Analog Devices Inc. 的 LTC1262 规格书

L7H”. Mp LTCI262 TECHNOLOGY L7LELEL%
1
LTC1262
12V, 30mA Flash Memory
Programming Supply
S
FEATURE
D
U
ESCRIPTIO
U
A
O
PPLICATITYPICAL
■
Regulated 12V ±5% Output Voltage
■
No Inductors
■
Supply Voltage Range: 4.75V to 5.5V
■
Guaranteed 30mA Output
■
Low Power: I
CC
= 500
µ
A
■
I
CC
in Shutdown: 0.5µA
■
8-Pin PDIP or SO-8 Package
The LTC
®
1262 is a regulated 12V, 30mA output DC/DC
converter. It is designed to provide the 12V ±5% output
necessary to program byte-wide flash memories. The
output will provide up to 30mA from input voltages as low
as 4.75V without using any inductors. Only four external
capacitors are required to complete an extremely small
surface mountable circuit.
The TTL compatible shutdown pin can be directly con-
nected to a microprocessor and reduces the supply cur-
rent to less than 0.5µA. The LTC1262 offers improved
shutdown current performance and requires fewer exter-
nal components than competing solutions.
The LTC1262 is available in an 8-pin PDIP or SO-8
package.
1
2
3
4
8
7
6
5
0.22µF
4.7µF
FROM MPU
4.7µF
V
CC
VPP
LTC1262 • TA01
V
CC
4.75V TO 5.5V
FLASH
MEMORY
0.22µF
C1
–
C1
+
C2
–
C2
+
SHDN
GND
V
OUT
V
CC
LTC1262
+
+
U
S
A
O
PPLICATI
■
12V Flash Memory Programming Supplies
■
Compact 12V Op Amp Supplies
■
Battery-Powered Systems
5V
0V
SHDN
5V/DIV
5V
0V
12V
V
OUT
5V/DIV
1ms/DIV 1262 TA01a
In/Out of Shutdown
, LTC and LT are registered trademarks of Linear Technology Corporation.
PflCKflGE/OBDEB InFOfll'IIflTIOfl I’M—WWW UUUU L71LJEJWW
2
LTC1262
A
U
G
W
A
W
U
W
ARBSOLUTEXI T
I
S
WU
U
PACKAGE/ORDER I FOR ATIO
(Note 1)
Supply Voltage (V
CC
) ................................................ 6V
Input Voltage (SHDN) ................... –0.3V to V
CC
+ 0.3V
Output Current (I
OUT
) ........................................... 50mA
Operating Temperature Range
LTC1262C................................................ 0°C to 70°C
LTC1262I........................................... –40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ELECTRICAL CHARACTERISTICS
Consult factory for Military grade parts.
1
2
3
4
8
7
6
5
TOP VIEW
C1
–
C1
+
C2
–
C2
+
SHDN
GND
V
OUT
V
CC
N8 PACKAGE
8-LEAD PDIP S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C, θ
JA
= 100°C/W (N8)
T
JMAX
= 150°C, θ
JA
= 150°C/W (S8)
VCC = 4.75V to 5.5V, TA = –40°C to 85°C, (Notes 2, 3), unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OUT
Output Voltage 0mA ≤ I
OUT
≤ 30mA, V
SHDN
= 0V, 0°C ≤ T
A
≤ 70°C
●
11.4 12.6 V
0mA ≤ I
OUT
≤ 30mA, V
SHDN
= 0V, –40°C ≤ T
A
≤ 85°C
●
11.2 12.6 V
I
CC
Supply Current No Load, V
SHDN
= 0V, 0°C ≤ T
A
≤ 70°C
●
0.5 1.0 mA
No Load, V
SHDN
= 0V, –40°C ≤ T
A
≤ 85°C
●
0.5 1.3 mA
I
SHDN
Shutdown Supply Current No Load, V
SHDN
= V
CC
●
0.5 10 µA
f
OSC
Oscillator Frequency V
CC
= 5V, I
OUT
= 30mA
●
300 kHz
Power Efficiency V
CC
= 5V, I
OUT
= 30mA
●
74 %
R
SW
V
CC
to V
OUT
Switch Impedance V
CC
= V
SHDN
= 5V, I
OUT
= 0mA
●
0.18 2 kΩ
V
IH
SHDN Input High Voltage
●
2.4 V
V
IL
SHDN Input Low Voltage
●
0.8 V
SHDN Input Current V
CC
= 5V, V
SHDN
= 0V, 0°C ≤ T
A
≤ 70°C
●
–20 –10 –5 µA
V
CC
= 5V, V
SHDN
= 0V, –40°C ≤ T
A
≤ 85°C
●
–35 –10 –5 µA
V
CC
= 5V, V
SHDN
= 5V
●
0.06 10 µA
t
ON
Turn-On Time C1 = C2 = 0.22µF, C
IN
= C
OUT
= 4.7µF, (Figures 1, 2) 500 µs
t
OFF
Turn-Off Time C1 = C2 = 0.22µF, C
IN
= C
OUT
= 4.7µF, (Figures 1, 2) 3.3 ms
Note 2: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
Note 3: All typicals are given at V
CC
= 5V, T
A
= 25°C.
