synchronous step-down DC/DC switching controller that
drives all N-channel synchronous power MOSFET stages.
A constant frequency current mode architecture allows a
phase-lockable frequency of up to 770kHz. Power loss and
noise due to ESR of the input capacitors are minimized by
operating the three controller output stages out of phase.
The LTC3829 can be configured for 6-phase operation,
has DCR temperature compensation, and output foldback
current limiting. This device features a precision 0.6V ref-
erence and a power good indicator.
Light load efficiency is optimized by using a choice of
output Stage Shedding or Burst Mode operation. A dif-
ferential amplifier provides true remote sensing of the
output voltage at the point of load.
The LTC3829 is available in both low profile 38-pin 5mm
×
7mm QFN and Exposed Pad FE packages.
All registered trademarks and trademarks are the property of their respective owners. Protected
by U.S. Patents, including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258,
6498466, 6674274, 6611136.
Optional Nonlinear Control for Fast Response
±0.75%, 0.6V Reference Accuracy
PWM, Stage Shedding™ or Burst Mode
®
Operation
High Efficiency: Up to 95%
R
SENSE
or DCR Current Sensing
Programmable DCR Temperature Compensation
Phase-Lockable Fixed Frequency: 250kHz to 770kHz
True Remote Sense Differential Amplifier
Programmable Active Voltage Positioning (AVP)
Triple N-Channel MOSFET Synchronous Drive
Wide V
IN
Range: 4.5V to 38V Operation
V
OUT
Range: 0.6V to 5V without Diffamp
V
OUT
Range: 0.6V to 3.3V with Diffamp
Clock Input and Output for 6-Phase Operation
Adjustable Soft-Start or V
OUT
Tracking
38-Pin (5mm
×
7mm) QFN and FE Packages
APPLICATIONS
n
n
n
n
Notebook and Palmtop Computers
Telecom Systems
Portable Instruments
DC Power Distribution Systems
TYPICAL APPLICATION
4.7µF
INTV
CC
V
IN
+
TG1
SW1
BG1
PGND
SENSE1
+
SENSE1
–
TG2
0.6µH
0.002
22µF
35V
×3
V
IN
6V TO 28V
BOOST1
BOOST2
BOOST3
SW3 SW2 SW1
680pF
Efficiency
100
V
IN
= 12V
95 V
OUT
= 1.5V
16
14
12
POWER LOSS (W)
EFFICIENCY
10
8
6
POWER LOSS
4
2
1
10
LOAD CURRENT (A)
0
100
3829 TA01b
V
IN
EFFICIENCY (%)
0.6µH
0.002
V
OUT
1.2V
50A
90
85
80
75
70
65
60
0.002
55
50
0.1
100k
FREQ
I
TH
TK/SS
SGND
DIFFOUT
LTC3829
SW2
BG2
5k
0.1µF
SENSE2
+
SENSE2
–
TG3
SW3
BG3
SENSE3
+
SENSE3
–
V
IN
0.6µH
20k
20k
V
FB
DIFFN
DIFFP
+
C
OUT
470µF
4V
×4
3829 TA01
3829fd
For more information
www.linear.com/LTC3829
1
LTC3829
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Input Supply Voltage (V
