LT8337-1 [ADI]
28V, 5A Low IQ Synchronous Step-Up Silent Switcher with PassThru;
| 型号： | LT8337-1 |
| 厂家： | 
ADI |
| 描述： | 28V, 5A Low IQ Synchronous Step-Up Silent Switcher with PassThru |
| 文件： | 总20页 (文件大小：1637K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT8338
40V, 1.2A Micropower Synchronous
Boost Converter with PassThru
FEATURES
DESCRIPTION
The LT®8338 is a synchronous monolithic step-up reg-
n
Wide Input Voltage Range: 3.0V to 40V
Low Quiescent Current in Burst Mode® Operation
ulator that provides high efficiency for input and output
up to 40V. It consumes only 6µA quiescent current at
Burst Mode operation to maintain high efficiency at very
low output current, while keeping the output ripple below
20mVP-P. The LT8338 switching frequency can be set with
an external resistor over the range of 300kHz to 3MHz.
A SYNC/MODE pin allows synchronization to an external
clock. It can also be used to select between Burst Mode
operation and pulse-skipping mode, or to enable spread
spectrum modulation to reduce EMI. The EN/UVLO pin
has an accurate 1V threshold and can be used to program
n
n
<6µA I
Q
n
<20mV Output Ripple
P-P
n
n
n
Synchronous Operation for High Efficiency
Monolithic 40V, 240mΩ Power Switches
100% Duty Cycle PassThru™ Mode for Boost
Preregulation Applications
n
n
n
n
n
n
n
n
Adjustable and Synchronizable: 300kHz to 3MHz
Spread Spectrum for Reduced EMI/EMC Emissions
Accurate EN/UVLO
Internal Compensation
20MΩ Internal Feedback Divider
Output Voltage Up to 40V
Available in 10-Lead MSOP Package
AEC-Q100 Automotive Qualification in Progress
V
UVLO or to shut down the part. The LT8338 enters
IN
100% duty cycle PassThru mode when V is higher than
IN
the regulated V
The LT8338 also features frequency
OUT.
foldback and internal soft-start for inductor current con-
trol during start-up.
All registered trademarks and trademarks are the property of their respective owners.
APPLICATIONS
n
Industrial and Automotive Power Supplies
Battery-Powered Systems
n
n
General Purpose Step-Up
TYPICAL APPLICATION
8V to 16V Input, 36V Output Micropower Synchronous Boost Converter
Efficiency
ꢀ0ꢁꢂ
ꢀ00
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
0
ꢀ
ꢀ
ꢀ
ꢀ
0
ꢀ
ꢁꢂ
ꢃꢄꢀ ꢅꢆ ꢇꢈꢀꢉ
0.ꢀꢁꢂ
ꢀ.ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁꢂ
ꢀꢁꢁꢂꢃꢂꢀꢄꢃꢅ
ꢁꢂ
ꢀꢁ0ꢂꢃ ꢃꢄ ꢅꢆ ꢆ
ꢇꢈ
1MΩ
ꢀꢁ0ꢂꢃ ꢃꢄ ꢅꢆꢇ ꢇ
ꢈꢉ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢄꢅꢆꢀꢇ
ꢁꢂꢃ
ꢁꢂꢃ
ꢀ.ꢁꢂꢃ
ꢀꢁꢂꢃ
ꢀꢁꢂꢃꢃꢂ
ꢀ
ꢀ
ꢀ
ꢃ ꢄꢀ
ꢃ ꢄꢅꢀ
ꢃ ꢄꢅꢀ
ꢁꢂ
ꢁꢂ
ꢁꢂ
ꢀꢁꢂꢃꢄꢅꢆꢇꢈ
ꢀꢁꢂꢃ
ꢄꢄ
ꢀ.ꢀꢁꢂ
Rꢀ
ꢀꢁꢂ
ꢀꢁRꢂ
ꢀ0ꢁꢂ
ꢀ0.ꢁꢂ
ꢁ.ꢁ0ꢃꢄꢅ
ꢀꢁꢂꢃR ꢄꢁꢅꢅ
0.0ꢀꢁꢂ
1MΩ
ꢀ
ꢀ0
ꢀ00
ꢀꢁ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
ꢀꢁꢂꢃ ꢄꢅRRꢆꢇꢈ ꢉꢊꢂꢋ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
Rev. 0
1
Document Feedback
For more information www.analog.com
LT8338
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Note 1)
V , V , EN/UVLO, SW ..........................................40V
IN OUT
SYNC/MODE ..............................................................6V
ꢊꢌꢙ ꢅꢆꢔꢋ
CTRL Above INTV ................................................0.3V
CC
ꢅ
ꢀ
ꢁ
ꢂ
ꢃ
ꢄ
ꢀ0 ꢆꢇꢊꢅ
ꢒꢒ
ꢆꢇ
ꢈꢉꢊ
ꢉꢋ
ꢉꢋ
ꢎ
ꢏ
ꢐ
ꢑ
ꢒꢊRꢓ
RT .....................................................................(Note 2)
ꢚꢇꢘ
ꢀꢀ
ꢔꢇꢕꢍꢅꢓꢌ
Rꢊ
INTV ..............................................................(Note 2)
CC
ꢅ
ꢉꢖꢇꢒꢕꢗꢌꢘꢔ
ꢌꢍꢊ
BST Above SW ..................................................(Note 2)
Operating Junction Temperature Range (Notes 2, 3)
LT8338E ............................................ –40°C to 125°C
LT8338J............................................. –40°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
ꢗꢉꢔ ꢙꢛꢒꢜꢛꢚꢔ
ꢀ0ꢝꢓꢔꢛꢘ ꢙꢓꢛꢉꢊꢆꢒ ꢗꢉꢌꢙ
θ
ꢟ ꢃ0ꢠꢒꢕꢋ
ꢞꢛ
ꢔꢡꢙꢌꢉꢔꢘ ꢙꢛꢘ ꢢꢙꢆꢇ ꢀꢀꢣ ꢆꢉ ꢚꢇꢘꢤ ꢗꢍꢉꢊ ꢈꢔ ꢉꢌꢓꢘꢔRꢔꢘ ꢊꢌ ꢙꢒꢈ
ORDER INFORMATION
LEAD FREE FINISH
LT8338EMSE#PBF
LT8338JMSE#PBF
TAPE AND REEL
PART MARKING*
LTHGQ
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT8338EMSE#TRPBF
LT8338JMSE#TRPBF
10-Lead Plastic MSOP
10-Lead Plastic MSOP
–40°C to 125°C
–40°C to 150°C
LTHGQ
Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
Rev. 0
2
For more information www.analog.com
LT8338
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VOUT = 36V, CTRL = 2.0V, EN/UVLO = 12V, INTVCC = 2.2µF to
GND, RT = 40.2kΩ to GND, BST = 0.1µF to SW and SYNC/MODE is tied to GND.
PARAMETER
CONDITIONS
MIN
TYP
MAX
40
1
UNITS
V
l
V
V
Operating Voltage
3.0
IN
IN
Quiescent Current (Note 5)
EN/UVLO = 0V (Shutdown Mode)
EN/UVLO = 2V, SYNC/MODE = 0V,
Not Switching, V –V = +100mV
(Burst Mode Operation)
0.1
6
µA
18
µA
OUT IN
EN/UVLO = 2V, SYNC/MODE = 0V,
12
35
µA
µA
Not Switching, V –V < –100mV
OUT IN
(PassThru Mode)
EN/UVLO = 2V, SYNC/MODE = 2.6V
(Pulse-Skipping Mode + SSFM)
1200
1500
l
l
l
l
V
Regulation (Note 6)
V
V
V
= 3.3V, CTRL = 0.5V (D = 33.33%)
= 9V, CTRL = 1.0V (D = 50%)
8.8
9.00
18.00
36.00
41.4
9.2
V
V
OUT
IN
IN
IN
17.8
35.6
40.2
18.2
36.4
= 24V, CTRL = 2.0V (D = 66.67%)
V
V
V
Limit Threshold Voltage (Note 6)
V
OUT
OUT
I in Shutdown
Q
EN/UVLO = 0V
5
µA
l
l
l
EN/UVLO Threshold Voltage
EN/UVLO Falling
0.975
1.000
50
1.025
V
EN/UVLO Rising Hysteresis
EN/UVLO = 2V
mV
nA
EN/UVLO Input Bias Current
–40
40
INTV Regulation Voltage
2.56
2.6
2.64
0.02
0.04
18.15
V
CC
INTV Line Regulation
3V ≤ V ≤ 40V
%/V
%/mA
V/V
MΩ
nA
CC
IN
INTV Load Regulation
1µA ≤ I
≤ 10mA
CC
INTVCC
V
V
-to-CTRL Divider Ratio (Note 6)
OUT
Internal Divider Resistance
OUT
9V ≤ V
≤ 36V
17.85
18.00
20
OUT
CTRL Pin Input Current
Switching Frequency
–20
270
1.05
2.00
0.3
20
l
l
l
R = 301k
T
300
1.15
2.20
335
1.25
2.40
3.0
kHz
MHz
MHz
MHz
R = 80.6k
T
R = 40.2k
T
SYNC Function Input Frequency Range
Spread Spectrum Frequency Range
SYNC/MODE = External Clock
Range = (f
/f
• 100% SYNC/MODE = INTV
+14
10
%
kHz
V
SW(SPREAD-ON) SW(SPREAD-OFF)-1)
CC
Spread Spectrum Modulation Frequency
SYNC Function Input Low Threshold Voltage
SYNC Function Input High Threshold Voltage
SYNC/MODE Pin Voltage
SYNC/MODE Pulse Falling
SYNC/MODE Pulse Rising
SYNC/MODE = Floating
0.8
2.0
V
1.3
V
Rev. 0
3
For more information www.analog.com
LT8338
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VOUT = 36V, CTRL = 2.0V, EN/UVLO = 12V, INTVCC = 2.2µF to
GND, RT = 40.2kΩ to GND, BST = 0.1µF to SW and SYNC/MODE is tied to GND.
