automotive 12v, 24v and 42v systems dc/dc conversion solutions C infocard 21 linear technology corporation ? 1630 mccarthy blvd. ? milpitas, ca 95035-7417 ? (408) 432-1900 ? www.linear-tech.com ? literature only: 1-800-4-linear , ltc and lt are registered trademarks of linear technology corporation. automobile design artwork courtesy of ralph mcbride and western washington university. used by permission. always-on
monitors and
collision avoidance
micropower
regulators navigation systems
4v to 18v
battery conversion
to constant 12v
automotive 12v, 24v and 42v systems dc/dc conversion solutions C infocard 21 2 linear technology in 42v automotive power dc/dc conversion is a specialty of linear technology corporation. we offer an extensive line of innovative circuits for automotive systems including switching regulators that operate to 60v or higher for the new 42v standard. these integrated circuits are available tested and guaranteed for the automotive temperature range. n high current 42v step-down (to 3v, 5v, 14v, etc.) lt1339: high power synchronous dc/dc controller C up to 50a output n operation to 60v n current mode operation n synchronous dual n-channel drive 42v in , 5v out at 50a high power buck converter + 1 8 0.1 m f 1 m f 15 10k 1n914 sync i avg
v c
v ref sense +
sense
fb tg
ts
bg 13
2
4
3 5
7
10 19
18
16 11
12
9 run
5v ref
slope
ct sgnd 12v in boost 1n914 42v lt1339 pgnd 2200pf 4.7k 100k 12v 15k 2200pf 1500pf 1 m f 1 m f 2200 m f
6.3v
os-con 5v
50a irfz44
2 irfz44
4 10 m h
50a r select
3k r sense
0.002 w ztx649 ztx649 ztx749 ztx749 1k + 47 m f 17 20 + 1500 m f
63v
4 r select
18.2k
8.66k
3k
1.66k
1.25k v out
24v
12v
5v
3.3v
2.8v r sense
0.01 w
0.005 w 0.002 w i limit
10a
20a
50a 12v 3.3v 3a
10 output current (amps) 0 efficiency (%) 100
95
90
85
80
75
70
65
60
55
50 40 lt1339 ?ta02 10 20 30 50 42v to 5v efficiency curve (r sense = 0.002 w ) burst mode is a trademark of linear technology corporation. n programmable average load current limiting n programmable fixed frequency synchronizable to 150khz n adaptive nonoverlapping gate drive prevents shoot-through ltc1149: high efficiency synchronous dc/dc controller C 60v operation n synchronous fet switching for high efficiency n adaptive nonoverlap gate drives n 16-pin narrow so package n operation to 60v, to 5a output n constant off-time current mode operation, to 250khz n high efficiency over wide current range n automatic burst mode tm operation n logic-controlled micropower shutdown 10v-48v to 5v/2a high voltage buck converter measured efficiency output current (a) 0.001 50 efficiency (%) 70 80 90 100 0.01 0.1 2 60 1 v in = 12v v in = 48v v in = 36v v in = 24v 10v-48v to 5v/2a high voltage buck converter c2 united chemi-con (al) lxf63vb331m12.5 x 30
esr = 0.170 w i rms = 1.280a
c4 (ta)
c10 sanyo (os-con) 10sa22om esr = 0.035 w i rms = 2.360a
q1 ir pmos bv dss = 60v rds on = 0.280 w c rss = 65pf q g = 19nc
q2 ir nmos bv dss = 60v rds on = 0.100 w c rss = 79pf q g = 28nc
v cc v cc cap sd1 sd2 i th c t ltc1149-5 p gate v in sense + sense n gate d1
1n4148 + c9
0.01 m f + v in
10v
to 48v c1
0.1 m f
1n4148 c4
1 m f
c5
0.1 m f
c6
0.068 m f
z5u
r1
1k c7
3300pf
x7r
c8
680pf
npo
3
5
16
10
15
7
6
1
4
9
8
13
c3
0.047 m f
z5u
q1
irfu9024 q2
irfu024 d2
mbr160 c2
330 m f
63v
l1
62 m h
r2
0.05 w
5v
2a c10
220 m f 2
10v
quiescent current = 1.5ma
transition current (burst mode
operation/continuous
operation) = 570ma 2
11
12
14
s gnd p gnd p drive r gnd d1 silicon vbr = 75v
d2 motorola schottky vbr = 60v
r2 krl np-1a-c1-0r050j pd = 1w
l1 coiltronics ctx62-2-mp dcr = 0.040 w mpp core
all other capacitors are ceramic
automotive 12v, 24v and 42v systems dc/dc conversion solutions C infocard 21 n polyphase tm regulators for improved performance for high current step-down applications, two out-of-phase ic controllers provide significant improvements* and reduced component cost that offset the cost of the second controller ic. major benefits include: n two output inductors 1/8 the size of a single inductor (total 1/4 the magnetics) n significantly reduced output ripple n significantly reduced input capacitor ripple current allows the use of fewer input capacitors n greatly improved transient responsetwo smaller inductors: slew currents are additive n minimizes the size of mosfets, may save the need to parallel mosfets 3 n selection guide for 42v automotive dc/dc conversion * synchronous 2-switch transistor drive for maximum efficiency ** external comparator required ? plus minimum v cc load of a few ma ?? plus fet charge currents package codes: k = to-3, n = plastic power dip, r = 7-lead dd, s = narrow small outline, sw = wide so (0.300 " ), t = to-220, polyphase is a trademark of linear technology corporation. *see linear technology magazine, november 1998, p.27 5
10
11
13
14
7 4
6
8
12
3
1
2
9 ast
ast
?
