LTC1147LCS8-3.3#TRPBF

1
LTC1147-3.3
LTC1147-5/LTC1147L
sn1147 1147fds
High Efficiency Step-Down
Switching Regulator Controllers
Figure 1. High Efficiency Step-Down Converter
U
A
O
PP
L
IC
AT
ITY
P
I
CA
L
, LTC and LT are registered trademarks of Linear Technology Corporation.
0V = NORMAL
>1.5V = SHUTDOWN
P-CHANNEL
Si4431DY
+
1µF
L*
50µH
R
SENSE
**
0.05
V
OUT
5V/2A
+
C
IN
100µF
V
IN
(5.2V TO 14V)
I
TH
C
T
C
T
470pF
C
C
3300pF
R
C
1k
+
C
OUT
390µF
D1
MBRD330
LT1147 • F01
GND
V
IN
PDRIVE
LTC1147-5
SHDN
SENSE
+
SENSE
1000pF
COILTRONICS CTX50-2-MP
KRL SL-1-C1-0R050J
*
**
LOAD CURRENT (A)
0.001
70
EFFICIENCY (%)
90
95
100
0.01 0.1 1
LT1147 • TA01
85
80
75
V
IN
= 6V
V
IN
= 10V
LTC1147-5 Efficiency
Very High Efficiency: Over 95% Possible
Wide V
IN
Range: 3.5V* to 16V
Current Mode Operation for Excellent Line and Load
Transient Response
High Efficiency Maintained Over Three Decades of
Output Current
Low 160µA Standby Current at Light Loads
Logic Controlled Micropower Shutdown: I
Q
< 20µA
Short-Circuit Protection
Very Low Dropout Operation: 100% Duty Cycle
High Efficiency in a Small Amount of Board Space
Output Can Be Externally Held High in Shutdown
Available in 8-Pin SO Package
The LTC
®
1147 series are step-down switching regulator
controllers featuring automatic Burst Mode
TM
operation to
maintain high efficiencies at low output currents. These
devices drive an external P-channel power MOSFET at
switching frequencies exceeding 400kHz using a constant
off-time current mode architecture providing constant
ripple current in the inductor.
The operating current level is user-programmable via an
external current sense resistor. Wide input supply range
allows operation from 3.5V* to 14V (16V maximum).
Constant off-time architecture provides low dropout regu-
lation limited by only the R
DS(ON)
of the external MOSFET
and resistance of the inductor and current sense resistor.
The LTC1147 series incorporates automatic power saving
Burst Mode
operation to reduce switching losses when
load currents drop below the level required for continuous
operation. Standby power is reduced to only 2mW at
V
IN
= 10V (at I
OUT
= 0). Load currents in Burst Mode
operation are typically 0mA to 300mA.
For applications where even higher efficiency is required,
refer to the LTC1148 data sheet and Application Note 54.
Burst Mode
is a trademark of Linear Technology Corporation.
*LTC1147L and LTC1147L-3.3 only.
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
Notebook and Palmtop Computers
Portable Instruments
Battery-Operated Digital Devices
Cellular Telephones
DC Power Distribution Systems
GPS Systems
2
LTC1147-3.3
LTC1147-5/LTC1147L
sn1147 1147fds
Input Supply Voltage (Pin 1) .................... 16V to –0.3V
Continuous Output Current (Pin 8) ...................... 50mA
Sense Voltages (Pins 4, 5)
V
IN
12.7V ...........................................13V to –0.3V
V
IN
< 12.7V............................... (V
IN
+ 0.3V) to –0.3V
ABSOLUTE AXI U RATI GS
W
WW
U
Operating Ambient Temperature Range
LTC1147C ............................................... 0°C to 70°C
LTC1147I............................................. –40°C to 85°C
Extended Commercial
Temperature Range (Note 4) ................. 40°C to 85°C
Junction Temperature (Note 1)............................ 125°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
6
Feedback Voltage (LTC1147L) V
IN
= 9V 1.21 1.25 1.29 V
I
6
Feedback Current (LTC1147L) 0.2 1 µA
V
OUT
Regulated Output Voltage V
IN
= 9V
LTC1147-3.3, LTC1147L-3.3 I
LOAD
= 700mA 3.23 3.33 3.43 V
LTC1147-5 I
LOAD
= 700mA 4.90 5.05 5.20 V
V
OUT
Output Voltage Line Regulation V
IN
= 7V to 12V, I
LOAD
= 50mA 40 0 40 mV
Output Voltage Load Regulation
LTC1147-3.3, LTC1147L-3.3 5mA < I
LOAD
< 2A 40 65 mV
LTC1147-5 5mA < I
LOAD
< 2A 60 100 mV
Burst Mode Output Ripple I
LOAD
= 0A 50 mV
P-P
I
Q
Input DC Supply Current (Note 2) (Note 5)
LTC1147 Series
Normal Mode 4V < V
IN
< 12V 1.6 2.1 mA
Sleep Mode 4V < V
IN
< 12V 160 230 µA
Sleep Mode (LTC1147-5) 5V < V
IN
< 12V 160 230 µA
Shutdown V
SHDN
= 2.1V, 4V < V
IN
< 12V 10 20 µA