PARAMETER
CONDITIONS
MIN
30
TYP
MAX
UNITS
ns
SYNC/MODE Pulse Width High
SYNC/MODE Pulse Width Low
Bottom Switch Current Limit
Bottom Switch Minimum Off-Time
Bottom Switch Minimum On-Time
Bottom Switch On-Resistance
Top Switch Current Limit (Note 7)
Top Switch On-Resistance
Synchronization Mode
Synchronization Mode
30
ns
l
1.2
1.4
1.6
50
80
A
ns
ns
240
1.6
mΩ
A
PassThru Mode
1.3
1.9
240
mΩ
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 4: These ICs include overtemperature protection that is intended to
protect the device during momentary overload conditions. The maximum
rated junction temperature will be exceeded when this protection is active.
Continuous operation above the specified absolute maximum operating
junction temperature may impair device reliability or permanently damage
the device.
Note 2: Do not drive these pins.
Note 3: The LT8338E is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT8338J is guaranteed over the full –40° to 150°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes; operating lifetime is derated for junction temperatures of greater
than 125°C.
Note 5: The V Quiescent Current specifications include the 2.6µA current
IN
implied by the specified R
= 1M resistor.
INTVCC
Note 6: V
regulation is tested in a servo loop.
OUT
Note 7: Top Switch Current Limit prevents the bottom switch from turning
on until the switch current has dropped below the limit.
Rev. 0
4
For more information www.analog.com
LT8338
TYPICAL PERFORMANCE CHARACTERISTICS
EN/UVLO Thresholds
vs Temperature
INTVCC Voltage vs Temperature
Output Voltage vs Temperature
ꢀꢁ.ꢂ
ꢀꢁ.ꢂ
ꢀꢁ.ꢀ
ꢀꢁ.ꢂ
ꢀꢁ.ꢂ
ꢀꢁ.0
ꢀꢁ.ꢂ
ꢀꢁ.ꢂ
ꢀꢁ.ꢂ
ꢀꢁ.ꢂ
ꢀꢁ.ꢁ
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢀ
ꢀ.ꢁꢂ
ꢀ.ꢁ0
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢁ
ꢀ0ꢁ0
ꢀ0ꢁ0
ꢀ0ꢁ0
ꢀ0ꢁ0
ꢀ0ꢁ0
ꢀ0ꢀ0
ꢀ000
ꢀꢀ0
ꢀ
ꢃ ꢄꢅꢀ
ꢀ
ꢃ ꢄꢅꢀ
ꢁꢂ
ꢁꢂ
ꢀ
ꢃ ꢄꢅꢀ
ꢁꢂ
ꢀ
ꢁꢂꢃꢄꢅꢆꢇꢅꢇ
ꢁꢂꢃꢄꢅꢆꢇꢅꢈ
ꢀ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢁꢀ ꢂ0ꢁ
ꢀꢁꢁꢀ ꢂ0ꢃ
ꢀꢁꢁꢀ ꢂ0ꢃ
Burst Mode Switching Frequency
vs Load Current
Switching Frequency
vs Temperature
Switching Frequency vs
Temperature
ꢀ
ꢀ.ꢁ0
ꢀ.ꢀꢁ
ꢀ.ꢀꢁ
ꢀ.ꢀꢁ
ꢀ.ꢀꢀ
ꢀ.ꢀ0
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢀ
ꢀ.ꢁ0
ꢀ0ꢁ
ꢀ0ꢁ
ꢀ0ꢀ
ꢀ0ꢁ
ꢀ0ꢁ
ꢀ00
ꢀꢁꢁ
ꢀꢁꢂ
ꢀꢁꢂ
ꢀꢁꢂ
ꢀꢁꢂ
ꢀ
ꢄ ꢅꢆꢀ ꢇ ꢄ ꢈ0ꢉꢊ
R
T
= 40.2kΩ
ꢁꢂꢃ
R = 301kΩ
T
ꢀ
0.ꢀ
ꢀ
ꢀ
ꢀ
ꢃ ꢄꢅꢀ
ꢃ ꢄꢅꢀ
ꢃ ꢄꢅꢀ
ꢁꢂ
ꢁꢂ
ꢁꢂ
0.0ꢀ
ꢀ
ꢀ0
ꢀ00
ꢀ00
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢂꢃ ꢄꢅRRꢆꢇꢈ ꢉꢊꢂꢋ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢁꢀ ꢂ0ꢃ
ꢀꢁꢁꢀ ꢂ0ꢃ
ꢀꢁꢁꢀ ꢂ0ꢃ
Switching Frequency vs
Temperature
Burst Mode Efficiency
vs Inductor Value
No-Load VIN Current
vs Temperature, VIN
ꢀ00.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
0
ꢀ.ꢁ0
ꢀ.0ꢁ
ꢀ.0ꢁ
ꢀ.0ꢁ
ꢀ.0ꢁ
ꢀ.00
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢂ
ꢀ.ꢁꢀ
ꢀ.ꢁ0
ꢀ00
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
0
R
T
= 28.7kΩ
ꢀ
ꢀ
ꢀ
ꢀ ꢁꢂ ꢄ ꢃ
ꢀ ꢁꢂꢃ
ꢀ ꢁꢂꢃ
ꢀ ꢁꢂꢃ
ꢀꢁ
ꢀꢁ
ꢀꢁ
ꢀꢁꢂ
ꢀ ꢁꢂ ꢄ ꢃ
ꢀꢁꢂ
ꢀ ꢁꢂ ꢄ ꢃ
ꢀꢁꢂ
ꢀ
ꢀ
ꢀ
ꢄ ꢅꢆꢇ
ꢁꢂꢃ
ꢁꢂꢃ
ꢁꢂꢃ
ꢄ ꢅ0ꢆꢇ
ꢄ ꢅ00ꢆꢇ
ꢀ
ꢃ ꢄꢅ ꢆ ꢀ
ꢃ ꢊꢋ ꢆ ꢌ ꢀꢁ.ꢁꢂꢃꢄ
ꢇꢈꢉ ꢀꢁ
ꢁꢂ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀ
ꢀ0
ꢀꢁꢂꢃꢄꢅꢆR ꢇꢈꢉꢊ
ꢀ00
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢁꢀ ꢂ0ꢃ
ꢀꢁꢁꢀ ꢂ0ꢃ
ꢀꢁꢁꢀ ꢂ0ꢀ
Rev. 0
5
For more information www.analog.com
LT8338
TYPICAL PERFORMANCE CHARACTERISTICS
Power Switch Current Limit
vs Temperature
Bottom Switch On-Resistance
vs Temperature
Bottom Switch Minimum On-Time
vs Temperature
ꢀ.ꢁ0
ꢀ.ꢁꢁ
ꢀ.ꢁ0
ꢀ.ꢁꢂ
ꢀ.ꢁ0
ꢀ.ꢁꢂ
ꢀ.ꢁ0
ꢀ.ꢁꢂ
ꢀ.ꢁ0
ꢀ00
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
0
ꢀ00
ꢀꢁ0
ꢀ00
ꢀꢁ0
ꢀ00
ꢀꢁ0
ꢀ00
ꢀꢁ0
ꢀ00
ꢀ0
0
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢁꢀ ꢂꢃ0
ꢀꢁꢁꢀ ꢂꢃꢄ
ꢀꢁꢁꢀ ꢂꢃꢃ
Bottom Switch Minimum Off-Time
vs Temperature
Switch Waveforms
(In CCM)
Switching Waveforms
(In Light Burst Mode Operation)
ꢀ00
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
0
ꢀ
ꢀ
ꢀ00ꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢀ00ꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢀꢁ
ꢀ0ꢁꢂꢃꢄꢁ
ꢀꢁ
ꢀ0ꢁꢂꢃꢄꢁ
ꢀꢁꢁꢀ ꢂꢃꢄ
ꢀꢁꢁꢀ ꢂꢃꢄ
ꢀ00ꢁꢂꢃꢄꢅꢆ
ꢀ00ꢁꢂꢃꢄꢅꢆ
ꢀꢁꢁ ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁ
ꢀꢁ ꢀꢁꢂ ꢀꢁꢁ
ꢀꢁꢂꢃꢁRꢄꢀꢅRꢁ ꢆꢇꢈꢉ
ꢀꢁꢁꢀ ꢂꢃꢁ
Switching Waveforms
(In Sleep Mode)
Switching Waveforms
(VIN Approaching VOUT
)
Start-Up Waveforms
ꢀ
ꢁ
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ꢀ
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ꢀ00ꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢀ00ꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀꢁ
ꢀ
ꢀꢁ
ꢀ0ꢁꢂꢃꢄꢁ
ꢀ
ꢀꢁ
ꢀ0ꢁꢂꢃꢄꢁ
ꢀ0ꢁꢂꢃꢄꢁ
ꢀꢁꢁꢀ ꢂꢃꢀ
ꢀꢁꢁꢀ ꢂꢃꢄ
ꢀꢁꢁꢀ ꢂꢃꢄ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀ
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ꢀ ꢁꢂ ꢄ ꢅ
ꢀ ꢁ00ꢂꢃ
ꢀꢁꢂꢃ
ꢀꢁ
ꢀꢁꢂ
Rev. 0
6
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LT8338
TYPICAL PERFORMANCE CHARACTERISTICS
Load Step Response
Load Step Response
(Burst Mode Operation)
(Pulse-Skipping Mode)
ꢀ
ꢀ
ꢁꢂꢃꢄ
ꢅ00ꢆꢃꢇꢄꢀꢈ
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ꢀ
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ꢂ00ꢃꢄꢅꢆꢀꢇ
ꢀ
ꢀ
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ꢁꢂꢃ
ꢄ00ꢅꢀꢆꢇꢈꢀ
ꢀ
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ꢁꢂꢃꢀꢄꢄ
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ꢀꢁꢁꢀ ꢂꢃꢄꢅ0
ꢀꢁꢁꢀ ꢂꢃꢄ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀꢁꢂꢃꢄꢅꢆ
PIN FUNCTIONS
IN
a low ESR ceramic capacitor of 0.1µF or greater. Place the
capacitor as close to the pin as possible.
V (Pin 1): Input Supply Pin. Bypass this pin to GND with
Pulse-Skipping = Skipped pulse(s) at light load (aligned to clock)
SYNC = Switching frequency synchronized to external clock
SSFM = Spread Spectrum Frequency Modulation for low EMI
