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02/95/97
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.
V
CC
VPP1
G1
VPP2
G2
ON/OFF
GNDPGND
SW
D
S
BSS84
D
S
BSS84
POWER ON*
DN97 • F03
12/5
SOFT START
AVPP
1M 0.1µF
3/5 DETECT
VPP VALID
1µF
D1
L1
10µH
1µF
VPP1
VPP2
V
CC
3.3V/5V
LT
®
1106
VPP VALID
3/5
12V
60mA
0.1µF
0.1µF
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
*1 = PROGRAM, 0 = SHUTDOWN
60mA from 3.3V/5V Input
Designed for PCMCIA Type I or Type II in-card use. The
LT1106 includes VPP bank switching for up to four memory
chips.
12V
30mA
4.7µF
GND
C1
+
C1
–
C2
+
C2
–
LTC
®
1262
DN97 • F01
INPUT
5V
SHDN
SHUTDOWN*
V
CC
V
OUT
+
220nF
*0 = PROGRAM, 1 = SHUTDOWN
220nF
4.7µF
+
12V
60mA
4.7µF
GND
C1
+
C1
–
C2
+
C2
–
LTC1263
DN97 • F02
INPUT
5V
SHDN
SHUTDOWN*
V
CC
V
OUT
+
470nF
*0 = PROGRAM, 1 = SHUTDOWN
470nF
4.7µF
+
30mA from 5V Input 60mA from 5V Input
Charge pump design uses no inductors. This is a minimum
component count, minimum size solution. Charge pump design uses no inductors. This is a minimum
component count, minimum size solution.
60mA/120mA from 3.3V/5V Input
+
SENSE
V
IN
PGND GND
LT1109ACS8-12
SHUTDOWN
SW
MBRS130T3
C2
47µF
20V
V
OUT
12V
L1*
33µH
COILTRONICS CTX33-2
SUMIDA CD54-330LC
1 = PROGRAM
0 = SHUTDOWN
+
+V
IN
3.3V/5V
C1
22µF
10V
DN97 • F04
**
*
**
All surface mount, minimum component
count solution.
, LTC and LT are registered trademarks of Linear Technology Corporation.
C2
33µF
20V
12V
OUTPUT
+
L1
33µHD1
C1
47µF
SW
I
LIM
PGND GND
SENSE
LT1301
SELECT
DN97 • F05
5V
OR
3.3V
*
**
SHDN
SHUTDOWN** N/C
V
IN
+
0.1µF*
REQUIRED FOR 5V OUTPUT
0 = PROGRAM, 1 = 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
LINEAR TECHNOLOGY CORPORATION 1995
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7487
(408) 432-1900
●
FAX
: (408) 434-0507
●
TELEX
: 499-3977
LT/GP 0295 160K • PRINTED IN THE USA
For literature on our Switching Regulators,
call 1-800-4-LINEAR. For applications help,
call (408) 432-1900, Ext. 361
60mA/120mA from 3.3V/5V Input
Efficiency is 84% to 88% at full load.
120mA from 12.7V to 17V Input
LT1172 FB
VN2222EL
L1*
50µH1N5817
DN97 • F07
100µF
16V
INPUT
3.3V
5V
PROGRAM SHUTDOWN E1
V
C
V
IN
V
SW
GNDE2
*COILTRONICS CTX 50-1
1.24k
390µF
25V
10.7k
12V
+
120mA/240mA from 3.3V/5V Input
High output current converter programs up to eight memory
chips simultaneously.
Number of Flash Chips
V
IN
= 3.3V V
IN
= 5V V
IN
= 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
Table 1. Summary of Flash Memory VPP Generator Solutions
LT1121CS8
DN97 • F06
12.7V TO
17V**
SHUTDOWN*
*
**
SHDN
IN OUT
ADJ
1 = PROGRAM, 0 = SHUTDOWN
30V ABSOLUTE MAXIMUM
2.2nF
8.25k
3.74k
1µF 1µF
12V
120mA
OUTPUT
This circuit serves as a post regulator for flyback convert-
ers or overwindings. Output automatically falls to zero in
shutdown.
This shutdown circuit allows output to drop to zero when
switching converter is disabled.
DN97 • F08
CONVERTER
OUTPUT
V
IN
VPP TO
FLASH MEMORY
ZETEX
FZT 749
2.4k to 10k
250mA to 60mA
Output Disconnect
