1
LTC1629-6
16296f
Desktop Computers
Internet Servers
Large Memory Arrays
DC Power Distribution Systems
APPLICATIO S
U
PolyPhase, Synchronous
Step-Down Switching Regulator
The LTC
®
1629-6 is a PolyPhase
TM
synchronous stepdown
current mode switching regulator controller with 0.6V
reference that drives N-channel external power MOSFET
stages in a phase-lockable fixed frequency architecture.
The PolyPhase controller drives its two output stages out
of phase at frequencies up to 300kHz to minimize the RMS
ripple currents in both input and output capacitors. The
output clock signal allows expansion for up to 12 evenly
phased controllers for systems requiring 15A to 200A of
output current. The multiple phase technique effectively
multiplies the fundamental frequency by the number
of channels used, improving transient response while
operating each channel at an optimum frequency for
efficiency. Thermal design is also simplified.
An internal differential amplifier provides true remote
sensing of the regulated supply’s positive and negative
output terminals as required for high current applications.
A RUN/SS pin provides both soft-start and optional timed,
short-circuit shutdown. Current foldback limits MOSFET
dissipation during short-circuit conditions when the
overcurrent latchoff is disabled. OPTI-LOOP compensa-
tion allows the transient response to be optimized over a
wide range of output capacitance and ESR values. The
LTC1629-6 includes a power good output pin that
indicates when the output voltage is inside the ±10%
tolerance window.
Figure 1. High Current Dual Phase Step-Down Converter
Reduces Required Input Capacitance and Power
Supply Induced Noise
True Remote Sensing Differential Amplifier
0.6V,
±
1% Voltage Reference Accuracy
PolyPhase Controller Operates from Two to Twelve
Phases
Current Mode Control Ensures Current Sharing
Phase-Lockable Fixed Frequency: 150kHz to 300kHz
1.8MHz Effective Switching Frequency Capability
OPTI-LOOP
®
Compensation Reduces C
OUT
Power Good Output Voltage Monitor
Wide V
IN
Range: 4V to 36V Operation
Very Low Dropout Operation: 99% Duty Cycle
Adjustable Soft-Start Current Ramping
Internal Current Foldback Plus Shutdown Timer
Overvoltage Soft-Latch Eliminates Nuisance Trips
Micropower Shutdown
Available in 28-Lead SSOP Package
1629 TA01
TG1
BOOST1
SW1
BG1
PGND
SENSE1
+
SENSE1
TG2
BOOST2
SW2
BG2
INTV
CC
SENSE2
+
SENSE2
V
IN
CLKOUT
RUN/SS
EAIN
I
TH
V
DIFFOUT
V
OS
V
OS
+
LTC1629-6
SGND
0.1µF
PGOOD
0.1µF
10k
3300pF
S
S
S
S
S
S
S
S
10
1.5k
60.4k
10µF ×6
35V
CERAMIC
+
C
OUT
270µF ×4
2V
L1, L2: CEPH149-IROMC-HC
OUT
: T510E108K004AS
D1, D2: UPS840
M1, M3: Si7840DP
M2, M4: Si7440DP
V
OUT
0.7V/40A
L1
1µH
0.002
V
IN
5V TO 15V
L2
1µH
D2
D1
M1
M2
×2
M3
M4
×2
0.47µF
S
0.47µF
10µF CER
X5R
0.002
FEATURES
TYPICAL APPLICATIO
U
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
OPTI-LOOP is a registered trademark of Linear Technology Corporation.
PolyPhase is a trademark of Linear Technology Corporation.
2
LTC1629-6
16296f
ORDER PART
NUMBER
LTC1629EG-6
ABSOLUTE AXI U RATI GS
W
WW
U
PACKAGE/ORDER I FOR ATIO
UUW
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
G PACKAGE
28-LEAD PLASTIC SSOP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RUN/SS
SENSE1
+
SENSE1
EAIN
PLLFLTR
PLLIN
PHASMD
I
TH
SGND
V
DIFFOUT
V
OS
V
OS
+
SENSE2
SENSE2
+
CLKOUT
TG1
SW1
BOOST1
V
IN
BG1
EXTV
CC
INTV
CC
PGND
BG2
BOOST2
SW2
TG2
PGOOD
T
JMAX
= 125°C, θ
JA
= 95°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS
= 5V unless otherwise noted.