The ● denotes specifications which apply over the full operating
temperature range.
Note 1: Absolute maximum ratings are those values beyond which the life
of the device may be impaired.
ORDER PART
NUMBER
LTC1262CN8
LTC1262CS8
LTC1262IS8
S8 PART MARKING
1262
1262I
L7LELEL%
3
LTC1262
TYPICAL PERFORMANCE CHARACTERISTICS
UW
PI FU CTIO S
U
UU
V
OUT
(Pin 6): 12V Output. Connect a 4.7µF bypass capaci-
tor C
OUT
to ground. When in the shutdown mode V
OUT
=
V
CC
.
GND (Pin 7): Ground.
SHDN (Pin 8): Logic Level Shutdown Pin. Application of a
logic low at SHDN pin will place the regulator in normal
operation. With no external connection, or with SHDN tied
to V
CC
, the device will be put into shutdown mode. Connect
to GND for normal operation. In shutdown mode the
charge pump is turned off and V
OUT
= V
CC
.
Efficiency vs Output Current Shutdown Supply Current
vs Temperature
Output Voltage vs Output Current
C1
–
(Pin 1): C1 Negative Input. Connect a 0.22µF capaci-
tor C1 between C1
+
and C1
–
.
C1
+
(Pin 2): C1 Positive Input. Connect a 0.22µF capaci-
tor C1 between C1
+
and C1
–
.
C2
–
(Pin 3): C2 Negative Input. Connect a 0.22µF capaci-
tor C2 between C2
+
and C2
–
.
C2
+
(Pin 4): C2 Positive Input. Connect a 0.22µF capaci-
tor C2 between C2
+
and C2
–
.
V
CC
(Pin 5): Positive Supply Input Where 4.75V ≤ V
CC
≤ 5.5V. Connect a 4.7µF bypass capacitor C
IN
to ground.
Supply Current vs Supply Voltage
SUPPLY VOLTAGE (V)
4.5
480
SUPPLY CURRENT (µA)
500
520
540
560
600
4.75 5.0 5.25 5.5
LTC1262 G03
5.75 6.0
580
T
A
= 70°C
I
OUT
= 0
T
A
= 25°C
T
A
= 0°C
OUTPUT CURRENT (mA)
0
55
EFFICIENCY (%)
60
65
70
75
85
10 20 30 40
LTC1262 G01
50
80
V
CC
= 4.75V
V
CC
= 5V
V
CC
= 5.5V
TEMPERATURE (°C)
–50
0
SHUTDOWN SUPPLY CURRENT (µA)
0.6
1.2
1.8
2.4
3.6
–25 02550
LTC1262 G02
75 100
3.0
V
CC
= 5V
OUTPUT CURRENT (mA)
0 5 10 15 20 25 30 35 40 45 50
OUTPUT VOLTAGE (V)
12.2
12.0
11.8
11.6
11.4
11.2
11.0
10.8
10.6
10.4
10.2
1262 G04
V
CC
= 4.75V
V
CC
= 5.5V
V
CC
= 5V
___________________________________________________________
4
LTC1262
BLOCK DIAGRAM
W
TI I G DIAGRA S
WWU
Figure 2. LTC1262 Timing Circuit
–
+
S3B
S3D
S3A
S4A
S4B
S1 AND S2 SHOWN WITH SHDN PIN LOW.
S3A, S3B, S3C, S3D, S4A AND S4B SHOWN WITH OSCILLATOR OUTPUT LOW AND V
DIV
< V
BGAP
– V
HYST
.
COMPARATOR HYSTERISIS IS ±V
HYST
.