+t
ret
rcc sync1 v cc v c ss sync2 nc nc f osc = 200khz cx
rx
rst
q
q
osc
gnd c1
0.1 f c2
100pf r2
16.5k u1
cd4047 + + + + sync1 r1
10k r7
10k r4
0.010
1% c4
0.1 f
25v c3
150 f
16v
sanyo
os-con-sp c14
1000pf r5
191k
1% r8
4.3k r21
16k r12
10.7k
1% r13
1.24k
1% q7
mjd112 17 20 19 18 11 12 16 14 13 9 815 12v bias d2
mmsz4699t1
12v d3
bat54 d4
mbrs340l feedback d1
bat54 12v l1
15 h v in
42v output
12v
15a c10
1000pf c11
0.1 f c15
1000pf c16
6800pf c12
2000pf c13
1000pf c7, 0.22 f c6
0.1 f
50v c33
1300pf
50v c5
1500 f
50v
sanyo
mv-gx c8
150 f
16v
sanyo
os-con-sa c9
150 f
16v
sanyo
os-con-sa q2
irfz34s q4
irfz44s sync 5v ref
sl/sdj
1 2
4
sgnd pgnd u2
lt1339 12v in
boost tg ts s + s bg phase run/sd v fb
c t
i avg
ss
v c
v ref 3
5
6
7
10 + + + + sync2 r15
0.010
1% 17 20 19 18 11 12 16 14 13 9 815 12v bias d6
bat54 d7
mbrs340l feedback l2
15 h v in
42v c31
1000pf c30
1000pf c22, 0.22 f c21
0.1 f
50v c19
0.22 f
25v c20
1500 f
50v
sanyo
mv-gx c24
150 f
16v
sanyo
os-con-sa c25
150 f
16v
sanyo
os-con-sa q5
irfz34s q6
irfz44s sync 5v ref
sl/sdj
1 2
4
sgnd pgnd u4
lt1339 12v in
boost tg ts s + s bg phase run/sd run nc v fb
c t
i avg
ss
v c
v ref ss
v c
3
5
6
7
10 r16
191k
1% c28
1000pf c29
0.1 f ic21/1339 design approach for very low ripple/noise and improved transient response regulator v in i out synch burst i q shutdown circuit range range drive* mode supply current package features 60v input step-down switching regulators lt1676 7.4v to 60v 10ma to 500ma x** 3.2ma ? 30 m a s8 no pulse skipping at light load, 100khz lt1776 7.4v to 60v 10ma to 500ma x** 3.2ma ? 30 m a s8 no pulse skipping at light load, 200khz lt1076hv 8v to 64v to 2a 8.5ma 140 m a k,t,r onboard switches lt1074hv 8v to 64v to 5a 8.5ma 140 m a k,t,t7 low quiescent current ltc1149 4v to 60v to 5a yes x 2ma 135 m a s16 high efficiency over wide range lt1339 10v to 60v 1a to 50a yes 14ma ?? 65 m a n20, sw20 high current n-channel drive 42v output step-up (or sepic) switching regulators lt1680 10v to 60v 1a to 50a 12ma 65 m a n16, sw16 to 10,000pf gate capacitance lt1339 10v to 60v 1a to 50a yes 16ma ?? 65 m a n20, sw20 adaptive gate drive ltc1624 3.5v to 36v 10a x 550 m a16 m a s8 optimum load step response
4 automotive 12v, 24v and 42v systems dc/dc conversion solutions C infocard 21 n 42v step-down (integrated switch) lt1074 series: high voltage, high efficiency switching voltage regulators n input voltage range to 60v or 75v n 1a, 2a and 5a onboard switches (see table, p.6) n current mode operation, may be synchronized to external clock n few external components n low quiescent current: < 10ma n micropower shutdown mode n pulse-by-pulse programmable current limiting n low thermal resistance packages lt1676/lt1776: high efficiency step-down switching regulators n wide input range: 7.4v to 60v* n true current mode control n 700ma peak switch current n adaptive switch drive prevents pulse skipping at light loads n fixed frequency lt1676: 100khz, lt1776: 200khz n lt1676 is synchronizable to 250khz (lt1776 to 400khz) n micropower shutdown mode n 8-pin so and power dip packages output load current (a) 0 efficiency (%) 60 70 80 90 1234 5 6 100 50 l = 50 h type 52 core
diode = mbr735 v = 5v, v = 15v out in v = 12v, v = 20v out in lt1074 buck converter efficiency v sw v in v c gnd fb lt1074hv 5v
5a c1
500 f r1
2.8k
1% r2
2.21k
1% mbr745* 10v
to 60v c3 ?
