DEMO MANUAL DC1624A LTC4225-1/LTC4225-2 Dual Ideal Diode and Hot Swap Controller Description Demonstration circuit 1624A contains two independent rail circuits each with Hot Swap™ and ideal diode functionality provided by the LTC4225-1/LTC4225-2 dual ideal diode and Hot Swap controller. rail, four LEDs to indicate power good and fault conditions separately for each channel, and input voltage snubbers. There are pads for optional RC circuits for each Hot Swap MOSFET gate in order to adjust output voltage slew rate. DC1624A facilitates evaluation of LTC4225 performance in different operation modes such as supply ramp-up, power supply switchover, steady state, and overcurrent faults. Power supply switchover mode can be realized as either an ideal diode functionality or as a prioritizer functionality. The standard configuration (as DC1624A populated by default) places the ideal diode MOSFET ahead of the Hot Swap MOSFET. The board also has pads for an alternative configuration with the Hot Swap MOSFET located ahead of the ideal diode MOSFET. Each DC1624A rail circuit is assembled to operate with a 12V supply and 11.5A maximum current load. Design files for this circuit board are available at http://www.linear.com/demo The main components of the board are the LTC4225 controller, two MOSFETs operating as ideal diodes, two MOSFETs operating as Hot Swap devices, two power sense resistors, two jumpers for independently enabling each L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. PERFORMANCE SUMMARY SYMBOL PARAMETER VIN Input Supply Range VINTVCC(UVL) Internal VCC Undervoltage Lockout VINTVCC(HYST) Internal VCC Undervoltage Lockout Hysteresis (TA = 25°C) CONDITIONS MIN TYP 2.9 INTVCC Rising MAX UNITS 18 V 2.1 2.2 2.3 V 30 60 90 mV 10 25 40 mV Ideal Diode Control ΔVFWD(REG) Forward Regulation Voltage (VINN - VOUT ) ΔVDGATE External N-Channel Gate Drive (VDGATEN - VINN) ΔVFWD = 0.1V IN < 7V IN = 7V to 18V 5 10 7 12 14 14 V V ICPO(UP) CPON Pull-Up Current CPO = IN = 2.9V CPO = IN = 18V –60 –50 –95 –85 –120 –110 µA µA IDGATE(FPU) DGATEN Fast Pull-Up Current ΔVFWD =0.2V, ΔVDGATE = 0V, CPO = 17V –1.5 A IDGATE(FPD) DGATEN Fast Pull-Down Current ΔVFWD = –0.2V, ΔVDGATE = 5V 1.5 A Hot Swap Control ΔVSENSE(CB) Circuit Breaker Trip Sense Voltage (VINN - VISENSEN) 47.5 50 52.5 mV ΔVSENSE(ACL) Active Current Limit Sense Voltage (VINN - VISENSEN) 55 65 75 mV dc1624af 1 DEMO MANUAL DC1624A Performance Summary (TA = 25°C) SYMBOL PARAMETER CONDITIONS MIN TYP MAX IHGATE(UP) External N-Channel Gate Pull-Up Current Gate Drive On, HGATE = 0V IHGATE(DN) External N-Channel Gate Pull-Down Current IHGATE(FPD) External N-Channel Gate Fast Pull-Down Current VON(TH) ONN On Pin Threshold Voltage VON(RESET) ONN Pin Fault Reset Threshold Voltage VEN(TH) UNITS 7 10 13 Gate Drive Off, OUT = 12V, HGATE = OUT + 5V 150 300 500 µA Fast Turn-Off, OUT = 12V, HGATE = OUT + 5V 100 200 300 mA ON Rising 1.21 1.235 1.26 V ON Falling 0.55 0.6 0.63 V ENN Pin Threshold Voltage EN Rising 1.185 1.235 1.284 V V TMR(TH) TMRN Pin Threshold Voltage TMR Rising TMR Falling 1.198 0.15 1.235 0.2 1.272 0.25 V V ITMR(UP) TMRN Pin Pull-Up Current TMR = 1V, In Fault Mode 75 100 125 µA ITMR(DN) TMRN Pin Pull-Down Current TMR = 2V, No Faults 1.4 2 2.6 µA ITMR(RATIO) TMRN Current Ratio ITMR(DN)/ ITMR(UP) 1.4 2 2.7 % µA