http://www.www.datasheet4u.com

900,000+ Datasheet PDF Search and Download

Datasheet4U offers most rated semiconductors datasheets pdf




Linear Technology Electronic Components Datasheet

LTC1735-1 Datasheet

High Efficiency Synchronous Step-Down Switching Regulator

No Preview Available !

LTC1735-1 pdf
FEATURES
s Dual N-Channel MOSFET Synchronous Drive
s Programmable/Synchronizable Fixed Frequency
s VOUT Range: 0.8V to 7V
s Wide VIN Range: 3.5V to 36V Operation
s Very Low Dropout Operation: 99% Duty Cycle
s OPTI-LOOPTM Compensation Minimizes COUT
s ±1% Output Voltage Accuracy
s Power Good Output Voltage Monitor
s Internal Current Foldback
s Output Overvoltage Crowbar Protection
s Latched Short-Circuit Shutdown Timer
with Defeat Option
s Optional Programmable Soft-Start
s Remote Output Voltage Sense
s Logic Controlled Micropower Shutdown: IQ < 25µA
s Available in 16-Lead Narrow SSOP and SO Packages
U
APPLICATIO S
s Notebook and Palmtop Computers, PDAs
s Power Supply for Mobile Pentium® III Processor with
SpeedStepTM Technology
s Cellular Telephones and Wireless Modems
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode and OPTI-LOOP are trademarks of Linear Technology Corporation.
Pentium is a registered trademark of Intel Corporation. SpeedStep is a trademark of Intel
Corporation.
LTC1735-1
High Efficiency
Synchronous Step-Down
Switching Regulator
DESCRIPTIO
The LTC®1735-1 is a synchronous step-down switching
regulator controller optimized for CPU power. OPTI-LOOP
compensation allows the transient response to be opti-
mized over a wide range of output capacitance and ESR
values.
The operating frequency (synchronizable up to 500kHz) is
set by an external capacitor allowing maximum flexibility
in optimizing efficiency. The output voltage is monitored
by a power good window comparator that indicates when
the output is within 7.5% of its programmed value, con-
forming to Intel Mobile CPU Specifications.
Protection features include internal foldback current lim-
iting, output overvoltage crowbar and optional short-
circuit shutdown. Soft-start is provided by an external
capacitor that can be used to properly sequence supplies.
The operating current level is user-programmable via an
external current sense resistor. Wide input supply range
allows operation from 3.5V to 30V (36V maximum).
Pin defeatable Burst ModeTM operation provides high
efficiency at low load currents while 99% duty cycle
provides low dropout operation.
TYPICAL APPLICATIO
PGOOD
VIN
4.5V TO 24V
COSC 47pF
CC2 330pF
47pF
1 16
COSC
TG
CSS 0.1µF
RC1 33k
2
RUN/SS
15
BOOST
3 14
ITH LTC1735-1 SW
CC1 47pF
4
PGOOD
13
VIN
5 SENSE
1000pF 6 SENSE +
12
INTVCC
11
BG
CB 0.22µF
D1
CMDSH-3
+
4.7µF
7
VOSENSE
PGND 10
8
SGND
9
EXTVCC
5V
(OPTIONAL)
10
10
Q1
FDS6680A
L1
1.2µH
D2
MBRS340T3
Q2, Q3
FDS6680A
×2
CIN
22µF
50V
CERAMIC
×2
RSENSE
0.004
47pF
47pF
R2
14.3k
0.5%
CIN: MARCON THCR70E1H226ZT
COUT: PANASONIC EEFUE06181R
L1: PANASONIC ETQP6RZ1R20HFA
RSENSE: IRC CRF2010-01-R004J
R1
10k
0.5%
R3
33.2k
1%
+
Q4
2N7002
VOUT
1.35V TO 1.60V
12A
COUT
180µF
4V
PANASONIC SP
×4
VSEL = 1: VOUT = 1.60V
VSEL = 0: VOUT = 1.35V
GND
1735-1 F01
Figure 1. CPU Core DC/DC Converter with Dynamic Voltage Selection from SpeedStep Enabled Processors
1


Linear Technology Electronic Components Datasheet

LTC1735-1 Datasheet

High Efficiency Synchronous Step-Down Switching Regulator

No Preview Available !