200 f r3
2.7k c2
0.01 f l1**
50 h (lt1074)
100 h (lt1076) * use mbr340 for lt1076
** coiltronics
#50-2-52 (lt1074)
#100-1-52 (lt1076)
pulse engineering, inc.
#pe-92114 (lt1074)
#pe-92102 (lt1076)
hurricane
#hl-ak147qq (lt1074)
#hl-ag210ll (lt1076)
? ripple current rating 3 i out /2
25v + + basic positive buck converter * the lt1776 is limited to 40v continuous dc input due to thermal constraints, but can withstand transients up to 60v. 39 f
63v 1676 f01 v in v cc v sw lt1676 fb v c shdn sync 2 5 4 3 7 8 1 6 gnd + 100 f
10v + mbr160 36.5k
1% 5v
400ma 12.1k
1% 22k 220 h* 2200pf v in
7.4v to 60v 100pf *65t #30 on magnetics
mpp #55030 i load (ma) 1 60 efficiency (%) 70 80 90 10 100 1000 1676 ta01 50 40 30 20 v in = 12v v in = 24v v in = 36v v in = 48v efficiency vs v in and i load
automotive 12v, 24v and 42v systems dc/dc conversion solutions C infocard 21 5 n high current 14v to 42v step-up dc/dc conversion for charging 36v batteries or powering 42v equipment from a 12v source lt1680: high power dc/dc step-up controller n operation to 60v n all n-channel drive handles up to 10,000pf gate capacitance n high power output to 250w or more n fixed frequency current mode operation n synchronizable to 200khz n programmable average current limiting n undervoltage lockout with hysteresis n user-adjustable slope compensation n 16-pin so and dip packages 1
2
3
4
5
6
7
8 16
15
14
13
12
11
10
9 sl/adj
c t
i avg
ss
v c
sgnd
v fb
v ref 5v ref
sync
12v in
gate
pgnd
run/shdn
sense
sense + + lt1680 mbr0520 r ct
15k r7
2k r vc , 4.7k 1n914 c ct
1nf c3, 2.2nf c vc , 4.7nf c4, 0.22 m f c2
1 m f c11, 1nf 1680 ta01 c6, 0.1 m f r6
64.9k r9
100k c12
1 m f m1
irfz44
3 d1
mbr20100ct
2 + c in
680 m f
25v
4 c out
680 m f
63v
3 v out
42v
6a l1
25 m h r sense
0.005 w 12v in
10v to 15v
24a (dc) + l1: kool m m , 18t #14 on 77314-a7
kool m m is a registered trademark of magnetics, inc. output power (w) 0 efficiency (%) 90 95 100 200 1680 ta02 85 80 75 50 100 150 250 v out = 48v 12v to 42v, 250w boost efficiency vs output power automotive power circuits power v in i out step-up/ batteries i q shutdown circuit range * max down charged supply current packages description or features lt1505 3v to 27v >5a nicd,nimh,li-ion,sla 12ma 5 m a g24 programmable or preset outputs; constant i & v lt1510 8v to 30v 1.5a nicd,nimh,li-ion 2.9ma 3 m a s8,n16,gn16 200khz or 500khz switching; precision reference lt1511 8v to 30v 3a nicd,nimh,li-ion 4.5ma 3 m a sw24 with input current limiting; undervoltage lockout lt1512 3v to 30v** 1a x nicd,nimh,li-ion,sla 4ma 12 m a n8,s8 step-up/step-down; 500khz; constant i/constant v lt1513 3v to 30v** 2a x nicd,nimh,li-ion,sla 4ma 12 m a t,r any number of cells to 20v ? ; programmable current lt1620/1 to 32v >10a nicd,nimh,li-ion,sla 2.8ma ms8,s8,gn current sense amp used with pwm controller ic * depending on battery types and quantity ** 40v max for on-chip switch ? lt1512 to 30v * with external diode the lt1339 will also provide 42v output, high current synchronous boost conversion (see data sheet). battery charger circuits (for in-vehicle cell phones, pcs, etc.) power driver circuits power v in i out number transient reverse i q shutdown circuit