Input/Output Pin quick start procedure The LTC4225 functions as an ideal diode with inrush current limiting and overcurrent protection by controlling two external back-to-back N-channel MOSFETs in a power path. The LTC4225 has two ideal diode and two Hot Swap controllers. Each ideal diode MOSFET is intended to operate with a defined Hot Swap MOSFET, because they are tied by common on/off control, and ideal diode controller sense voltage includes both MOSFETs and sense resistor voltage drop. Therefore, LTC4225 provides independent control for the two input supplies. An active current limit amplifier servos the gate of the MOSFET to 65mV across the current sense resistor. Inrush current can be further reduced, if desired, by adding a capacitor from HGATE to GND. When the MOSFET’s gate overdrive (HGATE to OUT voltage) exceeds 4.2V, the PWRGD pin pulls low. The LTC4225 gate drive amplifiers (DGATEN,) monitor the voltage between the INN and OUTN pins and drive the DGATEN pins. The amplifier quickly pulls up the DGATE pin, turning on the MOSFET (Q1 or Q3), for ideal diode control when it senses a large forward voltage drop. When both MOSFETs (Q1 and Q2 or Q3 and Q4) are turned on, the gate drive amplifier controls DGATE to servo the forward voltage drop (VIN - VOUT) across the sense resistor and the back-to-back MOSFETs to 25mV. If the load current causes more than 25mV of voltage drop, the gate voltage rises to enhance the MOSFET used for ideal diode control. For large output currents the MOSFET’s gate is driven fully on and the voltage drop is equal to the sum of the ILOAD • RDS(ON) of the two MOSFETs in series. Pulling the ON pin high and EN pins low initiates a 100ms debounce timing cycle. After 100ms, a 10µA current source from the charge pump ramps up the HGATEN pin. When the Hot Swap MOSFET (Q2 or Q4) turns on, the inrush current is limited to a set level set by an external sense resistor placed between IN and SENSE pins. In the case of an input supply short circuit when the MOSFETs are conducting, a large reverse current starts flowing from the load towards the input. The gate drive amplifier detects this failure condition as soon as it appears and turns off the ideal diode MOSFET by pulling down the DGATE pin. dc1624af 2 DEMO MANUAL DC1624A quick start procedure Demonstration circuit DC1624A can be easily to set up to evaluate the performance of the LTC4225-1/LTC4225-2. Refer to the Figure 1 for proper measurement equipment setup and follow the procedure below. position to the ON position. Observe the transient. The output voltage rise time should be in the range of 12ms to 29ms. PWRGD1 (PWRGD2) green LED should be lit. Turn off the rail using the ON1_SEL (ON2_SEL) jumper. The DC1624A test includes independent tests of the LTC4225 Hot Swap functionality, ideal diode functionality and two power rails prioritizer functionality with the channel 1 highest priority. Second Step HOT SWAP FUNCTIONALITY TEST This test is identical for each 12V rail and is performed in the three steps by the measuring of the transient’s parameters in the different operation modes. The first step is a power-up without any additional load. The second step is the current limit operation after successful power-up transient. The third step is a power-up with a shorted output. Initially