LTC1147L Series
Normal Mode 3.5V < V
IN
< 12V 1.6 2.1 mA
Sleep Mode 3.5V < V
IN
< 12V 160 230 µA
Shutdown (LTC1147L-3.3) V
SHDN
= 2.1V, 3.5V < V
IN
< 12V 10 20 µA
T
A
= 25°C, V
IN
= 10V, V
SHDN
= 0V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
Consult factory for Military grade parts.
PACKAGE/ORDER I FOR ATIO
UUW
* ADJUSTABLE OUTPUT VERSION
SHDN
(V
FB
*)
1
2
3
4
8
7
6
5
TOP VIEW
V
IN
C
T
I
TH
SENSE
PDRIVE
GND
SENSE
+
N8 PACKAGE
8-LEAD PLASTIC DIP
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 110°C/W (N)
T
JMAX
= 125°C,
θ
JA
= 150°C/W (S)
LTC1147IS8-5
LTC1147LCS8
LTC1147LCS8-3.3
LTC1147LIS8
11473
11475
1147I3
1147I5
1147L
1147L3
1147LI
LTC1147CN8-3.3
LTC1147CN8-5
LTC1147CS8-3.3
LTC1147CS8-5
LTC1147IS8-3.3
ORDER PART NUMBER S8 PART MARKING
3
LTC1147-3.3
LTC1147-5/LTC1147L
sn1147 1147fds
T
A
= 25°C, V
IN
= 10V, V
SHDN
= 0V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
5
– V
4
Current Sense Threshold Voltage (Note 6)
LTC1147-3.3, LTC1147L-3.3 V
SENSE
= V
OUT
+ 100mV (Forced) 25 mV
V
SENSE
= V
OUT
– 100mV (Forced) 130 150 170 mV
LTC1147–5 V
SENSE
= V
OUT
+ 100mV (Forced) 25 mV
V
SENSE
= V
OUT
– 100mV (Forced) 130 150 170 mV
LTC1147L V
SENSE
= 5V, V6 = V
OUT
/4 + 25mV (Forced) 25 mV
V
SENSE
= 5V, V6 = V
OUT
/4 – 25mV (Forced) 130 150 170 mV
V
6
SHDN Pin Threshold
LTC1147-3.3/LTC1147-5/LTC1147L-3.3 0.5 0.8 2 V
I
6
SHDN Pin Input Current
LTC1147-3.3/LTC1147-5/LTC1147L-3.3 0V < V
SHDN
< 8V, V
IN
= 16V 1.2 5 µA
I
2
C
T
Pin Discharge Current V
OUT
in Regulation, V
SENSE
= V
OUT
50 70 90 µA
V
OUT
= 0V 2 10 µA
t
OFF
Off-Time (Note 3) C
T
= 390pF, I
LOAD
= 700mA 4 5 6 µs
t
r
, t
f
Driver Output Transition Times C
L
= 3000pF (Pin 8), V
IN
= 6V 100 200 ns
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
6
Feedback Voltage (LTC1147L) V
IN
= 9V 1.20 1.25 1.30 V
V
OUT
Regulated Output Voltage V
IN
= 9V
LTC1147-3.3/LTC1147L-3.3 I
LOAD
= 700mA 3.17 3.33 3.43 V
LTC1147-5 I
LOAD
= 700mA 4.85 5.05 5.20 V
I
Q
Input DC Supply Current (Note 2) (Note 5)
LTC1147 Series
Normal Mode 4V < V
IN
< 12V 1.6 2.4 mA
Sleep Mode 4V < V
IN
< 12V 160 260 µA
Sleep Mode (LTC1147-5) 5V < V
IN
< 12V 160 260 µA
Shutdown V
SHDN
= 2.1V, 4V < V
IN
< 12V 10 22 µA
LTC1147L Series
Normal Mode 3.5V < V
IN
< 12V 1.6 2.4 mA
Sleep Mode 3.5V < V
IN
< 12V 160 260 µA
Shutdown (LTC1147L-3.3) V
SHDN
= 2.1V, 3.5V < V
IN
< 12V 10 22 µA
V
5
– V
4
Current Sense Threshold Voltage (Note 6)
LTC1147-3.3 V
SENSE
= V
OUT
+ 100mV (Forced) 25 mV
V
SENSE
= V
OUT
– 100mV (Forced) 125 150 185 mV
LTC1147-5 V
SENSE
= V
OUT
+ 100mV (Forced) 25 mV
V
SENSE
= V
OUT
– 100mV (Forced) 125 150 185 mV
LTC1147L V
SENSE
= 5V, 6V = V
OUT
/4 + 25mV (Forced) 25 mV
V
SENSE
= 5V, 6V = V
OUT
/4 – 25mV (Forced) 125 150 185 mV
V
6
SHDN Pin Threshold
LTC1147-3.3/LTC1147-5/LTC1147L-3.3 0V < V
SHDN
< 8V, V
IN
= 16V 0.5 0.8 2 V
t
OFF
Off-Time (Note 3) C
T
= 390pF, I
LOAD
= 700mA 3.8 5 6.5 µs
The denotes specifications which apply over the full specified
temperature range.
Note 1: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
LTC1147CN8-3.3/LTC1147CN8-5: T
J
= T
A
+ (P
D
)(110°C/W)
LTC1147LIS/LTC1147IS8/LTC1147LCS/
LTC1147CS8-3.3/LTC1147CS8-5: T
J
= T
A
+ (P
D
)(150°C/W)
Note 2: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 3: In applications where R
SENSE
is placed at ground potential, the off-
time increases approximately 40%.
Note 4: The LTC1147C is guaranteed to meet specified performance from
0°C to 70°C and is designed, characterized and expected to meet these
extended temperature limits, but is not tested at –40°C and 85°C. The
LTC1147I is guaranteed to meet the extended temperature limits.
Note 5: The LTC1147L/LTC1147L-3.3 allow operation to V
IN
= 3.5V.
Note 6: The LTC1147L is tested with external feedback resistors resulting
in a nominal output voltage of 2.5V.
–40°C T
A
85°C (Note 4), V
IN
= 10V, unless otherwise noted.

LTC1147LCS8-3.3#TRPBF

Mfr. #:
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators 3.3V LV Hi Eff Stepdn Reg
Lifecycle:
New from this manufacturer.
Delivery:
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