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LTC3809EMSE-1#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24
LTC3809-1
1
38091fc
TYPICAL APPLICATION
DESCRIPTION
No R
SENSE
TM
, Low Input
Voltage, Synchronous DC/DC
Controller with Output Tracking
The LTC
®
3809-1 is a synchronous step-down switching
regulator controller that drives external complementary
power MOSFETs using few external components. The
constant frequency current mode architecture with MOSFET
V
DS
sensing eliminates the need for a current sense resistor
and improves effi ciency.
Optional Burst Mode operation provides high effi ciency
operation at light loads. 100% duty cycle provides low
dropout operation, extending operating time in battery-
powered systems. Burst Mode is inhibited when the MODE
pin is pulled low to reduce noise and RF interference.
The LTC3809-1 allows either coincident or ratiometric
output voltage tracking. Switching frequency is fi xed at
550kHz. Fault protection is provided by an overvoltage
comparator and a short-circuit current limit comparator.
The LTC3809-1 is available in tiny footprint thermally
enhanced DFN and 10-lead MSOP packages.
High Effi ciency, 550kHz Step-Down Converter
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst
is a registered trademark of Linear Technology Corporation. No R
SENSE
is a trademark of
Linear Technology Corporation. All other trademarks are the property of their respective
owners. Protected by U.S. Patents including 5481178, 5929620, 6580258, 6304066,
5847554, 6611131, 6498466. Other Patents pending.
FEATURES
APPLICATIONS
n
1- or 2-Cell Lithium-Ion Powered Devices
n
Notebook and Palmtop Computers, PDAs
n
Portable Instruments
n
Distributed DC Power Systems
n
Programmable Output Voltage Tracking
n
No Current Sense Resistor Required
n
Constant Frequency Current Mode Operation for
Excellent Line and Load Transient Response
n
Wide V
IN
Range: 2.75V to 9.8V
n
Wide V
OUT
Range: 0.6V to V
IN
n
0.6V ±1.5% Reference
n
Low Dropout Operation: 100% Duty Cycle
n
Selectable Burst Mode
®
/Pulse-Skipping/Forced
Continuous Operation
n
Auxiliary Winding Regulation
n
Internal Soft-Start Circuitry
n
Selectable Maximum Peak Current Sense Threshold
n
Output Overvoltage Protection
n
Micropower Shutdown: I
Q
= 9μA
n
Tiny Thermally Enhanced Leadless (3mm × 3mm)
DFN and 10-lead MSOP Packages
Effi ciency and Power Loss vs Load Current
LTC3809-1
2.2μH
10μF
47μF
38091 TA01
15k
59k
187k
470pF
GND
IPRG
MODE
RUN
SW
TG
BG
V
IN
V
FB
V
IN
2.75V TO 9.8V
V
OUT
2.5V
2A
I
TH
LOAD CURRENT (mA)
EFFICIENCY (%)
100
90
80
70
60
50
POWER LOSS (mW)
10k
1k
100
10
1
0.1
1 100 1k 10k
38091 TA02
10
V
IN
= 3.3V
V
IN
= 5V
V
IN
= 4.2V
FIGURE 8 CIRCUIT
V
OUT
= 2.5V
TYPICAL POWER
LOSS (V
IN
= 4.2V)
EFFICIENCY
LTC3809-1
2
38091fc
ABSOLUTE MAXIMUM RATINGS
Input Supply Voltage (V
IN
) ........................ –0.3V to 10V
RUN, TRACK/SS, MODE,
IPRG Voltages ............................... –0.3V to (V
IN
+ 0.3V)
V
FB
, I
TH
Voltages ...................................... –0.3V to 2.4V
SW Voltage ......................... –2V to V
IN
+ 1V (10V Max)
TG, BG Peak Output Current (<10μs) ......................... 1A
Operating Temperature Range (Note 2)....–40°C to 85°C
(Note 1)
TOP VIEW
11
DD PACKAGE
10-LEAD (3mm s 3mm) PLASTIC DFN
10
9
6
7
8
4
5
3
2
1
SW
V
IN
TG
BG
IPRG
MODE
TRACK/SS
V
FB
I
TH
RUN
T
JMAX
= 125°C, θ
JA
= 43°C/W
EXPOSED PAD (PIN 11) IS GND
(MUST BE SOLDERED TO PCB)
1
2
3
4
5
MODE
TRACK/SS
V
FB
I
TH
RUN
10
9
8
7
6
SW
V
IN
TG
BG
IPRG
TOP VIEW
MSE PACKAGE
10-LEAD PLASTIC MSOP
11
T
JMAX
= 125°C, θ
JA
= 40°C/W
EXPOSED PAD (PIN 11) IS GND
(MUST BE SOLDERED TO PCB)
PIN CONFIGURATION
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3809EDD-1#PBF LTC3809EDD-1#TRPBF LBQZ
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 85°C