RT (Pin 7): Switching Frequency Set Pin. Set the switch-
ing frequency with a resistor between this pin and GND.
Do not leave this pin open. In frequency synchronization
BST (Pin 2): Top Switch Gate Driver Supply Pin. Tie a 0.1µF
capacitor between BST and SW as close as possible to the
pins to keep the trace length short.
mode, use a resistor R to program the frequency the
T
same as the synchronization signal.
SW (Pins 3, 4): Switch Node. Connect this pin to inductor,
and to the boost capacitor. SW is a high dV/dt node that
should be kept as compact as possible and away from high
impedance nodes.
EN/UVLO (Pin 8): Enable and Input Undervoltage
Lockout Pin. The LT8338 is shut down when this pin is
below 1V (typ), and is enabled when this pin is above
1.05V (typ). A resistor divider from V to GND pro-
V
(Pin 5): Output Voltage Pin. Bypass this pin to GND
IN
OUT
grams a V threshold below which the LT8338 is shut
with a low ESR ceramic capacitor of 4.7µF or greater. Place
the capacitor as close to the pin as possible. Additional
capacitance as required by specific applications must be
similarly closely placed. See the Applications and Physical
Layout sections for details. An 18:1 internal resistive
voltage divider provides feedback sensing of the output
voltage to the error amplifier.
IN
down. Tying this pin to GND shuts down operation and
reduces quiescent supply current to 0.2µA (max). Tie to
V if the shutdown feature is not used.
IN
CTRL (Pin 9): Reference Input Pin. Tie the tap point of
a resistive voltage divider between INTV and GND to
CC
this pin to set the error amplifier reference input to 1/18
of the desired system output voltage.
SYNC/MODE (Pin 6): External Synchronization Input and
Light Load Operation Mode Selection Pin. This pin allows
five selectable modes for optimization of performance.
INTV (Pin 10): Internal 2.6V Regulator Pin. Bypass
CC
this pin to GND with a low ESR ceramic capacitor of
2.2µF or greater. Place the capacitor as close to the pin
SYNC/MODE PIN INPUT
(1) GND or <0.14V
CAPABLE MODE(S) OF OPERATION
Burst
as possible. Set the output voltage (V ) by program-
OUT
ming the CTRL pin voltage via a resistive voltage divider
(2) 100k Resistor to GND
(3) Float (Pin Open)
Burst/SSFM
between INTV and GND. Use a minimum total resis-
CC
Pulse-Skipping
tance of 1M to keep the divider’s contribution to the V
quiescent current to 2.6µA in shut down.
IN
(4) INTV or >2.0V
Pulse-Skipping/SSFM
Pulse-Skipping/SYNC
CC
(5) External Clock
GND (Pin 11): Ground Pin. Connect this pin to system
where the selectable modes of operation are:
ground and to the ground plane to achieve the best ther-
Burst = Low I , low output ripple operation at light loads
Q
mal performance.
Rev. 0
7
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LT8338
BLOCK DIAGRAM
ꢄ
ꢊ
ꢊ
ꢖ
ꢄꢈ
ꢄꢈꢅꢖ
ꢆꢆ
ꢆꢗ
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ꢆꢘ
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ꢕꢂꢅ
ꢂꢃ
ꢆꢆ
ꢕꢉꢜRꢍꢏꢠ
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ꢁ
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Rꢗ
Rꢘ
Rꢍꢂꢍꢅ
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ꢘꢗ ꢦ R
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R
R
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ꢏꢕꢜꢚ
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ꢑꢍꢅꢍꢆꢅ
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Rꢚ
ꢆꢅRꢊ
ꢁ
Rꢅ
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Rꢎꢔꢒ
ꢉꢍꢈꢍRꢎꢅꢋR
ꢍꢎ
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Rꢙ
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R
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ꢂꢋꢏꢅꢐꢂꢅꢎRꢅ
ꢀꢁꢁꢀ ꢂꢃ
Rev. 0
8
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LT8338
OPERATION
If the EN/UVLO pin is lower than 0.3V, the LT8338 is
shut down and draws < 0.2μA from the input. When the
EN/UVLO pin is above 1.05V, the switching regulator
becomes active.
The LT8338 is a synchronous boost converter that uses a
fixed frequency, current mode control scheme to provide
excellent line and load regulation. Referring to the Block
Diagram, the Switching Logic and Charge Pump block
turns on the power switch MBOT through driver G1 at the
The LT8338 can be configured to work in different modes
by setting SYNC/MODE pin. If the SYNC/MODE pin is tied
to ground directly, the LT8338 provides low output ripple
Burst Mode operation with ultralow quiescent current
at light loads. Connecting SYNC/MODE pin to ground
througha100kresistorenablesBurstModeoperationwith
frequency spread spectrum modulation (see Frequency
Spread Spectrum Modulation section). When Burst Mode
operation is selected, all circuitries associated with con-
trolling the output switches are shut down to reduce the
quiescent current between bursts. When SYNC/MODE pin
is floated, the LT8338 operates in pulse-skipping mode,
which reduces output ripple compared to Burst Mode
operationandincreasesthequiescentcurrenttohundreds
start of each oscillator cycle. The inductor current I flows
L
throughMBOT, whosecurrentsensingsignalisaddedtoa
stabilizingslopecompensationrampandtheresultingsum
is fed into the positive terminal of the PWM comparator
A1. The level at the negative input of A1, labeled “V ”, is
C
set by the error amplifier EA and is an amplified version
of the difference between the feedback voltage (from the
internal voltage divider) and the reference voltage (from
CTRL pin). During the MBOT-on phase, I increases.
