DN261 Chip Set Offers Low Cost Alternative to 48V Telecom Modules

==
!48V !"#$%&'()*+,
! 261
Kurk Mathews
!"48V !"#$%&'()*+, !"#$%&'()*+,- ./01*
!"#$%&' ()*+,-"./0
!"#$%&'()*+,-./0123
LT®1681 / LTC®1698 !"#$%&'(
!"#$%&'()*+,-.$/012
!"#$%&'()*+,-./0123
!"#$
L T 1 6 8 1 !"#$%&'( )*+,
!"#$%LTC1698 !"#$%&'(
!"LT1681 !"#$250kHz !
!7 5 V !"#$%&'($)*+,= /
!"#$%&'"()*+,-./
LTC1698LT1681 !"#$%&'()*
!"#$%&'()*+,-./012
1 : !"#$3.3V/20A
95
36VIN
90
EFFICIENCY (%)
48V3.3V !"
336V IN - 72VIN 3.3V OUT/20A !"
!"#$%&'()*+= 3 0 = E = 5 F !"#$%&'()*+,-./012
!"#$%#&'()*+LTC1698 !
!"#$%&'L T 1 6 8 1 !"#$
MOSFET !"#$%2 LTC1698
!"#$%&'()*+#,-./4 3 1 !"#$%&'()*+,-./0123
!"#±5% !"#$%&'()*+,
!"#$%&'()*+,-./012
!"#$%&'E1F
LT1681 / LTC1698 !"#$%&'()*+, !"#$%&'()*+,-#./012
12/01/261
72VIN
85
48VIN
80
75
70
2
4
6
8
10 12 14
CURRENT (A)
16
18
20
dn261f02
2 : 3.3V
=EPF
!"#$%&'()*+,LT1681 / LTC1698
!"#$%&'()*+,-./0
=====LTC =LT !"#$%&'(
!"#
http: // www. linear-tech.com/go/dnLTC1698
http: // www. linear-tech.com/go/dnLT1681
!"#!$%& OOT ! NSNM 200003
(86)21-6375-9478
(86)21-6375-9479
!"#$%
Cytech Technology Ltd.
www.cytecht.com
!"#$ ! !"#$%
Unique-A Division of Memec (Asia Pacific) Ltd.
www.unique-ap.com
!"(852)2375-8866 (852)2375-7700 [email protected]
!"(010)8268-4280
!"(028)522-4111
!"(023)6860-8938
!"(020)8762-7232
!"(025)481-0877
!"(021)6440-1373
!"(0755)386-7431
!"(029)848-1716
!"(027)8736-0546
C2
1.5µF
100V
C3
1.5µF
100V
(010)8268-4277
(028)523-9451
(023)6860-8938
(020)8762-7227
(025)480-8023
(021)6440-0166
(0755)386-7954
(029)848-0985
(027)8736-0547
!"(852)2410-2778
!"(010)8519-1866
!"(028)620-0026
!"(021)3303-0261
!"(0755)366-4329
!"(027)8732-2646
!"(0592)516-4701
!"(029)822-9180
(852)2370-3247
(010)8519-1865
(028)620-0027
(021)6317-3446
(0755)366-4330
(027)8732-2729
(0592)516-4702
(029)825-8595
0.1µF
C26
68µF
20V
+
MMBZ5248LT1
18V
10k
MMBZ5245LT1
15V
267k
0.25W
1nF
24k
1.24k
1%
56k
20k
73.2k
1%
20
17
19
18
16
11
12
15
BAS21
BAS21
BAT54
330pF
10k
BAT54
MMBT3906LT1
Q12
ZVN3310F
10Ω
1µF
MMBT3906LT1
5VREF
52.3k
1%
5
6
4
4700pF
7
8
3k
3300pF
10Ω
10
3
1•
4
•6
1k
5
8
S
2
1 T1
4
2
14
5
10k
15
3
4700pF
1k
220pF
S
Q1
12
11
16 2
100Ω
2k
0.25W
6
0.1µF
VAUX
OPTODRV
SYNC
MARGIN
OVPIN
3
4
10
PGND GND PWRGD ICOMP
LTC1698
VFB
1.24k
1%
13
7
9
8
1k
1000pF
S
L2
2.35µH
2.43k
1%
dn261f03
1k
0.33µF
1.78k
1%
3.01k
Q6, Q15, Q17
FDS6680A
×3
MMBZ5240BLT1
10V
0.22µF
50V
MBR0540
4.7Ω
1000pF
100V
0.022µF
1000pF
100V 10Ω
0.25W
10Ω
0.25W
VDD ISNS ISNSGND FG CG VCOMP
1
4.7µF
16V
Q13
FZT690
Q5, Q14
FDS6680A
×2
C1
2200pF
250V
3.3Ω
5
7
VSEC
3 : 36V - 72V DC =3.3V/20A !"#$%&'
82pF
3
0.1µF
T2
ISO1
5VREF MOC207
4 3 1
7
6
3.3Ω
BAT54
0.025Ω
1/2W
Q3
MURS120T3
MMBT3906LT1
MURS120T3
VCC VBST BLKSENS TG BSTREF BG SENSE IMAX PGND 13
SG
2
LT1681
OVLO
9
1
THERM SYNC SGND SS VC VFB
SHDN 5VREF FSET
14
BAS21
0.1µF 100V
L3 1mH
C4
1.5µF
100V
10Ω
•
L1
3.3µH
C1: MURATA ERIE GHM3045X7R222K-GC
C2, C3, C4: VITRAMON VJ1825Y155MXB
C5 TO C8: 330µF 10V KEMET T510X337K010AS
C26: AVX TPSE686M020R0150
ISO1: QT OPTOELECTRONICS MOC207
L1: COILCRAFT DO1608C-332
L2: PULSE P1977 PLANAR INDUCTOR
L3: COILCRAFT DO1608C-105
Q1, Q3: SILICONIX Si4486EY
Q5, Q6, Q14,Q15, Q17: FAIRCHILD FDS6680A
Q12: ZETEX ZVN3310F
Q13: ZETEX FZT690
T1: PULSE P1976 PLANAR TRANSFORMER
T2: MIDCOM 31264R
VIN–
VIN+
•
•
!"#
Linear Technology Corporation Ltd.
www.linear.com.cn
!"#$#% OOP !" O ONMU (852)2428-0303
(852)2348-0885
!"#$%&'()*+,-./0
!"#$%&'()*+,-./
www.linear-tech.com =www.linear.com.cn
dn261f 1001 29K • PRINTED IN CHINA
 LINEAR TECHNOLOGY CORPORATION 2001
+
TRIM
S
VOUT–
C5 TO C8
330µF
10V
×4
VOUT+