range max drivers protection polarity supply current packages description or features fully enhanced mosfet drivers ltc1153 4.5v to 22v >20a single 40v* 15v 85 m a8 m a n8,s8 autoreset electronic circuit breaker ltc1154 4.5v to 22v 2.7a single 40v* 15v 85 m a8 m a n8,s8 high side mosfet driver ltc1155 4.5v to 22v 5a dual 40v* 15v* 85 m a8 m a n8,s8 micropower mosfet driver; overcurrent sense high voltage switch drivers lt1161 8v to 48v to 5a quad 60v 15v 4.5ma n20,s20 external mosfets; C15v to 60v transients lt1188 5v to 30v 1.5a single 60v 5ma 500 m a k,t on-chip switch; status output ltc1255 9v to 24v 1a dual 40v* 15v 0.5ma 12 m a n8,s8 external mosfets; overvoltage protection package codes: g = ssop (0.209" wide), gn = narrow ssop (0.150"), gw = wide ssop (0.300"), m = 3-lead dd, ms8 = 8-lead msop, n = plastic dip, q = 5-lead dd, r = 7-lead dd, s = narrow small outline (so), st = sot-223, t = plastic to-220
automotive 12v, 24v and 42v systems dc/dc conversion solutions C infocard 21 linear technology corporation ? 1630 mccarthy blvd. ? milpitas, ca 95035-7417 ? (408) 432-1900 ? www.linear-tech.com ? literature only: 1-800-4-linear ?1999 ic21 lt/tp 0299 3k automotive power circuits switching regulator dc/dc converters * synchronous 2-switch transistor drive for maximum efficiency ?? plus fet charge current power v in i out step-up step- switch burst i q shutdown circuit range max & sepic down volts mode supply current packages description or features high efficiency current mode switching regulators (on-chip power transistor) lt1676 7.4v to 60v 500ma x 60v x* 3.2ma** 30 m a n8,s8 no pulse skipping at light load; fixed 100khz lt1776 7.4v to 60v 500ma x 60v x* 3.2ma** 30 m a n8,s8 fixed 200khz, synchronize to 400khz lt1082 3v to 75v 1a* ? x 100v 4.5ma 120 m a q,t, n8 highest input voltage; all standard switch configurations lt1072 8v to 40v 1.25a* ? x 60v 6ma 50 m a k,t,n8,s8 self-protected against overloads; easy to use lt1072hv 8v to 64v 1.25a* ? x 84v 6ma 50 m a k,t,n8,s8 optional flyback-regulated mode for isolation lt1172 3v to 60v 1.25a* ? x 60v 6ma 50 m a k,t,n8,s16 adaptive antisat switch drive lt1176 5v to 38v 1a x 50v 8ma 140 m a n8,s20 100khz; few externals; improved dynamic behavior lt1071 3v to 60v 2.5a* ? x 60v 6ma 50 m a k,t bust proof and easy to use lt1076 8v to 45v 2a x 45v 8.5ma 140 m a k,t,r adjustable or fixed current limit; self-protecting lt1076hv 8v to 64v 2a x 84v 8.5ma 140 m a k,t,r switch voltage to 84v; to 64v input voltage lt1171 3v to 60v 2.5a* ? x 60v 6ma 50 m a k,t,n8,s16 self-protected against overloads lt1070 3v to 60v 5a* ? x 60v 6ma 50 m a k,t load power to 100w lt1170 3v to 60v 5a* ? x 60v 6ma 50 m a k,t,n8,s16 100khz, high efficiency lt1074 8v to 45v 5a x 64v 8.5ma 140 m a k,t pulse-by-pulse current limiting lt1074hv 8v to 64v 5a x 84v 8.5ma 140 m a k,t switch voltage to 84v; 100khz lt1372 2.7v to 30v 1.5a* ? x 35v 4ma 12 m a n8,s8 500khz, high efficiency lt1377 2.7v to 30v 1.5a* ? x 35v 4ma 12 m a n8,s8 1mhz, tiny inductors ltc1574 4.5v to 18.5v 1a x 18.5v x 450 m a2 m a s16 internal schottky diode lt1375 6v to 25v 1.2a x 35v 2.5ma 20 m a n8,s8 may be externally synchronized to 1mhz lt1376 6v to 25v 1.2a x 35v 2.5ma 20 m a n8,s8,s16 500khz; cycle-by-cycle and thermal protection lt1373 2.7v to 30v 1.5a* ? x 35v 1ma 12 m a n8,s8 35v switch; 250khz; easily synchronized lt1371 2.7v to 30v 3a* ? x 35v ? 