DC/DC Controller. LTC3735 Datasheet

LTC3735 Controller. Datasheet pdf. Equivalent

LTC3735 Datasheet
Recommendation LTC3735 Datasheet
Part LTC3735
Description 2-Phase High Efficiency DC/DC Controller
Feature LTC3735; FEATURES n Output Stages Operate Antiphase n ±1% Output Voltage Accuracy n 6-Bit IMVP-IV VID Code.
Manufacture Linear
Datasheet
Download LTC3735 Datasheet




Linear LTC3735
FEATURES
n Output Stages Operate Antiphase
n ±1% Output Voltage Accuracy
n 6-Bit IMVP-IV VID Code: VOUT = 0.7V to 1.708V
n Intel Compatible Power Saving Mode (PSIB)
n Stage Shedding Improves Low Current Efficiency
n Power Good Output with Adaptive Masking
n Lossless Voltage Positioning
n Dual Input Supply Capability for Load Sharing
n Resistor Programmable VOUT at Boot-Up and Deeper
Sleep State
n Resistor Programmable Deep Sleep Offset
n Programmable Fixed Frequency: 210kHz to 550kHz
n Adjustable Soft-Start Current Ramping
n Foldback Output Current Limit
n Short-Circuit Shutdown Timer with Defeat Option
n Overvoltage Protection
n Available in 36-Lead SSOP (0.209 Wide) and 38-Lead
(5mm × 7mm) Packages
APPLICATIONS
n Mobile and Desktop Computers
n Internet Servers
LTC3735
2-Phase, High Efficiency
DC/DC Controller for
Intel Mobile CPUs
DESCRIPTION
The LTC®3735 is a 2-phase synchronous step-down
switching regulator controller that drives all N-channel
power MOSFETs in a constant frequency architecture. The
output voltage is programmable by six VID bits during
normal operation and by external resistors during initial
boot-up and deeper sleep state. The LTC3735 drives its two
output stages out-of-phase at frequencies up to 550kHz
to minimize the RMS ripple currents in both input and
output capacitors. This antiphase technique also doubles
the apparent switching frequency, improving the transient
response while operating each phase at an optimum fre-
quency for efficiency. Thermal design is further simplified
by cycle-by-cycle current sharing between the two phases.
An Intel compatible PSIB input is provided to select between
two modes of operation. Fully enhanced synchronous
mode achieves a very small output ripple and very fast
transient response while power saving mode realizes
very high efficiency. OPTI-LOOP® compensation allows
the transient response to be optimized for a wide range
of output capacitance and ESR values.
L, LT, LTC, LTM, OPTI-LOOP, PolyPhase, Linear Technology and the Linear logo are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
TYPICAL APPLICATION
100pF
232k
4R.C74k
4C7C0pF
VOA+
4.5V TO 7V
4.7µF
BAT54A
0.1µF
0.47µF
SW2
0.47µF
SW1
MCH_PG
DPRSLPVR
STP_CPUB
PSIB
FREQSET
TG1
SW1
BG1
VID5-VID0 PGND
PGOOD
ITH
SSEENNSSEE11+–
RUN/SS
TG2
SGND
SW2
BG2
LTC3735
PVCC
SSEENNSSEE22+–
RBOOT
BOOST1 RDPRSLP
BOOST2 RDPVSOLAP+
OAVOOUAT
M1 1µH
M2 D1
M3 1µH
M4 D2
12.7k 13.3k
56.2k
1.27M
13.3k
549k VOA+
3735 F01
0.002Ω
0.002Ω
VOUT
0.7V TO 1.708V
+
COUT 40A
330µF
2V
×5
Figure 1. High Current 2-Phase Step-Down Converter
VIN
5V TO 24V
CIN
10µF
35V
×4
3735fa
1



Linear LTC3735
LTC3735
ABSOLUTE MAXIMUM RATINGS (Note 1)
Input Supply Voltage (PVCC)........................ 7V to – 0.3V
Topside Driver Voltages (BOOST1,2).......... 38V to –0.3V
Switch Voltage (SW1, 2)................................ 32V to –5V
Boosted Driver Voltages
(BOOST1-SW1, BOOST2-SW2)................ 7V to –0.3V
DPRSLPVR, STP_CPUB, MCH_PG, PGOOD,
RDPRSLP, RDPSLP, RBOOT Voltages .......... 5V to –0.3V
RUN/SS, PSIB, FREQSET Voltages ..............7V to – 0.3V
VID0-VID5 Voltages .....................................5V to – 0.3V
VVFOBA,+V, VolOtaAge................................................................................................3. .26VV
to
to
–0.3V
–0.3V
Peak Gate Drive Current <1µs
(TG1, TG2, BG1, BG2)..................................................5A
Operating Ambient Temperature Range
(Note 2) .................................................... –40°C to 85°C
Junction Temperature (Note 3).............................. 125°C
Storage Temperature Range
SSOP.................................................. –65°C to 150°C
QFN..................................................... –65°C to 125°C
QFN Reflow Peak Body Temperature..................... 260°C
Lead Temperature (Soldering, 10 sec)................... 300°C
PIN CONFIGURATION
TOP VIEW
VFB 1
DPRSLPVR 2
FREQSET 3
PSIB
VOA+
VOA–
OAOUT
4
5
6
7
STP_CPUB 8
SGND
SENSE1+
SENSE1
SENSE2+
SENSE2
9
10
11
12
13
RDPRSLP 14
RDPSLP 15
RUN/SS 16
ITH 17
RBOOT 18
36 MCH_PG
35 PGOOD
34 BOOST1
33 TG1
32 SW1
31 BOOST2
30 TG2
29 SW2
28 PVCC
27 BG1
26 PGND
25 BG2
24 VID5
23 VID4
22 VID3
21 VID2
20 VID1
19 VID0
G PACKAGE
36-LEAD PLASTIC SSOP
TJMAX = 125°C, θJA = 85°C/W
TOP VIEW
FREQSET 1
PSIB
VOA+
VOA–
OAOUT
2
3
4
5
STP_CPUB 6
SGND 7
SENSE1+ 8
SENSE19
SENSE2+ 10
SENSE211
RDPRSLP 12
38 37 36 35 34 33 32
39
13 14 15 16 17 18 19
31 NC
30 BOOST2
29 TG2
28 SW2
27 PVCC
26 BG1
25 PGND
24 BG2
23 VID5
22 VID4
21 VID3
20 VID2
UHF PACKAGE
38-LEAD (7mm × 5mm) PLASTIC QFN
TJMAX = 125°C, θJA = 34°C/W
EXPOSED PAD (PIN 39) IS SIGNAL GROUND, MUST BE CONNECTED TO PCB AND SGND
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC3735EG#PBF
LTC3735EG#TRPBF
LTC3735
36-Lead Plastic SSOP
–40°C to 85°C
LTC3735EUHF#PBF
LTC3735EUHF#TRPBF LTC3735
38-Lead (7mm × 5mm) Plastic QFN
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC 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/
2
3735fa