IN
) ......................... 40V to –0.3V
Topside Driver Voltages (BOOSTn) ............. 46V to –0.3V
Switch Voltage (SWn) ................................... 40V to –5V
Boosted Driver Voltage (BOOSTn – SWn) .... 6V to –0.3V
INTV
CC
, PGOOD, RUN, EXTV
CC
................... 6V to –0.3V
ITEMP, IFAST, V
FB
Pin Voltages ............ INTV
CC
to –0.3V
TK/SS, FREQ, DIFFP, DIFFN, DIFFOUT, ISET
AVP, I
LIM
, MODE, PLLIN Voltages ......... INTV
CC
to –0.3V
I
TH
Voltage ............................................ INTV
CC
to –0.3V
SENSE
+
n, SENSE
–
n................................... 5.7V to –0.3V
Operating Junction Temperature Range
(Notes 2, 3) ............................................ –45°C to 125°C
Storage Temperature Range .................. –65°C to 125°C
Lead Temperature (Soldering, 10 sec) (FE) ........... 300°C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
DIFFOUT
CLKOUT
BOOST1
ITEMP
MODE
IFAST
TG1
ITEMP
DIFFOUT
DIFFN
DIFFP
31 SW1
30 BG1
29 BG2
28 SW2
27 TG2
26 BOOST2
25 V
IN
24 INTV
CC
23 EXTV
CC
22 BG3
21 SW3
20 TG3
1
2
3
4
5
6
7
8
9
39
38 IFAST
37 MODE
36 CLKOUT
35 BOOST1
34 TG1
33 SW1
32 BG1
31 BG2
30 SW2
29 TG2
28 BOOST2
27 V
IN
26 INTV
CC
25 EXTV
CC
24 BG3
23 SW3
22 TG3
21 BOOST3
20 PLLIN
38 37 36 35 34 33 32
DIFFN 1
DIFFP 2
RUN 3
AVP 4
SENSE1
+
RUN
AVP
SENSE1
+
SENSE1
–
SENSE2
+
5
39
SENSE1
–
6
SENSE2
+
7
SENSE2
–
8
TK/SS 9
FREQ 10
SENSE3
+
11
SENSE3
–
12
SENSE2
–
10
TK/SS 11
FREQ 12
SENSE3
+
13
SENSE3
–
14
V
FB
15
I
TH
16
ISET 17
I
LIM
18
PGOOD 19
13 14 15 16 17 18 19
PLLIN
BOOST3
PGOOD
V
FB
I
TH
ISET
I
LIM
UHF PACKAGE
38-LEAD (5mm
×
7mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 34°C/W
EXPOSED PAD (PIN 39) IS SGND/PGND, MUST BE SOLDERED TO PCB
FE PACKAGE
38-LEAD PLASTIC TSSOP
T
JMAX
= 125°C,
θ
JA
= 25°C/W
EXPOSED PAD (PIN 39) IS SGND/PGND, MUST BE SOLDERED TO PCB
2
3829fd
For more information
www.linear.com/LTC3829
LTC3829
ORDER INFORMATION
LEAD FREE FINISH
LTC3829EUHF#PBF
LTC3829IUHF#PBF
LTC3829EFE#PBF
LTC3829IFE#PBF
TAPE AND REEL
LTC3829EUHF#TRPBF
LTC3829IUHF#TRPBF
LTC3829EFE#TRPBF
LTC3829IFE#TRPBF
http://www.linear.com/product/LTC3829#orderinfo
(Note 2)
PART MARKING*
3829
3829
LTC3829
LTC3829
PACKAGE DESCRIPTION
38-Lead (5mm
×
7mm) Plastic QFN
38-Lead (5mm
×
7mm) Plastic QFN
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
Consult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult ADI Marketing for information on non-standard lead based finish parts.
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.