LTC3809IDD-1#PBF LTC3809IDD-1#TRPBF LBQZ
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 85°C
LTC3809EMSE-1#PBF LTC3809EMSE-1#TRPBF LTBQV 10-Lead Plastic MSOP –40°C to 85°C
LTC3809IMSE-1#PBF LTC3809IMSE-1#TRPBF LTBQV 10-Lead Plastic MSOP –40°C to 85°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3809EDD-1 LTC3809EDD-1#TR LBQZ
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 85°C
LTC3809IDD-1 LTC3809IDD-1#TR LBQZ
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 85°C
LTC3809EMSE-1 LTC3809EMSE-1#TR LTBQV 10-Lead Plastic MSOP –40°C to 85°C
LTC3809IMSE-1 LTC3809IMSE-1#TR LTBQV 10-Lead Plastic MSOP –40°C to 85°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed 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 specifi
cations, go to: http://www.linear.com/tapeandreel/
Storage Ambient Temperature Range
DFN ....................................................–65°C to 125°C
MSOP ................................................–65°C to 150°C
Junction Temperature (Note 3) ............................ 125°C
Lead Temperature (Soldering, 10 sec)
MSOP Package ................................................. 300°C
LTC3809-1
3
38091fc
ELECTRICAL CHARACTERISTICS
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 LTC3809E-1 is guaranteed to meet specifi ed performance
from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating range
are assured by design characterization, and correlation with statistical
process controls. The LTC3809I-1 is guaranteed to meet specifi ed
performance over the full –40°C to 85°C operating temperature range.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loops
Input DC Supply Current
Normal Operation
Sleep Mode
Shutdown
UVLO
(Note 4)
RUN = 0V
V
IN
= UVLO Threshold –200mV
350
105
9
9
500
150
20
20
μA
μA
μA
μA
Undervoltage Lockout Threshold (UVLO) V
IN
Falling
V
IN
Rising
l
l
1.95
2.15
2.25
2.45
2.55
2.75
V
V
Shutdown Threshold of RUN Pin 0.8 1.1 1.4 V
Start-Up Current Source TRACK/SS = 0V 0.65 1 1.35 μA
Regulated Feedback Voltage (Note 5)
l
0.591 0.6 0.609 V
Output Voltage Line Regulation 2.75V < V
IN
< 9.8V (Note 5) 0.01 0.04 %/V
Output Voltage Load Regulation I
TH
= 0.9V (Note 5)
I
TH
= 1.7V
0.1
–0.1
0.5
–0.5
%
%
V
FB
Input Current (Note 5) 9 50 nA
Overvoltage Protect Threshold Measured at V
FB
0.66 0.68 0.7 V
Overvoltage Protect Hysteresis 20 mV
Auxiliary Feedback Threshold 0.325 0.4 0.475 V
Top Gate (TG) Drive Rise Time C
L
= 3000pF 40 ns
Top Gate (TG) Drive Fall Time C
L
= 3000pF 40 ns
Bottom Gate (BG) Drive Rise Time C
L
= 3000pF 50 ns
Bottom Gate (BG) Drive Fall Time C
L
= 3000pF 40 ns
Maximum Current Sense Voltage (ΔV
SENSE(MAX)
)
(V
IN
– SW)
IPRG = Floating (Note 6)
IPRG = 0V (Note 6)
IPRG = V
IN
(Note 6)
l
l
l
110
70
185
125
85
204
140
100
223
mV
mV
mV
Soft-Start Time (Internal) Time for V
FB
to Ramp from 0.05V to 0.55V 0.5 0.74 0.9 ms
Oscillator Frequency 480 550 600 kHz
The l indicates specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= 4.2V unless otherwise noted.
Note 3: T
J
is calculated from the ambient temperature TA and power
dissipation P
D
according to the following formula:
T
J
= T
A
+ (P
D
• θ
JA
°C/W)
Note 4: Dynamic supply current is higher due to gate charge being
delivered at the switching frequency.
Note 5: The LTC3809-1 is tested in a feedback loop that servos I
TH
to
a specifi ed voltage and measures the resultant V
FB
voltage.
Note 6: Peak current sense voltage is reduced dependent on duty cycle
to a percentage of value as shown in Figure 1.
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24

LTC3809EMSE-1#PBF

Mfr. #:
Buy LTC3809EMSE-1#PBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators No Rsense, Low EMI DC/DC Controller in MSE
Lifecycle:
New from this manufacturer.
Delivery:
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