LTC1735-1 pdf
LTC1735-1
ABSOLUTE AXI U RATI GS
(Note 1)
Input Supply Voltage (VIN)........................ 36V to – 0.3V
Topside Driver Supply Voltage (BOOST)... 42V to – 0.3V
Switch Voltage (SW) ................................... 36V to – 5V
INTVCC, EXTVCC (BOOST, SW) Voltages ..... 7V to – 0.3V
SENSE+, SENSE,
PGOOD Voltages ................ 1.1(INTVCC + 0.3V) to – 0.3V
ITH, VOSENSE, COSC Voltages .....................2.7V to – 0.3V
RUN/SS Voltage ....................(INTVCC + 0.3V) to – 0.3V
Peak Driver Output Current <10µs (TG, BG) .............. 3A
INTVCC Output Current ......................................... 50mA
Operating Ambient Temperature Range
LTC1735C-1 ............................................ 0°C to 85°C
LTC1735I-1 ........................................ – 40°C to 85°C
Junction Temperature (Note 2) ............................. 125°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
COSC 1
RUN/SS 2
ITH 3
PGOOD 4
SENSE5
SENSE+ 6
VOSENSE 7
SGND 8
16 TG
15 BOOST
14 SW
13 VIN
12 INTVCC
11 BG
10 PGND
9 EXTVCC
GN PACKAGE
S PACKAGE
16-LEAD PLASTIC SSOP 16-LEAD PLASTIC SO
TJMAX = 125°C, θJA = 130°C/W (GN)
TJMAX = 125°C, θJA = 110°C/W (S)
Consult factory for Military grade parts.
ORDER PART
NUMBER
LTC1735CGN-1
LTC1735CS-1
LTC1735IGN-1
LTC1735IS-1
ELECTRICAL CHARACTERISTICS The q denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 15V, VRUN/SS = 5V unless otherwise noted.
SYMBOL
PARAMETER
Main Control Loop
CONDITIONS
MIN TYP MAX
IVOSENSE
VOSENSE
VLINEREG
VLOADREG
Feedback Current
Feedback Voltage
Reference Voltage Line Regulation
Output Voltage Load Regulation
DF Max
gm
VOVL
IQ
VRUN/SS
IRUN/SS
ISCL
Maximum Duty Factor
Transconductance Amplifier gm
Feedback Overvoltage Lockout
Input DC Supply Current
Normal Mode
Shutdown
Run Pin Start Threshold
Run Pin Begin Latchoff Threshold
Soft-Start Charge Current
RUN/SS Discharge Current
UVLO
VSENSE(MAX)
ISENSE
tON(MIN)
Undervoltage Lockout
Maximum Current Sense Threshold
SENSE Pins Total Source Current
Minimum On-Time
(Note 3)
(Note 3)
VIN = 3.6V to 30V (Note 3)
(Note 3)
Measured in Servo Loop; VITH = 0.7V
Measured in Servo Loop; VITH = 2V
In Dropout
(Note 5)
3.6V < VIN < 30V
VRUN/SS = 0V
VRUN/SS, Ramping Positive
VRUN/SS, Ramping Positive
VRUN/SS = 0V
Soft Short Condition, VOSENSE = 0.5V,
VRUN/SS = 4.5V
Measured at VIN Pin (Ramping Negative)
VOSENSE = 0.7V
VSENSE– = VSENSE+ = 0V
Tested with a Square Wave (Note 4)
q 0.792
–4
0.8
0.001
– 25
0.808
0.02
q 0.1 0.3
q – 0.1 – 0.3
98 99.4
1.3
q 0.84 0.86 0.88
450
15
1.0 1.5
4.1
– 0.7 – 1.2
0.5 2
25
1.9
4.5
4
q
q 60
3.5 3.9
75 85
60 80
160 200
UNITS
nA
V
%/V
%
%
%
mmho
V
µA
µA
V
V
µA
µA
V
mV
µA
ns
2


Part Number LTC1735-1
Description High Efficiency Synchronous Step-Down Switching Regulator
Maker Linear Technology
Total Page 28 Pages
PDF Download
LTC1735-1 pdf
Download PDF File
LTC1735-1 pdf
View for Mobile



Buy Electronic Components




Related Datasheet

1 LTC1735-1 High Efficiency Synchronous Step-Down Switching Regulator Linear Technology
Linear Technology
LTC1735-1 pdf






Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

site map

webmaste! click here

contact us

Buy Components