1 dc1850aabf demo manual dc1850a-a/dc1850a-b description lt c 4366hts8 -1/ ltc 4366hts8- 2 very high voltage surge stopper demonstration circuit 1850a showcases the lt c ? 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 C100vdc are blocked from reaching the output. performance summary dc1850a-a features latchoff behavior after a fault and is reset by asserting the shutdown input high for at least 100s. 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. parameter conditions min typ max units input range operating dc survival 1ms transient load = 1.5a 18 C100 250 28 41 100 v v v output regulation 41 43.1 45.3 v surge timer cool-down timer input = 100v (dc1850a-b) 1.2 5.9 2.8 9 4.9 16 ms s specifications are at t a = 25c
2 dc1850aabf demo manual dc1850a-a/dc1850a-b overview the ltc4366 surge stopper operates in a floating topol- ogy, 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 ap- proximately 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 Ca and Cb ver - sions 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 signal- ling. a simple npn circuit provides level shifting between the shutdown turret and the ltc4366s 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, two- transistor 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 bot- tom 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. o ptional components tw o 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 o perate 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.
3 dc1850aabf demo manual dc1850a-a/dc1850a-b overview figure 1. dc1850a basic hookup 18v to 41v input 0a to 1.5a load
4 dc1850aabf demo manual dc1850a-a/dc1850a-b parts list item qty reference part description manufacturer / part number 1 1 cf cap., x7r, 1000pf 100v, 10%, 0603 avx , 06031c102 kat 2a 2 2 ct, cg cap., x7r, 0.01f 100v, 10%, 0603 avx , 06031c103 kat 2a 3 1 cload cap., alum. 100f 50v, 20% sun elect, 50ce100lx 4 1 c1 cap., x7r, 0.47f 25v, 10%, 0603 avx , 06033c474 kat 2a 5 0 cx ( opt ) cap., x7r, 0.01f 100v, 10%, 0603 6 1 csnub cap., x7r, 0.01f 500v, 20%, 1210 avx , 12107c103 mat 2a 7 5 d1, d2, d3, d4, d7 diode, switch 300v 400mw sod123 diodes inc, bav 3004w-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 d2 pak 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 r 4, 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,100, 5%, 1210 nic, nrcp25j101trf 26 4 stand off stand off 0.375" keystone, 8832
5 dc1850aabf demo manual dc1850a-a/dc1850a-b 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. schematic diagram 5 5 4 4 3 3 2 2 1 1 d d c c b b a a output 1.5a maximum clamped at 43.1v 18v - 41v -100v reverse voltage protection circuit wide voltage range constant current led driver input range dc operating dc survival 18v - 41v +/- 100v output clamp surge timer maximum load 2.8ms 1.5a 43.1v input * assy dc1850a-a ltc4366hts8-1 u1 dc1850a-b behavior latch off auto retry ltfmc ltfmf part number part marking LTC4366HTS8-2 * + shutdown level shifter output input 1ms transient 250v 100k opt gnd size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications ; however, it remains the customer's responsibility t o verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circu it performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology an d schematic supplied for use with linear technology parts. scale = none www.linear.com 3 wednesday, june 20, 2012 11 very high voltage surge stopper hz mitchell l. n/a ltc4366hts8 family demo circuit 1850a size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications ; however, it remains the customer's responsibility t o verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circu it performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology an d schematic supplied for use with linear technology parts. scale = none www.linear.com 3 wednesday, june 20, 2012 11 very high voltage surge stopper hz mitchell l. n/a ltc4366hts8 family demo circuit 1850a size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications ; however, it remains the customer's responsibility t o verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circu it performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology an d schematic supplied for use with linear technology parts. scale = none www.linear.com 3 wednesday, june 20, 2012 11 very high voltage surge stopper hz mitchell l. n/a ltc4366hts8 family demo circuit 1850a revision history description date approved eco rev mitchell l. production 3 6-5-12 __ revision history description date approved eco rev mitchell l. production 3 6-5-12 __ revision history description date approved eco rev mitchell l. production 3 6-5-12 __ cload 100uf 50v cload 100uf 50v d1 bav3004w d1 bav3004w 1 2 r4 270k r4 270k e18 e18 e5 e5 r7 9.1k r7 9.1k r3 470k r3 470k q1 mmbt3904 q1 mmbt3904 1 3 2 e1 shutdown e1 shutdown e21 e21 e8 gnd e8 gnd ct 10nf 100v ct 10nf 100v rfb1 12.4k rfb1 12.4k e19 e19 q3 mmbt3904 q3 mmbt3904 1 3 2 csnub 10nf 500v csnub 10nf 500v e3 e3 r5 470k r5 470k r2 470k r2 470k r9 270k r9 270k m1 fdb33n25 m1 fdb33n25 g d s rx opt rx opt d5 green d5 green d2 bav3004w d2 bav3004w 1 2 cf 1nf 100v cf 1nf 100v r8 4.7k r8 4.7k d7 bav3004w d7 bav3004w 1 2 r1 470k r1 470k q2 mmbt3904 q2 mmbt3904 1 3 2 e4 e4 rin 392k rin 392k cx 10nf 100v cx 10nf 100v rg 10 rg 10 rss 34k rss 34k e20 e20 rsnub 100 rsnub 100 d6 green d6 green rfb2 422k rfb2 422k r10 200 r10 200 m2 fdb33n25 m2 fdb33n25 g d s u1 u1 vdd 1 gate 8 sd 2 out 7 fb 6 vss 4 base 5 timer 3 q4 pzta42 q4 pzta42 1 3 4 c1 470nf 25v c1 470nf 25v d3 bav3004w d3 bav3004w 1 2 d4 bav3004w d4 bav3004w 1 2 cg 10nf 100v cg 10nf 100v r6 270k r6 270k e6 e6
6 dc1850aabf demo manual dc1850a-a/dc1850a-b linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax : (408) 434-0507 www.linear.com ? linear technology corporation 2012 lt 1012 ? printed in usa demonstration board important notice linear technology corporation ( lt c ) 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 lt c 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 lt c 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 . lt c assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. lt c 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 lt c applica- tion engineer . mailing address: linear technology 1630 mccarthy blvd. milpitas, ca 95035 copyright ? 2004, linear technology corporation
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