DN97 - Flash Memory VPP Generator Reference Designs

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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
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