DEMO MANUAL DC1850A-A/DC1850A-B LTC4366HTS8-1/LTC4366HTS8-2 Very High Voltage Surge Stopper Description Demonstration Circuit 1850A showcases the LTC®4366 high voltage surge stopper in a 28V vehicular application. DC1850A withstands inputs of up to 100VDC and input transients of up to 250V while maintaining the output at 43.1V. Reverse battery and errant inputs of up to –100VDC are blocked from reaching the output. DC1850A-A features latchoff behavior after a fault and is reset by asserting the SHUTDOWN input high for at least 100µs. DC1850A-B features auto-retry 9 seconds after tripping off in an overvoltage fault condition. The 9 second delay can be interrupted by pulsing the SHUTDOWN input. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Performance Summary PARAMETER CONDITIONS Input Range Operating DC Survival 1ms Transient Load = 1.5A Specifications are at TA = 25°C Output Regulation Surge Timer Cool-Down Timer Input = 100V (DC1850A-B) MIN TYP MAX UNITS 18 –100 250 28 41 100 V V V 41 43.1 45.3 V 1.2 5.9 2.8 9 4.9 16 ms s dc1850aabf 1 DEMO MANUAL DC1850A-A/DC1850A-B Overview The LTC4366 surge stopper operates in a floating topology, permitting the design of circuits capable of operating at virtually unlimited input voltage. DC1850A has been designed to protect against ±100VDC and 250V for 1ms, in 28V vehicle applications. The input start-up range is 18V to 41V, while after start-up the input can fall to approximately 7V while still passing 1.5A load current. Careful attention has been paid to the layout to provide at least 87mil (2.2mm) clearance between input and output, and input and ground. This wide clearance is capable of withstanding 100VDC and spikes to 250V without arcing. The operating ranges are shown in silkscreen on the top of the board. The bottom shows the U1 part number, top mark and behavior associated with the –A and –B versions of DC1850A. This same information is shown on the schematic. Three ancillary circuits are located on the bottom of the board. Shutdown Level Shifter Since the LTC4366 operates in a floating topology, it is necessary to level shift ground-referred shutdown signalling. A simple NPN circuit provides level shifting between the SHUTDOWN turret and the LTC4366’s SD pin. Wide Voltage Range Constant Current LED Driver Making an LED operate at constant brightness over a wide operating range is made possible by a simple, twotransistor circuit. Input LED (D6) current is held constant from 18V to 250V, and emits some light as low as 7V. Output LED (D5) is biased with a 9.1k resistor (R7, on bottom of board). Its brightness will vary with output voltage. −100V Reverse Voltage Protection Circuit Reverse polarity inputs of up to −100V are blocked from reaching the load by M2, whose associated circuitry is located on the bottom of the board. This circuit blocks reverse inputs of up to −250VDC, provided the input is applied from a cold start. If DC1850A is already on and operating with a positive input voltage, instantaneous spikes must not exceed −100V. SHUTDOWN Turret If the SHUTDOWN turret is left open, DC1850A defaults to the ON state and turns on when an input supply is connected. Pulling SHUTDOWN to 1.8V or higher causes the LTC4366 to enter its shutdown state. The circuit board layout limits the maximum SHUTDOWN voltage to 60VDC, while R2 limits the peak applied transient voltage capability to 100V. Optional Components Two optional components, CX and RX are made available for those who wish to experiment with the frequency response of the overvoltage regulation loop. How to Operate DC1850A Operation of DC1850A is straightforward: connect an input supply of 18V to 41V, and an output load of up to 1.5A. If the SHUTDOWN turret is open