nous monolithic step-down regulator capable of operating
from input supplies up to 17V. The switching frequency is
fixed to 1MHz or 2.25MHz with a ±50% synchronization
range to an external clock. The regulator features ultralow
quiescent current and high efficiency over a wide output
voltage range.
The step-down regulators operate from an input voltage
range of 2.7V to 17V and provide an adjustable output
from 0.6V to V
IN
while delivering up to 1A of output cur-
rent. A user-selectable mode input is provided to allow
the user to trade off ripple noise for light load efficiency.
Burst Mode
®
operation provides the highest efficiency at
light loads, while pulse-skipping mode provides the lowest
ripple noise. The switching regulators can be synchronized
to an external clock. Furthermore, fixed V
OUT
options are
available to eliminate the external feedback resistors.
List of LTC3622 Options
PART NAME
LTC3622
LTC3622-2
LTC3622-23/5
FREQUENCY
1.00MHz
2.25MHz
2.25MHZ
V
OUT
Adjustable
Adjustable
5V/3.3V
n
n
n
n
n
n
n
n
Dual Step-Down Outputs: 1A Per Channel
Wide V
IN
Range: 2.7V to 17V
Wide V
OUT
Range: 0.6V to V
IN
Up to 95% Efficiency
No-Load I
Q
= 5µA with Both Channels Enabled;
I
Q
< 4µA with Only One Channel Enabled
High Efficiency, Low Dropout Operation
(100% Duty Cycle)
Constant Frequency (1MHz/2.25MHz) with External
Frequency Synchronization
±1% Output Voltage Accuracy
Current Mode Operation for Excellent Line and Load
Transient Response
Phase Shift Programmable with External Clock
Selectable Current Limit
Internal Compensation and Soft-Start
Compact 14-Pin DFN (3mm
×
4mm) and 16-Lead
MSOP Packages
APPLICATIONS
n
n
n
Battery Powered Systems
Point-of-Load Supplies
Portable – Handheld Scanners
L,
LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners. Protected by U.S. Patents, including 5481178, 6580258, 6498466, 6611131, 5705919.
TYPICAL APPLICATION
2.5V/5V V
OUT
Application, f
SW
= 1MHz
V
IN
5.5V TO 17V
C
IN
10µF
V
IN1
V
IN2
RUN1
RUN2
PHASE
I
LIM
6.8µH
SW1
C
OUT1
22µF
22pF
619k
FB1
196k
GND
FB2
84.5k
SW2
619k
22pF
INTV
CC
MODE/SYNC
C1
1µF
Efficiency vs Load Current
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
V
OUT1
= 2.5V
V
OUT2
= 5V
V
IN
= 12V
f
SW
= 1MHz
Burst Mode OPERATION
0.001
0.01
0.1
LOAD CURRENT (A)
1
3622 TA01b
0.6
0.5
0.4
0.3
0.2
0.1
0
POWER LOSS (W)
LTC3622
V
OUT1
2.5V
1A
4.7µH
V
OUT2
5V
1A
C
OUT2
22µF
0
0.0001
3622 TA01
3622fc
For more information
www.linear.com/LTC3622
1
LTC3622/
LTC3622-2/LTC3622-23/5
ABSOLUTE MAXIMUM RATINGS
(Note 1)
V
IN1
, V
IN2,
SV
IN
(MSOP Only) (Note 2) ....... –0.3V to 17V
RUN1, RUN2 ..............................................–0.3V to V
IN1
MODE/SYNC, FB1, FB2 ................................ –0.3V to 6V
PGOOD1, PGOOD2, I
LIM
, PHASE.................. –0.3V to 6V
Operating Junction Temperature Range (Note 3)
LTC3622E .......................................... –40°C to 125°C
LTC3622I ........................................... –40°C to 125°C
LTC3622H .......................................... –40°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