install the jumper heads in the following positions: ON1_SEL and ON2_SEL in position OFF; EN1_SEL and EN2_SEL in position LOW. First Step Connect a 12V power supply to the board input turrets IN1 (IN2) and GND. Do not load the output. Place current probe on the 12V supply and voltage probes on the OUT1 (OUT2) turret. Provide ON1 (ON2) signal at the ON1 (ON2) pin by moving the ON1_SEL (ON2_SEL) jumper header from OFF Initially adjust an electronic resistive load to 10Ω to 12Ω and connect it to the OUT1 (OUT2) turret and GND. Turn on the rail and slowly increase load current up to the circuit breaker threshold level. The current limit range should be from 11.5A to 13.3A. Turn off the rail using the ON1_SEL (ON2_SEL) jumper. Third Step Short the output to ground with a wire. Place the current probe on this wire. Turn on the rail and record the current shape. The maximum current should be in the (13.6A to 18.9A) range. The LTC4225-1 latches off after overcurrent condition, but the LTC4225-2 automatically retries after 200ms to 450ms. IDEAL DIODE FUNCTIONALITY TEST Use an individual 12V power supply for each rail; connect the two outputs together at a common load. Adjust each input voltage to 12V with maximum possible accuracy. In this test, both rails are active and small variations in the input voltage will force one channel off and the other channel on. dc1624af 3 DEMO MANUAL DC1624A quick start procedure Place a voltmeter between IN1 and IN2 turrets to measure the difference between two input voltages. Activate both rails and keep a load around 1A to 3A. Adjust with the input voltage levels and verify that when the difference between input voltages exceeds 40mV only one rail is active. THE PRIORITIZER FUNCTIONALITY TEST The DC1624A is assembled with components to implement a two power rails prioritizer with channel 1 having the higher priority. Install R17 with 470 and R18 with 41.2k. Place JP5 PPR_SEL (power priority select) jumper in position ON2 and JP4 ON2_SEL (ON2 select) in position OFF. Apply independent supply voltages (12V) to both inputs. Channel 1 will be connected to load. Reduce channel 1 input voltage until it reaches an undervoltage condition and D5 (PWRGD2) lights. At the same time channel 2 power supply will deliver power to the load. dc1624af 4 DEMO MANUAL DC1624A quick start procedure RL1 CL1 POWER SUPPLY 1 SW1 RL2 SW2 CL2 POWER SUPPLY 2 SW3 SW4 DC1624A F01 Figure 1. Measurement Equipment Setup for Hot Swap Functionality Test dc1624af 5 DEMO MANUAL DC1624A parts list ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 7 C1, C2, C3, C8, C9, C11, C14 CAP, X7R, 0.1µF, 50V, 0603 AVX, 06035C104KAT 2 2 C4, C5 CAP, X7R, 47nF, 50V, 0603 AVX, 06035C473KAT 3 2 C6, C7 CAP, X7R, 15nF, 50V, 0603 AVX, 06035C153KAT 4 0 C10, C13 OPT 5 2 C12, C15 CAP, AL, El, S/M 100µF, 50V SANYO, 50CE100BS 6 2 D1, D2 DIODE, VOLTAGE SUPP 13V 5% SMA VISHAY, SMAJ17A-E3 7 2 D3, D5 LED, SMT GREEN PANASONIC, LN1351C 8 2 D4, D6 LED, SMT RED PANASONIC, LN1251CTR 9 0 D7, D8, D10, D11 OPT 10 1 D9 DIODE, SWITCHING, SOD80 VISHAY, LS4148 11 8 E10 to E16, E18 TURRET, TESTPOINT, 2308 MILL-MAX, 2308-2-00-80-00-00-07-0 12 10 E1 to E9, E17 TURRET, TESTPOINT, 2501 MILL-MAX, 2501-2-00-80-00-00-07-0 13 8 J1 to J8 JACK BANANA KEYSTONE, 575-4 14 5 JP1, JP2, JP3, JP4, JP5 HEADERS, 3 PINS 2mm