advertisement Flash Memory VPP Generator Reference Designs Design Note 97 Mitchell Lee The VPP generator circuits shown here cover a range of 30mA to 240mA with 3.3V or 5V inputs as noted. Table 1 summarizes these circuits for quick reference. 30mA from 5V Input INPUT 5V + 60mA from 5V Input 4.7µF 4.7µF VOUT C1+ VCC + 4.7µF C1– C2+ 220nF C2 – SHUTDOWN* SHDN GND 470nF L1 10µH DN97 • F02 Charge pump design uses no inductors. This is a minimum component count, minimum size solution. 60mA from 3.3V/5V Input VPP2 0.1µF C2 – *0 = PROGRAM, 1 = SHUTDOWN DN97 • F01 Charge pump design uses no inductors. This is a minimum component count, minimum size solution. VPP1 0.1µF 470nF GND *0 = PROGRAM, 1 = SHUTDOWN VCC 3.3V/5V 4.7µF LTC1263 C2+ SHDN VOUT C1+ VCC LTC 1262 SHUTDOWN* 12V 60mA + 220nF C1– ® INPUT 5V 12V 30mA + 60mA/120mA from 3.3V/5V Input L1* 33µH D1 MBRS130T3 1µF D BSS84 S D BSS84 S POWER ON* VCC VPP1 G1 SW SW AVPP 1µF LT ®1106 +VIN 3.3V/5V 12V 60mA VPP2 VPP VALID VPP VALID G2 3/5 DETECT 3/5 C1 22µF 10V VIN LT1109ACS8-12 + VOUT 12V SENSE SHUTDOWN PGND GND + C2 47µF 20V ** SOFT START ON/OFF PGND GND 12/5 1M 0.1µF DN97 • F03 FOR TYPE I CARDS: L1: DALE ILS-3825-01 D1: 4 BAT54Cs IN PARALLEL (PHILIPS), 1.1mm MAXIMUM HEIGHT FOR TYPE II CARDS: L1: MURATA ERIE LQH3C100K04M00 D1: MOTOROLA MBRS0520, 2.1mm MAXIMUM HEIGHT * COILTRONICS CTX33-2 SUMIDA CD54-330LC ** 1 = PROGRAM 0 = SHUTDOWN DN97 • F04 All surface mount, minimum component count solution. *1 = PROGRAM, 0 = SHUTDOWN Designed for PCMCIA Type I or Type II in-card use. The LT1106 includes VPP bank switching for up to four memory chips. 02/95/97 , LTC and LT are registered trademarks of Linear Technology Corporation. 60mA/120mA from 3.3V/5V Input L1 33µH 5V OR 3.3V D1 SELECT SHUTDOWN** IN OUT 1µF 2.2nF SENSE SHDN + C2 SHDN ILIM PGND GND 33µF 20V N/C 0.1µF* DN97 • F05 DN97 • F06 CONVERTER OUTPUT 120mA/240mA from 3.3V/5V Input L1* 50µH VIN 1N5817 2.4k to 10k 250mA to 60mA 12V + VN2222EL 3.74k Output Disconnect Efficiency is 84% to 88% at full load. VIN 8.25k SHUTDOWN* This circuit serves as a post regulator for flyback converters or overwindings. Output automatically falls to zero in shutdown. L1: COILCRAFT DO3316-333 OR SUMIDA CD73-330KC D1: 1N5817 OR MOTOROLA MBRS130LT3 C1: AVX TPSD476M016R0100 OR SANYO OS-CON 165A47M C2: AVX TPSD336M020R0100 OR SANYO OS-CON 205A33M 100µF 16V ADJ *1 = PROGRAM, 0 = SHUTDOWN **30V ABSOLUTE MAXIMUM *REQUIRED FOR 5V OUTPUT **0 = PROGRAM, 1 = SHUTDOWN INPUT 3.3V 5V 1µF 12V 120mA OUTPUT LT1121CS8 LT1301 47µF 12.7V TO 17V** 12V OUTPUT SW VIN + C1 120mA from 12.7V to 17V Input VSW LT1172 FB E2 GND ZETEX FZT 749 VPP TO FLASH MEMORY DN97 • F08 10.7k 390µF 25V This shutdown circuit allows output to drop to zero when switching converter is disabled. VC 1.24k E1 PROGRAM SHUTDOWN *COILTRONICS CTX 50-1 DN97 • F07 High output current converter programs up to eight memory chips simultaneously. Table 1. Summary of Flash Memory VPP Generator Solutions Number of Flash Chips VIN = 3.3V VIN = 5V VIN = 12.6V To 17V Regulator Advantages — 1 — LTC1262 No Inductors — 2 — LTC1263 No Inductors 2 2 — LT1106 PCMCIA Type I In-Card Use. Includes VPP Bank Switching for 4 Memory Chips 2 4 — LT1109A Low Cost 2 4 — LT1301 High Efficiency — — 4 LT1121 Linear Post Regulator 4 8 — LT1172 High Current For literature on our Switching Regulators, call 1-800-4-LINEAR. For applications help, call (408) 432-1900, Ext. 361 Linear Technology Corporation LT/GP 0295 160K • PRINTED IN THE USA 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 ● FAX: (408) 434-0507 ● TELEX: 499-3977 LINEAR TECHNOLOGY CORPORATION 1995