Turn On. Observe both SUP_EN and RST LEDs turn on. After a short period, RST turns off. 7. Push down again and hold on Pushbutton SW1 for a Turn Off. Observe while SUP_EN LED is on, INT LED turns on momentarily. After a short period, both SUP_EN and INT LEDs turn off. Note: LED sequence in steps 6 and 7 are the same for configurations A through D. + – V1 BATTERY 2.7V-28V PUSHBUTTON dc1033b F01 Figure 1. Basic Equipment Setup 2 dc1033bf DEMO MANUAL DC1033B OPERATING PRINCIPLES The DC1033B operates from 2.7V to 28V applied to either V1 or V2. Configuration of M1 and M2 of the LTC2952 determines the power path to the output voltage and the example DC/DC converter (U4). P-Channel MOSFETs U2 and U3 are driven by the LTC2952 for the ideal diode feature providing a low forward voltage drop. J1 and J2 provide a bypass option if one or both of the PFETs in U3 are not needed. A pushbutton turns on and off the Enable that drives the DC/DC converter and in some configuration also turns on and off the ideal diode power paths. The pushbutton on and off times are set by jumper selectable external capacitors. The status of G1STAT indicates the status of G1. PFO gives an output signal (shown with an LED) if voltage at the PFI input is below the threshold. RST and INT provide maintenance to a microprocessor on a power up or power down. Immediate shutdown can be done by pulling low on KILL. CONFIGURATION A (M1 low, M2 low): Pushbutton Controller with Automatic Load Switching Between WALL and Battery Set both JP1 (M1CONFG) and JP2 (M2CONFG) to LO to enable both ideal diodes always. VS will be the ideal diode OR of V1 and V2 where VS equals the higher of the two supplies minus the slight ideal diode drop. G1STAT LED turns on when V2 > V1. The pushbutton turns on and off the EN pin which drives the shutdown of the DC/DC converter. CONFIGURATION B (M1 low, M2 monitor): Pushbutton Controller with Preferential WALL Operation and Automatic Load Switching to Battery Set JP1 (M1CONFG) to LO and JP2 (M2CONFG) to V2MON to configure M2 as a monitor on the Wall Adapter voltage V2. When V2 is above the trip threshold, the ideal diode for V2 is turned on always, while the ideal diode for V1 is shutdown, even if V1 is greater than V2. VS will then equal V2 minus the ideal diode voltage drop. When V2 falls below the trip threshold, both ideal diodes are enabled. VS will be the ideal diode OR of V1 and V2 where VS equals the higher of the two supplies minus the slight ideal diode drop. The pushbutton turns on and off the EN pin which drives the shutdown of the DC/DC converter. CONFIGURATION C (M1 high, M2 high): Pushbutton Control of Ideal Diodes Drivers Set JP1 (M1CONFG) to HI and JP2 (M2CONFG) to TIEM1. M1 has an internal pull-up current and pulls up M2 as well when tied together. This sets up the pushbutton to have full control on both ideal diodes and the EN pin. On a pushbutton turn on, both ideal diode drivers are turned on as well as the DC/DC converter. VS will be the ideal diode OR of V1 and V2 where VS equals the higher of the two supplies minus the ideal diode drop. On a pushbutton turn off, both ideal diode drivers are shutdown and VS is turned off. CONFIGURATION D (M1 high, M2 monitor): Battery Backup with Pushbutton Power Path Controller Set JP1 (M1CONFG) to HI and JP2 (M2CONFG) to V2MON. M1 is set high due to its internal pull-up current. M2 monitors V2. When V2 is below the trip threshold, both ideal diodes are shutdown always and the input to the PB pin is ignored. When V2 is above the trip threshold, the pushbutton has full control of the EN pin and ideal diode drivers. Also while M1 is high, a transition on M2 will force a pushbutton turn on or turn off. To test this, move the V2 input to be above and below the trip threshold. dc1033bf 3 DEMO MANUAL DC1033B OPERATING PRINCIPLES ONT/OFFT PROGRAMMING VOLTAGE MONITORS PFI AND VM Additional pushbutton turn on and off de-bounce time can be set by attaching a capacitor from the ONT and OFFT pins to GND and can be done through JP3 and JP4, respectively, on the DC1033B. Select OPEN for the Internal Default Time of the LTC2952 only or choose CAP for additional timing. See