L
When the signal at the positive input of A1 exceeds V ,
C
A1 sends a signal to turn off MBOT. When MBOT turns
off, the synchronous power switch MTOP turns on until
the next clock cycle begins or inductor current I falls to
L
zero.Ifoverloadconditionsresultinexcesscurrentflowing
throughthetopswitch,thenextclockcyclewillbedelayed
until switch current returns to a safe level. Through this
of microamps. Connecting the SYNC/MODE pin to INTV
CC
selects pulse-skipping operation with spread spectrum
modulation enabled. Spread spectrum modulation varies
the switching frequency to reduce EMI. When the SYNC/
MODE pin is driven by an external clock, the converter
switching frequency is synchronized to that clock and
pulse-skipping mode is enabled.
repetitive action, the EA sets the correct I peak current
level to keep the output voltage in regulation.
L
Rev. 0
9
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LT8338
APPLICATIONS INFORMATION
Programming V Turn-On and Turn-Off Thresholds
high transient currents required by the power MOSFET
IN
with the EN/UVLO Pin
gate drivers. Applications with high V voltage and high
IN
switching frequency will increase die temperature due to
The LT8338 is in shutdown when the EN/UVLO pin is
low. The falling threshold of the EN comparator is 1V,
with 50mV of hysteresis. The EN pin can be tied to V if
the shutdown feature is not used, or tied to a logic level
if shutdown control is required. The LT8338 draws very
low shutdown quiescent current (0.2µA typ) When EN/
UVLO is below 0.3V.
the higher power dissipation across the LDO. The INTV
CC
falling threshold (to stop switching and reset soft-start)
IN
is typically 2.2V, and the rising threshold is 2.3V. Do not
connect an external load to the INTV pin.
CC
Achieving Ultralow Quiescent Current
When LT8338 is set for Burst Mode operation to enhance
efficiency at light loads, the minimum peak inductor cur-
Adding a resistor divider from V to EN/UVLO programs
IN
the LT8338 to regulate the output only when V is above
IN
rent is set to approximately 300mA even though V node
C
a desired voltage. Typically, this threshold, VIN(EN), is used
in situations where the input supply is current limited, or
has a relatively high source resistance. A switching reg-
ulator draws constant power from the source, so source
current increases as source voltage drops. This looks like
a negative resistance load to the source and can cause
the source to current limit or latch low under low source
voltage conditions. The VIN(EN) threshold prevents the
regulator from operating at source voltages where the
problems might occur. This threshold can be adjusted by
setting the values R3 and R4 (refer to the Block Diagram)
such that they satisfy Equation 1.
indicates a lower value (refer to the Block Diagram). In
Burst Mode operation, the LT8338 delivers single pulses
of current to the output capacitor followed by sleep peri-
ods where the output power is supplied by the output
capacitor. That is, at light load condition, the LT8338
maintains the output regulation voltage by reducing the
switching frequency instead of reducing the inductor peak
current.
As the output load decreases, the frequency of single cur-
rent pulses decreases (see Figure 1) and the percentage of
time the LT8338 is in sleep mode increases, resulting in
much higher light load efficiency than typical converters.
By maximizing the time between pulses, the converter
quiescent current approaches 6μA for a typical application
when there is no output load. In addition, if high light load
efficiency is desired, a larger inductor value should be
chosen. See the Burst Mode Efficiency vs Inductor Value
curve in the Typical Performance Characteristics.
(R3+R4)
V
= 1V •
IN,FALLING
R3
(1)
(R3+R4)
R3
V
= 40mV •
+ V
IN,FALLING
IN,RISING
When operating in Burst Mode operation for light load
applications, the current through the R3 and R4 resis-
tor network can easily be greater than the supply current
consumed by the LT8338. Therefore, R3 and R4 should
be large to minimize their effect on efficiency at low loads.
ꢀ
ꢀ
ꢀ ꢁꢂ ꢄ ꢅ ꢀ ꢆ0ꢇꢈ
ꢀꢁꢂ
ꢀ
0.ꢀ
INTV Regulator
CC
An internal low dropout (LDO) regulator produces the
2.6V supply from VIN that powers the drivers and the
internal bias circuitry. INTVCC can supply enough cur-
rent for the LT8338’s circuitry and must be bypassed
to ground with a minimum of 2.2μF low ESR ceramic
capacitor. Good bypassing is necessary to supply the
0.0ꢀ
0.00ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢃ ꢄꢀ
ꢁꢂ
ꢁꢂ
ꢁꢂ
ꢁꢂ
ꢁꢂ
ꢃ ꢄꢀ
ꢃꢄꢅꢀ
ꢃ ꢄꢅꢀ
ꢃ ꢄꢅꢀ
ꢀ
ꢀ0
ꢀ00
ꢀꢁ
ꢀꢁꢂꢃ ꢄꢅRRꢆꢇꢈ ꢉꢊꢂꢋ
ꢀꢁꢁꢀ ꢂ0ꢃ
Figure 1. Burst Mode Frequency vs Load
Rev. 0
10
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LT8338
APPLICATIONS INFORMATION
While in Burst Mode operation (Figure 2), the current
limit of the bottom switch is approximately 300mA (as
shown in Switching Waveforms in Burst Mode Operation
in Typical Performance Characteristics), resulting in larger
output voltage ripple comparing to that in pulse-skipping
mode operation. Increasing the output capacitance will
decrease output ripple proportionally. As the load ramps
upward from zero, the switching frequency increases until
The LT8338 uses a constant-frequency architecture that
can be programmed over a 300kHz to 3MHz range with
a single external resistor from the RT pin to ground, as
shown in the Block Diagram.
Table 1 gives some specific examples of RT values for
specific switching frequencies.
Table 1. SW Frequency (fSW) vs RT Value
reaching the switching frequency programmed by the R
f
(MHz)
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
R (kΩ)
f
(MHz)
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
R (kΩ)
SW
T
SW
T
T
resistor. The output load at which the LT8338 reaches the
programmed frequency varies based on input voltage,
output voltage, and inductor choice.
301
226
182
154
133
118
102
93.1
84.5
76.8
71.5
64.9
60.4
56.2
52.3
49.9
46.4
44.2
42.2
40.2
38.3
36.5
34.8
33.2
32.4
30.9
29.4
28.7
ꢀ
ꢀ
ꢀ00ꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀꢁ
ꢀ0ꢁꢂꢃꢄꢁ
ꢀꢁꢁꢀ ꢂ0ꢃ
ꢀꢁꢂꢃꢄꢅꢆ
Figure 2. Burst Mode Operation Waveforms
For some applications it is desirable for the LT8338 to
operate in pulse-skipping mode. Pulse-skipping mode
operation offers two major differences from Burst Mode
operation. First the clock stays awake at all times and all
switching cycles are aligned to the clock. In this mode
much of the internal circuitry is awake at all times, increas-
ing quiescent current to thousand μA (compared to 6μA
quiescent current in Burst Mode operation). Secondly
pulse-skipping mode operation exhibits lower output
ripple as well as lower audio noise and RF interference.
The operating frequency of the LT8338 can be synchro-
nized to an external clock source. By providing a clock
signal into the SYNC/MODE pin, the LT8338 operates
at the SYNC pulse frequency and automatically enters
pulse-skipping mode operation at light load. If this feature
is used, an R resistor should be chosen to program a
T
switching frequency equal to, or slightly less than the
SYNC pulse frequency. For example, if the synchroniza-
tion signal is 500kHz or higher, the R should be selected
T
for 500kHz. The slope compensation is set by the RT
value, while the minimum slope compensation required
to avoid subharmonic oscillations is established by the
inductor size, input voltage, and output voltage. Since
the synchronization frequency will not change the slope
of the inductor current waveform, if the inductor is large
enough to avoid subharmonic oscillation at the frequency
Operating Frequency and Synchronization
The choice of operating frequency is a trade-off between
efficiency and component size. Low frequency operation
improves efficiency by reducing the power switches’
switching losses and gate drive current. However, lower
frequency operation requires a physically larger inductor.
set by R , then the slope compensation will be sufficient
T
for all synchronization frequencies.
Rev. 0
11
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LT8338
TYPICAL APPLICATIONS
The input synchronization clock signal can be square
wave, triangle wave, or sinusoidal wave. The input signal
should have valleys that are below 1V and peaks above 2V.
