1 2 3 4 5 A 6 7 8 REVISION HISTORY This circuit is proprietary to Linear Technology and supplied for use with Linear Technology parts. 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 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 Applications Engineering for assistance. ECO REV R39 200K DESCRIPTION 3 INTVCC R1 200K * DATE PROD APPROVED 05/14/09 OPTIONAL DCR SENSING: NOTE: WHEN DCR SENSING IS IMPLEMENTED, SHORT R10 AND R17, DO NOT STUFF R8,R9,R20 AND R21 E1 PGOOD1 A E16 PGOOD2 R26 VOUT2 C2 10pF TRACK1 OPT VOUT1 JP5 E10 SS TRACK R2 3 TRACK1 35.7K R3 11.5K 1 R4 R5 R6 182K 1% 0 C1 2 INTVCC E2 57.6K 1% 0.1uF C19 [1] VIN JP3 R34 OPT RUN1 OFF 2 RUN2 OFF 3 R35 [1] 5 1 2 ON R36 OPT 29 JP4 1 2 ON 6 3 7 C28 ITH1 PGOOD2 4700pF R37 [1] OPT C29 8 OPT 33 PGOOD1 TRACK/SS1 TG1 FREQ SW1 PLLIN/MODE BOOST1 SGND 3 CLKOUT PHASE 13 R16 120 4 47pF PHSMD R22 VOUT2 C22 4.7uF 10V R18 102K 1% 0 C18 2 3 TRACK2 [1] C13 47uF 50V 10V + BG2 SHT 2 18 17 16 4 D3 R15 2.2 15 0.1uF TG2 SHT 2 -A LTC3857EUH R32 OPT VOUT2 GND R33 OPT C L2 7.2uH * VOUT2 R17 CDEP105-7R2M SW2 SHT 2 0.008 J5 VOUT2 C20 10uF 16V C27 R20 0 R21 0 * * GND E6 E13 4 COUT2 + 68uF 10V COUT4 + OPT J6 VOUT2 8.5V / 3A GND GND R23 1 0 CONTRACT NO. 0.1uF APPROVALS R35 R37 APPROVED OPT OPT DESIGNER ENGINEER DATE 10/26/07 TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 D TITLE SCH, LTC3857EUH / LTC3858EUH, LOW QUIESCENT CURRENT DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER SIZE CAGE CODE [2] DWG NO REV 3 DC1381A -B LTC3858EUH 1 66.5K 12.7K [2] FOR REGULATION VIN > 9V 2 [2] E14 CHECKED U1 J4 SNS2+ Q4 BSZ097N04LS DRAWN MI ASSY 4.7uF 50V OPT CMDSH-4E Q3 BSZ097N04LS 4.7uF 50V VIN 4.5V - 36V SNS2- VIN INTVCC C16 C7 R31 INTVCC C23 R25 10K 1% D EXTVCC OPTIONAL DCR SENSING 4.7uF C12 0.1uF C17 SS OPT 97.6K1% VIN C11 J3 VIN 100pF R19 976K 1% C21 TRACK 4 R14 0 VIN SNS1+ OPTIONAL DCR SENSING SNS2+ JP6 R24 CMDSH-4E 19 1000pF TRACK2 E15 SW2 TG2 SNS2- E3 14V MAX BOOST2 ITH2 EXTVCC EXTVCC BG2 TRACK/SS2 VFB2 E9 12 3300pF C14 3 60 SGND C15 2 90 R41 OPT 15K 20 ILIM 11 JP8 1 R40 OPT C EXTVCC BG1 SHT 2 INTVCC SNS2+ 28 INTVCC 21 SNS2- INTVCC GND E5 OPT D2 R13 2.2 24 GND E12 SNS1- 25 VIN INTVCC B R30 0.1uF PGND CLKOUT 9 4 3.3V / 5A J2 R29 OPT Q2 BSZ097N04LS 26 22 GND R28 OPT + C5 OPT C10 27 23 RUN2 BSZ097N04LS 14 BG1 RUN1 E17 CLKOUT Q1 4 5 6 7 8 30 VIN TG1 SHT 2 + COUT1 220uF 4V 1 2 3 PLLIN / MODE 8.2K C4 COUT3 100uF 6.3V 1 2 3 R11 VOUT1 0.005 5 6 7 8 0 J1 VOUT1 100pF 1 2 3 E4 VOUT1 * R10 5 6 7 8 C3 22pF B 5 6 7 8 R7 1000pF L1 3.2uH CDEP105-3R2M VIN 1 2 3 BURST MODE E11 SW1 SHT 2 C26 32 6 * C6 SNS1+ 5 PULSE SKIP * U1 31 100K 4 R38 OPT VFB1 3 INTVCC CCM R9 0 1 2 R27 R8 0 SNS1- 2.2uF JP2 1 SNS1- MODE 10 INTVCC SNS1+ INTVCC 3 Friday, August 21, 2009 4 5 6 SCALE: NONE FILENAME: 1381A-3.DSN 7 SHEET 1 8 OF 2 This circuit is proprietary to Linear Technology and supplied for use with Linear Technology parts. 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 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 Applications Engineering for assistance. REVISION HISTORY ECO VIN REV DESCRIPTION 3 C24 C25 OPT OPT DATE PROD APPROVED 05/14/09 5 6 7 8 VIN Q5 OPT 4 1 2 3 TG1 5 6 7 8 SW1 Q6 OPT 4 1 2 3 BG1 VIN 5 6 7 8 SHT 1 Q7 OPT 4 1 2 3 TG2 5 6 7 8 SW2 Q8 4 OPT 1 2 3 BG2 5 6 7 8 VIN Q1X 4 OPT 1 2 3 TG1 5 6 7 8 SW1 X6 1 1 X5 X7 1 1 1 X1 1 X2 Represents Tooling Holes 4 REPRESENTS STAND OFFS 1 2 3 BG1 Q2X OPT X4 on PCB VIN 5 6 7 8 SHT 1 1 2 3 DRAWN MI CHECKED 5 6 7 8 SW2 APPROVED Q4X OPT 4 1 2 3 BG2 CONTRACT NO. APPROVALS 4 TG2 Q3X OPT ENGINEER DESIGNER DATE 10/26/07 TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 TITLE SCH, LTC3857EUH / LTC3858EUH, LOW QUIESCENT CURRENT DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER SIZE CAGE CODE DWG NO REV 3 DC1381A Friday, August 21, 2009 SCALE: NONE FILENAME: 1381A-3.DSN SHEET 2 OF 2