LTC1629-6 Datasheet, PDF (1/28 Pages) Linear Technology – PolyPhase, Synchronous

LTC1629-6
PolyPhase, Synchronous
Step-Down Switching Regulator
FEATURES
DESCRIPTIO
s _{Reduces Required Input Capacitance and Power}
Supply Induced Noise
s _{True Remote Sensing Differential Amplifier}
s _{0.6V, ±1% Voltage Reference Accuracy}
s _{PolyPhase Controller Operates from Two to Twelve}
Phases
s _{Current Mode Control Ensures Current Sharing}
s _{Phase-Lockable Fixed Frequency: 150kHz to 300kHz}
s _{1.8MHz Effective Switching Frequency Capability}
s _OPTI-LOOP^® _{Compensation Reduces COUT}
s _{Power Good Output Voltage Monitor}
s _{Wide VIN Range: 4V to 36V Operation}
s _{Very Low Dropout Operation: 99% Duty Cycle}
s _{Adjustable Soft-Start Current Ramping}
s _{Internal Current Foldback Plus Shutdown Timer}
s _{Overvoltage Soft-Latch Eliminates Nuisance Trips}
s _{Micropower Shutdown}
s _{Available in 28-Lead SSOP Package}
U
APPLICATIO S
s _{Desktop Computers}
s _{Internet Servers}
s _{Large Memory Arrays}
s _{DC Power Distribution Systems}
, 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.
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.
TYPICAL APPLICATIO
0.1µF
0.1µF
3300pF
1.5k
10k
60.4k
V_IN ^LTC1629-6 TG1
BOOST1
SW1
RUN/SS
BG1
PGOOD
I_TH
CLKOUT
PGND
SENSE1⁺
SENSE1^–
TG2
SGND
BOOST2
SW2
V_DIFFOUT
EAIN
V_OS–
V_OS+
BG2
INTV_CC
SENSE2⁺
SENSE2^–
10Ω
0.47µF
0.47µF
10µF CER
X5R
10µF ×6
M1
35V
CERAMIC
0.002Ω
L1
M2
1µH
×2
D1
M3
L2
M4
1µH
×2
D2
0.002Ω
C_OUT: T510E108K004AS
D1, D2: UPS840
L1, L2: CEPH149-IROMC-H
M1, M3: Si7840DP
M2, M4: Si7440DP
Figure 1. High Current Dual Phase Step-Down Converter
V_IN
5V TO 15V
V_OUT
0.7V/40A
+ C_OUT
270µF ×4
2V
1629 TA01
16296f
1