C1
C1
+
C1
–
C2
C2
+
C2
–
CHARGE
PUMP
S3C
D2
D1
V
BGAP
S1
LTC1262 • BD
S2
R3
R1
R2
V
OUT
V
CC
SHDN
GND
C
OUT
BANDGAP
REFERENCE
OSCILLATOR
C
IN
V
DIV
+
+
Figure 1. LTC1262 Timing Diagram
1
2
3
4
8
7
6
5
C1
0.22µF
C2
0.22µF
C
OUT
4.7µF
V
SHUTDOWN
V
OUT
LTC1262 • F02
V
CC
4.75V TO 5V
C
IN
4.7µF
C1
–
C1
+
C2
–
C2
+
SHDN
GND
V
OUT
V
CC
LTC1262
+
+
1.4V
5.1V
1.4V
V
SHDN
V
OUT
V
CC
V
CC
V
OUT
11.4V
0V
LTC1262 • F01
t
OFF
t
ON
L7LELEL%
5
LTC1262
APPLICATIONS INFORMATION
WUU U
Operation
The LTC1262 uses a charge pump tripler to generate 12V
from a V
CC
of 5V. The charge pump operates when clocked
by a 300kHz oscillator. When the oscillator output is low,
C1 and C2 are connected between V
CC
and GND, charging
them to V
CC
. When the oscillator output goes high, C1 and
C2 are stacked in series with the bottom plate of C1 pulled
to V
CC
. The top plate of C2 is switched to charge C
OUT
and
V
OUT
rises. V
OUT
is regulated to within 5% of 12V by an
oscillator pulse gating scheme. A resistor divider senses
V
OUT
. When the output of the divider (V
DIV
) is less than the
output of a bandgap (V
BGAP
) by the hysteresis voltage
(V
HYST
) of the comparator, oscillator pulses are applied to
the charge pump to raise V
OUT
. When V
DIV
is above V
BGAP
by V
HYST
, the oscillator pulses are prevented from clock-
ing the charge pump. V
OUT
drops until V
DIV
is below V
BGAP
by V
HYST
again. The gates of all internal switches are
driven between V
OUT
and GND. An internal diode ensures
that the LTC1262 will start up under load by charging C
OUT
to one diode drop below V
CC
.
To reduce supply current the LTC1262 may be put into
shutdown mode by floating the SHDN pin or taking it to
V
CC
. In this mode the bandgap, comparator, oscillator and
resistor divider are switched off to reduce supply current
to typically 0.5µA. At the same time an internal switch
shorts V
OUT
to V
CC
; V
OUT
takes 3.3ms to reach 5.1V (see
t
OFF
in Figure 1). When the SHDN pin is low, the LTC1262
exits shutdown and the charge pump operates to raise
V
OUT
to 12V. V
OUT
takes 500µs to reach the lower regula-
tion limit of 11.4V (see t
ON
in Figure 1).
Choice of Capacitors
The LTC1262 is tested with the capacitors shown in
Figure 2. C1 and C2 are 0.22µF ceramic capacitors and
C
IN
and C
OUT
are 4.7µF tantalum capacitors. Refer to
Table 1 if other choices are desired.
Table 1. Recommended Capacitor Types and Values
CAPACITOR CERAMIC TANTALUM ALUMINUM
C1, C2 0.22µF to 1µF Not Not
Recommended Recommended
C
OUT
2µF (Min) 4.7µF (Min) 10µF (Min)
C
IN
1µF (Min) 4.7µF (Min) 10µF (Min)
C1 and C2 should be ceramic capacitors with values in the
range of 0.22µF to 1µF. Higher values provide better load
regulation. Tantalum capacitors are not recommended as
the higher ESR of these capacitors degrades performance
when the load current is above 25mA with V
CC
= 4.75V.
C
IN
and C
OUT
can be ceramic, tantalum or electrolytic
capacitors. The ESR of C
OUT
introduces steps in the V
OUT
waveform whenever the charge pump charges C
OUT
. This
tends to increase V
OUT
ripple. Ceramic or tantalum capaci-
tors are recommended for C
OUT
if minimum ripple is
desired. The LTC1262 does not require a 0.1µF capacitor
between V
CC
and V
OUT
for stability.
Maximum Load Current
The LTC1262 will source up to 50mA continuously without
any damage to itself. Do not short the V
OUT
pin to ground.
If the V
OUT
pin is shorted to ground, irreversible damage
to the device will result.
L71LJEJWW
6
LTC1262
Burst Mode is a trademark of Linear Technology Corporation.