figures 2, 3, 4 and 5 for timing differences. The additional timing can be calculated using the following equations: Voltage monitoring is also provided by the Power Fail Input (PFI) and Voltage Monitor (VM) pins. If the voltage at PFI falls below its threshold, a signal is given at PFO and shown with an LED. If the voltage at VM falls below its threshold, a signal is given at RST and also shown with an LED. RST is typically connected to the Reset of a microcontroller to reset the device and halt operation until the supply voltage is above a specified voltage. tONT = CONT [F] • 9.3 x 106 [Ω] tOFFT = COFFT [F] • 9.3 x 106 [Ω] INT/KILL The INT pin can be tied to the KILL pin through JP5 to immediately shutdown when INT pulls low during a turn off sequence. When the pins are untied, the INT pin becomes open collector for the interrupt period before power is turned off. 4 WATCHDOG AND EXTEND FUNCTION WITH WDE During a shutdown process after the INT pin goes high impedance, a rising or falling edge on the WDE pin within a 500ms period extends the waiting period before the EN line is set low. See figure 6 and 7 for timing comparison. The WDE pin can also be used with the VM pin to provide a watchdog timer. Figure 2. Pushbutton Turn ON with No Additional Timing dc1033bf DEMO MANUAL DC1033B OPERATING PRINCIPLES Figure 3. Pushbutton Turn ON with 22nF at ONT Figure 4. Pushbutton Turn OFF with No Additional Timing Figure 5. Pushbutton Turn OFF with 68nF at OFFT dc1033bf 5 DEMO MANUAL DC1033B OPERATING PRINCIPLES 6 Figure 6. Pushbutton Turn OFF with No WDE Extension Figure 7. Pushbutton Turn OFF with Transitions at WDE for Time Extension dc1033bf DEMO MANUAL DC1033B PCB LAYOUT Top Layer Layer 2 dc1033bf 7 DEMO MANUAL DC1033B PCB LAYOUT Layer 3 Bottom Layer 8 dc1033bf Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. A B C D GND PB# M1 M2 PFI GND V1(BAT) 2.7V - 28V GND E8 E9 LO HI E18 E17 E15 E21 E10 E20 5 JP1 R10 100k 1% 1% LO TIEM1 R12 1k CV1 OPT 50V PB# M1 M2 PFI V2 V1 G1 CAP OPEN JP3 ONT PB# SW1 4 19 18 2 13 15 16 PB# M1 M2 PFI V2 V1 G1 4 3 J2 0 (OPT) NOTE 4 3 NOTE 2 J1 0 (OPT) U1 LTC2952 5 8 PFO# RST# INT# KILL# WDE 6 5 10 20 3 JP4 OPEN G1STAT 17 OFFT EN D4 GRN SUP_EN 11 CAP /SHDN IN R11 100 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CUSTOMER NOTICE 1 R18 100k 2 1 D3 ORN PFO# R6 100 2 R14 100k 1% R13 105k 1% 2 SCALE = NONE DILIAN R. KIM T. APPROVALS D2 ORN G1STAT R7 100 LT3010EMS8E U4 ADJ OUT LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED APP ENG. CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 2 COFFT 1 0.068uF 2 WDE KILL# INT# RST# PFO# G1STAT EN CVS 0.47uF 50V VS 3 CONT 0.022uF VM 3 1. ALL RESISTORS AND CAPACITORS ARE 0603. 2. BYPASS V1 SECOND FET OPTION WITH 0 OHM RESISTOR. 3. BYPASS V2 SECOND FET OPTION WITH 0 OHM RESISTOR. 4. REMOVE R3 AND INCLUDE R17 TO MONITOR V2 AT PFI. 5. REMOVE R1 AND INCLUDE R16 FOR VM TO MONITOR VS INSTEAD OF DC/DC OUTPUT VOLTAGE. 6. CV1, CV2 SHOULD BE SMALL IF NEEDED. JP2 1 3 V2MON R3 511k U3 Si7923DN NOTE: UNLESS OTHERWISE SPECIFIED 2 1 C2 1nF 16V VS M2CONFG 6 5 R4 100k 1% R17 511k 1% OPT 4 R9 845k 1% NOTE 3 2 M1CONFG 3 C1 0.1uF 50V U2 Si7923DN 6 8 CV2 OPT 50V 3 D2 D1 5 D2 D1 7 G2 4 S2 S1 1 G1 2 V2(WALL) 2.7V - 28V E11 1 2 2 D1 4 G2 G1 1 D2 6 D2 D1 5 S2 GND 9 1 2 GND 4 GND 9 1 2 S1 21 1 2 7 7 1 2 8 G2 12 G2 ONT 8 GND VS 14 VS OFFT 1 VM D5 RED INT# R8 100 1 R15 100k 1% R2 100k R1 365k 1% E7 E6 E5 E4 E3 E2 E1 E14 E13 1 JP5 E19 DILIAN R. APPROVED GND WDE KILL# INT# RST# PFO# G1STAT EN 2P6V VM GND VS 1 DATE 08-31-15 DATE: N/A SIZE 1 LTC2952CUF DEMO CIRCUIT 1033B Monday, August 31, 2015 IC NO. SHEET 1 OF 1 1 REV. PUSHBUTTON ON/OFF POWERPATH CONTROLLER 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only TIE INT# / KILL# 3 UNTIE 2 NOTE 5 R16 511k 1% OPT E22 E12 REBUILD WITH CHANGE DESCRIPTION REVISION HISTORY TECHNOLOGY REV TITLE: SCHEMATIC D1 ORN RST# R5 100 CO 0.47uF 2P6V __ ECO 1 2 4 TO MICROPROCESSOR 5 A B C D DEMO MANUAL DC1033B SCHEMATIC DIAGRAM dc1033bf 9 DEMO MANUAL DC1033B DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation 10 Linear Technology Corporation dc1033bf LT 0116 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2016