PIN CONFIGURATION
TOP VIEW
V
IN1
PGOOD1
MODE/SYNC
PHASE
PGOOD2
I
LIM
V
IN2
1
2
3
4
5
6
7
15
GND
14 SW1
13 RUN1
12 FB1
11 INTV
CC
10 FB2
9 RUN2
8 SW2
TOP VIEW
V
IN1
SV
IN
PGOOD1
MODE/SYNC
PHASE
PGOOD2
I
LIM
V
IN2
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
SW1
NC
RUN1
FB1
INTV
CC
FB2
RUN2
SW2
17
GND
DE PACKAGE
14-LEAD (4mm
×
3mm) PLASTIC DFN
T
JMAX
= 150°C,
θ
JA
= 40°C/W,
θ
JC
= 4.4°C/W
EXPOSED PAD (PIN 15) IS GND, MUST BE SOLDERED TO PCB
MSE PACKAGE
16-LEAD PLASTIC MSE
T
JMAX
= 150°C,
θ
JA
= 40°C/W,
θ
JC
= 10°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC3622EDE#PBF
LTC3622IDE#PBF
LTC3622HDE#PBF
LTC3622EMSE#PBF
LTC3622IMSE#PBF
LTC3622HMSE#PBF
LTC3622EDE-2#PBF
LTC3622IDE-2#PBF
LTC3622HDE-2#PBF
LTC3622EMSE-2#PBF
LTC3622IMSE-2#PBF
LTC3622HMSE-2#PBF
LTC3622EDE-23/5#PBF
LTC3622IDE-23/5#PBF
LTC3622HDE-23/5#PBF
TAPE AND REEL
LTC3622EDE#TRPBF
LTC3622IDE#TRPBF
LTC3622HDE#TRPBF
LTC3622EMSE#TRPBF
LTC3622IMSE#TRPBF
LTC3622HMSE#TRPBF
LTC3622EDE-2#TRPBF
LTC3622IDE-2#TRPBF
LTC3622HDE-2#TRPBF
LTC3622EMSE-2#TRPBF
LTC3622IMSE-2#TRPBF
LTC3622HMSE-2#TRPBF
LTC3622EDE-23/5#TRPBF
LTC3622IDE-23/5#TRPBF
LTC3622HDE-23/5#TRPBF
http://www.linear.com/product/LTC3622#orderinfo
PART MARKING*
3622
3622
3622
3622
3622
3622
36222
36222
36222
36222
36222
36222
223/5
223/5
223/5
PACKAGE DESCRIPTION
14-Lead (3mm x 4mm) Plastic DFN
14-Lead (3mm x 4mm) Plastic DFN
14-Lead (3mm x 4mm) Plastic DFN
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
14-Lead (3mm x 4mm) Plastic DFN
14-Lead (3mm x 4mm) Plastic DFN
14-Lead (3mm x 4mm) Plastic DFN
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
14-Lead (3mm x 4mm) Plastic DFN
14-Lead (3mm x 4mm) Plastic DFN
14-Lead (3mm x 4mm) Plastic DFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
2
3622fc
For more information
www.linear.com/LTC3622
LTC3622/
LTC3622-2/LTC3622-23/5
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
V
IN1
, V
IN2
Operating Voltage
SV
IN
Operating Voltage
V
OUT
Operating Voltage
I
Q
Input Quiescent Current
Active Mode, V
RUN1
= V
RUN2
= 2V (Note 4)
Burst Mode Operation, V
RUN1
= V
RUN2
= 2V,
MODE/SYNC = 3V, No Load
Shutdown Mode; V
RUN1
= V
RUN2
= 0V
LTC3622/LTC3622-2
l
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN1
= V
IN2
= 12V, unless otherwise noted. (Notes 3, 6)
CONDITIONS
MSOP Package
MIN
2.7
2.7
0.6
3
5
0.1
0.594
0.591
4.950
4.925
3.267
3.250
0.6
0.6
5.0
5.0
3.3
3.3
1
0.01
0.1
0.1
0.1
V
IN
= 5V
V
FB
= 0V
V
FB
= 0.7V, V
IN1
= V
IN2
= 5
0.35
V
RUN
= 12V
V
INTVCC
–0.4
Input Low
Input High
Input Low
Input High
V
IN
> 5V
V
ILIM
= 0.1V (Both Channels)
V
ILIM
= INTV
CC
– 0.1V (Both Channels)
V
ILIM
= Floating, Channel 1
V
ILIM
= Floating, Channel 2
V
IN
Ramping Up
l
l
TYP
MAX
17
17
V
IN
10
±1
0.606
0.609
10
5.050
5.075
3.333
3.350
5
0.015
1
1
UNITS
V
V
V
mA
µA
µA
V
nA
V
V
V
V
µA
%/V
%
µA
µA
Ω
Ω
%
ns
V
FB
I
FB
V
OUT1
V
OUT2
I
FB(VOUT)
Regulated Feedback Voltage
FB Input Current
Regulated Fixed Output Voltage
(Channel 1)
Regulated Fixed Output Voltage
(Channel 2)