ELECTRICAL CHARACTERISTICS
SYMBOL
V
IN
V
OUT
V
FB
I
FB
V
REFLNREG
V
LOADREG
PARAMETER
Input Voltage Range
Output Voltage Range
Regulated Feedback Voltage
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN
= 5V, unless otherwise noted. (Note 2)
CONDITIONS
MIN
4.5
0.6
I
TH
Voltage = 1.2V (Note 4) –40°C to 85°C
l
l
I
TH
Voltage = 1.2V (Note 4) T
J
= 125°C
(Note 4)
V
IN
= 4.5V to 38V (Note 4)
(Note 4)
Measured in Servo Loop,
∆I
TH
Voltage = 1.2V to 0.7V
Measured in Servo Loop,
∆I
TH
Voltage = 1.2V to 1.6V
I
TH
= 1.2V, Sink/Source 5µA (Note 4)
(Note 5)
V
IN
= 15V
V
RUN
= 0V
In Dropout, f
OSC
= 500kHz
V
INTVCC
Ramping Down
Measured at V
FB
Each Channel, V
SENSE1,2,3
= 3.3V,
V
DIFFP
= 3.3V
V
ITEMP
= 0.2V
V
TK/SS
= 0V
V
RUN
Rising
V
FB
= 0.5V, V
SENSE1,2,3
= 3.3V
I
LIM
= 0V
I
LIM
= Float
I
LIM
= INTV
CC
V
FB
= 0.5V, V
SENSE1,2,3
= 3.3V
I
LIM
= 0V
I
LIM
= Float
I
LIM
= INTV
CC
l
l
l
TYP
MAX
38
5.0
UNITS
V
V
V
V
nA
%/V
%
%
mmho
mA
µA
%
V
V
V
µA
µA
µA
V
mV
0.5955
0.593
0.600
0.600
–15
0.002
0.01
–0.01
2.2
4
40
0.6045
0.607
–50
0.02
0.1
–0.1
g
m
I
Q
DF
MAX
UVLO
UVLO Hyst
V
OVL
I
SENSE1,2,3+
I
TEMP
I
TK/SS
V
RUN
V
SENSE(MAX)
Transconductance Amplifier g
m
Input DC Supply Current
Normal Mode
Shutdown
Maximum Duty Factor
Undervoltage Lockout
UVLO Hysteresis
Feedback Overvoltage Lockout
SENSE
+
Pins Bias Current
DCR Tempco Compensation Current
Soft-Start Charge Current
RUN Pin On Threshold
RUN Pin On Hysteresis
Maximum Current Sense Threshold
(E-Grade)
60
3.6
0.68
±2
11
1.5
1.35
93
3.0
0.64
94
3.3
0.6
0.66
±1
l
l
l
l
l
9
1.0
1.1
10
1.25
1.22
100
l
l
l
l
l
l
25
45
68
23
43
66
30
50
75
30
50
75
35
55
82
37
57
84
mV
mV
mV
mV
mV
mV
3829fd
Maximum Current Sense Threshold
(I-Grade)
For more information
www.linear.com/LTC3829
3
LTC3829
ELECTRICAL CHARACTERISTICS
SYMBOL
TG1,2,3 t
r
TG1,2,3 t
f
BG1,2,3 t
r
BG1,2,3 t
f
TG/BG t
1D
BG/TG t
2D
t
ON(MIN)
V
INTVCC
V
LDO
INT
V
EXTVCC
V
LDO
EXT
V
LDOHYS
f
NOM
f
LOW
f
HIGH
R
PLLN
I
FREQ
I
ISET
CLKOUT
CLKHIGH
CLKLOW
PGOOD Output
V
PGL
I
PGOOD
V
PG
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level, Either Controller
I
PGOOD
= 2mA
V
PGOOD
= 5V
V
FB
with Respect to Set Output Voltage
V
FB
Ramping Negative
V
FB
Ramping Positive
l
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN
= 5V, unless otherwise noted. (Note 2)
PARAMETER
TG Transition Time
Rise Time
Fall Time
BG Transition Time
Rise Time
Fall Time
CONDITIONS
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
MIN
TYP
25
25
25
25
30
30
90
4.8
l
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
Top Gate Off to Bottom Gate On Delay C
LOAD
= 3300pF Each Driver
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay C
LOAD
= 3300pF Each Driver
Top Switch-On Delay Time
Minimum On-Time
Internal V
CC
Voltage
INTV
CC
Load Regulation
EXTV
CC
Switchover Voltage
EXTV
CC
Voltage Drop
EXTV
CC
Hysteresis
Nominal Frequency