CTRS SAMTEC TMM-103-02-L-S 15 5 XJP1, XJP2, XJP3, XJP4, XJP5 SHUNT, 2mm CTRS SAMTEC 2SN-BK-G 16 4 Q1, Q2, Q3, Q4, N-CHANNEL 30-V MOSFET, PPSO-8 VISHAY, Si7336ADP 17 0 Q5, Q6, Q7, Q8 OPT 18 2 RS1, RS2 RES, CHIP, 0.004, 1/2W, 1%, 2010 19 0 RS3, RS4 OPT VISHAY, WSL20104L000FEA 20 4 R1, R3, R13, R14 RES, CHIP, 10, 1%, 0603 VISHAY, CRCW060310R0FKEA 21 2 R2, R4 RES, CHIP, 47, 1%, 0603 VISHAY, CRCW060347R0FKEA 22 4 R5, R6, R7, R8 RES, CHIP, 3k, 1%, 0805 VISHAY, CRCW08053K00FKEA 23 2 R9, R11 RES, CHIP, 20k, 1%, 0603 VISHAY, CRCW0060320K0FKEA 24 2 R10, R12 RES, CHIP, 137k, 1%, 0603 VISHAY, CRCW0603137KFKEA 25 0 R15, R16, R17, R18 OPT 26 4 MTGS AT 4 CORNERS STANDOFF, NYLON, 0.25, 1/4" KEYSTONE, 8832 (SNAP ON) dc1624af 6 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 J7 E7 E10 E17 E9 E18 E6 J6 J5 E5 GND GND 5 E8 J8 2.9V TO 18V IN2 IN2 ON2 GND PROBE GND ON1 GND GND 2.9V TO 18V IN1 IN1 ON2 IN2 OFF ON2 SMAJ17A D1 + 3 1 3 R13 10 20K 1% R11 R9 20K 1% LTC4225CUFD-1 LTC4225CUFD-2 -B C14 0.1uF 50V R14 10 C3 0.1uF 50V C9 0.1uF 50V C8 0.1uF 50V C2 0.1uF 50V ASSY -A 2 1 U1 1% C11 0.1uF 50V R10 137K 2 1 R12 137K 1% D2 SMAJ17A JP4 2 ON2_SEL JP3 2 ON1_SEL 1 + 4 1. ALL RESISTORS ARE IN OHMS, 0603. ALL CAPACITORS ARE IN MICROFARADS, 0603. NOTE: UNLESS OTHERWISE SPECIFIED * C13 100uF 50V OPT IN2 OFF ON1 IN1 C10 100uF 50V OPT IN1 RS4 0.004 0.5W RS2 0.004 0.5W R16 OPT 1 2 3 6 5 8 7 U1 6 5 8 7 Q7 OPT Si7336ADP 1 2 3 7 8 5 6 * 2 1 D10 CMHZ4706 OPT Q3 Si7336ADP ON2 GND EP ON1 3 2 1 Q1 Si7336ADP INTVCC HG1 1 3 2 1 2 D7 CMHZ4706 OPT Q5 OPT Si7336ADP 7 8 5 6 R15 OPT HG2 5 4 25 18 3 INTVCC C1 0.1uF 50V 2010 RS1 0.004 0.5W 2010 RS3 0.004 0.5W DG1 24 4 23 CPO1 4 D8 CMHZ4706 3 2 1 7 8 5 6 1 OPT 2 R1 10 3 2 1 1 2 3 6 5 8 7 R3 10 C7 15nF 50V R4 47 TMR2 PWRGD2 FAULT2 EN2 EN1 FAULT1 PWRGD1 TMR1 C6 15nF 50V D11 CMHZ4706 OPT 6 5 8 7 C5 47nF 16V X7R C4 47nF 16V D3 GREEN R5 3K 0805 IN1 R7 3K 0805 OUT2 R8 3K 0805 D6 RED D9 LS4148 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 2 SCALE = NONE + 3 DATE: N/A SIZE 2 EXT JP2 3 LOW 1 EXT JP1 3 LOW 1 EN2_SEL 2 ON2 JP5 3 OFF EN1_SEL 2 PPR_SEL 1 E1 1 APPROVED GND GND OUT2 11.5A OUT2 PWRGD2 FAULT2 EN2 EN1 FAULT1 PWRGD1 GND GND 11.5A OUT1 OUT1 VLADIMIR O. DATE 11-09-10 1 SHEET 1 LTC4225CUFD-1/-2 DEMO CIRCUIT 1624A Tuesday, December 07, 2010 IC NO. 3 REV. OF 1 DUAL IDEAL DIODE AND HOT SWAP CONTROLLER 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only E4 J4 J3 E3 E11 E12 E13 E14 E15 E16 ON2 E2 J2 J1 PRODUCTION DESCRIPTION REVISION HISTORY TECHNOLOGY REV TITLE: SCHEMATIC C15 100uF 50V R17 OPT + __ ECO R18 OPT C12 100uF 50V INTVCC OUT1 APPROVALS IN2 D5 GREEN D4 RED R6 3K 0805 2 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. AK VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. VLADIMIR O. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. CUSTOMER NOTICE Q8 OPT Si7336ADP 3 2 1 DG2 Q4 Si7336ADP 1 2 3 15 12 13 14 17 19 20 16 4 R2 47 7 8 5 6 DG1 Q6 OPT Si7336ADP Q2 Si7336ADP 3 1 2 4 6 CPO2 9 2 IN1 IN2 1 2 4 7 4 DGATE1 1 SENSE1 SENSE2 22 10 HG2 DGATE2 8 DG2 HGATE1 HGATE2 21 OUT1 OUT2 11 HG1 4 2 1 4 4 2 1 5 A B C D DEMO MANUAL DC1624A Schematic Diagram dc1624af 7 DEMO MANUAL DC1624A 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 dc1624af 8 Linear Technology Corporation LT 0611 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2011