Feedback Input Leakage Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
NMOS Switch Leakage
PMOS Switch Leakage
LTC3622/LTC3622-2
LTC3622-23/5
l
LTC3622-23/5
l
LTC3622-23/5
V
IN
= 2.7V to 17V (Note 5)
(Note 5)
R
DS(ON)
NMOS On-Resistance
PMOS On-Resistance
Maximum Duty Cycle
Minimum On-Time
RUN Input High
RUN Input Low
RUN Input Current
Pulse-Skipping Mode
Burst Mode Operation
PHASE Input Threshold
I
LIM
Input Threshold
0.15
0.37
100
75
1.0
0.1
±20
0.15
0.4
0.1
INTV
CC
0.5
1.6
0.8
1.6
0.8
2.3
18
1.8
1.0
1.8
1.0
2.5
160
19
300
20
2.0
1.2
2.0
1.2
2.65
t
ON(MIN)
V
RUN
V
V
nA
V
V
V
V
V
V
ms
A
A
A
A
V
mV
V
mV
V
MODE
2.0
V
INTVCC
–0.1
t
SS
I
LIM
Soft Start Time
Peak Current Limit
V
INTVCC
Undervoltage Lockout
V
INTVCC
Undervoltage Lockout Hysteresis
V
IN
Overvoltage Lockout Rising
V
IN
Overvoltage Lockout Hysteresis
3622fc
For more information
www.linear.com/LTC3622
3
LTC3622/
LTC3622-2/LTC3622-23/5
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
f
OSC
Oscillator Frequency
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN1
= V
IN2
= 12V, unless otherwise noted. (Notes 3, 6)
CONDITIONS
LTC3622-2/LTC3622-23/5
LTC3622
LTC3622
–40°C ≤ T
A
≤ 150°C
–40°C ≤ T
A
≤ 125°C
–40°C ≤ T
A
≤ 150°C
l
l
l
MIN
1.8
0.82
0.75
0.4
50
3.3
TYP
2.25
1.00
1.00
MAX
2.6
1.16
1.16
V
INTVCC
–0.3
150
UNITS
MHz
MHz
MHz
V
%
V
%
Ω
Cycles
Cycles
Deg
Deg
External CLK Amplitude
SYNC Capture Range
V
INTVCC
R
PGOOD
t
PGOOD
INTV
CC
Voltage
Power Good Range
Power Good Resistance
PGOOD Delay
V
IN
> 4V
PGOOD R
DS(ON)
at 2mA
PGOOD Low to High
PGOOD High to Low
% of Programmed Frequency
3.6
–7.5
275
0
32
0
180
3.9
–11
350
Phase Shift Between Channel 1 and Channel V
PHASE
= 0V
2
V
PHASE
= INTV
CC
, V
MODE/SYNC
= 0V
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 2.
Transient Absolute Maximum Voltages should not be applied for
more than 4% of the switching duty cycle.
Note 3.
The LTC3622 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3622E is guaranteed to meet specified performance from
0°C to 85°C. Specifications over the –40°C to 125°C operating junction
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3622I is guaranteed over the
–40°C to 125°C operating junction temperature range and the LTC3622H
is guaranteed over the -40°C to 150°C operating junction temperature
range. High junction temperatures degrade operating lifetimes; operating
lifetime is derated for junction temperatures greater than 125°C. Note that
the maximum ambient temperature consistent with these specifications
is determined by specific operating conditions in conjunction with board
layout, the rated package thermal impedance and other environment
factors.
Note 4.
The quiescent current in active mode does not include switching
loss of the power FETs.
Note 5.
The LTC3622 is tested in a proprietary test mode that connects
1 Introduction
In the mid-1960s, American scientist Maas conducted extensive experimental research on the charging process of open-cell batteries and proposed an acceptable charging curve for ...[详细]
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