The minimum duration time that the input signal ampli-
tude stays higher than the 2V threshold and lower than
the 0.8V threshold, should be no less than 30ns.
V to V
PassThru Mode Operation
IN
OUT
When V rises above the regulated V
voltage pro-
OUT
IN
grammed by the CTRL pin voltage, the LT8338 boost con-
verter enters PassThru operation, where the synchronous
power switch MTOP (refer to the Block Diagram) is kept
on continuously and power switch MBOT is kept off con-
tinuously. An internal charge pump circuit is activated to
deliver sufficient current to the boost capacitor (CBST)
to maintain the MTOP’s gate drive voltage. In PassThru
Frequency Spread Spectrum Modulation
The LT8338 features spread spectrum operation to further
reduce EMI/EMC emissions. The user can select frequency
spectrum modulation with Burst Mode operation by con-
necting the SYNC/MODE pin to ground through a 100k
resistor, or frequency spread modulation with pulse-skip-
ping operation by connecting the SYNC/MODE pin to
mode V
is essentially shorted to V by the inductor
OUT
IN
and power switch. When V falls below V
voltage, or
IN
OUT
the inductor conducts more than 300mA current from
V
V
to V , LT8338 exits PassThru mode operation. If
OUT
OUT
IN
is lower than the desired voltage, the normal boost
INTV . When frequency spectrum modulation is selected
switching operation resumes.
CC
and the converter operates at heavy load, the triangu
-
lar frequency modulation varies the switching frequency
Switching Frequency Foldback when V
Approaches V
IN
between the value programmed by R to approximately
T
OUT
14% higher than that value. The modulation frequency
is approximately 0.42% of the switching frequency. For
example, when the LT8338 is programmed to 2MHz, the
frequency will vary from 2MHz to 2.3MHz at a 9kHz rate.
When operating at light load, frequency spread spectrum
modulation is more effective in pulse-skipping mode than
in Burst Mode operation, due to the fact that pulse-skip-
ping operation maintains the switching frequency with
spread spectrum down to a much lower load current com-
pared to Burst Mode operation.
In some boost applications, V may rise to a voltage very
IN
close to V . When this occurs, the switching regulator
OUT
must operate at very low duty cycle to keep V
in reg-
OUT
ulation. However, the minimum on-time limitation may
prevent the switcher from attaining a sufficiently low duty
cycle at the programmed switching frequency; as a result
a typical boost converter may experience a large output
ripple. LT8338 addresses this issue by adopting a switch-
ing frequency foldback function to smoothly decrease the
switching frequency when its minimum on-time starts
to limit the switcher from attaining a sufficiently low
duty cycle. The typical switching waveforms when VIN
CTRL Resistor Network
The output voltage is internally set as shown in Equation 2.
approaches V
are shown in the Typical Performance
OUT
Characteristics section.
V
OUT
= V
• 18
(2)
CTRL
Typically, the CTRL pin voltage is programmed with a
Soft-Start
resistor divider between the INTV and ground (refer to
CC
High peak switch currents during start-up may occur
the Block Diagram).
in switching regulators. Since V
is far from its final
value, the feedback loop is satuOraUtTed and the regulator
tries to charge the output capacitor as quickly as possible,
resulting in large peak currents. A large surge current may
cause inductor saturation or power switch failure.
1% resistors are recommended to maintain output voltage
accuracy. The current flowing in the divider acts as a load
current of the internal LDO and will increase the no-load
input current to the converter. If low input quiescent cur-
rent and good light-load efficiency are desired, use large
resistor values for the CTRL resistor divider.
The LT8338 utilizes a soft-start function to limit peak
switch currents and output voltage (VOUT) overshoot
during start-up or recovery from a fault condition to
Rev. 0
12
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LT8338
APPLICATIONS INFORMATION
ꢀ
prevent damage to external components or the load.
As shown in the Block Diagram, the soft-start function
controls the ramp of the power switch current by con-
trolling the ramp of VC through Q1. This allows the output
capacitor to be charged gradually toward its final value
while limiting the start-up peak currents. The typical
start-up waveforms are shown in the Typical Performance
Characteristics section.
ꢀ
ꢀ
ꢁꢂ
ꢀꢁ
ꢀ
ꢀꢁ
ꢁꢂ
ꢀ
ꢀ
ꢁꢂꢃ
ꢁꢂꢃ
ꢀꢁ
ꢀꢁꢂꢃꢃꢂ
ꢀꢁꢂ
Hot Plug
ꢀꢁꢁꢀ ꢂ0ꢁ
If the LT8338 boost converter is plugged into a live sup-
ply, VOUT can ring to twice the VIN voltage due to the
resonant circuit composed by L, C2, and the body diode
of MTOP (refer to the Block Diagram). If such overshoot
Figure 3. A Simplified LT8338 Power Stage with a
Diode Added Between VIN and VOUT
exceeds the V
rating, it needs to be limited to protect
OUT
maximum duty cycles of the converter (see Minimum
On-Time, Minimum Off-Time, and Switching Frequency
in the Electrical Characteristics table) as:
the load and the converter. In these conditions, a small
diode (Schottky diode or silicon diode) can be connected
between V and V
to deactivate the resonant circuit
IN
OUT
Minimum Allowable Duty Cycle =
and limit V
overshoot as shown in Figure 3. With the
OUT
Minimum On-Time
• f
diode connected, the LT8338 boost is also more robust
against output fault conditions such as output short cir-
cuit or overload, due to the diode's ability to divert a great
amount of output current from the LT8338. The diode
can be rated for about one-half to one-fifth the full load
current since it only conducts current during start-up or
output fault conditions.
(MAX) OSC(MAX)
Maximum Allowable Duty Cycle =
1 – Minimum Off-Time
• f
(MAX) OSC(MAX)
The required switch duty cycle range for a boost converter
operating in continuous conduction mode (CCM) can be
calculated using Equation 3.
V
– V
IN(MAX)
OUT
D
=
Fault Protection
MIN
V
OUT
(3)
INTV undervoltage (INTV < 2.2V), or thermal lockout
CC
(TJ > 170°C) will immediaCteCly stop the converter from
V
– V
IN(MIN)
OUT
D
=
MAX
switching, pull down V and reset soft-start. Faults are
C
V
OUT
removed when INTV > 2.3V, and the die temperature
CC
If the above duty cycle calculations for a given appli-
cation violate the minimum and/or maximum allowed
duty cycles, operation in discontinuous conduction
mode (DCM) may provide a solution. For the same V and
has dropped down to 165°C or lower. Once all faults are
removed, the LT8338 will resume switching with a soft-
started V inductor peak current limiting.
C
In addition, converter will stop switching immediately
V
levels, operation in DCM does not demand asIlNow a
OUT
when V
overvoltage (V
> 41.4V) happens, and will
is lower than 40.6V.
OUT
OUT
OUT
duty cycle as in CCM. DCM also allows higher duty cycle
operation than CCM. The additional advantage of DCM is
the removal of the limitations to inductor value and duty
cycle required to avoid sub-harmonic oscillations and the
right half plane zero (RHPZ). While DCM provides these
resume switching once V
Duty Cycle Consideration
The LT8338 minimum on-time, minimum off-time and
switching frequency define the allowable minimum and
Rev. 0
13
For more information www.analog.com
LT8338
TYPICAL APPLICATIONS
benefits, the trade-off is higher inductor peak current,
lower available output power and reduced efficiency.
bulk capacitance may be necessary. This can be provided
with a low performance electrolytic capacitor.
The voltage rating of the input capacitor, C1, should com-
fortably exceed the maximum input voltage. Although
ceramic capacitors can be relatively tolerant of overvolt-
age conditions, aluminum electrolytic capacitors are not.
Be sure to characterize the input voltage for any possible
overvoltage transients that could apply excess stress to
the input capacitors.
Inductor Selection
The inductor peak-to-peak current ripple ∆ISW has a direct
effect on the choice of the inductor value, the converter’s
maximum output current capability, and the light load effi-
ciency in Burst Mode operation. Smaller values of ∆I
SW
increase output current capability and light load efficiency
in Burst Mode operation, but require large inductances
and reduces the current loop gain (the converter will
Output Capacitor Selection
approach voltage mode). Larger values of ∆I provide
SW
The output capacitor has two essential functions. First, it
filters LT8338’s discontinuous top switch current to pro-
duce the DC output. In this role it determines the output
ripple, and thus low impedance at the switching frequency
is important. The second function is to store energy in
order to satisfy transient loads and stabilize the LT8338’s
control loop. The X5R or X7R type ceramic capacitors
have very low equivalent series resistance (ESR), which
provides low output ripple and good transient response.