4ma 12 m a r,sw20 500khz, high efficiency; reduced overshoot lt1374 6v to 25v 4.5a x 40v 2.5ma 20 m a s8 constant 500khz, synchronize to 1mhz, 1.8 m h lt1370 2.7v to 30v 6a* ? x 35v ? 4.5ma 12 m a r,t7 500khz, tiny inductors; easy synchronization ultralow noise switching regulators (on-chip switch) lt1533 2.7v to 23v 2 1a* ? x x 30v 12ma 12 m a s16 ultralow noise 1a push-pull regulator lt1534 2.7v to 23v 2a* ? x 30v 12ma 12 m a s16 ultralow noise 2a boost regulator power v in i out step-up step- sync* burst i q shutdown circuit range max & sepic down drive mode supply current packages description or features switching regulator controllers (external power transistors) ltc1148hv 4v to 20v 10a x x x 1.6ma 10 m a n14,s14 very high efficiency ltc1149 4v to 60v 5a x x x 2ma 300 m a n16,s16 high efficiency over wide range; to 250khz ltc1159 4v to 40v 5a x x x 300 m a20 m a n16,s16,g20 high efficiency over wide range ltc1267 4v to 40v 5a x x x 550 m a25 m a g28 dual regulators ltc1435a 3.5v to 36v 5a x x x 260 m a25 m a g16,s16 ultrahigh efficiency, to 99% duty cycle ltc1436a 3.5v to 36v 5a x x 260 m a25 m a gn24 2.9v/5a with 5v auxiliary output ltc1437a 3.5v to 36v 5a x x 260 m a25 m a g28 2.5v/5a adjustable output with 5v auxiliary output ltc1438/9 3.5v to 36v 5a x x 320 m a30 m a g28,gw36 dual 5v/3v step-down converter, 400khz ltc1538/9 3.5v to 36v 5a x x x 320 m a70 m a g28,gw36 dual regulators, adaptive drive ltc1624 3.5v to 36v 10a x x x 550 m a16 m a s8 very low dropout, also good for flyback and inverting ltc1625 3.7v to 36v 10a x x x 500 m a30 m a gn,s16 no sense resistor required lt1339 60v max >50a x x x 14ma ?? 65 m a n20,sw20 high power synchronous current mode lt1680 60v max 20a x 12ma 65 m a n16,sw16 high power step-up converter power v in i out dropout transient reverse i q shutdown circuit range max max protection polarity supply current packages description or features lt1020 5v to 36v 125ma 0.6v 36v 40 m a n8,s8 with comparator and reference class b outputs lt1120 to 36v 125ma 0.65v 36v 40 m a n8,s8 with comparator and reference; logic shutdown lt1121 to 30v 150ma 0.4v 30v* 30v 30 m a16 m a z,n8,s8,st adjustable or fixed; micropower; self-protection lt1521 to 20v 300ma 0.6v 20v* 20v 12 m a5 m a ms8,s8,st no protection diodes required lt1129 to 30v 700ma 0.4v 30v* 30v 50 m a16 m a r,s8,t,st adjustable or fixed; micropower; self-protection lt1086 to 25v 1.5a 1.5v 30v* 5ma** k,t,m adjustable or fixed lt1085 to 25v 3a 1.5v 30v* 5ma** t,m handle surge currents to 100a lt1084 to 25v 5a 1.5v 30v* 5ma** k,p,t pin compatible with 3-terminal regulators lt1083 to 25v 7.5a 1.5v 30v* 5ma** k,p fixed 3.3v, 3.6v, 5v, 12v; adjustable versions low dropout voltage linear regulators * for higher ratings, consult factory ** flows into the load for higher efficiency * ? maximum switch current * with external comparator ** plus minimum v cc load of a few ma ? 45v with hv version
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