(Note 1)
Input Supply Voltage (V
IN
).........................36V to –0.3V
Topside Driver Voltages (BOOST1,2).........42V to –0.3V
Switch Voltage (SW1, 2) .............................36V to –5 V
SENSE1
+
, SENSE2
+
, SENSE1
,
SENSE2
Voltages........................ (1.1)INTV
CC
to –0.3V
EAIN, V
OS
+
, V
OS
, EXTV
CC
, INTV
CC
,
RUN/SS, PGOOD Voltages...........................7V to –0.3V
Boosted Driver Voltage (BOOST-SW) ..........7V to –0.3V
PLLFLTR, PLLIN, CLKOUT, PHASMD,
V
DIFFOUT
Voltages ................................ INTV
CC
to –0.3V
I
TH
Voltage................................................2.7V to –0.3V
Peak Output Current <1µs(TGL1,2, BG1,2)................ 5A
INTV
CC
RMS Output Current................................ 50mA
Operating Ambient Temperature Range
LTC1629EG-6 (Note 6) ......................... 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
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop
V
EAIN
Regulated Feedback Voltage (Note 3); I
TH
Voltage = 1.2V 0.594 0.600 0.606 V
V
SENSEMAX
Maximum Current Sense Threshold V
SENSE
= 5V 62 75 88 mV
65 75 85 mV
I
INEAIN
Feedback Current (Note 3) 5 50 nA
V
LOADREG
Output Voltage Load Regulation (Note 3)
Measured in Servo Loop; I
TH
Voltage = 0.7V 0.1 0.5 %
Measured in Servo Loop; I
TH
Voltage = 2V 0.1 0.5 %
V
REFLNREG
Reference Voltage Line Regulation V
IN
= 3.6V to 30V (Note 3) 0.002 0.02 %/V
V
OVL
Output Overvoltage Threshold Measured at V
EAIN
0.64 0.66 0.68 V
UVLO Undervoltage Lockout V
IN
Ramping Down 3 3.5 4 V
g
m
Transconductance Amplifier g
m
I
TH
= 1.2V; Sink/Source 5µA; (Note 3) 3 mmho
g
mOL
Transconductance Amplifier Gain I
TH
= 1.2V; (g
m
xZ
L
; No Ext Load); (Note 3) 1.5 V/mV
I
Q
Input DC Supply Current (Note 4)
Normal Mode EXTV
CC
Tied to V
OUT
; V
OUT
= 5V 470 µA
Shutdown V
RUN/SS
= 0V 20 40 µA
I
RUN/SS
Soft-Start Charge Current V
RUN/SS
= 1.9V 0.5 1.2 µA
V
RUN/SS
RUN/SS Pin ON Threshold V
RUN/SS
Rising 1.0 1.5 1.9 V
V
RUN/SSLO
RUN/SS Pin Latchoff Arming V
RUN/SS
Rising from 3V 4.1 4.5 V
3
LTC1629-6
16296f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
ELECTRICAL CHARACTERISTICS
The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS
= 5V unless otherwise noted.
I
SCL
RUN/SS Discharge Current Soft Short Condition V
EAIN
= 0.4V; V
RUN/SS
= 4.5V 0.5 2 4 µA
I
SDLDO
Shutdown Latch Disable Current V
EAIN
= 0.4V 1.6 5 µA
I
SENSE
Total Sense Pins Source Current Each Channel; V
SENSE1
, 2
– = V
SENSE1
+
, 2
+ = 0V 85 60 µA
DF
MAX
Maximum Duty Factor In Dropout 98 99.5 %
Top Gate Transition Time:
TG1, 2 t
r
Rise Time C
LOAD
= 3300pF 30 90 ns
TG1, 2 t
f
Fall Time C
LOAD
= 3300pF 40 90 ns
Bottom Gate Transition Time:
BG1, 2 t
r
Rise Time C
LOAD
= 3300pF 30 90 ns
BG1, 2 t
f
Fall Time C
LOAD
= 3300pF 20 90 ns
TG/BG t
1D
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time C
LOAD
= 3300pF Each Driver 90 ns
BG/TG t
2D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time C
LOAD
= 3300pF Each Driver 90 ns
t
ON(MIN)
Minimum On-Time Tested with a Square Wave (Note 5) 180 ns
Internal V
CC
Regulator
V
INTVCC
Internal V
CC
Voltage 6V < V
IN
< 30V; V
EXTVCC
= 4V 4.8 5.0 5.2 V
V
LDO
INT INTV
CC
Load Regulation I
CC
= 0 to 20mA; V
EXTVCC
= 4V 0.2 1.0 %
V
LDO
EXT EXTV
CC
Voltage Drop I
CC
= 20mA; V
EXTVCC
= 5V 80 160 mV
V
EXTVCC
EXTV
CC
Switchover Voltage I
CC
= 20mA, EXTV
CC
Ramping Positive 4.5 4.7 V
V
LDOHYS
EXTV
CC
Switchover Hysteresis I
CC
= 20mA, EXTV
CC
Ramping Negative 0.2 V
Oscillator and Phase-Locked Loop
f
NOM
Nominal Frequency V
PLLFLTR
= 1.2V 190 220 250 kHz
f
LOW
Lowest Frequency V
PLLFLTR
= 0V 120 140 160 kHz
f
HIGH
Highest Frequency V
PLLFLTR
2.4V 280 310 360 kHz
R
PLLIN
PLLIN
Input Resistance 50 k
I
PLLFLTR
Phase Detector Output Current
Sinking Capability f
PLLIN
< f
OSC
–15 µA
Sourcing Capability f
PLLIN
> f
OSC
15 µA
R
RELPHS
Controller 2-Controller 1 Phase V
PHASMD
= 0V, Open 180 Deg
V
PHASMD
= 5V 240 Deg
CLKOUT Phase (Relative to Controller 1) V
PHASMD
= 0V 60 Deg
V
PHASMD
= Open 90 Deg
V
PHASMD
= 5V 120 Deg
CLK
HIGH
Clock High Output Voltage 4 V
CLK
LOW
Clock Low Output Voltage 0.2 V
PGOOD Output
V
PGL
PGOOD Voltage Low I
PGOOD
= 2mA 0.1 0.3 V
I
PGOOD
PGOOD Leakage Current V
PGOOD
= 5V ±1 µA
V
PG
PGOOD Trip Level, Either Controller V
EAIN
with Respect to Set Output Voltage
V
EAIN
Ramping Negative 8 10 12 %
V
EAIN
Ramping Positive 8 10 12 %

LTC1629EG-6#TRPBF

Mfr. #:
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators Hi Pwr PolyPhase DC/DC Controllers
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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