Transient performance can be improved with higher value
output capacitance. Increasing the output capacitance will
also decrease the output voltage ripple. Lower values of
output capacitance can be used to save space and cost
but transient performance will suffer and may cause
loop instability.
fast transient response and allow the use of low induc-
tances, but result in higher input current ripple and greater
core losses, reduce the light load efficiency in Burst Mode
operation, and reduce output current capability.
Given an operating input voltage range, and having cho-
sen the operating frequency and ripple current in the
inductor, the inductor value of the boost converter can
be determined using the following equation:
V
IN(MIN)
L =
• D
MAX
(4)
∆I • ƒ
SW
here the ripple current ∆I can be set to 0.2A as a good
starting point. The peakSiWnductor current is the switch
current limit (1.2A typical). The user should choose an
inductor having a sufficient saturation and RMS current
A 4.7μF ceramic capacitor is adequate for the LT8338 out-
2
put capacitor. This ceramic should be placed near to V
/
rating, and a low DCR to minimize I R power losses.
OUT
GND. See the Board Layout section for more details. Note
that larger output capacitance is required when a lower
switching frequency is used. When choosing a capacitor,
special attention should be given to capacitor’s data sheet
to calculate the effective capacitance under the relevant
operating conditions of voltage bias and temperature. A
physically larger capacitor or one with a higher voltage
rating may be required. For good starting values, refer to
the Typical Application section.
Input Capacitor Selection
Bypass the input of the LT8338 circuit with a ceramic
capacitor of type X7R or X5R. The value of the input bypass
capacitor is a function of the source impedance, and in
general, the higher the source impedance, the higher the
required input capacitance. The capacitor value depends
on the input current ripple as well. The input ripple current
in a boost converter is relatively low (compared with the
output ripple current) because this current is continuous.
A 2.2μF to 10μF ceramic capacitor is adequate to bypass
the LT8338 and will easily handle the ripple current. If the
input power source has high impedance or there is sig-
nificant inductance due to long wires or cables, additional
Board Layout
Figure 4 shows a recommended PCB layout. For more
details and PCB design files refer to the Demo Board guide
for the LT8338.
Rev. 0
14
For more information www.analog.com
LT8338
APPLICATIONS INFORMATION
vias; these layers spread heat dissipated by the LT8338.
Placing additional vias can reduce thermal resistance
further. The maximum load current should be derated
as the ambient temperature approaches the maximum
junction temperature rating. Power dissipation within the
LT8338 can be estimated by calculating the total power
loss from an efficiency measurement and subtracting the
inductor loss. The junction temperature can be calculated
by multiplying the total LT8338 power dissipation by the
thermal resistance from junction to ambient and adding
the ambient temperature. The LT8338 includes internal
overtemperature protection that is intended to protect
the device during momentary overload conditions. The
overtemperature protection triggers the internal soft-start
when junction temperature exceeds 170°C. The maximum
rated junction temperature is exceeded when this protec-
tion is active. Continuous operation above the specified
absolute maximum operating junction temperature (see
Absolute Junction Ratings section) may impair device
reliability or permanently damage the device.
The output capacitor, along with the inductor and input
capacitor, should be placed on the same side of the circuit
board, and their connections should be made on that layer.
Place a local, unbroken power ground plane under the
application circuit on the layer closest to the surface layer.
The SW and BST nodes should be as small as possible.
Keep the CTRL and R nodes small so that the ground
T
traces will shield them from the noise generated by the
