5 4 3 2 1 REVISION HISTORY ECO REV __ DESCRIPTION APPROVED PRODUCTION 2 MARK T. DATE 2-23-11 D D CS# SCK MOSI VCC MISO C29 RFLAG# 1 S0 1 3 JP4 2 17 23 18 JP5 2 3 20 21 22 19 JP6 2 3 C 1 S2 1 3 JP7 3 JP8 12 10 11 9 100pF 1206 CLR LDAC RFLAG RFB RFB 2 26 IOUT1 25 VOSADJ R22 R23 1K 10K R24 C33 10K 1uF 1206 VOSADJ C32 R25 1uF 1206 +5V 1K C34 OPT 5 ROFS 3 4 3 U11A LTC6244CDD R26 OPT R28 10 - E1 V- V- E2 C35 R30 1K OPT 1206 V+ 3 VOSADJ E4 V+ + JP1 6 EXT GND GND 4.02K 2 - V- U7 LT1012ACS8 EXT 2 GND 3 3 2 4 JP11 VOUT C 7 E3 - OPT -5V C31 100pF VREF 1 GEADJ U9 LT1360CS8 R29 U8 LTC2054CS5 2 V- 2 R27 V+ + V+ + 6 + 1 1 2 REF RCOM 3 3 RIN IOUT2 GEADJ 5 4 7 GND GND GND GND GND JP9 GND 3 24 1 16 15 13 8 6 2 MSPAN - 1 S0 S1 S2 M-SPAN FB JP12 V+ 28 27 2 S1 1206 C30 1 1 JP3 U1 LTC2756ACG 4 LDAC# 3 VDD 1 2 CLR# OPT. SRO SDI SCK CS/LD 14 10K 0 2 1 VCC 7 R11-R17 V- B B +5V C36 0.1uF NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. C40 0.1uF C41 0.1uF C37 0.1uF U11C +5V 8 V+ VV- LTC6244CDD 4 9 6 5 + -5V U11B LTC6244CDD CUSTOMER NOTICE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 0 0 0 0 5 0 0 0 1 0 10 0 0 1 0 -5 5 0 0 1 1 -10 10 0 1 0 0 -2.5 2.5 0 1 0 1 -2.5 7.5 APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. A SPAN 0 - 7 -5V S3 S2 S1 S0 TECHNOLOGY JW MARK T. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC 18-BIT SOFT SPAN DAC W/SPI INTERFACE SIZE N/A SCALE = NONE 2 DATE: IC NO. REV. LTC2756ACG DEMO CIRCUIT 1792A 2-23-11 2 SHEET 1 1 OF 2 A 5 4 3 2 1 MISO MOSI D D SCK CS# C7 1 12V 2 MISO R2 10.0K 10 9 11 12 14 2 GND GND GND 13 8 3 SCL SDA WP A2 A1 A0 C3 10uF 1206 R4 4.99K JP10 VIN VOUT GND TRIM C2 10uF 1206 5 1 V+ AMP V+ 3 E7 E8 D2 BAT54C D3 BAT54C 1 B C6 10uF 1206 C5 10uF 1206 AMP V- C13 10uF 1206 C15 10uF 1206 IN SHDN GND BYP 5 4 C18 10uF 1206 C19 10uF 1206 E10 A T2 E11 OPT. OPT. R34 R33 OPT. OPT. CUSTOMER NOTICE 4 2 4 3 C20 10uF 1206 SD GND BYP 3 IN OUT 5 C21 -5V TECHNOLOGY JW MARK T. B 0.01uF APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 C11 10uF 1206 1 U6 LT1964ES5-5 R32 C10 0.01uF 2 V- R31 C +5V OUT E9 T1 VCC E6 +5V 3 GND 2 4 U5 LT1761ES5-5 24LC025-I /ST VCC VCC REF REG 6 6 5 7 3 2 1 1 4 VSS VCC C4 0.1uF R3 4.99K 8 U4 5V JP2 EXT 2 6 U3 OPT R5 4.99K C OUTS 3 MOSI R1 88.7K SD# 7 3 4 OUTF 1 ADJ 2 Vin GND SCK GND C1 10uF 1206 BAT54C 3 EEVCC EESDA EESCL EEGND AUX CS# 6 4 7 5 2 CS SCK/SCL MOSI/SDA MISO 2 2 V+ 5V 1 2 1 3 5 GND OUT 3 GND IN 1 VREF E5 8 D1 BYP GND 1 5 V+ J1 HD2X7-079-MOLEX VREF U2 LTC6655 0.01uF 3 4 U10 LT1761ES5-BYP 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC 18-BIT SOFT SPAN DAC W/SPI INTERFACE SIZE N/A SCALE = NONE 2 DATE: IC NO. REV. LTC2756ACG DEMO CIRCUIT 1792A 2-24-11 2 SHEET 2 1 OF 2 A