Lowest Frequency
Highest Frequency
PLLIN Input Resistance
Frequency Setting Current
Shed and Burst Mode Program
Current
Phase (Relative to Controller 1)
Clock High Output Voltage
Clock Low Output Voltage
Non-Shedding Mode
Channel 2 and 3 Shedding
4
9
6.5
V
FREQ
= 1.2V
V
FREQ
= 0V
V
FREQ
≥ 2.4V
450
210
700
(Note 7)
6V < V
IN
≤ 38V
I
CC
= 0mA to 20mA
EXTV
CC
Ramping Positive
I
CC
= 20mA, V
EXTVCC
= 5V
4.5
INTV
CC
Linear Regulator
5.0
0.5
4.7
50
200
500
250
770
100
10
7.5
60
180
5
0
0.1
0
–12
8
0.997
–10
10
1
80
2.5
100
3
INTV
CC
= 5V, I
DIFFOUT
= 300µA
(Note 8)
(Note 8)
V
INTVCC
– 1.4 V
INTVCC
– 1.1
3
2
0.2
0.3
±2
–7
13
1.003
11
8.5
550
290
850
100
5.2
2.0
V
%
V
mV
mV
kHz
kHz
kHz
kΩ
µA
µA
Deg
Deg
V
V
V
µA
%
%
V/V
kΩ
mV
dB
mA
V
MHz
V/µs
3829fd
Oscillator and Phase-Locked Loop
Differential Amplifier
A
DA
R
IN
V
OS
PSRR
I
CL
V
OUT(MAX)
GBW
SR
Gain
Input Resistance
Input Offset Voltage
Power Supply Rejection Ratio
Maximum Output Current
Maximum Output Voltage
Gain-Bandwidth Product
Slew Rate
Measured at DIFFP Input
V
DIFFP
= V
DIFFOUT
= 1.5V,
I
DIFFOUT
= 100µA
5V < V
IN
< 38V
4
For more information
www.linear.com/LTC3829
LTC3829
ELECTRICAL CHARACTERISTICS
SYMBOL
I
FAST
I
SINK
I
SOURCE
V
AVP
On-Chip Driver
TG R
UP
TG R
DOWN
BG R
UP
BG R
DOWN
TG Pull-Up R
DS(ON)
TG Pull-Down R
DS(ON)
BG Pull-Up R
DS(ON)
BG Pull-Down R
DS(ON)
TG High
TG Low
BG High
BG Low
2.6
1.5
4
1.1
Ω
Ω
Ω
Ω
PARAMETER
Fast Transient Programmable Current
Sink Current of AVP Pin
Source Current of AVP Pin
Maximum AVP Voltage
Nonlinear Fast Transit Mode
V
IFAST
= 400mV
SENSE
+
= 1.2V
SENSE
+
= 1.2V
SENSE
+
= 1.2V
l
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN
= 5V, unless otherwise noted. (Note 2)
CONDITIONS
MIN
9
TYP
10
250
2
180
2.5
MAX
11
UNITS
µA
µA
mA
mV
V
AVP (Active Voltage Positioning)
V
AVP
-V
O(MAX)
Maximum Voltage Drop V
AVP
to V
O
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:
The LTC3829 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3829E is guaranteed to meet performance specifications
from 0°C to 85°C operating 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 LTC3829I is guaranteed to meet performance specifications over the
full –40°C to 125°C operating junction temperature range.
Note 3:
T
J
is calculated from the ambient temperature, T
A
, and power
dissipation, P
D
, according to the following formula:
LTC3829UHF: T
J
= T
A
+ (P
D
• 34°C/W)
LTC3829FE: T
J
= T
A
+ (P
D
• 25°C/W)
Note 4:
The LTC3829 is tested in a feedback loop that servos V
ITH
to a
specified voltage and measures the resultant V
FB
.
Note 5:
Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 7:
The minimum on-time condition corresponds to the on inductor
peak-to-peak ripple current ≥40% of I
MAX
(see Minimum On-Time
Considerations in the Applications Information section).
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