1
2
3
4
8
7
6
5
C1
–
C1
+
C2
–
C2
+
SHDN
GND
V
OUT
V
CC
PDRIVE
SENSE
+
SENSE
–
NDRIVE
PGND
3
10
6
4
11
1
8
7
14
12
V
IN
SHDN
I
TH
C
T
SGND
C7
0.22µF
SHUTDOWN
C9
1µF
LTC1262 • TA02
PANASONIC
ECGCOKB220R
U2
LTC1262
U1
LTC1148-3.3
C8
0.22µF
+
V
OUT
3.3V
10A
V
IN
5V
C2
150pF
C3
1000pF
C4
220µF
8V
× 3
C5
330µF
6.3V
× 2
OS-CON
Q3
Si9410
D1
MBRS120T3
Q5
Si9410
R6
22k Burst Mode
TM
DEFEAT;
USE IF REQUIRED
Q2
VN7002
R2
100Ω
R3
100Ω
R4
0.01Ω
2W
L2
3µH/10A
Q1
TP0610
Q4
Si9410
C1
3300pF
R1
510Ω
C6
10µF
25V
+
+ + +
+ +
5V to 3.3V/10A Converter
U
A
O
PPLICATITYPICAL
5 w, EL%7 Lflgm HHHH
7
LTC1262
PACKAGE DESCRIPTION
U
Dimensions in inches (millimeters) unless otherwise noted.
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
N8 1197
0.100 ± 0.010
(2.540 ± 0.254)
0.065
(1.651)
TYP
0.045 – 0.065
(1.143 – 1.651)
0.130 ± 0.005
(3.302 ± 0.127)
0.020
(0.508)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
0.125
(3.175)
MIN
12 34
8765
0.255 ± 0.015*
(6.477 ± 0.381)
0.400*
(10.160)
MAX
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
1234
0.150 – 0.157**
(3.810 – 3.988)
8765
0.189 – 0.197*
(4.801 – 5.004)
0.228 – 0.244
(5.791 – 6.197)
0.016 – 0.050
0.406 – 1.270
0.010 – 0.020
(0.254 – 0.508)× 45°
0°– 8° TYP
0.008 – 0.010
(0.203 – 0.254)
SO8 0996
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
TYP
DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH 
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD 
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
*
**
L71LJEJWW
8
LTC1262
LINEAR TECHNOLOGY CORPORATION 1994
LT/TP 0298 REV A 2K • PRINTED IN USA
OUTPUT CURRENT (mA)
0 10203040506070 80 90 100
OUTPUT VOLTAGE (V)
12.4
12.2
12.0
11.8
11.6
11.4
11.2
11.0
10.8
10.6
10.4
1262 TA04
V
CC
= 4.75V
V
CC
= 5.5V
V
CC
= 5V
1
2
3
4
8
7
6
5
0.22µF
10µF
10µF
TIE TO V
CC
OR FLOAT
TO SHUTDOWN BOTH
DEVICES
LTC1262 • TA03
V
CC
4.75V TO
5.5V
0.22µF
1
2
3
4
8
7
6
5
0.22µF
12V OUTPUT
0.22µF
NOTE: KEEP DEVICES CLOSE TOGETHER OR
USE SEPARATE 4.7µF TANTALUM
CAPACITORS IF THIS IS NOT POSSBILE.
C1
–
C1
+
C2
–
C2
+
SHDN
GND
V
OUT
V
CC
LTC1262
C1
–
C1
+
C2
–
C2
+
SHDN
GND
V
OUT
V
CC
LTC1262
+
+
Paralleling Devices
SEE FIGURE AT LEFT.
U
A
O
PPLICATITYPICAL
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LT1106* Micropower Step-Up DC/DC Converter for PCMCIA Card Flash Memory PCMCIA Card Power Control, 9µA I
SHDN
, Small SMT
Components, Requires External Inductor
LT1109-12 Micropower Low Cost DC/DC Converter Adjustable and Fixed 12V Three-Lead Z Package, Requires External Inductor
LT1109A-12 Micropower DC/DC Converter Flash Memory VPP Generator Requires External Inductor
Adjustable and Fixed 12V
LT1301 Micropower High Efficiency 5V/12V Step-Up DC/DC 7µA I
SHDN
, SMT Inductor and Capacitors
Converter for Flash Memory
LT1309 500kHz Micropower DC/DC Converter for Flash Memory Small SMT Inductor and Capacitors, 6µA I
SHDN
* See also LT1312/LT1313 PCMCIA VPP drivers/regulators, LT1314/LT1315 PCMCIA switch matrix and the LTC1470/LTC1471/LTC1472 Protected V
CC
and VPP switching matrices
Output Voltage vs Output Current for
Two Paralleled Devices
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
●
(408) 432-1900
FAX: (408) 434-0507
●
TELEX: 499-3977
●
www.linear-tech.com