SW and BST nodes. The exposed pad on the bottom of
the package should be soldered to GND to reduce ther-
mal resistance to ambient temperature. To keep thermal
resistance low, extend the power ground plane from GND
as much as possible and add thermal vias to additional
power ground planes within the circuit board and on the
bottom side.
Thermal Considerations
Care should be taken in the layout of the PCB to ensure
good heat sinking of the LT8338. The power ground
plane should consist of large copper layers with thermal
0ꢒ0ꢎ
0ꢒ0ꢎ
0ꢁ0ꢄ
0ꢒ0ꢎ
ꢀꢅ
ꢀꢆ
0ꢁ0ꢄ
Rꢅ
Rꢄ
ꢈ
ꢅ
ꢄ
ꢆ
ꢅ0ꢉꢊꢌꢈ
ꢉꢊ
ꢀꢀ
ꢇ
0ꢁ0ꢄ
0ꢁ0ꢄ
ꢀꢎ
ꢋꢂꢌ
ꢂꢍ
ꢑ
ꢒ
ꢀꢌRꢇ
Rꢁ
Rꢆ
0ꢁ0ꢄ
ꢀꢁ
ꢓꢊꢔ
ꢙꢊꢘ
ꢅꢅ
ꢐꢈꢇꢏ
0ꢁ0ꢄ
0ꢁ0ꢄ
ꢂꢍ
ꢈ
ꢁ
ꢎ
ꢕ
ꢖ
Rꢌ
R
ꢌ
ꢂꢗꢊꢀꢔ
ꢃꢏꢘꢓ
ꢏꢐꢌ
R
ꢂꢃ
0ꢁ0ꢄ
0ꢁ0ꢄ
0ꢒ0ꢎ
ꢀꢄ
ꢀꢁꢁꢀ ꢂ0ꢃ
Figure 4. A Recommended PCB Layout for the LT8338
Rev. 0
15
For more information www.analog.com
LT8338
TYPICAL APPLICATION
Efficiency
8V to 16V Input, 24V Output Boost Converter
ꢀ00
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
0
ꢀ
ꢀ0ꢁꢂ
ꢀ
ꢁꢂ
ꢀꢁꢂ ꢃꢄ ꢅꢆꢂꢇ
ꢀꢁ
ꢀꢁ
0.ꢀꢁꢂ
ꢀ.ꢀꢁꢂ
Rꢀ
ꢀ
ꢀꢁ
ꢀꢁꢂ
ꢁꢂ
ꢀꢁꢂꢃ
ꢀꢁ0ꢂꢃ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢁꢂꢃ
ꢁꢂꢃ
ꢀꢁ
ꢀꢁꢂꢃꢄ
Rꢀ
ꢀ.ꢁꢂꢃ
ꢀꢁꢂꢃ
ꢀꢁꢂꢃꢃꢂ
ꢀꢁꢂꢃꢄꢅꢆꢇꢈ
ꢀꢁꢂꢃ
ꢄꢄ
ꢀꢁ
ꢀ.ꢀꢁꢂ
Rꢀ
Rꢀ
ꢀꢁꢂ
ꢀꢁRꢂ
ꢀ
ꢀ
ꢀ
ꢃ ꢄꢀ
ꢃ ꢄꢅꢀ
ꢃ ꢄꢅꢀ
ꢁꢂ
ꢁꢂ
ꢁꢂ
ꢀꢁꢂꢃ
Rꢀ
ꢀ0.ꢁꢂ
ꢀꢁ
0.0ꢀꢁꢂ
Rꢀ
ꢀ.ꢀ0ꢁꢂꢃ
ꢀꢁꢂꢃ
ꢀ
ꢀ0
ꢀ00
ꢀꢁ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
ꢀꢁꢂꢃ ꢄꢅRRꢆꢇꢈ ꢉꢊꢂꢋ
ꢀꢁ ꢂꢃRꢄꢅ ꢆꢀꢆꢇꢄRꢈꢉꢊꢇ ꢋꢌꢍꢎꢌꢎꢎꢏꢐ00
ꢑꢐꢁ ꢄꢒꢇ ꢑꢓꢔꢍꢕꢎꢖꢋRꢐꢅꢗꢗꢘꢇꢐꢗꢘꢔꢙ
ꢑꢗꢁ ꢄꢒꢇ ꢑꢓꢔꢍꢕꢐꢖꢋRꢐꢅꢍꢋꢘꢇꢐꢗꢘꢔꢑ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
Efficiency
5V to 30V Input, 30V Output Boost Converter
ꢀ00
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
0
ꢀ
ꢀ0ꢁꢂ
ꢀ
ꢁꢂ
ꢀꢁꢂ ꢃꢄ ꢅ0ꢂꢆ
ꢀꢁ
ꢀꢁ
0.ꢀꢁꢂ
ꢀ.ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁꢂ
Rꢀ
ꢁꢂ
ꢀꢁꢂꢃ
ꢀ00ꢁꢂ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢁꢂꢃ
ꢁꢂꢃ
ꢀꢁ
ꢀꢁ0ꢂꢃ
Rꢀ
ꢀ.ꢁꢂꢃ
ꢀꢁꢂꢃ
ꢀꢁꢂꢃꢃꢂ
ꢀꢁꢂꢃꢄꢅꢆꢇꢈ
ꢀꢁꢂꢃ
ꢄꢄ
ꢀꢁ
ꢀ.ꢀꢁꢂ
ꢀ
ꢀ
ꢀ
ꢃ ꢄꢀ
ꢃꢄꢅꢀ
ꢃ ꢄꢅꢀ
Rꢀ
ꢀꢁꢂꢃ
ꢁꢂ
ꢁꢂ
ꢁꢂ
Rꢀ
ꢀꢁꢂ
ꢀꢁRꢂ
Rꢀ
ꢀ0.ꢁꢂ
ꢀꢁ
0.0ꢀꢁꢂ
Rꢀ
ꢀ
ꢀ0
ꢀ00
ꢀꢁ
ꢀ.ꢀ0ꢁꢂꢃ
ꢀꢁꢂꢃ
ꢀꢁꢂꢃ ꢄꢅRRꢆꢇꢈ ꢉꢊꢂꢋ
ꢀꢁꢁꢀ ꢂꢃ0ꢁꢄ
ꢀꢁꢁꢀ ꢂꢃ0ꢁꢄ
ꢀꢁ ꢂꢃRꢄꢅ ꢆꢀꢆꢇꢄRꢈꢉꢊꢇ ꢋꢌꢍꢎꢌꢎꢎꢏꢐ00
ꢑꢐꢁ ꢄꢒꢇ ꢑꢓꢔꢍꢕꢎꢖꢋRꢐꢅꢗꢗꢘꢇꢐꢗꢘꢔꢙ
ꢑꢗꢁ ꢄꢒꢇ ꢑꢓꢔꢍꢕꢐꢖꢋRꢐꢅꢍꢋꢘꢇꢐꢗꢘꢔꢑ
Rev. 0
16
For more information www.analog.com
LT8338
TYPICAL APPLICATION
3V to 40V Input, 24V Output Pre-Boost Converter
Efficiency
ꢀ00
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
ꢀ0
0
ꢀ
ꢀ.ꢁꢂꢃ
ꢀ
ꢁꢂ
ꢀꢁꢂ ꢃꢄ ꢅ0ꢂꢆ
ꢀꢁ
ꢀꢁ
ꢀ.ꢀꢁꢂ
0.ꢀꢁꢂ
ꢀ
ꢀꢁ
ꢀꢁꢂ
Rꢀ
ꢁꢂ
ꢀꢁꢂꢃ
ꢀ0ꢁꢂ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢁꢂꢃ
ꢁꢂꢃ
ꢀꢁ
ꢀꢁꢂꢃꢄ
Rꢀ
ꢀ.ꢁꢂꢃ
ꢀꢁꢂꢃ
ꢀꢁꢂꢃꢃꢂ
ꢀꢁꢂꢃꢄꢅꢆꢇꢈ
ꢀꢁꢂꢃ
ꢄꢄ
ꢀꢁ
ꢀ.ꢀꢁꢂ
Rꢀ
ꢀꢁꢂ
ꢀꢁRꢂ
Rꢀ
ꢀꢁꢂꢃ
ꢀ
ꢀ
ꢃ ꢄꢀ
ꢁꢂ
ꢁꢂ
Rꢀ
ꢃ ꢄꢅꢀ
ꢀ0.ꢁꢂ
ꢀꢁ
Rꢀ
ꢀꢁꢂꢃ
ꢀ.ꢀ0ꢁꢂꢃ
0.0ꢀꢁꢂ
ꢀ
ꢀ0
ꢀ00
ꢀꢁ
ꢀꢁꢂꢃ ꢄꢅRRꢆꢇꢈ ꢉꢊꢂꢋ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
ꢀꢁ ꢂꢃRꢄꢅ ꢆꢀꢆꢇꢄRꢈꢉꢊꢇ ꢋꢌꢍꢎꢌꢎꢎꢏ0ꢍꢋ
ꢐꢑꢁ ꢄꢒꢇ ꢐꢓꢔꢍꢕꢎꢖꢋRꢑꢅꢗꢗꢘꢇꢑꢗꢘꢔꢙ
ꢐꢗꢁ ꢄꢒꢇ ꢐꢓꢔꢍꢕꢑꢖꢋRꢑꢅꢍꢋꢘꢇꢑꢗꢘꢔꢐ
3V to 3.6V Input, 5V Output Boost Converter
Efficiency
ꢀ00.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
ꢀ0.00
0
ꢀ
ꢀ.ꢀꢁꢂ
ꢀ
ꢁꢂ
ꢃꢄꢀ ꢅꢆ ꢄ.ꢇꢀꢈ
ꢀꢁ
ꢀꢁ
ꢀ.ꢀꢁꢂ
0.ꢀꢁꢂ
Rꢀ
ꢀ
ꢀꢁ
ꢀꢁꢂ
ꢁꢂ
ꢀꢁꢂꢃ
ꢀ00ꢁꢂ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀ
ꢀ
ꢁꢂꢃ
ꢁꢂꢃ
ꢀꢁꢂꢃ
Rꢀ
ꢀꢁ
ꢀꢁꢂꢃ
ꢀ.ꢁꢂꢃ
ꢀꢁꢂꢃꢃꢂ
ꢀꢁꢂꢃꢄꢅꢆꢇꢈ
ꢀꢁꢂꢃ
ꢄꢄ
ꢀꢁ
ꢀ.ꢀꢁꢂ
ꢀ
ꢀ ꢁ.0ꢂ
ꢀ ꢁ.ꢁꢂ
ꢀ ꢁ.ꢂꢃ
Rꢀ
ꢀꢁꢂ
ꢀꢁRꢂ
ꢀꢁ
ꢀꢁ
ꢀꢁ
Rꢀ
ꢀꢁꢂꢃ
ꢀ
Rꢀ
ꢀ
ꢀ0.ꢁꢂ
ꢀꢁ
0.0ꢀꢁꢂ
Rꢀ
ꢀꢁꢀꢂ
ꢀ.ꢀ0ꢁꢂꢃ
ꢀ
ꢀ0
ꢀ00
ꢀꢁ
ꢀꢁꢂꢃ ꢄꢅRRꢆꢇꢈ ꢉꢊꢂꢋ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
ꢀꢁ ꢂꢃRꢄꢅ ꢆꢀꢆꢇꢄRꢈꢉꢊꢇ ꢋꢌꢌꢋꢍꢌꢎ0ꢏ
ꢐꢑꢁ ꢄꢒꢇ ꢐꢓꢔꢌꢕꢖꢗꢋRꢑꢅꢏꢏꢘꢇꢑꢏꢘꢔꢙ
ꢐꢏꢁ ꢄꢒꢇ ꢐꢓꢔꢌꢕꢑꢗꢋRꢑꢅꢌꢋꢘꢇꢑꢏꢘꢔꢐ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
Rev. 0
17
For more information www.analog.com
LT8338
TYPICAL APPLICATION
4V to 16V Input, 24V Output Micropower Synchronous Boost Converter with SSFM
ꢀꢁꢂꢃꢄ ꢅꢆꢀ ꢇꢀꢈꢄꢅR
ꢀꢁꢂ
ꢀꢁ
ꢀ.ꢁꢂꢃ
0.ꢃꢄꢅꢆ
ꢀ
ꢁꢂ
ꢀꢁ
0.ꢀꢁꢂ
ꢀ
ꢀꢁꢂ ꢃꢄ
ꢅꢆꢂꢇ
ꢀꢁ
0.ꢀꢁꢂ
ꢀꢁ
ꢀ.ꢁꢂꢃ
ꢀꢁꢂ
ꢀꢀꢁꢂ
ꢀꢁ
ꢀ0ꢁꢂ
ꢀꢁꢂꢃꢁꢂ ꢄꢅꢆ ꢇꢆꢈꢂꢄR
Rꢀ
ꢀꢁꢂꢃ
ꢀ
ꢀꢁ
ꢀꢁꢂ
ꢀꢁꢂ
ꢁꢂ
0.ꢃꢄꢅꢆ
ꢀꢁꢂꢃꢄ
ꢁꢂꢃ
ꢀꢁꢂꢃꢄꢅꢆ
ꢀ
ꢁꢂꢃ
ꢀ
Rꢀ
ꢀꢁꢂꢃ
ꢀꢁꢂ
0.ꢀꢁꢂ
ꢀꢁꢂ
0.ꢀꢁꢂ
ꢀꢁ
ꢀ0ꢁꢂ
ꢀꢁꢂ
0.ꢀꢁꢂ
ꢀꢁ
0.ꢀꢁꢂ
ꢀꢁ0ꢂꢃ
ꢀꢁꢂꢃꢃꢂ
ꢃꢄ ꢅꢆꢇ
ꢇ
ꢈꢉ
ꢀꢁꢂꢃꢄꢅꢆꢇꢈ
ꢀꢁꢂꢃ
ꢄꢄ
ꢀꢁꢂ ꢃꢄRꢅꢆ ꢇꢀꢇꢈꢅRꢉꢊꢋꢈ ꢌꢍꢍꢎꢏꢎꢎꢐ0ꢍꢌ
ꢀꢁꢂꢃ ꢄꢅRꢆꢇ ꢈꢉꢈꢊꢆRꢋꢌꢍꢊ ꢎꢏꢏꢎꢐꢑꢎꢒꢂꢏꢎ
ꢀꢁꢂꢃ ꢄꢅRꢆꢇ ꢈꢉꢈꢊꢆRꢋꢌꢍꢊ ꢎꢏꢂꢎꢐꢂ0ꢏ0
ꢀꢁ
Rꢀ
ꢀꢁꢂ
ꢀꢁRꢂ
ꢀ.ꢀꢁꢂ
Rꢀ
ꢀꢁꢂꢃ
ꢀꢁꢂꢀꢁꢃꢂꢀꢁꢄꢂꢀꢁꢅꢆ ꢇꢈRꢉꢊꢉ ꢋRꢇꢁꢅꢅRꢌꢍꢉꢁ0ꢄꢎꢏꢁꢄꢐ
ꢀꢁꢂꢀꢃꢄ ꢅꢆꢇꢈꢉ ꢈꢊꢋꢌꢍ ꢊꢎꢏꢁꢐꢃꢀꢑꢒ0ꢓꢏꢎꢔꢕ
ꢀꢁꢂ ꢃꢄꢅ ꢀꢆꢇꢈꢉꢊꢋꢌRꢍꢎꢍ0ꢏꢅ
Rꢀ
ꢀ00ꢁ
Rꢀ
Rꢀ
ꢀꢁꢂꢃ
ꢀ0.ꢁꢂ
ꢀꢁꢁ
0.0ꢀꢁꢂ
ꢀꢁꢂ ꢃꢄꢅ ꢆꢇ0ꢈꢉꢀꢊꢁꢉꢋꢃꢌꢇꢃ
ꢀ.ꢀ0ꢁꢂꢃ
ꢀꢁꢂꢃ ꢄꢅꢆ ꢇꢈꢇꢀꢉRꢊꢆꢋꢀ ꢋꢆꢌꢅꢄꢉRꢋꢇꢄ ꢀꢊRꢍ ꢎ0ꢀꢇꢏꢏꢐꢄ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