Linear LTC3735
LTC3735
E LECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VPVCC = 5V, VRUN/SS = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
Main Control Loop
Reference
VSENSEMAX
VLOADREG
VREFLNREG
VPSIB
IPSIB
VOVL
gm
gmOL
VACTIVE
IQ
UVR
IRUN/SS
VRUN/SS
VRUN/SSARM
VRUN/SSLO
ISCL
ISDLHO
ISENSE
DFMAX
TG1,
TG1,
2
2
ttrf
BG1, 2 tr
BG1, 2 tf
TG/BG t1D
Regulated Feedback Voltage
Maximum Current Sense Threshold
Output Voltage Load Regulation
Reference Voltage Line Regulation
Forced Continuous Threshold
ITH Voltage = 0.5V; Measured at VFB (Note 4)
ITH Voltage = Max; VCM = 1.7V
(Note 4)
Measured
Measured
in
in
Servo
Servo
Loop,
Loop,
∆∆IITTHH
Voltage:
Voltage:
1.2V
1.2V
to
to
0.7V
2V
VPVCC = 4.5V to 7V
Forced Continuous Current
VPSIB = 0V
Output Overvoltage Threshold
Measured with Respect to VFB = 0.6V
Transconductance Amplifier gm
ITH = 1.2V, Sink/Source 25µA (Note 4)
Transconductance Amplifier Gain
ITH = 1.2V, (gm • ZL; No Ext Load) (Note 4)
Output Voltage in Active Mode
VID
VID
=
=
010110,
010110,
IITTHH
=
=
0.5V
0.5V
(0°C to 85°C)
(Note 2)
Input DC Supply Current
Normal Mode
Shutdown
(Note 5)
VRUN/SS = 0V
Undervoltage RUN/SS Reset
PVCC Lowered Until the RUN/SS Pin is Pulled Low
Soft-Start Charge Current
VRUN/SS = 1.9V
RUN/SS Pin ON Threshold
VRUN/SS Rising
RUN/SS Pin Latchoff Arming
VRUN/SS Rising from 3V
RUN/SS Pin Latchoff Threshold
VRUN/SS, Ramping Negative
RUN/SS Discharge Current
Soft-Short Condition VFB = 0.375V, VRUN/SS = 4.5V
Shutdown Latch Disable Current
VFB = 0.375V, VRUN/SS = 4.5V
Total Sense Pins Source Current
Each Channel: VSENSE1–, 2– = VSENSE1+, 2+ = 0V
Maximum Duty Factor
In Dropout, VSENSEMAX ≤ 45mV
Top Gate Transition Time:
Rise Time
Fall Time
(Note 6)
CCLLOOAADD
=
=
3300pF
3300pF
Bottom Gate Transition Time:
Rise Time
Fall Time
(Note 6)
CLOAD = 3300pF
CLOAD = 3300pF
Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF Each Driver (Note 6)
Synchronous Switch-On Delay Time
l
l
l
l
l
BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF Each Driver (Note 6)
Top Switch-On Delay Time
tON(MIN)
Minimum On-Time
VID Parameters
Tested with a Square Wave (Note 7)
RATTEN
ATTENERR
VIDTHLOW
VIDTHHIGH
VIDLEAK
VID Top Resistance
Resistive Divider Error
VID0 to VID5 Logic Threshold Low
VID0 to VID5 Logic Threshold High
VID0 to VID5 Leakage
(Note 8)
l
MIN
59
0.57
0.64
4.5
1.342
1.336
3.2
–2.3
1.0
–5
–85
95
–0.25
0.7
TYP
0.600
72
0.1
–0.1
0.02
0.6
–0.5
0.66
6
3
1.356
1.356
2
20
3.7
–1.5
1.5
3.9
3.2
–1.5
1.5
–60
98.5
30
40
60
50
50
60
100
5.33
MAX
85
0.5
–0.5
0.1
0.63
–1
0.68
7.5
1.370
1.376
3
100
4.2
–0.8
1.9
5
90
90
90
90
0.25
0.3
±1
UNITS
V
mV
%
%
%/V
V
µA
V
mmho
V/mV
V
V
mA
µA
V
µA
V
V
V
µA
µA
µA
%
ns
ns
ns
ns
ns
ns
ns
%
V
V
µA
3735fa
3







@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)