LTC3729
30
3729fb
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035‑7417
(408) 432‑1900
●
FAX: (408) 434‑0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 2001
0311 REV B • PRINTED IN USA
RELATED PARTS
TYPICAL APPLICATION
Figure 12. 3.3V/30A Power Supply with Active Voltage Positioning
V
IN
: 5V TO 16V
V
OUT
: 3.3V/30A
SWITCHING FREQUENCY = 250kHz
MI, M3: IRF7811
M2, M4: IRF7809
L1, L2: 1µH SUMIDA CEP125-1R0MC-H
C
IN
: OS CON 2-16SP270M
C
OUT
: KEMET 3-T510 470mF
D3, D4: CENTRAL CMDSH-3TR
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
CLKOUT
TG1
SW1
BOOST1
V
IN
BG1
EXTV
CC
INTV
CC
PGND
BG2
BOOST2
SW2
TG2
PGOOD
RUN/SS
SENSE1
+
SENSE1
–
EAIN
PLLFLTR
PLLIN
PHASMD
I
TH
SGND
V
DIFFOUT
V
OS
–
V
OS
+
SENSE2
–
SENSE2
+
LTC3729
M4M3
0.1µF
13.2k
3.3k
16.5k
1000pF
1000pF
1000pF
100pF
33pF
M2M1
D1
UPS840
D2
UPS840
0.47µF
POWER
GOOD
100k
4.7µF
6.3V
+
0.1µF
1µF,6.3V
5V
D4
D3
10Ω
0.47µF
V
OUT
3.3V/30A
V
IN
6V TO
16V
+
L1
0.003Ω
L2
0.003Ω
3729TA02
C
OUT
+
C
IN
PART NUMBER DESCRIPTION COMMENTS
LTC3856
Single Output 2‑Channel Polyphase Synchronous Step‑Down
DC/DC Controller with Diff Amp and up to 12‑Phase Operation
PLL Fixed 250kHz to 770kHz Frequency, 4.5V ≤ V
IN
≤ 38V,
0.8V≤ V
OUT
≤ 5V
LTC3880/LTC3880‑1 Dual Output PolyPhase Step‑Down DC/DC Controller with
Digital Power System Management
I
2
C/PMBus Interface with EEPROM and 16‑Bit ADC, V
IN
Up to 24V,
0.5V ≤ V
OUT
≤ 5.5V, Analog Control Loop
LTC3829
Single Output 3‑Channel Polyphase Synchronous Step‑Down
DC/DC Controller with Diff Amp and up to 6‑Phase Operation
PLL Fixed 250kHz to 770kHz Frequency, 4.5V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 5V
LTC3869/LTC3869‑2 Dual Output, 2‑Phase Synchronous Step‑Down DC/DC
Controller, with Accurate Current Share
PLL Fixed 250kHz to 750kHz Frequency, 4V ≤ V
IN
≤ 38V,
V
OUT3
Up to 12.5V
LTC3850/LTC3850‑1
LTC3850‑2
Dual Output, 2‑Phase Synchronous Step‑Down DC/DC
Controller, R
SENSE
or DCR Current Sensing
PLL Fixed 250kHz to 780kHz Frequency, 4V ≤ V
IN
≤ 30V,
0.8V ≤ V
OUT
≤ 5.25V
LTC3855
Dual Output, 2‑phase, Synchronous Step‑Down DC/DC
Controller with Diff Amp and DCR Temperature Compensation
PLL Fixed Frequency 250kHz to 770kHz, 4.5V ≤ V
IN
≤ 38V,
0.8V ≤ V
OUT
≤ 12V
LTC3853
Triple Output, Multiphase Synchronous Step‑Down DC/DC
Controller, R
SENSE
or DCR Current Sensing and Tracking
PLL Fixed 250kHz to 750kHz Frequency, 4V ≤ V
IN
≤ 24V,
V
OUT3
Up to 13.5V
LTC3860
Dual, Multiphase, Synchronous Step‑Down DC/DC Controller
with Diff Amp and Three‑State Output Drive
Operates with Power Blocks, DRMOS Devices or External
MOSFETs 3V ≤ V
IN
≤ 24V, t
ON(MIN)
= 20ns
LTC3857/LTC3857‑1 Low I
Q
, Dual Output 2‑Phase Synchronous Step‑Down DC/DC
Controller with 99% Duty Cycle
Phase‑Lockable Fixed Operating Frequency 50kHz to 900kHz,
4V ≤ V
IN
≤ 38V, 0.8V ≤ V
OUT
≤ 24V, I
Q
= 50µA