Conducted EMI Performance (CISPR25 Class 5 Peak)
Conducted EMI Performance (CISPR25 Class 5 Average)
ꢀ0
ꢀ0
ꢀ0
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0
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ꢀꢁꢂꢃꢃ ꢄ ꢂꢅꢆRꢂꢇꢆ ꢁꢈꢉꢈꢊ
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ꢀꢁꢂꢃꢃꢂ ꢄ.ꢄꢅꢆꢇ ꢈ ꢋꢌꢍRꢋꢎꢍ ꢍꢅꢏ
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0
.
0
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Radiated EMI Performance (CISPR25 Class 5 Peak)
Radiated EMI Performance (CISPR25 Class 5 Average)
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0
.
0
.
Rev. 0
18
For more information www.analog.com
LT8338
PACKAGE DESCRIPTION
MSE Package
10-Lead Plastic MSOP, Exposed Die Pad
(Reference LTC DWG # 05-08-1664 Rev I)
BOTTOM VIEW OF
EXPOSED PAD OPTION
1.88
(.074)
1.88 ±0.102
(.074 ±.004)
0.889 ±0.127
(.035 ±.005)
1
0.29
REF
1.68
(.066)
0.05 REF
5.10
(.201)
MIN
1.68 ±0.102
3.20 – 3.45
DETAIL “B”
(.066 ±.004) (.126 – .136)
CORNER TAIL IS PART OF
THE LEADFRAME FEATURE.
FOR REFERENCE ONLY
DETAIL “B”
10
NO MEASUREMENT PURPOSE
0.50
(.0197)
BSC
0.305 ± 0.038
(.0120 ±.0015)
TYP
3.00 ±0.102
(.118 ±.004)
(NOTE 3)
0.497 ±0.076
(.0196 ±.003)
10 9
8
7 6
RECOMMENDED SOLDER PAD LAYOUT
REF
3.00 ±0.102
(.118 ±.004)
(NOTE 4)
4.90 ±0.152
(.193 ±.006)
DETAIL “A”
0° – 6° TYP
0.254
(.010)
1
2
3
4 5
GAUGE PLANE
0.53 ±0.152
(.021 ±.006)
0.86
(.034)
REF
1.10
(.043)
MAX
DETAIL “A”
0.18
(.007)
SEATING
PLANE
0.17 – 0.27
(.007 – .011)
TYP
0.1016 ±0.0508
(.004 ±.002)
0.50
(.0197)
BSC
MSOP (MSE) 0213 REV I
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
6. EXPOSED PAD DIMENSION DOES INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD
SHALL NOT EXCEED 0.254mm (.010") PER SIDE.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
19
subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
LT8338
TYPICAL APPLICATION
3V to 40V Input, 12V Output Pre-Boost Converter
Efficiency
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0
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ꢃ ꢄꢀ
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Rꢀ
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ꢏꢖꢁ ꢄꢑꢇ ꢏꢒꢓꢍꢔꢐꢕꢋRꢐꢅꢍꢋꢗꢇꢐꢖꢗꢓꢏ
ꢀꢁꢁꢀ ꢂꢃ0ꢄꢅ
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT8336
Boost, Monolithic Converter with 2.5A/40 Switch
2.7V ≤ V ≤ 40V, Current Mode Control, 300kHz to 3MHz Programmable
IN
Operation Frequency, QFN-16 Package
LT8335
LT8362
LT8330
28V, 2A, Low IQ Boost/SEPIC/Inverting 2MHz
Converter
V
= 3V to 25V, V
= 25V, I = 6µA (Burst Mode Operation), 3mm ×
IN
OUT(MAX) Q
2mm DFN package
60V, 2A, Low I Boost/SEPIC/Inverting Converter
V
= 2.8V to 60V, V
= 60V, I = 9µA (Burst Mode Operation), MSOP-
OUT(MAX) Q
Q
IN
16(12)E, 3mm × 3mm DFN-8 packages
V = 3V to 40V, V = 60V, I = 6µA (Burst Mode Operation),
IN
60V, 1A, Low I Boost/SEPIC/Inverting 2MHz
Q
OUT(MAX)
Q
Converter
6-Lead TSOT-23, 3mm × 2mm DFN packages
LT3958
LT3757A
LT3758
High Input Voltage, Boost, Flyback, SEPIC and
Inverting Converter with 3.5A/80V Switch
5V ≤ V < 80V, Current Mode Control, 100kHz to 1MHz Programmable
IN
Operation Frequency, 5mm × 6mm QFN-36 Package
Boost, Flyback, SEPIC and Inverting Controller
2.9V ≤ V ≤ 40V, Current Mode Control, 100kHz to 1MHz Programmable
IN
Operation Frequency, 3mm × 3mm DFN-10 and MSOP-10E Package
Boost, Flyback, SEPIC and Inverting Controller
5.5V ≤ V ≤ 100V, Current Mode Control, 100kHz to 1MHz Programmable
IN
Operation Frequency, 3mm × 3mm DFN-10 and MSOP-10E Package
Rev. 0
04/21
www.analog.com
20
ANALOG DEVICES, INC. 2021
相关型号：
LT8362EMSE#PBF
LT8362 - Low IQ Boost/SEPIC/Inverting Converter with 2A, 60V Switch; Package: MSOP; Pins: 16; Temperature Range: -40°C to 85°C
Linear
LT8362IDD#PBF
LT8362 - Low IQ Boost/SEPIC/Inverting Converter with 2A, 60V Switch; Package: DFN; Pins: 10; Temperature Range: -40°C to 85°C
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LT8362IMSE#PBF
LT8362 - Low IQ Boost/SEPIC/Inverting Converter with 2A, 60V Switch; Package: MSOP; Pins: 16; Temperature Range: -40°C to 85°C
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LT8364HMSE#PBF
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