circuit the output will power up. If the input voltage is increased above ≈ 43.1V, the output will limit and shut off after 2.8ms. DC inputs of up to ±100V may be applied. The basic hookup is shown in Figure 1. dc1850aabf 2 DEMO MANUAL DC1850A-A/DC1850A-B Overview 18V TO 41V INPUT 0A TO 1.5A LOAD Figure 1. DC1850A Basic Hookup dc1850aabf 3 DEMO MANUAL DC1850A-A/DC1850A-B Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 1 2 1 CF CAP., X7R, 1000pF 100V, 10%, 0603 AVX, 06031C102KAT2A 2 CT, CG CAP., X7R, 0.01µF 100V, 10%, 0603 AVX, 06031C103KAT2A 3 1 CLOAD CAP., ALUM. 100µF 50V, 20% SUN ELECT, 50CE100LX 4 1 C1 CAP., X7R, 0.47µF 25V, 10%, 0603 AVX, 06033C474KAT2A 5 0 CX (OPT) CAP., X7R, 0.01µF 100V, 10%, 0603 6 1 CSNUB CAP., X7R, 0.01µF 500V, 20%, 1210 AVX, 12107C103MAT2A 7 5 D1, D2, D3, D4, D7 DIODE, SWITCH 300V 400MW SOD123 DIODES INC, BAV3004W-7-F 8 2 D5, D6 LED, GREEN S-GW TYPE SMD PANASONIC, LN1371SGTRP 9 6 E1, E3, E4, E5, E6, E8 TESTPOINT, TURRET, .094" MILL-MAX, 2501-2-00-80-00-00-07-0 10 4 E18, E19, E20, E21 JACK, BANANA KEYSTONE, 575-4 11 2 M1, M2 MOSFET, N-CH 250V 33A D2PAK FAIRCHILD, FDB33N25TM 12 3 Q1, Q2, Q3 TRANSISTOR, GP NPN AMP SOT-23 DIODES INC, MMBT3904-7-F 13 1 Q4 TRANS., AMP NPN GP 300V SOT-223 FAIRCHILD, PZTA42 TR 14 1 RFB1 RES., CHIP, 12.4k, 1%, 0603 NIC, NRC06F1242TRF 15 1 RFB2 RES., CHIP, 422k, 1%, 0603 NIC, NRC06F4223TRF 16 1 RG RES., CHIP, 10, 5%, 0603 NIC, NRC06J100TRF 17 1 RSS RES., CHIP, 34k, 1%, 0603 VISHAY, CRCW060334K0FKEA 18 1 RIN RES., CHIP, 392k, 1%, 1206 VISHAY, CRCW1206392KFKEA 19 4 R1, R2, R3, R5 RES., CHIP, 470k, 5%, 0603 NIC, NRC06J474TRF 20 3 R4, R6, R9 RES., CHIP, 270k, 5%, 1206 NIC, NRC12J274TRF 21 1 R7 RES., CHIP, 9.1k, 5%, 1206 NIC, NRC12J912TRF 22 1 R8 RES., CHIP, 4.7k, 5%, 0603 NIC, NRC06J472TRF 23 1 R10 RES., CHIP, 200, 5%, 0603 NIC, NRC06J201TRF 24 0 RX (OPT) RES., CHIP, 100k, 1%, 0603 25 1 RSNUB RES., CHIP,100Ω, 5%, 1210 NIC, NRCP25J101TRF 26 4 STAND OFF STAND OFF 0.375" KEYSTONE, 8832 dc1850aabf 4 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 E21 INPUT 18V - 41V MMBT3904 Q3 2 1 R10 200 5 R2 470k LTFMF 4 PART MARKING E8 E1 DC1850A-B LTC4366HTS8-2 U1 GND SHUTDOWN Q1 MMBT3904 AUTO RETRY CT 10nF 100V E5 VSS TIMER SD VDD E19 E20 GND RSS 34k U1* CUSTOMER NOTICE 4 3 2 1 3 E4 BASE FB OUT GATE 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. R1 470k LATCH OFF RIN 392k CF 1nF 100V D2 BAV3004W D1 BAV3004W 1 2 BEHAVIOR R3 470k 1 SHUTDOWN LEVEL SHIFTER PROTECTION CIRCUIT -100V REVERSE VOLTAGE 1 LTFMC ASSY D R4 270k Q2 MMBT3904 3 4 G DC1850A-A LTC4366HTS8-1 * 2 M2 S FDB33N25 R5 470k PART NUMBER D6 GREEN INPUT Q4 PZTA42 R8 4.7k D7 BAV3004W R6 270k D4 BAV3004W D3 BAV3004W WIDE VOLTAGE RANGE CONSTANT CURRENT LED DRIVER 1 R9 270k 1 2 1 1 2 1 E6 3 2 4 3 SCALE = NONE HZ Mitchell L. PCB DES. 2 DATE: N/A SIZE 1.5A MAXIMUM LOAD LTC4366HTS8 FAMILY DEMO CIRCUIT 1850A Wednesday, June 20, 2012 IC NO. DATE 6-5-12 1 SHEET 1 OF 1 3 REV. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only 2.8ms 43.1V SURGE TIMER OUTPUT CLAMP E18 VERY HIGH VOLTAGE SURGE STOPPER TECHNOLOGY 250V 1ms TRANSIENT TITLE: SCHEMATIC +/- 100V CLOAD 100uF 50V E3 Mitchell L. APPROVED OUTPUT 1.5A MAXIMUM CLAMPED AT 43.1V DESCRIPTION PRODUCTION CSNUB 10nF 500V 18V - 41V 1 REVISION HISTORY RSNUB 100 + D5 GREEN OUTPUT R7 9.1k INPUT RANGE RFB2 422k RFB1 12.4k M1 FDB33N25 3 REV DC SURVIVAL G __ ECO DC OPERATING CX 10nF 100V OPT RX OPT 100k 10 APPROVALS C1 470nF 25V CG 10nF 100V RG APP ENG. 5 6 7 8 2 D S 2 3 2 5 A B C D DEMO MANUAL DC1850A-A/DC1850A-B Schematic Diagram dc1850aabf 5 DEMO MANUAL DC1850A-A/DC1850A-B 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 dc1850aabf 6 Linear Technology Corporation LT 1012 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2012